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We introduce an egocentric video and eye-tracking dataset, comprised of 108 first-person videos of 36 shoppers searching for three different products (orange juice, KitKat chocolate bars, and canned tuna) in a convenience store, along with the frame-centered eye fixation locations for each video frame. The dataset also includes demographic information about each participant in the form of an 11-question survey. The paper describes two applications using the dataset — an analysis of eye fixations during search in the store, and a training of a clustered saliency model for predicting saliency of viewers engaged in product search in the store. The fixation analysis shows that fixation duration statistics are very similar to those found in image and video viewing, suggesting that similar visual processing is employed during search in 3D environments and during viewing of imagery on computer screens. A clustering technique was applied to the questionnaire data, which resulted in two clusters being detected. Based on these clusters, personalized saliency prediction models were trained on the store fixation data, which provided improved performance in prediction saliency on the store video data compared to state-of-the art universal saliency prediction methods. • Egocentric video dataset of shopper search in a convenience store. • Eye-tracking dataset of shopper search in a convenience store. • Analysis of fixated objects and fixation durations during search. • Fine-tuning of clustered task-dependent saliency models for search. [ABSTRACT FROM AUTHOR]

Abstract Efficient perspective taking abilities are critical for successful social interactions. The aim of this study was to investigate whether and to what extent we spontaneously adopt others' perspectives in interpreting a visual scene. Through four distinct studies, we tested whether another person's point of view is adopted when interpreting an ambiguous stimulus. In addition, we manipulated the relevance of another person's perspective to a stimulus by altering sensory and action capabilities. The vast majority of participants spontaneously endorsed the other perspective rather than their own when asked to identify the target stimulus. Strikingly, and contrary to our expectations, they also overwhelmingly took the other's perspective when it was not relevant visually (blindfolded person) or behaviourally (armless person). A smaller number of subjects also adopted an external perspective in the absence of a person. Additionally, two control experiments show that viewing an injured person induces more compassion but does not trigger more perspective taking than viewing a healthy person. Our results demonstrate an overwhelming human tendency to predominantly consider non-egocentric perspectives while interpreting the surrounding world. Highlights • Humans spontaneously endorse others level-2 visuospatial perspective. • Others' perspectives are endorsed even when irrelevant (e.g. for a blinded person). • Non-egocentric perspectives are considered even in the absence of others. • Experience compassion does not predict spontaneous perspective-taking. [ABSTRACT FROM AUTHOR]

Highlights • Response times to read analog clocks is investigated as a function of orientation. • Egocentric and environmental reference frames are dissociated. • Response times are sinusoidal functions of egocentric orientation. • Shifts in best-fit sinusoidal functions reveal effects of the environmental frame. • A virtual reality experiment dissociates vestibular from visual cues. Abstract We investigated how performance in the real-life perceptual task of analog clock reading is influenced by the clock’s orientation with respect to egocentric, gravitational, and visual-environmental reference frames. In Experiment 1, we designed a simple clock-reading task and found that observers’ reaction time to correctly tell the time depends systematically on the clock’s orientation. In Experiment 2, we dissociated egocentric from environmental reference frames by having participants sit upright or lie sideways while performing the task. We found that both reference frames substantially contribute to response times in this task. In Experiment 3, we placed upright or rotated participants in an upright or rotated immersive virtual environment, which allowed us to further dissociate vestibular from visual cues to the environmental reference frame. We found evidence of environmental reference frame effects only when visual and vestibular cues were aligned. We discuss the implications for the design of remote and head-mounted displays. [ABSTRACT FROM AUTHOR]

