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Functional Near Infrared Spectroscopy (fNIRS) may be a suitable, simple, and cost-effective brain imaging technique for detecting divergent neuronal patterns at an early stage of neurodegeneration. In course of Mild Cognitive Impairment (MCI) or Alzheimer's disease (AD), a deficit in visual-spatial processing, located in the parietal cortex, is a reliable risk factor. Earlier, we established the application of the clock-hand-angle-discrimination task (ADT) during fNIRS to identify neuronal correlates of the visual-spatial processing in a healthy elderly sample. In this analysis, we aimed to measure and find out differences in the hemodynamic response in MCI participants compared to matched healthy controls. As expected, MCI participants showed more errors over all conditions of pointer length and a higher reaction time in the long and middle pointer length condition. Moreover, results revealed a significant reduction of cortical activation in MCI patients. There was a generally increased activity in both the right as compared to the left hemisphere and the superior parietal brain region as compared to the inferior parietal brain region in both groups. In summary, fNIRS can be implemented in the measurement of visual-spatial processing in MCI patients and healthy elderly based on ADT. MCI participants had difficulties to cope with the ADT. Since neuronal hypoactivity occurs with concomitant behavioral deficits, an additional analysis was performed on a subgroup of MCI patients who performed as well as the control group in behavior. This subgroup analysis also showed a hypoactivation of the parietal cortex, without evidence of a compensatory activation. Therefore, we assume that MCI patients are characterized by a deficit in the parietal cortex. Overall, these findings confirm our hypothesis that hemodynamic deficits in visual-spatial processing, localized in the parietal cortex, are reliable and early diagnostic markers for cognitive decline in risk groups for the development of AD.

Objective The purpose of this study was to determine better- ear listening effect on spatial separation with the N1–P2 complex. Methods Twenty individuals with normal hearing participated in this study. The speech stimulus /ba/ was presented in front of the participant (0°). Continuous Speech Noise (5 dB signal-to-noise ratio) was presented either in front of the participant (0°), left-side (-90°), or right-side (+90°). N1- P2 complex has been recorded in quiet and three noisy conditions. Results There was a remarkable effect of noise direction on N1, P2 latencies. When the noise was separated from the stimulus, N1 and P2 latency increased in terms of when noise was co-located with the stimulus. There was no statistically significant difference in N1-P2 amplitudes between the stimulus-only and co-located condition. N1-P2 amplitude was increased when the noise came from the sides, according to the stimulus-only and co-located conditions. Conclusion These findings demonstrate that the latency shifts on N1-P2 complex explain cortical mechanisms of spatial separation in better-ear listening.

The superior colliculus, or tectum in the case of non-mammalian vertebrates, is a part of the brain that registers events in the surrounding space, often through vision and hearing, but also through electrosensation, infrared detection, and other sensory modalities in diverse vertebrate lineages. This information is used to form maps of the surrounding space and the positions of different salient stimuli in relation to the individual. The sensory maps are arranged in layers with visual input in the uppermost layer, other senses in deeper positions, and a spatially aligned motor map in the deepest layer. Here, we will review the organization and intrinsic function of the tectum/superior colliculus and the information that is processed within tectal circuits. We will also discuss tectal/superior colliculus outputs that are conveyed directly to downstream motor circuits or via the thalamus to cortical areas to control various aspects of behavior. The tectum/superior colliculus is evolutionarily conserved among all vertebrates, but tailored to the sensory specialties of each lineage, and its roles have shifted with the emergence of the cerebral cortex in mammals. We will illustrate both the conserved and divergent properties of the tectum/superior colliculus through vertebrate evolution by comparing tectal processing in lampreys belonging to the oldest group of extant vertebrates, larval zebrafish, rodents, and other vertebrates including primates.

Objectives: Hamstring injuries in athletes can lead to significant time away from competition as a result of persistent posterior thigh pain. These cases are often difficult to treat as the state of the tissues alone cannot explain symptoms. In non-athletic populations with persistent pain, disruptions to tactile, proprioceptive, and spatial cortical representations exist, which has led to promising brain-based treatments.Here, we explored whether athletes with persistent posterior thigh pain also display impairments in these cortical representations.Design: Cross-sectional study.Methods: Fourteen male professional athletes with persistent posterior thigh pain (‘Patients’) and 14pain-free age, sport, body mass index and level-matched controls (‘Controls’) participated. The tactile cortical representation was assessed using two-point discrimination (TPD) threshold and accuracy of tactile localisation; the proprioceptive cortical representation was assessed using a left/right judgement task; spatial processing was assessed using an auditory detection task. Results: TPD thresholds were similar for Patients and Controls (p = 0.70). Patients were less accurate at localising tactile stimuli delivered to their affected leg, slower to make left/right judgements when the lower limb image corresponded to the side of their affected leg, and less accurate at detecting auditory stimuli delivered near their affected leg, when compared to their healthy leg or to the leg of Controls(p < 0.01 for all). Conclusions: Leg-specific tactile, proprioceptive, and spatial processing deficits exist in athletes with persistent posterior thigh pain. That these processing deficits exist despite rehabilitation and normal tissue healing time suggests they may play a role in the persistence of posterior thigh pain. Refereed/Peer-reviewed

Objectives Visuospatial neglect (VSN) is a common cognitive disorder after stroke. The primary aim of this systematic review was to provide an overview of the impact of VSN in 3 aspects: (1) activities of daily living (ADL), (2) participation, and (3) caregiver burden. The second aim was to investigate the differences in studies focusing on populations with mean age Methods PubMed, EMBASE, Web of Science, Cochrane Library, Emcare, PsychINFO, Academic Search Premier and CENTRAL were searched systematically. Quality was assessed with the Mixed Methods Appraisal Tool. Results Of the 115 included studies, 104 provided outcomes on ADL, 15 on participation (4 studies with mean age ≥ 65), and 2 on caregiver burden (1 study with mean age ≥ 65). Quality assessment yielded scores ranging from 0 to 100%. VSN had a negative impact on ADL (i.e., independence during ADL and performance in self-care, household tasks, reading, writing, walking, wheelchair navigation) and participation (i.e., driving, community mobility, orientation, work). The impact of VSN on fulfilling social roles was unclear. VSN had a negative effect on caregiver burden. We found no clear age-related differences. Conclusions and implications VSN has a negative impact not only on patients’ independence but particularly on the performance of ADL. Despite the far fewer studies of VSN as compared with ADL, VSN also seems to hamper participation and increase caregiver burden, but further research is needed. Because of the large impact, VSN should be systematically and carefully assessed during rehabilitation. A considerable number of different instruments were used to diagnose VSN. Diagnosing VSN at more than one level [function (i.e., pen-and-paper test), activities, and participation] is strongly recommended. Consensus is needed on how to assess VSN and its negative impact for research and rehabilitation practice. Systematic review Registration No. PROSPERPO Registration No. CRD42018087483.

