Abstract
Simultanagnosia, in which subjects report a piecemeal visual experience, offers an important probe of human attention. We studied 2 subjects with simultanagnosia following bilateral superior occipital strokes. Compared with controls, they could orient attention to spatial targets in visual, auditory, and mixed-modal conditions. A different task required immediate response to the appearance or disappearance at unpredictable intervals of any element in a random-dot CRT display. The subject tested could detect less than 50% of 1,600 events, and had increased "mirages" and prolonged reaction times. Undetected events occurred anywhere and formed temporal clusters. Application of signal-detection theory confirmed abnormal sensitivity and response bias (d′ and beta). Yet performance improved when a valid cue introduced events in the random display. Our results suggest that simultanagnosia was related to an inability to sustain visuospatial attention across an array, corresponding to processing failure at a level of long-range (global) spatiotemporal interactions among converging inputs from early vision. The operations for orienting and sustaining attention may be dissociable at visual association cortex levels.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 447-455 |
| Number of pages | 9 |
| Journal | Neurology |
| Volume | 40 |
| Issue number | 3 |
| State | Published - Mar 1990 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Neuroscience(all)
Cite this
Simultanagnosia : A defect of sustained attention yields insights on visual information processing. / Rizzo, Matthew; Robin, Donald A.
In: Neurology, Vol. 40, No. 3, 03.1990, p. 447-455.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Simultanagnosia
T2 - A defect of sustained attention yields insights on visual information processing
AU - Rizzo, Matthew
AU - Robin, Donald A.
PY - 1990/3
Y1 - 1990/3
N2 - Simultanagnosia, in which subjects report a piecemeal visual experience, offers an important probe of human attention. We studied 2 subjects with simultanagnosia following bilateral superior occipital strokes. Compared with controls, they could orient attention to spatial targets in visual, auditory, and mixed-modal conditions. A different task required immediate response to the appearance or disappearance at unpredictable intervals of any element in a random-dot CRT display. The subject tested could detect less than 50% of 1,600 events, and had increased "mirages" and prolonged reaction times. Undetected events occurred anywhere and formed temporal clusters. Application of signal-detection theory confirmed abnormal sensitivity and response bias (d′ and beta). Yet performance improved when a valid cue introduced events in the random display. Our results suggest that simultanagnosia was related to an inability to sustain visuospatial attention across an array, corresponding to processing failure at a level of long-range (global) spatiotemporal interactions among converging inputs from early vision. The operations for orienting and sustaining attention may be dissociable at visual association cortex levels.
AB - Simultanagnosia, in which subjects report a piecemeal visual experience, offers an important probe of human attention. We studied 2 subjects with simultanagnosia following bilateral superior occipital strokes. Compared with controls, they could orient attention to spatial targets in visual, auditory, and mixed-modal conditions. A different task required immediate response to the appearance or disappearance at unpredictable intervals of any element in a random-dot CRT display. The subject tested could detect less than 50% of 1,600 events, and had increased "mirages" and prolonged reaction times. Undetected events occurred anywhere and formed temporal clusters. Application of signal-detection theory confirmed abnormal sensitivity and response bias (d′ and beta). Yet performance improved when a valid cue introduced events in the random display. Our results suggest that simultanagnosia was related to an inability to sustain visuospatial attention across an array, corresponding to processing failure at a level of long-range (global) spatiotemporal interactions among converging inputs from early vision. The operations for orienting and sustaining attention may be dissociable at visual association cortex levels.
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M3 - Article
C2 - 2314587
AN - SCOPUS:0025230738
VL - 40
SP - 447
EP - 455
JO - Neurology
JF - Neurology
SN - 0028-3878
IS - 3
ER -