Differential effects of socioeconomic status on working and procedural memory systems.
While prior research has shown a strong relationship between socioeconomic status (SES) and working memory performance, the relation between SES and procedural (implicit) memory remains unknown. Convergent research in both animals and humans has revealed a fundamental dissociation, both behaviorally and neurally, between a working memory system that depends on medial temporal-lobe structures and the dorsal lateral prefrontal cortex (DLPFC) vs. a procedural memory system that depends on the basal ganglia. Here, we measured performance in adolescents from lower- and higher-SES backgrounds on tests of working memory capacity (complex working memory span) and procedural memory (probabilistic classification) and their hippocampal, DLPFC, and caudate volumes. Lower-SES adolescents had worse working memory performance and smaller hippocampal and DLPFC volumes than their higher-SES peers, but there was no significant difference between the lower- and higher-SES groups on the procedural memory task or in caudate volumes. These findings suggest that SES may have a selective influence on hippocampal-prefrontal-dependent working memory and little influence on striatal-dependent procedural memory.
Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research, Massachusetts Institute of Technology Cambridge, MA, USA.
Julia A
JA
Leonard
Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research, Massachusetts Institute of Technology Cambridge, MA, USA.
Allyson P
AP
Mackey
Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research, Massachusetts Institute of Technology Cambridge, MA, USA.
Amy S
AS
Finn
Department of Brain and Cognitive Sciences and McGovern Institute for Brain Research, Massachusetts Institute of Technology Cambridge, MA, USA.
John D E
JD
Gabrieli
caudate; hippocampus; procedural memory; socioeconomic status; working memory