A dual task was designed to involve a tracking mission with various tracking speeds and a spatial compatibility task with various signal-key mappings and presentation modalities. This dual task was used to investigate the effects of workload and resource competition in distinct parts of the dual-task process. The results demonstrated that increasing the tracking speed adversely affected the tracking performance but led to positive arousal to the secondary discrete response task. Visual spatial signals gave the shortest reaction time due to the optimal time-sharing of the visual resources in the focal and ambient channels. Compared with visual spatial signals, spatial signals of auditory and tactile modalities did not lead to an improved performance because of their cross-modality nature. These findings provided practical design guidelines for dual tasks in which the operators need to complete a continuous monitoring task visually and elicit timely and accurate responses to spatial information.

This study aimed to evaluate the effects of time of day and taxi route complexity on navigation errors. Nine pilots participated in the experiment. Four testing conditions defined by time of day conditions (i.e., nighttime versus daytime) and taxi route complexity (i.e., more complex versus less complex) were examined. Participants were instructed to perform simulated taxiing tasks in each of the testing conditions. Navigation errors during taxiing were counted. In addition, eye movement measures can reflect pilots' attention allocation, situation awareness and mental workload that are closely related to the risk of navigation errors. Thus, eye movement measures including fixation rate, average fixation duration and average pupil area were also selected as dependent variables. We found that navigation errors were fewer at night compared to in daytime. This could be explained by the finding that pilots paid more attention to the environmental clues out of the window at night, inducing better situation awareness for accurate taxiing. More complex taxi route was found to be associated with more navigation errors, but participants' visual behaviors were consistent between route complexity conditions, indicating that pilots' visual operation strategies did not contribute to the increased number of navigation errors in the more complex taxi route condition.

In discrete aiming movements the task criteria of time-minimization to a spatial target (e.g., Fitts, 1954) and time-matching to a spatial-temporal goal (e.g., Schmidt et al., 1979) tend to produce different functions of the speed-accuracy trade-off. Here we examined whether the task-related movement speed-accuracy characteristics were due to differential space-time trade-offs in time-matching, velocity-matching and time-minimizing task goals. Twenty participants performed 100 aiming trials for each of 15 combinations of task-type (3) and space-time condition (5). The prevalence of the primary types of sub-movement (none, pre-peak, post-peak, undershooting and overshooting) was determined from the kinematics of the movement trajectory. There were comparable distributions of trajectory sub-movement profiles and space-time movement outcomes across the three tasks at the short movement duration that became increasingly dissimilar over decreasing movement velocity and increasing movement time conditions. Movement time was the most influential variable in mediating sub-movement characteristics and the spatial/temporal outcome accuracy and variability of discrete aiming tasks - a role that was magnified in the explicit task demands of time-matching. The time-matching and time-minimization task goals in discrete aiming induce qualitatively different control processes that progressively contribute beyond the minimal time conditions to task-specific space-time accuracy and variability characteristics of the respective movement speed-accuracy functions.

Even though we frequently execute saccades, we perceive the external world as coherent and stable. An important mechanism of trans-saccadic perception is spatial remapping: the process of updating information across eye movements. Previous studies have indicated a right hemispheric dominance for spatial remapping, which has been proposed to translate into enhanced trans-saccadic memory for locations that are remapped into the right compared to the left hemisphere in healthy participants. Previous study designs suffered from several limitations, however (i.e. multiple eye movements had to be made instead of one, fixations were not controlled for, and ceiling effects were likely present). We therefore compared accuracy of trans-saccadic memory for central items after left- versus rightward eye movements, and secondary, for items that were remapped within the left versus right visual field. Participants memorized the location of a briefly presented item, made one saccade, and subsequently decided in what direction the item had shifted. We used a staircase to adjust task difficulty. Bayesian repeated measures ANOVAs were used to compare between left versus right eye movements and items in the left versus right visual field. We found most evidence against directional differences in trans-saccadic memory (BF10=0.23). We found some evidence suggestive of enhanced trans-saccadic memory for items that were remapped within the left compared to the right visual field (BF10=4.00). The latter result could be explained by a leftward spatial attention bias. As such, the hypothesized right hemispheric dominance for spatial remapping does not result in asymmetric trans-saccadic memory capacities in healthy participants.

When face was inverted, dynamic gaze cues could still effectively direct attention despite the disruption of configural face processing, but the static gaze cues could not. The present study investigated the role of the motion cue in the dynamic Gaze-Cueing Effect (GCE). With schematic and real faces, we employed the gaze-cueing paradigm to examine the differences among three kinds of cues (static gaze cue, dynamic gaze cue and motion cue) based on behavioral results and event-related potentials. Behavioral results revealed significant GCE in all conditions. In the schematic face group, the motion cue (two symmetrical dots shifting slightly to the side) induced a significantly smaller GCE than the dynamic gaze cues (two symmetrical dots moving within a rounded circle), while in the real face group, the motion cue (that is, the inverted-face gaze cue) remained a strong GCE compared with other conditions. With regard to the ERP results, we found the early directing attention negativity (EDAN), which was sensitive to voluntary cues (e.g. arrow cue) rather than gaze cue, in the schematic motion cue condition, but not in the inverted-face gaze cue condition. We supposed that the motion cue (real face) could activate the configural face processing even when the face is inverted. This finding supported that EDAN reflected a cue-triggered attention shift.

The "blue-on" and "blue-off" receptive fields in retina and dorsal lateral geniculate nucleus (LGN) of diurnal primates combine signals from short-wavelength sensitive (S) cone photoreceptors with signals from medium/long wavelength sensitive (ML) photoreceptors. Three questions about this combination remain unresolved. Firstly, is the combination of S and ML signals in these cells linear or non-linear? Secondly, how does the timing of S and ML inputs to these cells influence their responses? Thirdly, is there spatial antagonism within S and ML subunits of the receptive field of these cells? We measured contrast sensitivity and spatial frequency tuning for four types of drifting sine gratings: S cone isolating, ML cone isolating, achromatic (S + ML), and counterphase chromatic (S - ML), in extracellular recordings from LGN of marmoset monkeys. We found that responses to stimuli which modulate both S and ML cones are well predicted by a linear sum of S and ML signals, followed by a saturating contrast-response relation. Differences in sensitivity and timing (i.e. vector combination) between S and ML inputs are needed to explain the amplitude and phase of responses to achromatic (S + ML) and counterphase chromatic (S - ML) stimuli. Best-fit spatial receptive fields for S and/or ML subunits in most cells (>80%) required antagonistic surrounds, usually in the S subunit. The surrounds were however generally weak and had little influence on spatial tuning. The sensitivity and size of S and ML subunits were correlated on a cell-by-cell basis, adding to evidence that blue-on and blue-off receptive fields are specialised to signal chromatic but not spatial contrast.