Highlights • The concept of conscious awareness implies vantage with respect to a reference frame. • Egocentric reference frame, viewer-dependent: Left-Right, Front-Behind, Above-Below. • Allocentric reference frame, viewer-independent: East-West, North-South, Higher-Lower. • Ventral (What) system, conscious/allocentric. Dorsal (How) not conscious & egocentric. • Clarifying geometries can help resolve model disputes in areas like baseball catching. Abstract Conscious experience implies a reference-frame or vantage, which is often important in scientific models. Control models of ball-interception are used as an example. Models that use viewer-dependent egocentric reference-frames are contrasted with viewer- in dependent allocentric ones. Allocentric reference-frames serve well for models like Newtonian physics, which utilize static coordinate-systems that allow forces and object-movements to be compartmentalized. In contrast, egocentric reference-frames are natural for modeling mobile organisms or robots when controlling perception-action behavior. Lower-level perception-action behavior is often characterized using egocentric coordinate-systems that optimize processing-speed, while higher-level cognitive-processes use allocentric frames that provide a stationary spatial reference. Brain-behavior models like the Ventral-Stream What System , and Dorsal-Stream Where-How System , also respectively utilize allocentric and egocentric reference-frames. Reference-frame clarification can resolve disputes about models of control-tasks like running to catch baseballs, and can provide insights for biomimetic-robots. Confusion regarding geometry and reference-frames contributes to a lack of clarity between how and when egocentric versus allocentric geometries are imposed, with perception-actions generally being more egocentric and conscious experience more allocentric. [ABSTRACT FROM AUTHOR]

Pantomime-grasps entail a response to an area adjacent to (i.e., spatially dissociated pantomime-grasp), or previously occupied by (i.e., no-target pantomime-grasp) a target. Previous work has reported that pantomime-grasps differ kinematically from naturalistic grasps (i.e., grasping a physical target object) - a result taken to evince that pantomime-grasps are perception-based and mediated via relative visual information. However, such actions differ not only in terms of their visual properties, but also because the former precludes haptic feedback related to a target's absolute size. The current study provides four experiments examining whether experimenter-induced haptic feedback influences the information mediating spatially dissociated and no-target pantomime-grasps. Just-noticeable-difference scores were computed to determine whether grasps adhered to, or violated, the relative psychophysical properties of Weber's law. Spatially dissociated pantomime-grasps performed with haptic feedback adhered to Weber's law (Experiments 1-3), whereas their no-target pantomime-grasp counterparts violated the law (Experiment 4). Accordingly, we propose that the top-down demands of decoupling stimulus-response relations in spatially dissociated pantomime-grasping renders aperture shaping via a visual percept that is not directly influenced by the integration of haptic feedback. In turn, the decreased top-down demands of no-target pantomime-grasps allows haptic feedback to serve as a reliable sensory resource supporting an absolute visuo-haptic calibration. [ABSTRACT FROM AUTHOR]

Mental imagery of one's body moving through space is important for imagining changing visuospatial perspectives, as well as for determining how we might appear to other people. Previous neuroimaging research has implicated the temporoparietal junction (TPJ) in this process. It is unclear, however, how neural activity in the TPJ relates to the rotation perspectives from which mental spatial transformation (MST) of one's own body can take place, i.e. from an egocentric or an allocentric perspective. It is also unclear whether TPJ involvement in MST is self-specific or whether the TPJ may also be involved in MST of other human bodies. The aim of the current study was to disentangle neural processes involved in egocentric versus allocentric MSTs of human bodies representing self and other. We measured functional brain activity of healthy participants while they performed egocentric and allocentric MSTs in relation to whole-body photographs of themselves and a same-sex stranger. Findings indicated higher blood oxygen level-dependent (BOLD) response in bilateral TPJ during egocentric versus allocentric MST. Moreover, BOLD response in the TPJ during egocentric MST correlated positively with self-report scores indicating how awkward participants felt while viewing whole-body photos of themselves. These findings considerably advance our understanding of TPJ involvement in MST and its interplay with self-awareness. [ABSTRACT FROM AUTHOR]

Both egocentric route-based learning and spatial learning, as assessed by the Cincinnati water maze (CWM) and Morris water maze (MWM), respectively, are impaired following an 80% dopamine (DA) loss in the neostriatum after 6-hydroxydopamine (6-OHDA) administration in rats. The dorsolateral striatum (DLS) and the dorsomedial striatum (DMS) are implicated in different navigational learning types, namely the DLS is implicated in egocentric learning while the DMS is implicated in spatial learning. This experiment tested whether selective DA loss through 6-OHDA lesions in the DMS or DLS would impair one or both types of navigation. Both DLS and DMS DA loss significantly impaired route-based CWM learning, without affecting spatial or cued MWM performance. DLS 6-OHDA lesions produced a 75% DA loss in this region, with no changes in other monoamine levels in the DLS or DMS. DMS 6-OHDA lesions produced a 62% DA loss in this region, without affecting other monoamine levels in the DMS or DLS. The results indicate a role for DA in DLS and DMS regions in route-based egocentric but not spatial learning and memory. Spatial learning deficits may require more pervasive monoamine reductions within each region before deficits are exhibited. This is the first study to implicate DLS and DMS DA in route-based egocentric navigation. [ABSTRACT FROM AUTHOR]

