Verbal working memory: magnetic resonance, morphometric analysis and a psychophisiological model

Abstract

Neuropsychological characteristics of verbal working memory (memory capacity, permanency, and different types of memory errors) of 43 healthy subjects of older age were compared with the anatomical characteristics of their brain structures (volume of the hippocampi and the caudate nuclei, size of the cingulate-cortex regions of both hemispheres). The obtained data demonstrate a correlation between the permanency of verbal- information maintenance and left caudate-nucleus volume and a positive correlation between associative-memory capacity and left hippocampus volume. A decline in the number of verbal-memory errors (confabulations) is related to the increased size of the left anterior cingulate cortex. Furthermore, verbal working-memory capacity and permanency correlate negatively with the size of the left posterior dorsal cingulate cortex, whereas the number of fluctuations and word replacements correlate positively with the increased size of this brain region. We suggest a psychophysiological model of verbalstimulus maintenance in working memory based on the results of our study and published research data.

Keywords

• magnetic resonance morphometric analysis
• working memory
• verbal memory
• caudate nucleus
• cingulate cortex
• hippocampus
• working-memory model