The center-surround receptive field structure, ubiquitous in the visual system, is hypothesized to be evolutionarily advantageous in image processing tasks. We address the potential functional benefits and shortcomings of spatial localization and center-surround antagonism in the context of an integrate-and-fire neuronal network model with image-based forcing. Utilizing the sparsity of natural scenes, we derive a compressive-sensing framework for input image reconstruction utilizing evoked neuronal firing rates. We investigate how the accuracy of input encoding depends on the receptive field architecture, and demonstrate that spatial localization in visual stimulus sampling facilitates marked improvements in natural scene processing beyond uniformly-random excitatory connectivity. However, for specific classes of images, we show that spatial localization inherent in physiological receptive fields combined with information loss through nonlinear neuronal network dynamics may underlie common optical illusions, giving a novel explanation for their manifestation. In the context of signal processing, we expect this work may suggest new sampling protocols useful for extending conventional compressive sensing theory.

The early detection of Alzheimer's disease requires our distinguishing it from cognitive aging. Here, we test whether spatial attentional changes might support that distinction. We engaged young normal (YN), older normal (ON), and patients with early Alzheimer's dementia (EAD) in an attentionally cued, self-movement heading discrimination task while we recorded push-button response times and event related potentials. YNs and ONs show the behavioral effects of attentional shifts from the cue to the target, whereas EAD patients did not (p < 0.001). YNs and ONs also show the shifting lateralization of a newly described attentional event related potentials component, whereas EAD patients did not (p < 0.001). Our findings suggest that spatial inattention in EAD patients may contribute to heading direction processing impairments that distinguish them from ONs and undermine their navigational capacity and driving safety.

BACKGROUND: Walking is an everyday activity that requires modifying patterns based on constraints posed by the environment. Meeting multiple constraints at once increases the challenge of modifying motor actions. RESEARCH QUESTION: We asked if adults’ strategies in adapting to spatial and temporal constraints were similar and if they would prioritize one constraint over the other when completing both. METHODS: Across three tasks, we investigated how adults altered their walking to cope with crossing obstacles (Task 1; N=30), walking to a metronome beat (Task 2; N=32), and crossing obstacles while walking to a metronome beat (Task 3; N=30). RESULTS: Adults recalibrated to their baseline gait, but showed carryover effects after meeting a temporal constraint (all ps>.05). We found an effect on the magnitude of deviation from metronome paces (F(2,62)=58.86, p

The basis for how we represent temporal intervals in memory remains unclear. One proposal, the mental time line theory (MTL), posits that our representation of temporal duration depends on a horizontal mental time line, thus suggesting that the representation of time has an underlying spatial component. Recent work suggests that the MTL is a learned strategy, prompting new questions of when and why MTL is used to represent temporal duration, and whether time is always represented spatially. The current study examines the hypothesis that the MTL may be a time processing strategy specific to centrally-located stimuli. In two experiments (visual eccentricity and prismatic adaptation procedures), we investigated the magnitude of the rightward bias, an index of the MTL, in central and peripheral space. When participants performed a supra-second temporal interval reproduction task, we observed a rightward bias only in central vision (within 3° visual angle), but not in the peripheral space (approximately 6–8° visual angle). Instead, in the periphery, we observed a leftward bias. The results suggest that the MTL may be a learned strategy specific to central space and that strategies for temporal interval estimation that do not depend on MTL may exist for stimuli perceived peripherally.

By taking into account Bruce Bridgeman's interest in an evolutionary framing of human cognition, we examine effective (cause-and-effect) connectivity among cortical structures related to different parts of the triune phylogenetic stratification: archicortex, paleocortex and neocortex. Using resting-state functional magnetic resonance imaging data from 25 healthy subjects and spectral Dynamic Causal Modeling, we report interactions among 10 symmetrical left and right brain areas. Our results testify to general rightward and top-down biases in excitatory interactions of these structures during resting state, when self-related contemplation prevails over more objectified conceptual thinking. The right hippocampus is the only structure that shows bottom-up excitatory influences extending to the frontopolar cortex. The right ventrolateral cortex also plays a prominent role as it interacts with the majority of nodes within and between evolutionary distinct brain subdivisions. These results suggest the existence of several levels of cognitive-affective organization in the human brain and their profound lateralization.

Recalling a spatial layout from multiple orientations – spatial flexibility – is challenging, even when the global configuration can be viewed from a single vantage point, but more so when it must be viewed piecemeal. In the current study, we examined whether experiencing the transition between multiple viewpoints enhances spatial memory and flexible recall for a spatial configuration viewed simultaneously (Exp. 1) and sequentially (Exp. 2), whether the type of transition matters, and whether action provides an additional advantage over passive experience. In Experiment 1, participants viewed an array of dollhouse furniture from four viewpoints, but with all furniture simultaneously visible. In Experiment 2, participants viewed the same array piecemeal, from four partitioned viewpoints that allowed for viewing only a segment at a time. The transition between viewpoints involved rotation of the array or participant movement around it. Rotation and participant movement were passively experienced or actively generated. The control condition presented the dollhouse as a series of static views. Across both experiments, participant movement significantly enhanced spatial memory relative to array rotation or static views. However, in Exp. 2, there was a further advantage for actively walking around the array compared to being passively pushed. These findings suggest that movement around a stable environment is key to spatial memory and flexible recall, with action providing an additional boost to the integration of temporally segmented spatial events. Thus, spatial memory may be more flexible than prior data indicate, when studied under more natural acquisition conditions.

Musical melodies have "peaks" and "valleys". Although the vertical component of pitch and music is well-known, the mechanisms underlying its mental representation still remain elusive. We show evidence regarding the importance of previous experience with melodies for crossmodal interactions to emerge. The impact of these crossmodal interactions on other perceptual and attentional processes was also studied. Melodies including two tones with different frequency (e.g., E4 and D3) were repeatedly presented during the study. These melodies could either generate strong predictions (e.g., E4-D3-E4-D3-E4-[D3]) or not (e.g., E4-D3-E4-E4-D3-[?]). After the presentation of each melody, the participants had to judge the colour of a visual stimulus that appeared in a position that was, according to the traditional vertical connotations of pitch, either congruent (e.g., high-low-high-low-[up]), incongruent (high-low-high-low-[down]) or unpredicted with respect to the melody. Behavioural and electroencephalographic responses to the visual stimuli were obtained. Congruent visual stimuli elicited faster responses at the end of the experiment than at the beginning. Additionally, incongruent visual stimuli that broke the spatial prediction generated by the melody elicited larger P3b amplitudes (reflecting 'surprise' responses). Our results suggest that the passive (but repeated) exposure to melodies elicits spatial predictions that modulate the processing of other sensory events.