Highlights: [•] We examined whether dissociable tactile cues mediate actions and perceptions. [•] Tactile cues for goal-directed grasping (action task) violated Weber’s law. [•] Tactile cues for manual estimation (perceptual task) adhered to Weber’s law. [•] Ego- and allocentric cues support tactile actions and perceptions, respectively. [ABSTRACT FROM AUTHOR]

Spatial navigation skills used in daily life are liable to decline with aging. They rely on a knowledge of landmarks, their locations (from egocentric and allocentric perspectives) and paths (learned in route and survey modes). This study investigated this knowledge in young, middle-aged and older people, also considering the role of individual visuospatial factors. Eighty-seven people in three age groups (20–30, 55–64, 65–75 years) were assessed on their visuospatial factors, and learned a path by walking in a real garden. Then their knowledge of landmarks (recognition task) and their positions (egocentric and allocentric pointing tasks), and the path (route repetition, order of landmarks, path finding and map drawing tasks) was tested. After controlling for sex and years of education, middle-aged and older adults performed similarly, and less well than young adults in allocentric pointing and map drawing tasks. Visuospatial working memory and sense of direction were the most influential individual factors, with specificity for each knowledge domain. In conclusion, the ability to use mental representations of environments learned from navigation relates to the domain of knowledge involved, age, and individual visuospatial factors. • Young, middle-aged and older adults learned a path by navigating in a garden. • Tasks were used to assess their landmark, location and path knowledge. • Individual visuospatial abilities and wayfinding inclinations were tested. • Location-allocentric and non-situated path-survey knowledge decreased with age. • Individual visuospatial factors relate differently to spatial knowledge domains. [ABSTRACT FROM AUTHOR]

Abstract: Unilateral infusion of 6-hydroxydopamine into the nigro-striatal pathway in the rat is the most common dopamine lesion model of Parkinson's disease. In the present study, we explore the impact of near complete unilateral loss of dopamine along the nigro-striatal pathway and subsequent cell replacement therapy in a choice reaction time task in rats, with assessment of spatial responding towards either side of the body (ipsilateral or contralateral to the lesion) on alternate days. Results indicated a stable contralateral deficit in response accuracy, reaction times and motor function for 50 consecutive days of testing, with no signs of recovery or compensation. All lesioned rats developed a near-hole bias and displayed prolonged movement and reaction times when responses had to be directed towards a distal response location on the side of the body contralateral to the lesion, as well as a smaller ipsilateral impairment in response accuracy and movement times. Grafts of dopamine-rich tissue into the denervated striatum improved some, but not all, of the deficits induced by the lesion. Specifically, grafted rats performed at a similar level to control animals when assessed on the ipsilateral side, they demonstrated a partial restitution of their ability to respond to far contralateral stimuli, and they exhibited a marked reduction in the time to complete all lateralised responses on both sides. The present characterisation of the task and the effects of cell replacement via primary fetal mesencephalic tissue demonstrate restorative properties in alleviating the marked spatial response bias induced by unilateral loss of dopamine. [Copyright &y& Elsevier]

Abstract: Successful navigation requires interactions among multiple but overlapping neural pathways mediating distinct capabilities, including egocentric (self-oriented, route-based) and allocentric (spatial, map-based) learning. Route-based navigation has been shown to be impaired following acute exposure to the dopaminergic (DA) drugs (+)-methamphetamine and (+)-amphetamine, but not the serotoninergic (5-HT) drugs (±)-3,4-methylenedioxymethamphetamine or (±)-fenfluramine. The dopaminergic-rich neostriatum is involved in both allocentric and egocentric navigation. This experiment tested whether dorsal striatal DA loss using bilateral 6-hydroxydopamine (6-OHDA) injections impaired one or both types of navigation. Two weeks following 6-OHDA injections, rats began testing in the Cincinnati water maze (CWM) followed by the Morris water maze (MWM) for route-based and spatial navigation, respectively. 6-OHDA treatment significantly increased latency and errors in the CWM and path length, latency, and cumulative distance in the MWM with no difference on cued MWM trials. Neostriatal DA levels were reduced by 80% at 2 and 7weeks post-treatment. In addition, 6-OHDA increased DA turnover and decreased norepinephrine (NE) levels. 6-OHDA injections did not alter monoamine levels in the prefrontal cortex. The data support that neostriatal DA modulates both types of navigation. [Copyright &y& Elsevier]

