PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Visual Perception”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed1991

[Prosopagnosia. A rare disorder of visual perception].

Prosopagnosia is a rare neurological sign, characterized by disturbance of recognition of faces. It is important to remember that prosopagnosia can appear as a result of a brain injury, and as such may be a major disability to the patient. We report a case of a nine year old boy with prosopagnosia due to brain injury at the age of 18 months. The main injury was localized to the boy's left hemisphere, but his right hemisphere was probably also affected. Most post mortem examinations of patients suffering from prosopagnosia show bilateral or right-sided parietal, temporal and occipetal pathological changes.

Agnosia↗
PubMed1992

Optical imaging of architecture and function in the living brain sheds new light on cortical mechanisms underlying visual perception.

Long standing questions related to brain mechanisms underlying perception can finally be resolved by direct visualization of the architecture and function of mammalian cortex. This advance has been accomplished with the aid of two optical imaging techniques with which one can literally see how the brain functions. The upbringing of this technology required a multi-disciplinary approach integrating brain research with organic chemistry, spectroscopy, biophysics, computer sciences, optics and image processing. Beyond the technological ramifications, recent research shed new light on cortical mechanisms underlying sensory perception. Clinical applications of this technology for precise mapping of the cortical surface of patients during neurosurgery have begun. Below is a brief summary of our own research and a description of the technical specifications of the two optical imaging techniques. Like every technique, optical imaging also suffers from severe limitations. Here we mostly emphasize some of its advantages relative to all alternative imaging techniques currently in use. The limitations are critically discussed in our recent reviews. For a series of other reviews, see Cohen (1989).

Brain↗
PubMed1978

Lateral asymmetries in visual perception with and without eye movements.

A signal detection analysis was made of single letter recognition in the right and left visual fields. When letters were presented 2 degrees 3' to the right or left of a central fixation there were no significant differences between the fields in perceptual accuracy independent of bias when the subject maintained a central fixation point. However, when subjects were free to move their eyes a right field advantage was found. The results were discussed in terms of attentional bias theories and hemispheric specialization theories.

Cerebral Cortex↗
PubMedDate not supplied

[Ontogenetic characteristics of the development of slow negative and positive potentials during the performance of a visual perceptive task].

In age aspect, topography and parameters were studied of late EPs and slow negative components (CNV) to successively presented visual stimuli: the preliminary signal and two compared contour images. Age characteristics of development of the frontal negativity N450 and the late positive complex (LPC) were revealed. in children 7 and 10 years old, the component N450 was present in response both to the preliminary and the first stimulus in the compared pair; LPC was recorded to all three presented visual stimuli. In 17 years old subjects and in adults, selectivity of N450 formation in the EP to the first of the compared stimuli and LPC to the second (imperative) stimulus correlates with involvement of rostral brain areas--central in youths, central and frontal ones in adults--both in the process of waiting (CNV) and evaluation of coming information (LPC).

Adolescent↗