Different electrophysiological (EEG) correlates may provide specific important assessment of the period that anticipates an imperative stimulus. Previous study of our group showed that a local (i.e. parietal) anticipatory EEG marker (i.e. the event related de-synchronization of the alpha rhythms; ERD) is selectively affected when transcranial magnetic stimulation (TMS) is delivered over crucial nodes belonging to well-known human networks involved in different cognitive domains. Here, we investigated whether such distinction is also present in the whole brain activity as seen through the pre-stimulus microstate's topography, representing a global and reference-free measure of the neural activity. First, when subjects received a pseudo-stimulation (sham), we found two distinct pre-stimulus topographies during perceptual or memory task, respectively. Second, we reported that, during the visuo-spatial attention task, stimulation of left intraparietal sulcus (IPS), but not left angular gyrus (AG), significantly modifies the topography observed in the Sham condition. Conversely, stimulation of AG, but not IPS, changes the topography observed in the Sham condition during a semantic memory task. These findings provide the first causal evidence for the task and region specificity of the pre-stimulus EEG microstates, thus proposing this EEG index as of particular interest for the assessment of the period that precedes a predictable event.

People divide their ongoing experience into meaningful events. This process, event segmentation, is strongly associated with visual input: when visual features change, people are more likely to segment. However, the nature of this relationship is unclear. Segmentation could be bound to specific visual features, such as actor posture. Or, it could be based on changes in the activity that are correlated with visual features. This study distinguished between these two possibilities by examining whether segmentation varies across first- and third-person perspectives. In two experiments, observers identified meaningful events in videos of actors performing everyday activities, such as eating breakfast or doing laundry. Each activity was simultaneously recorded from a first-person perspective and a third-person perspective. These videos presented identical activities but differed in their visual features. If segmentation is tightly bound to visual features then observers should identify different events in first- and third-person videos. In addition, the relationship between segmentation and visual features should remain unchanged. Neither prediction was supported. Though participants sometimes identified more events in first-person videos, the events they identified were mostly indistinguishable from those identified for third-person videos. In addition, the relationship between the video's visual features and segmentation changed across perspectives, further demonstrating a partial dissociation between segmentation and visual input. Event segmentation appears to be robust to large variations in sensory information as long as the content remains the same. Segmentation mechanisms appear to flexibly use sensory information to identify the structure of the underlying activity.

Animals have the ability to process information about an object or a conspecific’s physical features and location, and alter its behavior when such information is updated. In the laboratory, the object, spatial and social recognition are often studied in separate tasks, making them unsuitable to study the potential dissociations and interactions among various types of recognition memories. The present study introduced a single paradigm to detect the object and spatial recognition, and social recognition of a familiar and novel conspecific. Specifically, male and female Sprague-Dawley adult (>75 days old) or preadolescent (25–28 days old) rats were tested with two objects and one social partner in an open-field arena for four 10-min sessions with a 20-min inter-session interval. After the first sample session, a new object replaced one of the sampled objects in the second session, and the location of one of the old objects was changed in the third session. Finally, a new social partner was introduced in the fourth session and replaced the familiar one. Exploration time with each stimulus was recorded and measures for the three recognitions were calculated based on the discrimination ratio. Overall results show that adult and preadolescent male and female rats spent more time exploring the social partner than the objects, showing a clear preference for social stimulus over nonsocial one. They also did not differ in their abilities to discriminate a new object, a new location and a new social partner from a familiar one, and to recognize a familiar conspecific. Acute administration of MK-801 (a NMDA receptor antagonist, 0.025 and 0.10 mg/kg, i.p.) after the sample session dose-dependently reduced the total time spent on exploring the social partner and objects in the adult rats, and had a significantly larger effect in the females than in the males. MK-801 also dose-dependently increased motor activity. However, it did not alter the object, spatial and social recognitions. These findings indicate that the new triple recognition paradigm is capable of recording the object, spatial location and social recognition together and revealing potential sex and age differences. This paradigm is also useful for the study of object and social exploration concurrently and can be used to evaluate cognition-altering drugs in various stages of recognition memories.

Background Methamphetamine has long been considered as a neurotoxic substance causing cognitive deficits. Recently, however, the magnitude and the clinical significance of the cognitive effects associated with methamphetamine use disorder (MUD) have been debated. To help clarify this controversy, we performed a meta-analysis of the cognitive deficits associated with MUD. Methods A literature search yielded 44 studies that assessed cognitive dysfunction in 1592 subjects with MUD and 1820 healthy controls. Effect size estimates were calculated using the Comprehensive Meta-Analysis, for the following 12 cognitive domains: attention, executive functions, impulsivity/reward processing, social cognition, speed of processing, verbal fluency/language, verbal learning and memory, visual learning and memory, visuo-spatial abilities and working memory. Results Findings revealed moderate impairment across most cognitive domains, including attention, executive functions, language/verbal fluency, verbal learning and memory, visual memory and working memory. Deficits in impulsivity/reward processing and social cognition were more prominent, whereas visual learning and visuo-spatial abilities were relatively spared cognitive domains. A publication bias was observed. Discussion These results show that MUD is associated with broad cognitive deficits that are in the same range as those associated with alcohol and cocaine use disorder, as recently shown by way of meta-analysis. The prominent effects of MUD on social cognition and impulsivity/reward processing are based on a small number of studies, and as such, these results will need to be replicated. The functional consequences (social and occupational) of the cognitive deficits of methamphetamine will also need to be determined.

Oral contraceptive pill (OC) is one of the most popular form of contraception. Despite both behavioral and neuroimaging evidence of its significant impact on female brain and cognitive functions, much remains to be discovered regarding OCs targets in the brain and mechanisms of action. In the present study mental rotation performance was compared between women using anti-androgenic oral contraceptives (n = 35), naturally cycling (NC) women (n = 33) and men (n = 29). On average, OC users were less accurate than NC women and men. Men performed the task more accurately than NC women, but the difference reached significance only in the highest angular disparity condition (150 deg). The response time was positively related with progesterone level while accuracy was negatively related with 17s-estradiol level, in NC, but not OC women. The comparison of slope and intercept values (parameters relating response time to angular disparity) revealed the main result of present study: OC users exhibited significantly lower slope compared to men and NC women, but there were no differences in intercept between groups. These results suggest that OC users instead of using rotation in mind strategy implemented some alternative method(s). We conclude that lower performance accuracy of OC users could be related to a less efficient performance strategy.

An early functional onset of perceptual completion has been extensively documented during the first several months after birth. However, there is no indication for the developmental time periods at which these skills become fully developed. We used a version of an object-based attention task in which children and adults performed a same–different size judgment of two features appearing at two of four possible ends of overlapping objects. Single-object over two-object superiority (i.e., faster judgments when the features appeared on the same object than when they appeared on different objects) was observed for a complete object as early as at 4 years of age. However, it is only at 5 years of age that such a single-object advantage was obtained also for an occluded object, and even then the advantage of the single-object and occluded-object conditions over the two-object condition was observed only when the two features in the two-object condition were spatially distant, demonstrating the critical role of spatial proximity in perceptual organization during childhood. The results suggest that perceptual completion during infancy and early childhood demonstrates some rudimentary perceptual skills that become more firmly established with age.

