Abstract

Working memory tasks are associated with the activation of widely distributed neural networks. The Sternberg working memory task has been used to explore the neural correlates associated with changes in memory load and the resolution of interference. Preliminary research suggests that the integrity of the anterior cingulate is correlated with resolving load adjustments but not in resolving interference demands; the opposite pattern of associations have been observed with the right middle frontal gyrus.Participants in the present study were 28 children who had sustained moderate to severe traumatic brain injuries (TBI) and 28 children who had sustained orthopedic injuries (OI). Participants were aged between 7 and 17 years at the time of injury (mean age = 13.2, s.d.=2.3). The groups were matched on age, gender, socioeconomic level, and pre-injury measures of behavioral and emotional functioning. Participants completed the Sternberg working memory task and structural MRI scans three months post injury. Automated brain parcellation software (Freesurfer) was used to calculate volumetric data for regions of interest. Regions of interest included the anterior cingulate and right middle frontal gyrus; additionally, the volume of the corpus callosum was used as an index of overall brain integrity. There were no significant differences between the groups on percent errors on the Sternberg task. Participants in the TBI group had significantly longer reaction times overall than the OI group. Interference in the Sternberg task has the potential to either help or hinder performance. Participants in the OI group displayed the anticipated effects of interference on reaction time whereas the TBI group as a whole did not display this pattern (priming effect not observed). The TBI group had significantly lower volumes in the regions of interest than the OI group. Hypothesized correlations between the regions of interest and changes in load / interference demands were partially supported. Exploratory analyses identified positive correlations between the volume of the right middle frontal gyrus and reaction time measures that warrant further exploration.

Degree

PhD

College and Department

Family, Home, and Social Sciences; Psychology

Rights

http://lib.byu.edu/about/copyright/

Date Submitted

2010-04-29

Document Type

Dissertation

Handle

http://hdl.lib.byu.edu/1877/etd3583

Keywords

traumatic brain injury, Sternberg, working memory, priming, interference, executive functioning.

Language

English

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Psychology Commons

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