Neurophysiological measures of working memory and individual differences in cognitive ability and cognitive style

Citation
A. Gevins et Me. Smith, Neurophysiological measures of working memory and individual differences in cognitive ability and cognitive style, CEREB CORT, 10(9), 2000, pp. 829-839
Citations number
68
Categorie Soggetti
Neurosciences & Behavoir
Journal title
CEREBRAL CORTEX
ISSN journal
10473211 → ACNP
Volume
10
Issue
9
Year of publication
2000
Pages
829 - 839
Database
ISI
SICI code
1047-3211(200009)10:9<829:NMOWMA>2.0.ZU;2-W
Abstract
The capacity to deliberately control attention in order to hold and manipul ate information in working memory is critical to higher cognitive functions . This suggests that between-subject differences in general cognitive abili ty might be related to observable differences in the activity of brain syst ems that support working memory and attention control. To test this notion, electroencephalograms were recorded from 80 healthy young adults during sp atial working memory tasks. Measures of task-related neurophysiological and behavioral variables were derived from these data and compared to scores o n a test battery commonly used to assess general cognitive ability (the WAI S-R). Subjects who scored high on the psychometric test also tended to resp ond faster in the experimental tasks without any loss of accuracy. The ampl itude of the late positive component of the event-related potential was lar ger in high-ability subjects, and the frontal midline theta component of th e EEG signal was also selectively enhanced in this group under conditions o f sustained performance and high working memory load. These results suggest that subjects who scored high on the WAIS-R were better able to focus and sustain attention to task performance. Changes in the EEG alpha rhythm in r esponse to manipulations of task practice and load were also examined and c ompared between frontal and parietal regions. The results indicated that hi gh-ability subjects developed strategies that made relatively greater use o f parietal regions, whereas low-ability subjects relied more exclusively on frontal regions. Other analyses indicated that hemispheric asymmetries in alpha band measures distinguish between individuals with relatively high ve rbal aptitude and those with relatively high nonverbal aptitude. In particu lar, subjects with a verbal cognitive style tended to make greater use of t he left parietal region during task performance, and subjects with a nonver bal style tended to make greater use of the right parietal region. These re sults help clarify relationships between task related brain activity and in dividual differences in cognitive ability and style.