Dynamic visuospatial tasks, requiring continuous engagement of attention over long time periods, have been little studied with the electroencephalogram. Specifically, the role of the theta band in these tasks is unclear, with task-related theta enhancements improving performance in some studies, and hindering it in others. In this study, 30 participants performed the Pong videogame as a dynamic visuospatial task to analyze the influence of theta and alpha amplitude as well as alpha asymmetry on performance. The theta band increased significantly at central-parietal regions and correlated negatively with performance, especially at anterior regions. The alpha band showed a significant decrease, greater at right over left parietal regions, but neither the amplitude nor the asymmetry ratio correlated with performance. With theta being an indicator of top-down cognitive control, it may be concluded that proficient performance in dynamic visuospatial tasks depends on a bottom-up guidance of attention with little top-down intervention.

What has been long absent in understanding the neural circuit that supports spatial processing is a thorough description and rigorous study of the distributed neural networks associated with spatial processing-both in the human as well as in rodents. Most of our understanding regarding the elucidation of a spatial neural circuit has been based on rodents and therefore the present manuscript will concentrate on that literature. There is a trend emerging in research to expand beyond the hippocampus for evaluating spatial memory, but the thrust of the research still focuses on the role of the hippocampus as essential and other neural substrates as performing sub-servient roles to support hippocampus-dependent spatial processing. This review will describe spatial memory in terms of a system model incorporating partially overlapping and interacting event-based, knowledge-based and rule-based memory systems that are composed of different component processes or attributes associated with spatial processing which are mapped onto the corresponding neural substrates and larger networks. In particular, the interactions among brain systems that process spatial information will be emphasized. We propose that these interactions among brain regions are essential for spatial memory.

Sequential randomness is one of the three important assumptions for Pulliam's vigilance model (1973). Here we tested the sequential randomness in Black-necked cranes Grus nigricollis, to see if the vigilance sequence can be predicted. Not similar to other recent studies, we found that most vigilance sequences (44/46) passed runs randomness test, and the length of an inter-scan interval was usually unrelated to its previous scan duration. Our findings suggest high predation risk might favor a random pattern of vigilance.

Circulating levels of testosterone (T) have been hypothesized to influence spatial cognition in adult men, but empirical support for this idea is mixed. Many of testosterone's effects are mediated by the classic nuclear androgen receptor (AR), which contains a polymorphic glutamine repeat (CAG repeat sequence) that varies significantly across individual men and confers differences in receptor function and therefore individual responsivity to T. We genotyped the AR CAG repeat length in 146 healthy adult men who also performed cognitive tests of mental rotation and spatial visualization. Circulating T concentrations were measured in saliva. CAG repeat length was found to be a significant predictor of spatial scores on tests of visualization but not mental rotation. A weaker AR was associated with lower visualization scores. In contrast, T itself, but not CAG repeat length predicted scores on two mental rotation tests. These results support the view that T action in the brain modestly influences spatial cognition in healthy men, but suggest that T's effects on mental rotation might not be AR-dependent and instead occur through an alternative mechanism.

In this paper, we examine brain lateralization patterns for a complex visual-spatial task commonly used to assess general spatial abilities. Although spatial abilities have classically been ascribed to the right hemisphere, evidence suggests that at least some tasks may be strongly bilateral. For example, while functional neuroimaging studies show right-lateralized activations for some spatial tasks (e.g., line bisection), bilateral activations are often reported for others, including classic spatial tasks such as mental rotation. Moreover, constructive apraxia has been reported following left- as well as right-hemisphere damage in adults, suggesting a role for the left hemisphere in spatial function. Here, we use functional neuroimaging to probe lateralization while healthy adults carry out a simplified visual-spatial construction task, in which they judge whether two geometric puzzle pieces can be combined to form a square. The task evokes strong bilateral activations, predominantly in parietal and lateral occipital cortex. Bilaterality was observed at the single-subject as well as at the group level, and regardless of whether specific items required mental rotation. We speculate that complex visual-spatial tasks may generally engage more bilateral activation of the brain than previously thought, and we discuss implications for understanding hemispheric specialization for spatial functions.

In this study, the interaction performances and spatial perceptions in stereoscopic environments were investigated. The experiment compared direct user interactions during pointing at a target, which was continuously visible or presented briefly and disappeared, in both stereoscopic and real environments, at three parallax/depth levels. The position data, collected by a motion system, were used to compute accuracy, signed error, movement time, and throughput. The results showed inaccurate egocentric distance judgment in stereoscopic displays and accurate perceptions in the real world. The overall inaccuracy, which was overestimation of about 10 cm, was relatively better than that achieved in previous studies. The overestimation decreased as the egocentric distance increased. However, providing visual objects did not improve the accuracy. The study concluded that direct pointing could minimize the underestimation problems commonly reported in stereoscopic viewing studies and showed practical significance for developers to focus on incorporating more direct and natural human-virtual reality interactions for improved performance. The findings of this study provide insight towards the development of less expensive displays and their applications. Implications of this work and engineering solutions are also discussed.

The spatial pattern separation process has not yet been proposed as a pivotal neural activity affecting hippocampal volume, a metric of mental health. The dentate gyrus/CA3 region is increasingly implicated in hippocampal atrophy, its putative role in spatial pattern separation appears to be impaired in mental health disorders, and performance on a task indicative of pattern separation correlates with dentate gyrus/CA3 volume. Spatial pattern separation is thought to utilize the heightened neural plasticity of newborn neurons in the dentate gyrus to distinguish highly similar aspects of scene so that these remain distinct in memory rather than lost. The level of such activity associates with BDNF secretion, which may affect neuroplasticity and therefore hippocampal volume. Distinguishing fine-grained aspects of surroundings was likely of great importance during hunting and gathering for survival in nature. However the need to make subtle environmental discriminations is much reduced in modern survival activity. Ancestrally, exploration and utilization of the spatial pattern separation process may have resulted in detection of potential food items, an activity that was likely followed by intensive effort-based reward (EBR) activity to obtain the food. EBR activity and restorative walking in nature demonstrate positive mental health benefits, while their lack indicates negative effects on mental health. Data support the hypothesis that spatial pattern separation activity and neural circuitry are separate from, and may precede, those of EBR as well as restorative walking in nature. Spatial pattern separation therefore represents an additional nature-related neural process whose modern decrease in use may negatively affect mental health. Interventions that increase spatial pattern separation experiences may enhance BDNF secretion, neuroplasticity, hippocampal volume and mental health.

