While early and higher visual areas along the ventral visual pathway in the inferotemporal cortex are critical for the recognition of individual objects, the neural representation of human perception of complex global visual scenes remains under debate. Stroke patients with a selective deficit in the perception of a complex global Gestalt with intact recognition of individual objects - a defici...

Patients with Balint' s syndrome are typically impaired at perceiving multiple objects simultaneously, and at evaluating the relationship between multiple objects in a scene (simultanagnosia). These deficits may not only be observed in complex scenes, but also when local elements of individual objects must be integrated into a perceptual global whole. Thus, unlike normal observers, patients wit...

Simultanagnosia is a disorder of visual attention, defined as an inability to see more than one object at once. It has been conceived as being due to a constriction of the visual "window" of attention, a metaphor that we examine in the present article. A simultanagnosic patient (SL) and two non-simultanagnosic control patients (KC and ES) described social scenes while their eye movements were m...

Quantitative modeling of psychological data is both technically and mathematically challenging. The present article introduces a user friendly and flexible program package that enables quantitative fits of Bundesen's (1990) theory of visual attention to behavioral data from whole and partial report experiments. The program package is based on new computational formulas that are more general tha...

Following bi-parietal lesions patient AT showed a severe inability to relocate her attention within a visual field which perimetry proved to be near-normal. An experimental approach with tasks testing visuo-spatial attention demonstrated a shrinkage of A.T.'s attentional visual field. With her visual attention narrowed to a kind of functional tunnel vision, the patient exhibited simultanagnosia...

BACKGROUND Posterior cortical atrophy is a clinical syndrome that is characterized by the progressive loss of visuospatial integration and is associated with neurodegenerative conditions. CASE REPORT We describe a 60-year-old female with simultanagnosia, oculomotor apraxia, and optic ataxia for which she received an initial clinical diagnosis of posterior cortical atrophy. Three years later, ...

Attentional resource and distribution are specifically impaired in simultanagnosia, also the visuo-attentional form of developmental dyslexia. Both clinical conditions conceived as a limitation simultaneous visual processing after superior parietal lobule (SPL) dysfunction (review Valdois et al., 2019). However, reduced space-based attentional window (i.e. limited eccentricity at which target o...

Patients with posterior cortical atrophy may have dorsal visual system (occipital-parietal) dysfunction (optic ataxia, visuospatial disorientation, and simultanagnosia), ventral visual system (occipital-temporal) dysfunction (pure alexia, prosopagnosia, visual anomia, and agnosia), or both. We report a professional musician with ventral system dysfunction whose first symptom was alexia for musi...

Simultanagnosia is a neuropsychological disorder characterized by a restriction of visuospatial attention. In addition, patients are able to identify local elements of a scene, but not the global whole. This may be due to a failure to scan and assemble local elements into a global whole (i.e. connect-the-dots). We monitored the eye movements of a simultanagnosic patient while she identified loc...