Regional specificity and practice: Dynamic changes in object and spatial working memory
Citation:
Landau, S. M., Garavan, H., Schumacher, E.H., & D'Esposito, M., Regional specificity and practice: Dynamic changes in object and spatial working memory, Brain Research, 1180, 2007, 78, 89Download Item:
Landau BR07.pdf (PDF) 779.0Kb
Abstract:
Working memory (WM) tasks engage a network of brain regions that includes primary,
unimodal, and multimodal associative cortices. Little is known, however, about whether
task practice influences these types of regions differently. In this experiment, we used
event-related fMRI to examine practice-related activation changes in different region types
over the course of a scanning session while participants performed a delayed-recognition
task. The task contained separate WM processing stages (encoding, maintenance, retrieval)
and different materials (object, spatial), which allowed us to investigate the influence of
practice on different component processes. We observed significant monotonic decreases,
and not increases, in fMRI signal primarily in unimodal and multimodal regions. These
decreases occurred duringWMencoding and retrieval, but not during maintenance. Finally,
regions specific to the type of memoranda (e.g., spatial or object) showed a lesser degree of
sensitivity to practice as compared to regions activated by both types of memoranda,
suggesting that these regions may be specialized more for carrying out processing within a
particular modality than for experience-related flexibility. Overall, these findings indicate
that task practice does not have a uniform effect on stages of WM processing, the type of
WM memoranda being processed or on different types of brain regions. Instead, regions
engaged during WM encoding and retrieval may have greater capacity for functional
plasticity than WM maintenance. Additionally, the degree of specialization within brain
regions may determine processing efficiency. Unimodal and multimodal regions that
participate in both object and spatial processing may be specialized for flexible experiencerelated
change, while those supporting primary sensorimotor processing may operate at
optimal efficiency and are less susceptible to practice.
Sponsor
Grant Number
National Science Foundation
National Science Foundation
Dana Foundation
National Institutes of Health (NIH)
Author's Homepage:
http://people.tcd.ie/garavanhDescription:
PUBLISHED
Author: GARAVAN, HUGH PATRICK
Publisher:
ElsevierType of material:
Journal ArticleCollections:
Series/Report no:
1180Brain Research
Availability:
Full text availableKeywords:
Event-related fMRI, Learning, Practice, PlasticityLicences: