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In all vertebrates, visual signals from each visual field project to the opposite midbrain tectum (called the superior colliculus in mammals). The tectum/colliculus computes visual salience to select targets for context-contingent visually guided behavior: a frog will orient toward a small, moving stimulus (insect prey) but away from a large, looming stimulus (a predator). In mammals, visual signals competing for behavioral salience are also transmitted to the visual cortex, where they are integrated with collicular signals and then projected via the dorsal visual stream to the parietal and frontal cortices. To control visually guided behavior, visual signals must be encoded in body-centered (egocentric) coordinates, and so visual signals must be integrated with information encoding eye position in the orbit—where the individual is looking. Eye position information is derived from copies of eye movement signals transmitted from the colliculus to the frontal and parietal cortices. In the intraparietal cortex of the dorsal stream, eye movement signals from the colliculus are used to predict the sensory consequences of action. These eye position signals are integrated with retinotopic visual signals to generate scaffolding for a visual scene that contains goal-relevant objects that are seen to have spatial relationships with each other and with the observer. Patients with degeneration of the superior colliculus, although they can see, behave as though they are blind. Bilateral damage to the intraparietal cortex of the dorsal stream causes the visual scene to disappear, leaving awareness of only one object that is lost in space. This tutorial considers what we have learned from patients with damage to the colliculus, or to the intraparietal cortex, about how the phylogenetically older midbrain and the newer mammalian dorsal cortical visual stream jointly coordinate the experience of a spatially and temporally coherent visual scene. [ABSTRACT FROM AUTHOR]

We commonly label moral violations in terms of 'disgust', yet it remains unclear whether metaphorical expressions linking disgust and morality are genuinely shared at the cognitive/neural level. Using transcranial magnetic stimulation (TMS), we provide new insights into this debate by measuring motor-evoked potentials (MEPs) from the tongue generated by TMS over the tongue primary motor area (tM1) in a small group of healthy participants presented with vignettes of moral transgressions and non-moral vignettes. We tested whether moral indignation, felt while evaluating moral vignettes, affected tM1 excitability. Vignettes exerted a variable influence on MEPs with no net effect of the moral category. However, in accordance with our recent study documenting reduced tM1 excitability during exposure to pictures of disgusting foods or facial expressions of distaste, we found that the vignettes of highly disapproved moral violations reduced tM1 excitability. Moreover, tM1 excitability and moral indignation were linearly correlated: the higher the moral indignation, the lower the tM1 excitability. Respective changes in MEPs were not observed in a non-oral control muscle, suggesting a selective decrease of tM1 excitability. These preliminary findings provide neurophysiological evidence supporting the hypothesis that morality might have originated from the more primitive experience of oral distaste. [ABSTRACT FROM AUTHOR]

Amnesic patients can re‐experience emotions elicited by forgotten events, suggesting that brain systems for episodic and emotional memory are independent. However, the range of such emotional memories remains under‐investigated (most studies employing just positive–negative emotion dyads), and executive function may also play a role in the re‐experience of emotions. This is the first investigation of the intensity of the emotional re‐experience of a range of discrete emotions (anger, fear, sadness, and happiness) for a group of amnesic patients. Twenty Korsakoff syndrome (KS) patients and 20 neurologically normal controls listened to four novel emotional vignettes selectively eliciting the four basic emotions. Emotional experience was measured using pen‐and‐paper Visual Analogue Mood Scales and episodic memory using verbal recollections. After 30 min, the recollection of stories was severely impaired for the patient group, but the emotional re‐experience was no different from that of controls. Notably, there was no relationship between episodic recall and the intensity of the four emotions, such that even profoundly amnesic patients reported moderate levels of the target emotion. Exploratory analyses revealed negative correlations between the intensity of basic emotions and executive functions (e.g., cognitive flexibility and response inhibition) for controls but not patients. The results suggest that discrete emotions can be re‐experienced independently of episodic memory, and that the re‐experience of certain discrete emotions appears to be dampened by executive control. KS patients with absent or mild cognitive symptoms should benefit from emotion‐regulation interventions aimed at reducing the recognized affective burden associated with their episodic memory deficit. [ABSTRACT FROM AUTHOR]

The superior colliculus (SC) plays a critical role in mediating reflexive eye movements. Under optimal conditions, for example including a temporal 'gap' of 200 ms after fixation offset and prior to target onset, it is possible to isolate a population of 'express saccades' with very short latencies between 80 and 120 ms. Ablation of the SC abolishes express saccades in monkeys. However, it remains to be established whether express saccade generation is dependent upon visual afferents transmitting direct retinal projections to SC via the retinotectal tract (RTT). In nineteen healthy human participants, we used a gap paradigm to investigate whether express saccades demonstrate shorter latencies to targets in the temporal hemifield, a marker for RTT function. A population of predominantly reflexive saccades (with latencies between 70 and 150 ms) was isolated in which latencies toward temporal hemifield targets were shown to be shorter than toward nasal hemifield targets. The advantages for reflexive saccades toward temporal hemifield targets suggest that visual efferents from the retina to the superior colliculus contribute to generating reflexively triggered saccades. • Reflexive saccade latency is shorter toward temporal versus nasal hemifield targets. • Temporo-nasal asymmetry is not present for regular, voluntary saccades. • Retinal efferents to superior colliculus contribute to generating reflexive saccades. [ABSTRACT FROM AUTHOR]

Probabilistic diffusion tractography was used to provide the first direct evidence for a subcortical pathway from the retina to the amygdala, via the superior colliculus and pulvinar, that transmits visual stimuli signaling threat. A bias to orient toward threat was measured in a temporal order judgement saccade decision task, under monocular viewing, in a group of 19 healthy participants who also underwent diffusion weighted MR imaging. On each trial of the behavioural task a picture depicting threat was presented in one visual field and a competing non-threatening stimulus in the other. The onset interval between the two pictures was randomly varied and participants made a saccade toward the stimulus that they judged to have appeared first. The bias to orient toward threat was stronger when the threatening stimulus was in the temporal visual hemifield, suggesting that afferents via the retinotectal tract contributed to the bias. Probabalistic tractography was used to virtually dissect connections between the superior colliculus and the amygdala traversing the pulvinar. Individual differences in microstructure (fractional anisotropy) of the streamline predicted the magnitude of the bias to orient toward threat, providing supporting evidence for a functional role of the subcortical SC-amygdala pathway in processing threat in healthy humans. • First direct evidence for subcortical pathway transmitting visual threat. • Orienting is biased to threatening compared to pleasant stimuli. • Bias to threat is greater in the temporal visual hemifield. • Microstructure (FA) of SC-Amygdala pathway predicts threat bias. [ABSTRACT FROM AUTHOR]

A consensus has emerged that the cerebellum makes important contributions to a spectrum of linguistic processes, but that the psychobiology of these contributions remains enigmatic (Mariën et al., Cerebellum 13(3):386-410, 2014). One aspect of this enigma arises from the fact that, although the language-dominant left cerebral hemisphere is connected to the right cerebellum, distinctive contributions of the left cerebellar hemisphere have been documented (Murdoch and Whelan, Folia Phoniatr Logop 59:184-9, 2007), but remain poorly understood. Here, we report that neurodisruption of the left and right cerebellar hemispheres have opposite effects on associative word priming in a lexical decision task. Reaction time was measured for decisions on whether a target letter string constituted a word (e.g. bread) or, with equal probability, a pronounceable non-word (e.g. dreab). A prime word was presented for 150 ms before the target and could either, and with equal probability, be related (e.g. BUTTER) or unrelated (TRACTOR). Associative word priming was computed as the reduction in lexical decision RT on trials with related primes. Left cerebellar hemisphere continuous theta-burst transcranial magnetic stimulation (TMS) decreased, and right hemisphere stimulation increased, priming. The results suggest that the cerebellum contributes to predictive sequential processing, in this case language, through an opponent process mechanism coordinated by both cerebellar hemispheres. [ABSTRACT FROM AUTHOR]

Disgust is a multifaceted experience that might affect several aspects of life. Here, we reviewed research on neurological and psychiatric disorders that are characterized by abnormal disgust processing to test the hypothesis of a shared neurocognitive architecture in the representation of three disgust domains: i) personal experience of ‘core disgust’; ii) social disgust, i.e., sensitivity to others’ expressions of disgust; iii) moral disgust, i.e., sensitivity to ethical violations. Our review provides some support to the shared neurocognitive hypothesis and suggests that the insula might be the “hub” structure linking the three domains of disgust sensitivity, while other brain regions may subserve specific facets of the multidimensional experience. Our review also suggests a role of serotonin core and moral disgust, supporting “neo-sentimentalist” theories of morality, which posit a causal role of affect in moral judgment. [ABSTRACT FROM AUTHOR]

The tongue holds a unique role in gustatory disgust. However, it is unclear whether the tongue representation in themotor cortex (tM1) is affected by the sight of distaste-related stimuli. Using transcranialmagnetic stimulation (TMS) in healthy humans, we recorded tonguemotor-evoked potentials (MEPs) as an index of tM1 cortico-hypoglossal excitability. MEPs were recorded while participants viewed pictures associated with gustatory disgust and revulsion (i.e. rotten foods and faces expressing distaste), non-oral-related disgusting stimuli (i.e. invertebrates like worms) and control stimuli. We found that oralrelated disgust pictures suppressed tM1 cortico-hypoglossal output. This tM1 suppression was predicted by interindividual differences in disgust sensitivity. No similar suppression was found for disgusting invertebrates or whenMEPs were recorded froma controlmuscle. These findings suggest that revulsion-eliciting food pictures trigger anticipatory inhibitionmechanisms, possibly preventing toxin swallowing and contamination. A similar suppression is elicited when viewing distaste expressions, suggesting vicariousmotor inhibition during social perception of disgust. Our study suggests an avoidant-defensive mechanismin human cortico-hypoglossal circuits and its 'resonant' activation in the vicarious experience of others' distaste. These findings support a role for themotor system in emotion-drivenmotor anticipation and social cognition. [ABSTRACT FROM AUTHOR]

Evidence documents a direct relationship between disgust processing and Body Mass Index (BMI). People with high BMI tend to have a lower disgust sensitivity (DS) threshold, while this trait is more accentuated in people with low BMI. Here we provide new insights to this issue by exploring the relationship between BMI and the experience of moral disgust. Results document a significant negative correlation between BMI and moral disapproval rating (MDR) for ethical violations, in that the higher the BMI the lower the MDR. In concordance with previous investigations, we also found that BMI correlates with DS, as measured with a standard test, in that the higher the BMI the lower the DS. Overall, the main result of this paper, which might have direct implication for research in social justice, highlights the relevance of BMI, as an individual variable, in predicting ethical behavior. [ABSTRACT FROM AUTHOR]

It has been suggested that some cortically blind patients can process the emotional valence of visual stimuli via a fast, subcortical pathway from the superior colliculus (SC) that reaches the amygdala via the pulvinar. We provide in vivo evidence for connectivity between the SC and the amygdala via the pulvinar in both humans and rhesus macaques. Probabilistic diffusion tensor imaging tractography revealed a streamlined path that passes dorsolaterally through the pulvinar before arcing rostrally to traverse above the temporal horn of the lateral ventricle and connect to the lateral amygdala. To obviate artifactual connectivity with crossing fibers of the stria terminalis, the stria was also dissected. The putative streamline between the SC and amygdala traverses above the temporal horn dorsal to the stria terminalis and is positioned medial to it in humans and lateral to it in monkeys. The topography of the streamline was examined in relation to lesion anatomy in five patients who had previously participated in behavioral experiments studying the processing of emotionally valenced visual stimuli. The pulvinar lesion interrupted the streamline in two patients who had exhibited contralesional processing deficits and spared the streamline in three patients who had no deficit. Although not definitive, this evidence supports the existence of a subcortical pathway linking the SC with the amygdala in primates. It also provides a necessary bridge between behavioral data obtained in future studies of neurological patients, and any forthcoming evidence from more invasive techniques, such as anatomical tracing studies and electrophysiological investigations only possible in nonhuman species [ABSTRACT FROM AUTHOR]

Abstract: Five patients with lesions involving intra-parietal cortex (IPCx) were tested in a rapid version of the double step paradigm to investigate the role of the IPCx in the rapid, online, updating of a saccade program. Saccades were executed to a single target in either the contra- or the ipsilesional visual field. In two thirds of the trials, a step change in target position required that the saccade shifted to a new location within the same field but in the contra- or the ipsilesional direction, allowing us to investigate whether patients are able to update their saccade program given new exogenous information about the required endpoint of the saccade. This set-up resulted in three types of initial saccades: saccades to the target on no-step trials, uncorrected saccades to the original target location on step trials and corrected saccades to the new target location on step trials. Furthermore, if the updating of the original eye movement program failed, patients performed a second saccade to the new target location that required a rapid error correction. The analysis of the double-step task on a group level indicated that latencies for all trial types were longer when saccades were directed to the contralesional versus the ipsilesional field. Furthermore, longer latencies were required for patients to initiate a corrective second saccade after making an uncorrected first saccade in their contralesional compared to ipsilesional field. There were no differences in the ultimate landing positions of the eye movements for such corrected saccades. These results reveal that deficits in updating of saccade programs only seem to be present if the updating must occur after the gaze has shifted to a new location, pointing to a role of intra-parietal cortex in the processes involved in updating information when the current reference frame has to be updated. In conclusion, the paradigm deployed in the current study allows for a refinement of the role of the intra-parietal cortex in the updating of saccade programs. [Copyright &y& Elsevier]

Parkinson's disease is known for its effects on sensorimotor coordination caused by degeneration of the nigrostriatal dopamine pathway. Dopamine-innervated areas of the ventral striatum also become compromised in Parkinson's disease, and little is known about the potential impact of this pathology on motivational processes mediated by the mesolimbic dopamine system. The current study tested the hypothesis that patients with Parkinson's disease would show a deficit in appetitive motivational arousal. Patients with Parkinson's disease and age-matched healthy controls completed a visual discrimination task in which control and appetitive food images (incidental to the task) were presented in the background. Response rate changes indicated appetitive motivational arousal. The healthy controls showed an increase in response rate on the task when appetitive food cues were present compared with control stimuli. In contrast, the Parkinson's disease group showed an inverse pattern to the healthy controls. The reduction in appetitive motivation correlated with an individual's Parkinsonian symptomology. Patients with Parkinson's disease demonstrated an impairment in appetitive motivational arousal consistent with the progression of dopaminergic degeneration across the course of the disease. Dysfunction of this system affects quality of life in Parkinson's disease, and a blunting of the anticipatory motivation may contribute to the high prevalence of depression in Parkinson's disease. © 2011 Movement Disorder Society [ABSTRACT FROM AUTHOR]

Abstract: When searching for a target presented among distractors by means of Rapid Serial Visual Presentation (RSVP), participants often report the stimulus that is preceding or following the target as being the target. These so-called temporal binding errors are accompanied by high levels of confidence so that participants are bemused with the mismatch between their perceptual experience and the actual presented stimulus. By contrast with spatial binding the neural basis for temporal binding errors remains unexplored. Previous neuropsychology studies using non-spatial selective attention tasks have shown that right temporo-parietal cortex is involved in the temporal deployment of attention. Here we investigated the neural basis of temporal binding in five patients with visual extinction whose lesions involved different cortical areas in the right hemisphere, including the temporo-parietal cortex. Patients made significantly more binding errors for contralesional than ipsilesional stimuli and more binding errors than healthy controls. Incorrect binding from distractors near to the target was the most common for both patients and controls. Eye movements did not contribute to the pattern of results. These results show that right hemisphere cortical areas contribute to the accurate temporal coding of visual features. [Copyright &y& Elsevier]

Akt/protein kinase B (PKB) activation/phosphorylation by angiotensin II (Ang II) is a critical signaling event in hypertrophy of vascular smooth muscle cells (VSMCs). Conventional wisdom asserts that Akt activation occurs mainly in plasma membrane domains. Recent evidence that Akt activation may take place within intracellular compartments challenges this dogma. The spatial identity and mechanistic features of these putative signaling domains have not been defined. Using cell fractionation and fluorescence methods, we demonstrate that the early endosomal antigen-1 (EEA1)-positive endosomes are a major site of Ang II-induced Akt activation. Akt moves to and is activated in EEA1 endosomes. The expression of EEA1 is required for phosphorylation of Akt at both Thr-308 and Ser-473 as well as for phosphorylation of its downstream targets mTOR and S6 kinase, but not for Erk1/2 activation. Both Akt and phosphorylated Akt (p-Akt) interact with EEA1. We also found that PKC-α is required for organizing Ang II-induced, EEA1-dependent Akt phosphorylation in VSMC early endosomes. EEA1 expression enables PKC-α phosphorylation, which in turn regulates Akt upstream signaling kinases, PDK1 and p38 MAPK. Our results indicate that PKC-α is a necessary regulator of EEA1-dependent Akt signaling in early endosomes. Finally, EEA1 down-regulation or expression of a dominant negative mutant of PKC-α blunts Ang II-induced leucine incorporation in VSMCs. Thus, EEA1 serves a novel function as an obligate scaffold for Ang II-induced Akt activation in early endosomes. [ABSTRACT FROM AUTHOR]

Perhaps the most intriguing disorders of body representation are those that are not due to primary disease of brain tissue. Strange and sometimes painful phantom limb sensations can result from loss of afference to the brain; and Complex Regional Pain Syndrome (CRPS)—the subject of the current report—can follow limb trauma without pathology of either the central or peripheral nervous system. This enigmatic and vexing condition follows relatively minor trauma, and can result in enduring misery and a useless limb. It manifests as severe pain, autonomic dysfunction, motor disability and ‘neglect-like’ symptoms with distorted body representation. For this special issue on body representation we describe the case of a patient suffering from CRPS, including symptoms suggesting a distorted representation of the affected limb. We report contrasting effects of mirror box therapy, as well as a new treatment—prism adaptation therapy—that provided sustained pain relief and reduced disability. The benefits were contingent upon adapting with the affected limb. Other novel observations suggest that: (1) pain may be a consequence, not the cause, of a disturbance of body representation that gives rise to the syndrome; (2) immobilisation, not pain, may precipitate this reorganisation of somatomotor circuits in susceptible individuals; and (3) limitation of voluntary movement is neither due to pain nor to weakness but, rather, to derangement of body representation which renders certain postures from the repertoire of hand movements inaccessible. [ABSTRACT FROM AUTHOR]

Lesions to the right temporo-parietal cortex commonly result in hemispatial neglect. Lesions to the same area are also associated with hyperattention to local details of a scene and difficulty perceiving the global structure. This local processing bias is an important factor contributing to neglect and may contribute to the higher prevalence of the disorder following right compared with left hemisphere strokes. In recent years, visuomotor adaptation to rightward-shifting prisms has been introduced as a promising treatment for hemispatial neglect. Explanations for these improvements have generally described a leftward realignment of attention, however, the present investigation provides evidence that prism adaptation reduces the local processing bias. Five patients with right temporal-parietal junction lesions were asked to identify the global or local levels of hierarchical figures before and after visuomotor adaptation to rightward-shifting prisms. Prior to prism adaptation the patients had difficulty ignoring the local elements when identifying the global component. Following prism adaptation, however, this pattern was reversed, with greater global interference during local level identification. The results suggest that prism adaptation may improve non-spatially lateralized deficits that contribute to the neglect syndrome. [ABSTRACT FROM PUBLISHER]

Abstract: We examined the effect of an irrelevant visual transient on the decision where to look for a hidden object. Participants also performed a conventional ‘inhibition of return’ localization task. In Experiments 1 and 2 the two tasks were blocked and in Experiments 3 and 4 they were randomly interleaved. In every experiment there was a bias to select the cued location in the spatial decision task. This facilitory effect was greatest when the cue occurred at a strategically unfavored location and even occurred for participants who reported strategically selecting a non-cued location, indicating that the facilitory effect is automatic and independent of other strategic biases. Inhibition of return was observed only when the tasks were blocked and the localization task preceded the decision task. The findings suggests that spatial decisions engage different attentional control settings than those engaged when detecting visual transients; and that this attentional mode affects the processing of visual transients such that they do not inhibit the subsequent speeded detection of onset targets. [Copyright &y& Elsevier]

The reduction in saccade latency when the fixation point is removed (fixation offset effect–FOE) reflects the degree to which fixation neurons are under influence by a stimulus at fixation. Strategic manipulations of oculomotor readiness that bring these neurons under endogenous control reduce the magnitude of the FOE. Using an aging foreperiod paradigm, and the FOE as a marker for cortical control of reflexive fixation, we showed that, for both prosaccades and antisaccades, increasing preparation across the foreperiod reduced both saccade latency and the FOE. Consistent with Los’s trace conditioning account, these effects reflected greater preparation for trials when the current short foreperiod was preceded by a trial with a short foreperiod. The FOE was also smaller for antisaccades than for prosaccades demonstrating strategic modulation. However, the effects of trace conditioning were comparable in the two tasks, demonstrating that strategic and unconscious priming effects both independently modulate the control of ocular fixation. [ABSTRACT FROM AUTHOR]

Unilateral damage to visual cortex of the parietal or occipital lobe can cause the patient to be unaware of contralesional visual information due to either hemispatial neglect or hemianopia. It is now known that both neglect and hemianopia result from the disruption of a dynamic interaction between cortical visual pathways and more phylogenetically primitive visual pathways to the midbrain. We consider the therapeutic implications of these cortical–subcortical interactions in the rehabilitation of hemianopia. We start with the pheonmenon of “blindsight”, in which patients with hemianopia can be shown, by implicit measures of visual detection or discrimination, to process visual information without conscious awareness. Some variants of blindsight have been postulated to recruit subcortical processes, while others may reflect compensatory optimisation of processing of spared visual cortex. Both mechanisms may offer opportunities for innovative strategies for rehabilitation of visual field defects. We relate the neural mechanisms that have been proposed to underlie blindsight to those that have been suggested to underlie the recovery of visual function after rehabilitation. It is suggested that the similarity and overlap of the neural processes supporting blindsight and recovery of visual function might provide insights for effective rehabilitation strategies for restoring visual functions. [ABSTRACT FROM AUTHOR]

Primary objective : To investigate the utility of feedback of brain-imaging findings as an intervention for improving impaired awareness, depression and anxiety levels. Research design and methods : A prospective within-subjects repeated measures design was used with an intervention sample of 17 adults with acquired brain injury. Baseline and post-intervention measures included self-report and questionnaire-based self-awareness instruments and self-report questionnaires for depression and anxiety. Participants also completed a range of neuropsychological tests. Intervention : The intervention consisted of a session where a Consultant Neurologist explained the findings of brain scans in terms of pathological findings and possible neurobehavioural outcome. Results : Scores on measures of unawareness and two of three mood measures decreased significantly following the intervention. This improvement was maintained at 2-week follow-up. Conclusion : Individuals with an acquired brain injury may benefit from a feedback procedure where the findings of brain scans are presented. [ABSTRACT FROM AUTHOR]

