A restricted 'spotlight' of attention in visual object recognition.
We describe a patient (NJ), with a progressive visual disturbance, who showed an impairment in identifying larger visually-presented objects relative to their smaller counterparts. NJ showed this size effect for line drawings of objects, words and single letters. When presented with large letters comprised of smaller letters and asked to give speeded identification responses to either the large or small letters, NJ was grossly impaired at identifying the large letter. Additionally, when presented with a context meant to bias responding to either the large or small letter, NJ showed faster and more accurate responding in the small direction, but not in the large direction. We interpret these results as indicative of an impaired 'spotlight' of attention, which is deployed across the visual array, and is necessary for providing the selective visual attention responsible for the integration of visual features.
Stark
M E
ME
Cognitive Neuroscience Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1440, USA. stark@helix.nih.gov
Grafman
J
J
Fertig
E
E
D000368:Aged; D000544:Alzheimer Disease / Q000209:etiology; D001284:Atrophy / Q000473:pathology; D001288:Attention; D001921:Brain / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual; D010468:Perceptual Disorders / Q000175:diagnosis*; D011930:Reaction Time