Abstract: Estradiol treatment administered systemically or directly to the dorsolateral striatum across two days impairs performance on a response task in which rats learn to make a specific body turn to locate food on a maze. Estradiol can act through both slow and rapid signaling pathways to regulate learning impairments, however it is impossible to dissociate the slow from the rapid contributions of estradiol following long exposures. To assess the rapid effects of estradiol on striatum-sensitive learning, we trained rats on a response learning task after either relatively short or long treatments of estradiol infused directly into the striatum. Three-month-old female rats were ovariectomized 21days before training and received guide cannulae implanted bilaterally into the dorsolateral striatum. For short duration treatments, rats were given bilateral infusions (0.5μl) of 17β-estradiol-sulfate (0, 5, 50, or 500nM in aCSF-vehicle) either 2h or 15min prior to training. For long duration treatments, rats received a series of estradiol infusions (500nM) at 48, 24, and 2h prior to training. Replicating previous findings (Zurkovsky et al., 2007), intra-striatal estradiol treatments given for two days prior to training impaired response learning. Estradiol-induced impairments in performance were also demonstrated 2h, but not 15min, after single infusions. Thus, estradiol acts within hours of exposure in the striatum, a structure lacking classical estrogen receptors, to impair response learning. [Copyright &y& Elsevier]

Abstract: Path integration is a navigation strategy widely observed in nature where an animal maintains a running estimate, called the home vector, of its location during an excursion. Evidence suggests it is both ancient and ubiquitous in nature, and has been studied for over a century. In that time, canonical and neural network models have flourished, based on a wide range of assumptions, justifications and supporting data. Despite the importance of the phenomenon, consensus and unifying principles appear lacking. A fundamental issue is the neural representation of space needed for biological path integration. This paper presents a scheme to classify path integration systems on the basis of the way the home vector records and updates the spatial relationship between the animal and its home location. Four extended classes of coordinate systems are used to unify and review both canonical and neural network models of path integration, from the arthropod and mammalian literature. This scheme demonstrates analytical equivalence between models which may otherwise appear unrelated, and distinguishes between models which may superficially appear similar. A thorough analysis is carried out of the equational forms of important facets of path integration including updating, steering, searching and systematic errors, using each of the four coordinate systems. The type of available directional cue, namely allothetic or idiothetic, is also considered. It is shown that on balance, the class of home vectors which includes the geocentric Cartesian coordinate system, appears to be the most robust for biological systems. A key conclusion is that deducing computational structure from behavioural data alone will be difficult or impossible, at least in the absence of an analysis of random errors. Consequently it is likely that further theoretical insights into path integration will require an in-depth study of the effect of noise on the four classes of home vectors. [Copyright &y& Elsevier]

Abstract: Neural resources subserving spatial processing in either egocentric or allocentric reference frames are, at least partly, dissociated. However, it is unclear whether these two types of representations are independent or whether they interact. We investigated this question using a learning transfer paradigm. The experiment and material were designed so that they could be used in a clinical setting. Here, we tested healthy subjects in an imagined viewer-rotation task and an imagined object-rotation task. The order of the tasks was counterbalanced across subjects. The results showed that subjects who did the viewer-rotation task first had fewer errors and shorter latencies of response in the object-rotation task, whereas subjects who did the object-rotation task first had little if any advantage in the viewer-rotation task. In other words, the results revealed an asymmetric learning transfer between tasks, which suggests that spatial representations are hierarchically organized. Specifically, the results indicate that the viewer-rotation task engaged allocentric representations and egocentric representations, whereas the object-rotation task engaged only egocentric representations. [Copyright &y& Elsevier]