Abstract: In bedside testing of patients with hemispatial neglect, we have found that extinction for contralesional stimuli is less when the contralesional and ipsilesional items are different on the dimension to be reported relative to when they are the same. Importantly, a study that investigated this observation found that similarity on visual features that are not necessary for response does not impact the amount of extinction. These findings suggest that response requirements may determine what stimuli will and what stimuli will not gain access to awareness. In a related study, we found that extinction of contralesional stimuli was not determined by perceptual similarity of the ipsilesional and contralesional items but by whether they shared the same semantics (e.g., ONE + 1 ) or the same response (e.g., ONE = WON). Here, we report a single case study in which extinction was determined by whether the competing items shared the same response, regardless of whether they shared or differed in their visual features or semantics. When asked to read the item in each field, there was equivalent extinction in the conditions (ONE + ONE) and (ONE + 1) but less extinction in the condition (ONE + TWO). By contrast, when asked to count the number of characters in each field, there was more extinction in the condition (ONE + TWO) than (ONE + 1). When asked to categorize each item as either a word or digit, the degree of extinction was determined both by whether the items shared the same semantics and by whether they required the same response. The results are consistent with a biased competition model in which competition for selection is resolved flexibly depending on response requirements. Furthermore, the data provide evidence that unattended stimuli are processed to the level of response. [Copyright &y& Elsevier]

In two experiments, an inhibitory tag was activated by a peripheral cue after which a saccade was made to either the cued or, with equal probability, the uncued location. Key press RTs were measured for detecting a target that then appeared, with equal probability, either at fixation or at an eccentric location. In Experiment 1, the peripheral cue onset 400 ms before the saccade instruction, and participants therefore were obliged to inhibit a saccade towards the cue. Detection was slower at the cued location whether it appeared at, or eccentric from, fixation. In Experiment 2, the peripheral cue onset after the instruction to make the saccade but before the eyes had moved. Inhibitory tagging was again observed for targets at fixation, but the effect was smaller than for eccentric targets. These findings confirm that withdrawal of attention from a cued location is not required to generate an inhibitory tag, and that the cued locus remains inhibited even if it is subsequently attended and a saccade made to fixate it. Moreover, saccade inhibition is not sufficient to account for inhibitory tagging, although it may also engender an independent inhibitory effect. [ABSTRACT FROM AUTHOR]

Summary: It has been proposed that the mental representation of a graspable object involves not only a description of its visual properties but also encodings of the motor programs to act upon it []. Thus, observing a handle automatically primes the motor programs responsible for reaching and grasping it. Here, we provide neurological evidence that such action-related object features can bias visual selection. Two patients with visual extinction after right-parietal injury detected cups with left- or right-oriented handles, briefly displayed in either or both visual fields. People with this disorder have deficient awareness for stimuli toward the contralesional, left side of space, especially when competing stimuli appear further to the right []. This contralesional extinction was significantly reduced when cups had handles affording a left-hand grasp, even though no hand response was required. No effect was found when handles were replaced with patches equated for position, size, and mean luminance. These data suggest that action-related information may be correctly extracted by the visual system, even though they are unavailable for conscious report. It is proposed that an object affordance for grasping modulates attentional selection by activating specific motor schema that, in turn, enhance the competitive strength of that object representation. [Copyright &y& Elsevier]

Summoning attention to a peripheral location, either by a peripheral cue with the eyes fixed or when a voluntary saccade is made to it and gaze is then returned to the centre, delays detection of subsequent targets at that location compared to a location in the opposite visual field. It has been proposed that oculomotor activation generates this inhibition of return (IOR). This account presupposes that the asymmetry in detection results from inhibition at the cued location rather than facilitation at the uncued location. This has been confirmed for exogenously generated IOR. However, it has not, heretofore, been confirmed for "IOR" generated by voluntary saccades. The current study investigated whether the asymmetry in target detection, elicited either by a peripheral flash or by an eye movement generated in response to a central arrowhead, reflects facilitation at the opposite location due to the path of attentional momentum. Reaction times at the cued location were slower than reaction times at the opposite or perpendicular locations, which did not differ. Opposite facilitation due to attentional momentum requires that opposite be faster than perpendicular, which was not obtained. The results were the same whether IOR was generated by an exogenous cue or by a saccade executed endogenously to a central arrow. [ABSTRACT FROM AUTHOR]

Fourteen patients with a chronic, unilateral lesion restricted to the frontal lobe (twelve involving the frontal eye field (FEF)), nine patients with a chronic, unilateral lesion restricted to posterior association cortex (eight involving the intraparietal sulcus (IPS)), and twelve neurologically normal control subjects were studied in an anti-saccade task. A combination of manipulating cuing and fixation offset enabled us to examine the effects of chronic oculomotor lesions on both saccade preparation and voluntary control over ocular fixation. Patients with lesions of the FEF made more errors (reflexive glances) toward contralesional targets, whereas patients with IPS lesions made fewer errors toward contralesional targets. Patients with IPS lesions had increased latencies to initiate saccades away from contralesional targets. For FEF patients, the presence of a fixation point inhibited the initiation of contralesionally directed saccades less than those directed ipsilesionally. Saccade preparation in response to a cue did not reduce the inhibitory effect of a fixation point on initiating anti-saccades directed either ipsilesionally or contralesionally for either patient group. We conclude that chronic IPS lesions result in a reduced contralesional visual grasp reflex (VGR) and delayed utilization of visual signals in the contralesional field for planning voluntary eye movements. In contrast, patients with chronic FEF lesions are impaired in inhibiting the VGR toward contralesional signals, and manifest an asymmetry in the balance between fixation and saccade activity. Moreover, voluntary control of fixation is compromised after chronic damage to either frontal or parietal oculomotor cortex. [ABSTRACT FROM AUTHOR]

