Effects of traumatic brain injury on working memory-related brain activation in adolescents.
Eight adolescents (ages 13-18 years) who sustained traumatic brain injury (TBI) and eight gender- and age-matched typically developing (TD) adolescents underwent event-related functional MRI (fMRI) while performing a Sternberg letter recognition task. Encoding, maintenance, and retrieval were examined with memory loads of one or four items during imaging. Both groups performed above a 70% accuracy criterion and did not differ in performance. TD adolescents showed greater increase in frontal and parietal activation during high-load relative to low-load maintenance than the TBI group. The TBI patients showed greater increase in activation during high-load relative to low-load encoding and retrieval than the TD group. Results from this preliminary study suggest that the capability to differentially allocate neural resources according to memory load is disrupted by TBI for the maintenance subcomponent of working memory. The overrecruitment of frontal and extrafrontal regions during encoding and retrieval following TBI may represent a compensatory process.
Newsome
Mary R
MR
Cognitive Neuroscience Laboratory, Department of Physical Medicine & Rehabilitation, Baylor College of Medicine, TX 77030, USA. mnewsome@bcm.edu
Steinberg
Joel L
JL
Scheibel
Randall S
RS
Troyanskaya
Maya
M
Chu
Z
Z
Hanten
Gerri
G
Lu
Hanzhang
H
Lane
Summer
S
Lin
Xiaodi
X
Hunter
Jill V
JV
Vasquez
Carmen
C
Zientz
Jennifer
J
Li
Xiaoqi
X
Wilde
Elisabeth A
EA
Levin
Harvey S
HS
D000293:Adolescent; D000704:Analysis of Variance; D001921:Brain / Q000098:blood supply / Q000503:physiopathology*; D001930:Brain Injuries / Q000150:complications* / Q000473:pathology* / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood
D010100:Oxygen