Abstract: Mounting evidence indicates that the retrosplenial cortex (RSP) has a critical role in spatial navigation. The goal of the present study was to characterize the specific nature of spatial memory deficits that are observed following damage to RSP. Rats with RSP lesions or sham lesions were first trained in a working memory task using an 8-arm radial arm maze. Rats were allowed 5min to visit each arm and retrieve food pellets and a 5-s delay was imposed between arm choices. Consistent with previous research, rats with RSP damage committed more errors than controls. In particular, RSP-lesioned rats committed more errors of omission (failing to visit an arm of the maze), but there were no lesion effects on errors of commission (revisiting an arm). Neither group of rats exhibited a turn bias (i.e., always turning a certain direction when choosing an arm). At the end of the training phase of the experiment, both groups had reached asymptote and committed very few errors. In the subsequent test phase, a longer delay (30-s) was imposed during some sessions. Both control and RSP-lesioned rats continued to make few errors during sessions with the standard 5-s delay, but RSP-lesioned rats were impaired at the 30-s delay and committed more errors of commission, consistent with an increase in taxing spatial working memory. [Copyright &y& Elsevier]

The postrhinal cortex (POR) serves as a key input area to the hippocampal system. It receives highly processed information from the ventral visual stream and other limbic areas including the retrosplenial cortex, parahippocampal areas, and portions of the limbic thalamus. The POR was studied early on by David Bucci and colleagues who first postulated that the POR plays a major role in contextual learning. Here we review a number of approaches and experimental studies that have explored POR's role in contextual processing. We discuss POR lesion studies that monitored deficits in fear conditioning tasks and the effects that these lesions had on processing visual landmark information. We then review the types of spatial correlates encoded by POR cells. A large number of head direction (HD) cells are present, although recent findings suggest that many of them are more accurately characterized as landmark modulated-HD cells as opposed to classic HD cells. A significant number of POR cells are also tuned to egocentric properties of the environment, such as the spatial relationship of the animal to the center of its environment, or the distance between the animal and either the environment's center or its boundaries. We suggest potential frameworks through which these functional cell types might support contextual processing. We then discuss deficits seen in humans who have damage to the homologous parahippocampal cortex, and we finish by reviewing functional imaging studies that found activation of this area while human subjects performed various tasks. A preponderance of evidence suggests that the POR, along with its interactions with retrosplenial cortex, plays a key role in contextual information processing. [ABSTRACT FROM AUTHOR]

Abstract: The registration of spatial information by neurons of the parietal cortex takes on many forms. In most experiments, spatially modulated parietal activity patterns are found to take as their frame of reference some part of the body such as the retina. However, recent findings obtained in single neuron recordings from both rat and monkey parietal cortex suggest that the frame of reference utilized by parietal cortex may also be abstract or arbitrary in nature. Evidence in rats comes from work indicating that parietal activity in freely behaving rodents is organized according to the space defined by routes taken through an environment. In monkeys, evidence for an object-centered frame of reference has recently been presented. The present work reviews single neuron recording experiments in parietal cortex of freely behaving rats and considers the potential contribution of parietal cortex in solving navigational tasks. It is proposed that parietal cortex, in interaction with the hippocampus, plays a critical role in the selection of the most appropriate route between two points and, in addition, produces a route-based positional signal capable of guiding sensorimotor transitions. [Copyright &y& Elsevier]

Abstract: Neighboring contextual elements can dramatically affect the manner in which the brain processes the perceptual characteristics of an object. Indeed, many well-known visual illusions rely on misleading contextual cues to create misperceptions of size, length or orientation (e.g., in the Ebbinghaus, Muller-Lyer or rod-and-frame illusions, respectively). However, little is known about the brain regions underlying these integrative computations. The current study used fMRI to delineate the brain areas responsible for processing visuospatial contextual information. Participants were asked to determine whether a small target was positioned left or right of midline in the presence of an offset rectangle designed to induce a shift in the participant''s perception of straight-ahead (the induced Roelofs effect). We found localized, bilateral regions in superior parietal cortex and precuneus that were specifically active when participants judged the target location in the presence of this shifted context; significantly less activation was present when a color judgment was made with identical stimuli, or when the location judgment was made without a Roelofs-inducing frame. We propose that this portion of parietal cortex is selectively involved in processing visuospatial contextual information. Additional findings support the notion that perceptual judgments of target location based on an egocentric frame of reference fall within the purview of the dorsal stream of visual processing, rather than the ventral stream. [Copyright &y& Elsevier]