We report observations in patients with visual extinction demonstrating that detection of visual events is gated by attention at the level of processing at which a stimulus is selected for action. In one experiment, three patients reported the identity of numerical words and digits presented either in the ipsilesional field, the contralesional field, or both fields. On the critical bilateral trials, extinction was greater when the competing items shared the same meaning and response, regardless of whether the items were visually different (e.g., ONE + 1), or identical (e.g., 1 + 1). A fourth patient was tested in a second experiment in which the competing items on bilateral trials were either different (e.g., ONE + TWO), identical (e.g., ONE + ONE) or homophones that were visually and semantically different but shared the same response (e.g., ONE + WON). Homophones and identical items caused similar extinction with less extinction occurring on different item trials. [ABSTRACT FROM AUTHOR]

Examines the effects of inhibition of return on endogenously generated and visually guided saccades. Response to a peripheral target by making a prosaccade or an antisaccade; Responses to a peripheral and central precue; Effects of saccades on target detection and motor alternation bias; Effects of inhibition of return on perceptual processing.

Focuses on the simultaneous measurement of both space-based and object-based attention in a patient with disconnected cerebral hemispheres. Role of left cerebral hemisphere in controlling the shifts of attention between objects; Influence of interhemispheric interactions in the induction of object-based attentional process; Object-based component of attention.

Explores the relationship between spatial attention and feature integration in a parietal patient from a neuropsychological perspective. Importance of spatial attention in facilitating the detection of simple features; Effects of degraded attention on feature conjunctions; Problems encountered in conjoining features.

Focuses on the examination of object-based attention in two split-brain patients. Movements of a precued object; Examination of normal individuals in relation to split-brain patients in the movement of objects; Details on the object's detection.

Cites the results of the study conducted by Claus Hilgetag et al. which adapted the technique of repetitive transcranial magnetic stimulation to temporarily inactivate parietal cortex in normal volunteers and produce a model of hemispatial neglect. Mechanisms of hemispatial neglect, a neurological disorder of attention; Importance of converging techniques in cognitive neuroscience.

The article presents a study on the reach target selection deficits in hand-reaching movements during the temporary localized inactivation of the midbrain's superior colliculus (SC). It states that rhesus monkeys could perceive the target even at the inactivated part of the visual field. It says that results indicate that SC is a part of target selection system affecting the choice of targets for other acts such as hand-reaching.

We examined the contributions of the human pulvinar to goal directed selection of visual targets in 3 patients with chronic, unilateral lesions involving topographic maps in the ventral pulvmar. Observers completed 2 psychophysical tasks in which they discriminated the orientation of a lateralized target grating in the presence of vertically-aligned distracters. In experiment 1, where distracter contrast was varied while target contrast remained constant, the patients' contralesional contrast thresholds for discriminating the orientation of grating stimuli were elevated only when the task required selection of a visual target in the face of competition from a salient distracter. Attentional selectivity was restored in the patients in experiment 2 where target contrast was varied while distracter contrast remained constant. These observations provide the first evidence that the human pulvinar plays a necessary role in modulating physical saliency in attentional selection, and supports a' homology in global pulvinar structure between humans and monkey. [ABSTRACT FROM AUTHOR]

Abstract: Patients with right hemisphere brain lesions often suffer from deficits in spatial attention that can be manifested in different sensory modalities. It has recently been claimed that a relationship (i.e., association) could exist between symptoms of hemi-inattention in different modalities, based on correlations between the results of visual and auditory clinical tests of neglect or extinction. However, it should be noted that the visual and auditory tasks varied greatly both in response type and level of sensitivity. Here, we have examined cross-modal associations in spatial attention deficits using a temporal order judgment task (TOJ) in which patients were required to identify which of two visual or auditory objects had appeared first. When compared to age and education matched control participants, the patients needed, on average, the contralesional stimulus to lead the ipsilesional stimulus to achieve the point of subjective simultaneity (PSS). No association between the degree of visual and auditory hemi-inattention was observed amongst the patients, suggesting that there is a certain degree of independence between the mechanisms subserving spatial attention across sensory modalities. [Copyright &y& Elsevier]

The relation between reflexive and voluntary orienting of visual attention was investigated with 4 experiments: a simple detection task, a localization task, a saccade toward the target task, and a target identification task in which discrimination difficulty was manipulated. Endogenous and exogenous orienting cues were presented in each trial and their validity was manipulated orthogonally to examine whether attention mechanisms are mediated by separate systems and whether they have additive and independent effects on visual detection and discrimination. The results showed that each orienting mechanism developed its typical and independent effect in every case except for the difficult identification task. A theoretical framework for understanding the relationship between endogenous and exogenous orienting of attention is proposed, tested, and confirmed. [ABSTRACT FROM AUTHOR]

Reaching toward a target viewed through laterally refracting prisms results in adaptation of both visual and (limb) proprioceptive spatial representations. Common ways to measure adaptation after-effect are to ask a person to point straight ahead with their eyes closed ("manual straight ahead", MSA), or to a seen target using their unseen hand ("open-loop pointing", OLP). MSA measures changes in proprioception only, whereas OLP measures the combined visual and proprioceptive shift. The behavioural and neurological mechanisms of prism adaptation have come under scrutiny following reports of reduced hemispatial neglect in patients following this procedure. We present evidence suggesting that shifts in proprioceptive spatial representations induced by prism adaptation are larger following lesions to the intraparietal cortex – a brain region that integrates retinotopic visual signals with signals of eye position in the orbit and that is activated during prism adaptation. Six healthy participants and six patients with unilateral intraparietal cortex lesions underwent prism adaptation. After-effects were measured with OLP and MSA. After-effects of control participants were larger when measured with OLP than with MSA, consistent with previous research and with the additional contribution of visual shift to OLP after-effects. However, patients' OLP shifts were not significantly different to their MSA shifts. We conclude that, for the patients, correction of pointing errors during prism adaptation involved proportionally more changes to arm proprioception than for controls. Since lesions to intraparietal cortex led to enhanced realignment of arm proprioceptive representations, our results indirectly suggest that the intraparietal cortex could be key for visual realignment. • Prism adaptation shifted controls' open-loop pointing more than manual straight ahead. • Manual straight ahead shifted more in people with intraparietal cortex lesions than controls. • Shifts in open-loop pointing for the two groups were not different. • Results indicate greater proprioceptive realignment following intraparietal cortex damage. • This could also be indirect evidence of reduced visual realignment. [ABSTRACT FROM AUTHOR]