Objectives Contra-lateral routing of signals (CROS) devices re-route sound between the deaf and hearing ears of unilaterally-deaf individuals. This rerouting would be expected to disrupt access to monaural level cues that can support monaural localisation in the horizontal plane. However, such a detrimental effect has not been confirmed by clinical studies of CROS use. The present study aimed to exercise strict experimental control over the availability of monaural cues to localisation in the horizontal plane and the fitting of the CROS device to assess whether signal routing can impair the ability to locate sources of sound and, if so, whether CROS selectively disrupts monaural level or spectral cues to horizontal location, or both. Design Unilateral deafness and CROS device use were simulated in twelve normal hearing participants. Monaural recordings of broadband white noise presented from three spatial locations (−60°, 0°, and +60°) were made in the ear canal of a model listener using a probe microphone with and without a CROS device. The recordings were presented to participants via an insert earphone placed in their right ear. The recordings were processed to disrupt either monaural level or spectral cues to horizontal sound location by roving presentation level or the energy across adjacent frequency bands, respectively. Localisation ability was assessed using a three-alternative forced-choice spatial discrimination task. Results Participants localised above chance levels in all conditions. Spatial discrimination accuracy was poorer when participants only had access to monaural spectral cues compared to when monaural level cues were available. CROS use impaired localisation significantly regardless of whether level or spectral cues were available. For both cues, signal re-routing had a detrimental effect on the ability to localise sounds originating from the side of the deaf ear (−60°). CROS use also impaired the ability to use level cues to localise sounds originating from straight ahead (0°). Conclusions The re-routing of sounds can restrict access to the monaural cues that provide a basis for determining sound location in the horizontal plane. Perhaps encouragingly, the results suggest that both monaural level and spectral cues may not be disrupted entirely by signal re-routing and that it may still be possible to reliably identify sounds originating on the hearing side., Highlights • Rerouting sounds from a deaf ear to a hearing ear impairs monaural localisation. • Distinct effects of rerouting were observed on monaural level and spectral cues. • Rerouting disrupts level cues distinguishing sounds at 0° azimuth and at the deaf ear. • Rerouting selectively disrupts spectral cues that identify sounds at the deaf ear.

Experimental data about brain function accumulate faster than does our understanding of how the brain works. To tackle some general principles at the grain level of behavior, I start from the omnipresent brain-environment connection that forces regularities of the physical world to shape the brain. Based on top-down processing, added by sparse sensory information, people are able to form individual "caricature worlds," which are similar enough to be shared among other people and which allow quick and purposeful reactions to abrupt changes. Temporal dynamics and social interaction in natural environments serve as further essential organizing principles of human brain function.

The influence of visuo-spatial skills on numerical magnitude processing is the subject of a long-standing debate. As most of the numerical and non-numerical magnitude abilities underpinning mathematical development are visual by nature, they are often assessed in the visual modality, thereby confusing visuo-spatial and numerical processing. In order to assess the influence of visuo-spatial processing on numerical magnitude representation, we examined magnitude processing in patients with 22q11.2 deletion syndrome (22q11DS), a genetic condition characterized by a cognitive profile with a relative weakness in visuo-spatial abilities but with preserved verbal abilities. Twenty-seven participants with 22q11DS were compared to two control groups (one matched on verbal intelligence and the other on visuo-spatial abilities) on several magnitude comparison tasks each with different visuo-spatial processing requirements. Our results showed that participants with 22q11DS present a consistent pattern of impairment in magnitude comparison tasks requiring the processing of visuo-spatial dimensions: comparison of lengths and collections. In contrast, their performance did not differ from the control groups in a visual task with no spatial processing requirement (i.e. numerical comparison of flashed dot sequences) or in auditory tasks (i.e., duration comparison and numerical comparison of sound sequences). Finally, a specific deficit of enumeration processes was observed in the subitizing range. Taken together, these results show that deficits in magnitude can occur as a consequence of a visuo-spatial deficit. This highlights the influence of the nature of the tasks selected to assess magnitude representation.

In ERP studies of cognitive processes during attentional tasks, the cue signals containing information about the target can increase the amplitude of the parietal cue P3 in relation to the 'neutral' temporal cue, and reduce the subsequent target P3 when this information is valid, i.e. corresponds to the target's attributes. The present study compared the cue-to-target P3 ratios in neutral and visuospatial cueing, in order to estimate the contribution of valid visuospatial information from the cue to target stages of the task performance, in terms of cognitive load. The P3 characteristics were also correlated with the results of individuals' performance of the visuospatial tasks, in order to estimate the relationship of the observed ERP with spatial reasoning. In 20 typically developing boys, aged 10-13 years (11.3±0.86), the intelligence quotient (I.Q.) was estimated by the Block Design and Vocabulary subtests from the WISC-III. The subjects performed the Attentional Network Test (ANT) accompanied by EEG recording. The cued two-choice task had three equiprobable cue conditions: No cue, with no information about the target; Neutral (temporal) cue, with an asterisk in the center of the visual field, predicting the target onset; and Spatial cues, with an asterisk in the upper or lower hemifield, predicting the onset and corresponding location of the target. The ERPs were estimated for the mid-frontal (Fz) and mid-parietal (Pz) scalp derivations. In the Pz, the Neutral cue P3 had a lower amplitude than the Spatial cue P3; whereas for the target ERPs, the P3 of the Neutral cue condition was larger than that of the Spatial cue condition. However, the sums of the magnitudes of the cue and target P3 were equal in the spatial and neutral cueing, probably indicating that in both cases the equivalent information processing load is included in either the cue or the target reaction, respectively. Meantime, in the Fz, the analog ERP components for both the cue and target stimuli did not depend on the cue condition. The results show that, in the parietal site, the spatial cue P3 reflects the processing of visuospatial information regarding the target position. This contributes to the subsequent "decision-making", thus reducing the information processing load on the target response, which is probably reflected in the lower P3. This finding is consistent with the positive correlation of parietal cue P3 with the individual's ability to perform spatial tasks as scored by the Block Design subtest.

We examined the role of attention and visual working memory in the evaluation of the number of target stimuli as well as their relative spatial position using the N2pc and the SPCN. Participants performed two tasks: a simple counting task in which they had to determine if a visual display contained one or two coloured items among grey fillers and one in which they had to identify a specific relation between two coloured items. The same stimuli were used for both tasks. Each task was designed to permit an easier evaluation of either the same-coloured or differently-coloured stimuli. We predicted a greater involvement of attention and visual working memory for more difficult stimulus-task pairings. The results confirmed these predictions and suggest that visuospatial configurations that require more time to evaluate induce a greater (and presumably longer) involvement of attention and visual working memory.

Both anxiety and major depression disorder (MDD) were reported to involve a maladaptive selective attention mechanism, associated with bias toward negative stimuli. Previous studies investigated attentional bias using distractors that required processing as part of task settings, and therefore, in our view, these distractors should be regarded as task-relevant. Here, we applied a unique task that used peripheral distractors that presented emotional and spatial information simultaneously. Notably, the emotional information was not associated in any way to the task, and thus was task-irrelevant. The spatial information, however, was task-relevant as it corresponded with task instructions. Corroborating previous findings, anxious patients showed attentional bias toward negative information. MDD patients showed no indication of this bias. Spatial information influenced all groups similarly. These results indicate that anxiety, but not MDD, is associated with an inherent negative information bias, further illustrating that the two closely related disorders are characterized by different processing patterns.

