Related Experiment Video
Updated: May 3, 2026

Virtual Reality Tools for Assessing Unilateral Spatial Neglect: A Novel Opportunity for Data Collection
Published on: March 10, 2021
Unilateral neglect: the fate of the extinguished visual stimuli
P D'Erme1, I Robertson2, P Bartolomeo1
1Institute of Neurology, Neuropsychology Service, Catholic University, Rome, Italy.
Abstract:
Recent neuropsychological literature has provided evidence for the phenomenon of perception without awareness, also referred to as covert (or implicit) knowledge or tacit awareness. Yet little is known to date about the fate of extinguished stimuli in patients with unilateral spatial neglect. Six right brain-damaged patients with USN and one control subject were presented with single lateralized visual stimuli and with pairs of same or different visual stimuli (one right, one left). A same/different judgement and a multiple choice recognition task were performed on overtly unidentified left-sided stimuli, to unveil possible phenomena of covert knowledge. Some evidence of covert knowledge was observed, and its relation to stimulus characteristics and task demands is discussed.
Related Concept Videos
Visual Agnosia
Photoreceptors and Visual Pathways
Unrenewable Cells
Photoreceptors
The retina is composed of several layers and contains specialized cells called photoreceptors. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. There are two types of photoreceptors—rods and cones—which differ in the shape of...
Color Vision
Olfactory Receptors: Location and Structure