To determine whether the parietal lobes contribute to the selection of nonspatial features known to be processed in the ventral stream, the current study examined the effect of chronic unilateral parietal lobe lesions in humans on color and location priming. Patients and normal controls performed a go/no-go color discrimination task in which either the same color and different color pairs of stimuli (prime and probe) were projected sequentially either in the same hemifield or in opposite hemifields. Control subjects and patients both showed independent effects of color and location priming. In the patients, primes in either field produced color priming for target probes in the ipsilesional field but not for probes in the contralesional field. This observation implicates the parietal cortex in processing activated codes of stimulus attributes not only for spatial information but also for visual features processed in the ventral visual pathways. [ABSTRACT FROM AUTHOR]

Presents a study which examined spatial orienting effects, without being aware to signals presented in the neglected hemifield of 2 hemispatial-neglect patients. Methods used for measurement of effects of visual attention; Findings which supports the claim that orienting can occur independently of overt detection; Indications that location information is listed in the neglected field.

We examined the performance of an individual with subcortical damage, but an intact somatosensory thalamocortical pathway, to examine the functional architecture of tactile detection and tactile localization processes. Consistent with the intact somatosensory thalamocortical pathway, tactile detection on the contralesional hand was well within the normal range. Despite intact detection, the individual demonstrated substantial localization biases. Across all localization experiments, he consistently localized tactile stimuli to the left side in space relative to the long axis of his hand. This was observed when the contralesional hand was palm up, palm down, rotated 90° relative to the trunk, and when making verbal responses. Furthermore, control experiments demonstrated that this response pattern was unlikely a motor response error. These findings indicate that tactile localization on the body is influenced by proprioceptive information specifically in a hand-centered frame of reference. Furthermore, this also provides evidence that aspects of tactile localization are mediated by pathways outside of the primary somatosensory thalamocortical pathway. • We report a brain-damaged individual who has completely normal tactile detection but substantial localization biases. • Tactile localization showed an ulnar bias when the hand was palm down, and a radial bias when the hand was palm up. • Always biased towards the left side in space relative to the hand proximodistal axis. • Provides evidence for a strong single dissociation between tactile detection and tactile localization. • Provides evidence that tactile localization on the body surface is influenced by body position in external space. [ABSTRACT FROM AUTHOR]

Current concepts of the extended amygdala posit that basolateral to central amygdala projections mediate fear‐conditioned autonomic alerting, whereas projections to the bed nucleus of the stria terminalis mediate sustained anxiety. Using diffusion tensor imaging tractography in humans, we show that microstructure of the stria terminalis correlates with an orienting bias towards threat in a saccade decision task, providing the first evidence that this circuit supports decisions guiding evaluation of threatening stimuli. [ABSTRACT FROM AUTHOR]

Human history is studded with instances where instinctive motivations take precedence over ethical choices. Nevertheless, the evidence of any linking between motivational states and morality has never been systematically explored. Here we addressed this topic by testing a possible linking between appetite and moral judgment. We compared moral disapproval ratings (MDR) for stories of ethical violations in participants under fasting and after having eaten a snack. Our results show that subjective hunger, measured via self-reported rating, reduces MDR for ethical violations. Moreover, the higher the disgust sensitivity the higher the MDR for ethical violations. This study adds new insights to research on physiological processes influencing morality by showing that appetite affects moral disapproval of ethical violations. [ABSTRACT FROM AUTHOR]

Although a direct link has been established between self-experienced disgust and salivary secretion, it is unclear whether this physiological index is modulated by the social experience of disgust (i.e., exposure to the facial expression of disgust). We tested this issue in a pilot study by collecting salivary samples in a group of 20 healthy humans watching pictures of faces expressing disgust. Moreover, we tried to replicate previous evidence by testing saliva secretion in response to pictures of unpalatable (i.e., rotten) food and non-gustatory disgusting stimuli (i.e., disgusting insects). Overall, our analysis shows a general reduction of saliva secretion in response to disgust stimuli, compared to their positive counterparts, although further analyses for specific stimulus categories indicated that this difference was statistically significant only for food pictures. The non-significance of the face and insect categories might be due to insufficient power of our small sample. Overall, a general reduction of saliva secretion for different disgust-related stimuli suggests a shared mechanism of encoding, in line with theories of neural reuse. [ABSTRACT FROM AUTHOR]

Sequential foreperiod effects in temporal preparation are typically asymmetric such that a previous experience of preparation has a strong impact on participants’ responses to a forthcoming target stimulus presented at the current short rather than at the current long foreperiod. The trace-conditioning model explains this asymmetry by an automatic process of trace-conditioning, which is sufficient and independent from a strategic process of conditional probability monitoring considered by the dual-process model. The present study contrasted trace-conditioning and dual-process models in three experiments that employed a non-aging distribution to keep conditional probability of target occurrence constant across foreperiod durations. In Experiment 1 (no catch trials), the typical pattern of asymmetric sequential effects was replicated, whereas in Experiments 2 and 3 (25% and 50% of catch trials, respectively) the results showed shorter RTs when previous and current foreperiods were repeated rather than alternated for both current short and long foreperiods. These results are discussed in relation to the two most influential models of sequential effects and to a novel account based on repetition priming. [ABSTRACT FROM AUTHOR]