The nonverbal learning disability (NLD) is a neurological dysfunction that affects cognitive functions predominantly related to the right hemisphere such as spatial and abstract reasoning. Previous evidence in healthy adults suggests that acoustic pitch (i.e., the relative difference in frequency between sounds) is, under certain conditions, encoded in specific areas of the right hemisphere that also encode the spatial elevation of external objects (e.g., high vs. low position). Taking this evidence into account, we explored the perception of pitch in preadolescents and adolescents with NLD and in a group of healthy participants matched by age, gender, musical knowledge and handedness. Participants performed four speeded tests: a stimulus detection test and three perceptual categorization tests based on colour, spatial position and pitch. Results revealed that both groups were equally fast at detecting visual targets and categorizing visual stimuli according to their colour. In contrast, the NLD group showed slower responses than the control group when categorizing space (direction of a visual object) and pitch (direction of a change in sound frequency). This pattern of results suggests the presence of a subtle deficit at judging pitch in NLD along with the traditionally-described difficulties in spatial processing.

Patients with multimodal semantic deficits following stroke ('semantic aphasia') have largely intact knowledge, yet difficulty controlling conceptual retrieval to suit the circumstances. Although conceptual representations are thought to be largely distinct from episodic representations of recent events, controlled retrieval processes may overlap across semantic and episodic memory domains. We investigated this possibility by examining item familiarity and source memory for recent events in semantic aphasia following infarcts affecting left inferior frontal gyrus. We tested the hypothesis that the nature of impairment in episodic judgements reflects the need for control over retrieval: item familiarity might be relatively intact, given it is driven by strong cues (re-presentation of the item), while source recollection might be more impaired since this task involves resolving competition between several potential sources. This pattern was observed most strongly when the degree of competition between sources was higher, i.e., when non-meaningful sources had similar perceptual features, and existing knowledge was incongruent with the source. In contrast, when (i) spatial location acted as a strong cue for retrieval; (ii) existing knowledge was congruent with episodic memory and (iii) distinctiveness of sources was increased by means of self-referential processing, source memory reached normal levels. These findings confirm the association between deregulated control of semantic and episodic memory in patients with semantic aphasia and delineate circumstances that ameliorate or aggravate these deficits.

Previous studies suggested that highly math-anxious (HMA) individuals invest more attentional resources than their low math-anxious (LMA) peers in numerical tasks, and have worse spatial skills. We aimed to explore whether they also need to apply more resources in spatial tasks. In this study, HMA and LMA individuals saw normal or mirror-reversed letters in six orientations and made mirror-normal decisions. In both groups, response times and errors increased with angular deviation from upright and the ERP mental rotation effect was found. However, HMAs were slower to respond than their LMA counterparts. Interestingly, the HMA group showed a larger P3b in greater deviations for normal letters and in all mirrored letters. Since P3b amplitude reflects the attentional resources invested in the categorization of relevant stimuli, HMA individuals may need to devote more processing effort than their LMA peers when performing mental rotation. This finding is consistent with the Attentional Control Theory.

Noise-induced hearing loss (NIHL) is known to have significant consequences for temporal, spectral, and spatial resolution. However, much remains to be discovered about their underlying pathophysiology. This report extends the recent development of a nonhuman primate model of NIHL to explore its consequences for hearing in noisy environments, and its correlations with the underlying cochlear pathology. Ten macaques (seven with normal-hearing, three with NIHL) were used in studies of masked tone detection in which the temporal or spatial properties of the masker were varied to assess metrics of temporal and spatial processing. Normal-hearing (NH) macaques showed lower tone detection thresholds for sinusoidally amplitude modulated (SAM) broadband noise maskers relative to unmodulated maskers (modulation masking release, MMR). Tone detection thresholds were lowest at low noise modulation frequencies, and increased as modulation frequency increased, until they matched threshold in unmodulated noise. NH macaques also showed lower tone detection thresholds for spatially separated tone and noise relative to co-localized tone and noise (spatial release from masking, SRM). Noise exposure caused permanent threshold shifts that were verified behaviorally and audiologically. In hearing-impaired (HI) macaques, MMR was reduced at tone frequencies above that of the noise exposure. HI macaques also showed degraded SRM, with no SRM observed across all tested tone frequencies. Deficits in MMR correlated with audiometric threshold changes, outer hair cell loss, and synapse loss, while the differences in SRM did not correlate with audiometric changes, or any measure of cochlear pathophysiology. This difference in anatomical-behavioral correlations suggests that while many behavioral deficits may arise from cochlear pathology, only some are predictable from the frequency place of damage in the cochlea.

In the past decade, hyperspectral imaging has emerged and matured into one of the most powerful and rapidly growing methods for non-destructive food quality analysis and control. This paper demonstrates fast and automatic quantification of food ingredients with hyperspectral imaging in the visible and near-infrared range in combination with chemometrics and image processing techniques. The application of ingredient quantification in bread flour recipes requires high spatial resolution in addition to spectral discrimination power. Our results show that automatic and accurate quantification of all ingredients can be done, reaching pixel discrimination accuracies above 90% and ingredient quantification errors within the required 1% absolute error in weight. The classification accuracy obtained using 15 wavebands on the test images is around 15% higher than what was obtained with colour imaging.

Aging affects the interplay between peripheral and cortical auditory processing. Previous studies have demonstrated that older adults are less able to regulate afferent sensory information and are more sensitive to distracting information. Using auditory event-related potentials we investigated the role of cortical inhibition on auditory and audiovisual processing in younger and older adults. Across puretone, auditory and audiovisual speech paradigms older adults showed a consistent pattern of inhibitory deficits, manifested as increased P50 and/or N1 amplitudes and an absent or significantly reduced N2. Older adults were still able to use congruent visual articulatory information to aid auditory processing but appeared to require greater neural effort to resolve conflicts generated by incongruent visual information. In combination, the results provide support for the Inhibitory Deficit Hypothesis of aging. They extend previous findings into the audiovisual domain and highlight older adults' ability to benefit from congruent visual information during speech processing.

Background Few studies have addressed the effect of treatment of unruptured intracranial aneurysm (UIA) on cognitive function. Objective Neuropsychological assessment after UIA treatment is underreported, and prospective trials have repeatedly been demanded. In 2014, we conducted a prospective controlled study to evaluate the differences in cognitive processing caused by the treatment of anterior circulation UIAs. Patients and Methods Thirty patients were enrolled until September 2015. Ten patients received endovascular aneurysm occlusion (EV), 10 patients were treated microsurgically (MS), and 10 patients with surgically treated degenerative lumbar spine disease (LD) served as control. All patients underwent extended standardized neuropsychological assessment before (t 1 ) and 6 weeks after treatment (t 2 ). Tests included verbal, visual, and visuospatial memory, psychomotor functioning, executive functioning, and its subdomains verbal fluency and cognitive flexibility. We statistically evaluated intragroup and intergroup changes. Results Intragroup comparisons and group-rate analysis showed no significant impairment in overall neuropsychological performance, either postinterventionally or postoperatively. However, the postoperative performance in cognitive processing speed, cognitive flexibility, and executive functioning was significantly worse in the MS group than in the EV ( P = 0.038) and LD group ( P = 0.02). Compared with the EV group, patients with MS showed significant postoperative impairment in a subtest for auditory-verbal memory (Wechsler Memory Scale, Fourth Edition, Logical Memory II; MS vs. EV P = 0.011). The MS group trended toward posttreatment impairment in subtests for verbal fluency and semantic memory (Regensburg Word Fluency Test; MS vs. EV P = 0.083) and in auditory-verbal memory (Wechsler Memory Scale, Fourth Edition, Logical Memory II; MS vs. LD P = 0.06). Conclusions Our preliminary data showed no effect of anterior circulation UIA treatment on overall neuropsychological function but impaired short-term executive processing in surgically treated patients.

