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Biomedical subjects

Ia A Meerson

Publications and source records attributed to Ia A Meerson.

At least 19 recordsLinked to original sources
PubMed1981

[Several mechanisms of visual gnosis disorders in local brain lesions].

The object of the studies were peculiarities of recognizing visual images by patients with local cerebral lesions under conditions of incomplete sets of the image features, disjunction of the latter, distortion of their spatial arrangement, and unusual spatial orientation of the image as a whole. It was found that elimination of even one essential feature sharply hampered the recognition of the image both by healthy individuals (control), and patients with extraoccipital lesions, whereas elimination of several nonessential features only slowed down the process. In distinction from this the difficulties of the recognition of incomplete images by patients with occipital lesions were directly proportional to the number of the eliminated features irrespective of the latters' significance, i.e. these patients were unable to evaluate the hierarchy of the features. The recognition process in these patients were followed the way of scanning individual features. The reaccumulation and summation. The recognition of the fragmental, spatially distorted and unusually oriented images was found to be affected selectively in patients with parietal lobe affections. The patients with occipital lesions recognized such images practically as good as the ordinary ones.

Adult↗
PubMed1975

[Eye movement disorders in visual agnosia].

By the aid of photooptical methods the authors studied eye movements in 6 patients with disorders of visual gnosis due to focal lesions in the occipitallbrain lobes. The examination included studies of a fixation of immovable objects, a tracing of linear and pendulum moving objects and a voluntary change of points of fixation in space. It was demonstrated that expressed symptoms of agnosia are accompanied by defects in the organization of all forms of opticomotor activity. The authors discuss problems of the pathogenesis of oculomotor disorders in optical agnosia.

Agnosia↗