Background: Neuroimaging studies of chronic smokers report altered activity of several neural regions involved in the processing of rewarding outcomes. Neuroanatomical evidence suggests that these regions are directly connected to the tongue muscle through the corticobulbar pathways. Accordingly, we examined whether corticobulbar excitability might be considered a somatic marker for nicotine craving. Methods: We compared motor-evoked potential (MEP) amplitudes recorded from the tongue and the extensor carpi radialis (control muscle) of chronic smokers under drug withdrawal and intake conditions as well as a nonsmoker group. All participants were tested during passive exposure to pictures showing a smoking cue or a meaningless stimulus. In the intake condition, chronic smokers were asked to smoke a real cigarette (CSn: group 1) or a placebo (CSp: group 2). Results: Results show that MEP amplitudes recorded from the tongues of participants in the CSn and CSp groups under the withdrawal condition were selectively enhanced during exposure to a smoking cue. However, this effect on tongue MEP amplitudes disappeared in the intake condition for both the CSn and CSp groups. Limitations: Limitations include the fact that the study was conducted in 2 different laboratories, the small sample size, the absence of data on chronic smoker craving strength and the different tastes of the real and placebo cigarettes. Conclusion: These results suggest that, in chronic smokers, tongue muscle MEP amplitudes are sensitive to neural processes active under the physiological status of nicotine craving. This finding implicates a possible functional link between neural excitability of the corticobulbar pathway and the reward system in chronic smokers. [ABSTRACT FROM AUTHOR]

Highlights: [•] Six patients with a lesion to the frontal oculomotor cortex performed a double stimulus paradigm. [•] Latencies to the contralesional visual field were longer when a task instruction was given. [•] This effect was strongest when strong oculomotor inhibition was applied. [•] FEF lesions result in a slowing of the inhibitory signals associated with the rejection of a distractor. [•] These results reveal the important role of the FEF in the voluntary control of eye movements. [ABSTRACT FROM AUTHOR]

This study examines how brain damage can affect the cognitive processes that support the integration of sensory input and prior knowledge during shape perception. It is based on the first detailed study of acquired ventral simultanagnosia, which was found in a patient (M.T.) with posterior occipitotem-poral lesions encompassing V4 bilaterally. Despite showing normal object recognition for single items in both accuracy and response times (RTs), and intact low-level vision assessed across an exten-sive battery of tests, M.T. was impaired in object identification with overlapping figures displays. Task performance was modulated by familiarity: Unlike controls, M.T. was faster with overlapping displays of abstract shapes than with overlapping displays of common objects. His performance with overlap-ping common object displays was also influenced by both the semantic relatedness and visual similarity of the display items. These findings challenge claims that visual perception is driven solely by feedfor-ward mechanisms and show how brain damage can selectively impair high-level perceptual processes supporting the integration of stored knowledge and visual sensory input. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports the first ever detailed study about eye movement patterns during single object recognition in visual agnosia. Eye movements were recorded in a patient with an integrative agnosic deficit during two recognition tasks: common object naming and novel object recognition memory. The patient showed normal directional biases in saccades and fixation dwell times in both tasks and was as likely as controls to fixate within object bounding contour regardless of recognition accuracy. In contrast, following initial saccades of similar amplitude to controls, the patient showed a bias for short saccades. In object naming, but not in recognition memory, the similarity of the spatial distributions of patient and control fixations was modulated by recognition accuracy. The study provides new evidence about how eye movements can be used to elucidate the functional impairments underlying object recognition deficits. We argue that the results reflect a breakdown in normal functional processes involved in the integration of shape information across object structure during the visual perception of shape. [Copyright &y& Elsevier]

The current paper describes a rare case of a patient who suffered from unilateral apraxia of eye closure as a result of a bilateral stroke. Interestingly, the patient's ability to voluntarily close both eyelids (i.e. blinking) was not affected, indicating that different neural mechanisms control each type of eye closure. The stroke caused damage to a large part of the right frontal cortex, including the motor cortex, pre-motor cortex and the frontal eye field (FEF). The lesion in the left hemisphere was restricted to the FEF. In order to further study the neural mechanisms of eye closure, we conducted an fMRI study in a group of neurological healthy subjects. We found that all areas of the oculomotor cortex were activated by both left and right winking, including the FEF, supplementary eye field (SEF), and posterior parietal cortex (PPC). Blinking activated FEF and SEF, but not PPC. Both FEF and PPC were significantly more active during winking than blinking. Together, these results provide evidence for a critical role of the FEF in voluntary unilateral eye closure. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the letter "Second thoughts on who goes where in author lists," by William F.Laurance in the vol. 442, 2006 of the Nature.

Parietal cortex has been implicated in the updating, after eye movements, of a salience map that is required for coherent visual experience and for the control of visually guided behavior. The current experiment investigated whether TMS over anterior intraparietal cortex (AIPCx), just after a saccade, would affect the ability to update and maintain a salience map. In order to generate a salience map, we employed a paradigm in which an uninformative cue was presented at one object in a display to generate inhibition of return (IOR)-an inhibitory tag that renders the cued object less salient than others in the display, and that slows subsequent responses to visual transients at its location. Following the cue, participants made a saccade to either left or right, and we then probed for updating of the location of IOR by measuring manual reaction time to targets appearing at cued location of the cued compared to an uncued object. Between the time of saccade initiation and target appearance, dual-pulse TMS was targeted over right (Experiment 1) or left AIPCx (Experiment 2), and a vertex control side. Updating of the location of IOR was eliminated by TMS over right, but not the left, AIPCx, suggesting that right parietal cortex is involved in the remapping of IOR. Remapping was eliminated by right AIPCx, regardless of whether the saccade was made to the left (contralateral), or right (ipsilateral) visual field, and regardless of which field the target appeared in. We conclude that right AIPCx is the neural substrate for maintaining a salience map across saccades, and not simply for propagating an efference copy of saccade commands. [ABSTRACT FROM AUTHOR]