[Abstract Title]. - Society for Neuroscience

ecent but currently unavailable contextual information, presumably maintained in WM, is used
by ACC in evaluating error likelihood during task performance. However, schizophrenia patients
showed significantly less error-likelihood related activity in ACC at the response. In fact, in
schizophrenia patients, we did not find ACC error-likelihood activity at the target response or at
the cue presentation. This was the case even for a subset of patients matched with controls on
DMTS performance and WM-related activation in DLPFC. This suggests a disturbance in the
use of contextual information stored in WM for the evaluation of error likelihood in ACC. It
further suggests that this disturbance is specific to ACC and not simply due to a deficit in WM
maintenance.
Disclosures: A. Krawitz , None; T.S. Braver, None; D.M. Barch, None; J.W. Brown, None.
Poster
288. Working Memory: Disorders, Genes and Connectivity
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 288.4/RR11
Topic: F.01.f. Working memory
Support: NIH R01 MH61625
National Science Foundation Graduate Research Fellowship
National MS Society SF1752-A-1
Title: Neural plasticity resulting from task repetition is reduced in multiple sclerosis
Authors: *C. A. MONTOJO 1 , S. SAYALA 1 , S. M. COURTNEY 1,2,3 ;
1 Psychological & Brain Sci., 2 Dept. of Neurosci., Johns Hopkins Univ., Baltimore, MD; 3 FM
Kirby Res. Ctr. for Functional Brain Imaging, Kennedy Krieger Inst., Baltimore, MD
Abstract: Neural plasticity following repeated performance of a working memory (WM) task
has been shown previously in healthy young adults, with observed decreases in fMRI activation
interpreted as reflecting increased neural efficiency resulting from short-term practice. Both
older adults and individuals with multiple sclerosis (MS) often show increased fMRI activation
compared to controls when the data is averaged across a scanning session. This overall greater
activation has been interpreted alternately as reflecting either compensatory neural plasticity or
inefficient neural processing. In order to better understand the nature of such examples of neural
plasticity and changes in efficiency, we examined whether individuals with MS and age-matched
controls show the same pattern as young healthy adults of decreasing fMRI activation during