Abstract: Path integration enables desert arthropods to find back to their nest on the shortest track from any position. To perform path integration successfully, speeds and turning angles along the preceding outbound path have to be measured continuously and combined to determine an internal global vector leading back home at any time. A number of experiments have given an idea how arthropods might use allothetic or idiothetic signals to perceive their orientation and moving speed. We systematically review the four possible model descriptions of mathematically precise path integration, whereby we favour and elaborate the hitherto not used variant of egocentric cartesian coordinates. Its simple and intuitive structure is demonstrated in comparison to the other models. Measuring two speeds, the forward moving speed and the angular turning rate, and implementing them into a linear system of differential equations provides the necessary information during outbound route, reorientation process and return path. In addition, we propose several possible types of systematic errors that can cause deviations from the correct homeward course. Deviations have been observed for several species of desert arthropods in different experiments, but their origin is still under debate. Using our egocentric path integration model we propose simple error indices depending on path geometry that will allow future experiments to rule out or corroborate certain error types. [Copyright &y& Elsevier]

Abstract: A number of cognitive and behavioral variables influence the performance in tasks of theory of mind (ToM). Since two of the most important variables, memory and explicit expression, are impaired in schizophrenic patients, the ToM appears inconsistent in these patients. An ideal instrument of ToM should therefore account for deficient memory and impaired ability of these patients to explicitly express intentions. If such an instrument is developed, it should provide information that can be used not only to understand the pathophysiology but also to monitor patients. [Copyright &y& Elsevier]

• Using allocentric visual information for aiming is implied by target context-dependency. • Swiping on a tablet to targets embedded in different local configurations was examined. • Verbalized and controlled movements showed context-dependency of swiping endpoints. • Verbalization did not provoke an increase in context-dependency. • Verbalization also did not induce a spatial numerical association bias. It has been claimed that increased reliance on context, or allocentric information, develops when aiming movements are more consciously monitored and/or controlled. Since verbalizing target features requires strong conscious monitoring, we expected an increased reliance on allocentric information when verbalizing a target label (i.e. target number) during movement execution. We examined swiping actions towards a global array of targets embedded in different local array configurations on a tablet under no-verbalization and verbalization conditions. The global and local array configurations allowed separation of contextual-effects from any possible numerical magnitude biases triggered from calling out specific target numbers. The patterns of constant errors in the target direction were used to assess differences between conditions. Variation in the target context configuration systematically biased movement endpoints in both the no-verbalization and verbalization conditions. Ultimately, our results do not support the assertion that calling out target numbers during movement execution increases the context-dependency of targeted actions. [ABSTRACT FROM AUTHOR]

Although spatial navigation competence improves greatly from birth to adulthood, different spatial memory capacities emerge at different ages. Here, we characterized the capacity of 5–9-year-old children to use path integration to build egocentric and allocentric spatial representations to navigate in their environment, and compared their performance with that of young adults. First, blindfolded participants were tested on their ability to return to a starting point after being led on straight and two-legged paths. This egocentric homing task comprising angular and linear displacements allowed us to evaluate path integration capacities in absence of external landmarks. Second, we evaluated whether participants could use path integration, in absence of visual information, to create an allocentric spatial representation to navigate along novel paths between objects, and thus demonstrate the ability to build a cognitive map of their environment. Ninety percent of the 5–9-year-old children could use path integration to create an egocentric representation of their journey to return to a starting point, but they were overall less precise than adults. Sixty-four percent of 5–9-year-old children were capable of using path integration to build a cognitive map enabling them to take shortcuts, and task performance was not dependent on age. Imprecisions in novel paths made by the children who built a cognitive map could be explained by poorer integration of the experienced turns during the learning phase, as well as greater individual variability. In sum, these findings demonstrate that 5–9-year-old children can use path integration to build a cognitive map in absence of visual information. [ABSTRACT FROM AUTHOR]