In your place: neuropsychological evidence for altercentric remapping in embodied perspective taking.

Humans are able to mentally adopt the spatial perspective of others and represent the visual world from their point of view. Here, we present neuropsychological evidence that information inaccessible from an egocentric perspective can be accessed from the perspective of another person. Patients affected by left neglect were asked to describe arrays of objects from their own egocentric perspective, from an opposite perspective (disembodied perspective taking), and from the point of view of another person actually seated in front of them (embodied perspective taking).

Pure topographical disorientation in a patient with right occipito-temporal lesion.

We describe a patient who presented with a pure topographical disorientation after a stroke involving the right mesial occipito-temporal cortex. He could not point to external unseen landmarks or draw a map of his city, while he could recognize landmarks, and judge the distance, and describe the route between pairs of landmarks of the same city. He underwent standardized cognitive tests, and 6 tasks were used to assess a topographical orientation route-survey.

Dissociation between time reproduction of actions and of intervals in patients with Parkinson's disease.

Alterations in temporal estimation have been observed in patients with Parkinson's disease (PD) and have been associated to dopaminergic dysfunction. Nevertheless, levodopa treatment and deep brain stimulation of the subthalamic nucleus (DBS-STN) have been shown to improve motor deficits and temporal estimation skills in such patients. So far, temporal estimation tasks in PD patients have evaluated the ability to reproduce intervals of time, but never the duration of an action.

Route and survey processing of topographical memory during navigation.

We investigated the characteristics of route and survey processing of a unique complex virtual environment both at the behavioral and brain levels. Prior to fMRI scanning, participants were trained to follow a route and to learn the spatial relationships between several places, acquiring both route and survey knowledge from a ground-level perspective. During scanning, snapshots of the environment were presented, and participants were required to either indicate the direction to take to follow the route (route task), or to locate unseen targets (survey task).

A systematic review of adverse events in placebo groups of anti-migraine clinical trials.

In analgesic clinical trials, adverse events are reported for the painkiller under evaluation and compared with adverse events in the placebo group. Interestingly, patients who receive the placebo often report a high frequency of adverse events, but little is understood about the nature of these negative effects. In the present study, we compared the rates of adverse events reported in the placebo arms of clinical trials for three classes of anti-migraine drugs: NSAIDs, triptans and anticonvulsants.

Collicular vision guides nonconscious behavior.

Following destruction or deafferentation of primary visual cortex (area V1, striate cortex), clinical blindness ensues, but residual visual functions may, nevertheless, persist without perceptual consciousness (a condition termed blindsight). The study of patients with such lesions thus offers a unique opportunity to investigate what visual capacities are mediated by the extrastriate pathways that bypass V1. Here we provide evidence for a crucial role of the collicular-extrastriate pathway in nonconscious visuomotor integration by showing that, in the absence of V1, the superior colliculus (SC) is essential to translate visual signals that cannot be consciously perceived into motor outputs.

Differentiated forgetting rates of spatial knowledge in humans in the absence of repeated testing.

Spatial knowledge, necessary for efficient navigation, comprises route knowledge (memory of the landmarks along a route) and survey knowledge (map-like). Available data on the retention in humans of spatial knowledge show that this does not decline systematically over months or years. Here, two groups of participants elaborated route and survey knowledge during navigation in a complex virtual environment before performing route and survey tasks.

Mental number line disruption in a right-neglect patient after a left-hemisphere stroke.

A right-neglect patient with focal left-hemisphere damage to the posterior superior parietal lobe was assessed for numerical knowledge and tested on the bisection of numerical intervals and visual lines. The semantic and verbal knowledge of numbers was preserved, whereas the performance in numerical tasks that strongly emphasize the visuo-spatial layout of numbers (e.g.

Effects of emotional face cueing on line bisection in neglect: a single case study.

One patient with left neglect (FM) and four right brain-damaged controls were tested on a line bisection task with pictures of neutral and emotional faces as unilateral cues. We thus manipulated the attentional salience of the cues (higher for emotional and lower for neutral faces) while keeping constant their physical dimensions. Our findings showed that left emotional faces were more effective than left neutral faces in reducing bisection errors only in FM.

Functional asymmetry and interhemispheric cooperation in the perception of emotions from facial expressions.

The present study used the redundant target paradigm on healthy subjects to investigate functional hemispheric asymmetries and interhemispheric cooperation in the perception of emotions from faces. In Experiment 1 participants responded to checkerboards presented either unilaterally to the left (LVF) or right visual half field (RVF), or simultaneously to both hemifields (BVF), while performing a pointing task for the control of eye movements. As previously reported (Miniussi et al.

Visual acceleration and spatial distortion in right brain-damaged patients.

A subset of right brain-damaged patients shows leftward overextension in the line extension task. It has been argued that this deficit can be attributed to a distortion of the metric structure of perceived space (spatial anisometry). We investigated whether spatial distortion of static stimuli is associated with a corresponding misperception of perceived acceleration of moving stimuli.

Acceleration perception and spatial distortion in a left unilateral neglect patient.

To explain relative leftward overextension in a line extension task by left unilateral neglect subjects, Bisiach et al. (1998) suggested that the representation of space is distorted--i.e.