Lin Naing

Publications (2)5.86 Total impact

• Source

  Available from: Vivek Prabhakaran

  Article: Validating age-related functional imaging changes in verbal working memory with acute stroke.

  Timothy B Meier, Lin Naing, Lisa E Thomas, Veena A Nair, Argye E Hillis, Vivek Prabhakaran
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  ABSTRACT: Functional imaging studies consistently find that older adults recruit bilateral brain regions in cognitive tasks that are strongly lateralized in younger adults, a characterization known as the Hemispheric Asymmetry Reduction in Older Adults model. While functional imaging displays what brain areas are active during tasks, it cannot demonstrate what brain regions are necessary for task performance. We used behavioral data from acute stroke patients to test the hypothesis that older adults need both hemispheres for a verbal working memory task that is predominantly left-lateralized in younger adults. Right-handed younger (age ⩽ 50, n = 7) and older adults (age > 50, n =21) with acute unilateral stroke, as well as younger (n =6) and older (n =13) transient ischemic attack (TIA) patients, performed a self-paced verbal item-recognition task. Older patients with stroke to either hemisphere had a higher frequency of deficits in the verbal working memory task compared to older TIA patients. Additionally, the deficits in older stroke patients were mainly in retrieval time while the deficits in younger stroke patients were mainly in accuracy. These data suggest that bihemispheric activity is necessary for older adults to successfully perform a verbal working memory task.
  Behavioural neurology 01/2011; 24(3):187-99. · 1.77 Impact Factor
• Source

  Available from: Dr. Veena A Nair

  Article: Capacity-speed relationships in prefrontal cortex.

  Vivek Prabhakaran, Bart Rypma, Nandakumar S Narayanan, Timothy B Meier, Benjamin P Austin, Veena A Nair, Lin Naing, Lisa E Thomas, John D E Gabrieli
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  ABSTRACT: Working memory (WM) capacity and WM processing speed are simple cognitive measures that underlie human performance in complex processes such as reasoning and language comprehension. These cognitive measures have shown to be interrelated in behavioral studies, yet the neural mechanism behind this interdependence has not been elucidated. We have carried out two functional MRI studies to separately identify brain regions involved in capacity and speed. Experiment 1, using a block-design WM verbal task, identified increased WM capacity with increased activity in right prefrontal regions, and Experiment 2, using a single-trial WM verbal task, identified increased WM processing speed with increased activity in similar regions. Our results suggest that right prefrontal areas may be a common region interlinking these two cognitive measures. Moreover, an overlap analysis with regions associated with binding or chunking suggest that this strategic memory consolidation process may be the mechanism interlinking WM capacity and WM speed.
  PLoS ONE 01/2011; 6(11):e27504. · 4.09 Impact Factor