Abnormal temporal dynamics of visual attention in spatial neglect patients
Abstract
WHEN we identify a visual object such as a word or letter, our ability to detect a second object is impaired if it appears within 400ms of the first1-5. This phenomenon has been termed the attentional blink or dwell time and is a measure of our ability to allocate attention over time (temporal attention). Patients with unilateral visual neglect are unaware of people or objects con-tralateral to their lesion6,7. They are considered to have a disorder of attending to a particular location in space (spatial attention)6-11. Here we examined the non-spatial temporal dynamics of attention in patients, using a protocol for assessing the attentional blink. Neglect patients with right parietal, frontal or basal ganglia strokes had an abnormally severe and protracted attentional blink. When they identified a letter, their awareness of a subsequent letter was significantly diminished for a length of time that was three times as long as for individuals without neglect. Our results demonstrate for the first time that visual neglect is a disorder of directing attention in time, as well as space.
- Publication:
-
Nature
- Pub Date:
- January 1997
- DOI:
- 10.1038/385154a0
- Bibcode:
- 1997Natur.385..154H