The integration of multiple sensory inputs is essential for perception of the external world. The spatial factor is a fundamental property of multisensory audiovisual integration. Previous studies of the spatial constraints on bimodal audiovisual integration have mainly focused on the spatial congruity of audiovisual information. However, the effect of spatial reliability within audiovisual information on bimodal audiovisual integration remains unclear. In this study, we used event-related potentials (ERPs) to examine the effect of spatial reliability of task-irrelevant sounds on audiovisual integration. Three relevant ERP components emerged: the first at 140-200ms over a wide central area, the second at 280-320ms over the fronto-central area, and a third at 380-440ms over the parieto-occipital area. Our results demonstrate that ERP amplitudes elicited by audiovisual stimuli with reliable spatial relationships are larger than those elicited by stimuli with inconsistent spatial relationships. In addition, we hypothesized that spatial reliability within an audiovisual stimulus enhances feedback projections to the primary visual cortex from multisensory integration regions. Overall, our findings suggest that the spatial linking of visual and auditory information depends on spatial reliability within an audiovisual stimulus and occurs at a relatively late stage of processing.

Human languages may be more than completely arbitrary symbolic systems. A growing literature supports sound symbolism, or the existence of consistent, intuitive relationships between speech sounds and specific concepts. Prior work establishes that these sound-to-meaning mappings can shape language-related judgments and decisions, but do their effects generalize beyond merely the linguistic and truly color how we navigate our environment? We examine this possibility, relating a predominant sound symbolic distinction (vowel frontness) to a novel associate (spatial proximity) in five studies. We show that changing one vowel in a label can influence estimations of distance, impacting judgment, perception, and action. The results (1) provide the first experimental support for a relationship between vowels and spatial distance and (2) demonstrate that sound-to-meaning mappings have outcomes that extend beyond just language and can - through a single sound - influence how we perceive and behave toward objects in the world.

Gender stereotypes hold that males outperform females in mathematics and spatial tests, and females outperform males on verbal tests. According to meta-analyses, however, among both children and adults, females perform equally to males on mathematics assessments. The gender difference in verbal skills is small and varies depending on the type of skill assessed (e.g., vocabulary, essay writing). The gender difference in 3D mental rotation shows a moderate advantage for males, but this gender difference occurs in the absence of a spatial curriculum in the schools. Meta-analyses of gender differences across a wide array of psychological qualities support the Gender Similarities Hypothesis, which states that males and females are quite similar on most-but not all-psychological variables.

Spontaneous eye movements during imagery are not random and can be used to study and reveal mental visualization processes (Fourtassi et al., 2013; Johansson et al. 2006). For example, we previously showed that during memory recall of French towns via imagery healthy individuals looks straight ahead when recalling Paris and their subsequent gaze positions are significantly correlated with the real GPS coordinates of the recalled towns. This correlation suggests that memory retrieval is done via depictive representations as it is never found when the towns are recalled using verbal fluency. In the present paper we added to this finding by showing that the mental image is spontaneously centered on the head or body midline. In order to investigate the capacities of visual imagery in patients, and by extension, the role of primary visual cortex and fronto-parietal cortex in spatial visual imagery, we recorded gaze positions during memory recall of French towns in an imagery task, a non-imagery task (verbal fluency), and a visually-guided task in five patients with left or right hemianopia and in four patients with hemineglect (two with left hemianopia and two without). The correlation between gaze position and real GPS coordinates of the recalled towns was significant in all hemianopic patients, but in patients with hemineglect this was only the case for towns located on the right half of the map of France. This suggests hemianopic patients can perform spatially consistent mental imagery despite direct or indirect unilateral lesions of the primary visual cortex. In contrast, the left-sided towns recalled by hemineglect patients, revealed that they have some spatial inconsistency or representational difficulty. Hemianopic patients positioned and maintained their gaze in their contralesional hemispace, suggesting that their mental map was not centered on their head or body midline. This contralesional gaze positioning appeared to be a general compensation strategy and was not observed in patients with neglect (with or without hemianopia). Instead, neglect patients positioned their gaze in their ipsilesional hemispace and only when performing the visual imagery task. These findings are discussed in the context of the role of occipital and fronto-parietal cortices in the neuroanatomical model of visual imagery developed by Kosslyn et al. (2006).

For individuals with visual impairments, auditory spatial localization is one of the most important features to navigate in the environment. Many works suggest that blind adults show similar or even enhanced performance for localization of auditory cues compared to sighted adults (Collignon, Voss, Lassonde, & Lepore, 2009). To date, the investigation of auditory spatial localization in children with visual impairments has provided contrasting results. Here we report, for the first time, that contrary to visually impaired adults, children with low vision or total blindness show a significant impairment in the localization of static sounds. These results suggest that simple auditory spatial tasks are compromised in children, and that this capacity recovers over time.

Objectives Stress might be caused by various lifestyle factors and physical challenges and can result in severe diseases. The body responds to stressful events by release of hormones, like cortisol, as well as reaction of the sympathetic nervous system. One strategy to counteract stress is chewing gum. The present study aimed at investigating the influence of mastication on biomarkers of stress during performance of a stress test. Methods A two-armed cross-over study with 40 young male volunteers was performed. Hormone plasma concentrations were determined after an initial resting phase (2:30 p.m.), immediately before (3:00 p.m.) and two times after (3:20, 3:50 p.m.) performance of a multitasking test using magnetic beads and ELISA methods. In addition, visual analog scales were used to rate subjective mood and the breathing and heart rates were monitored throughout the entire study period using a sensor chest belt. Results Performance of the stress test led to an increase in plasma cortisol concentrations from 223 ± 23.3 to 325 ± 38.4 ng/ml (p = 0.023) and caused changes in subjective mood ratings as well as breathing rates. Although chewing gum base had no impact on the plasma hormone concentrations, it induced a stronger elevation of average heart rates compared to not chewing (p = 0.016). Discussion The effect of chewing gum on a mild stress load was less pronounced than in previous studies. Besides the detection of cortisol in saliva, not in plasma, in previous studies, flavored gum was used. Aroma active compounds might have substantially contributed to the beneficial effects of gum on biomarker of stress shown before.