Biomedical subjects

M G Kiefner

Publications and source records attributed to M G Kiefner.

2 recordsLinked to original sources

PubMed1988

Visuospatial functioning before and after commissurotomy. Disconnection in hierarchical processing.

A patient who underwent complete cerebral commissurotomy was tested before and after surgery on tasks involving drawing and recognition memory for visual hierarchical stimuli. These stimuli consisted of a large, higher-level form constructed from smaller, lower-level forms. Postoperatively, the patient was more accurate in drawing and recognizing higher-level forms relative to lower-level forms when responding with his left hand and primarily right hemisphere, whereas he showed the opposite pattern when responding with his right hand and primarily left hemisphere. Implications of these findings for theories of the cerebral organization of visuospatial processing are discussed.

Adult↗

PubMed1988

Visuospatial dysfunction following unilateral brain damage: dissociations in hierarchical and hemispatial analysis.

Unlike the aphasias, visuospatial dysfunction has resisted fractionation into meaningful spared and impaired component functions. In this study, we show that unilateral brain damage results in pronounced dissociations in both hierarchical and hemispatial processing. Patients with left-hemisphere damage showed the greatest impairment in drawing forms at the lower level of hierarchical stimuli presented in right hemispace, whereas patients with right-hemisphere compromise displayed the opposite pattern. We discuss implications of these results for research in visuospatial function and clinical assessment of visuospatial dysfunction.

Aged↗