A multi-channel near-infrared spectroscopy study of prefrontal cortex activation during working memory task in major depressive disorder

Neurosci Res. 2011 May;70(1):91-7. doi: 10.1016/j.neures.2011.01.001. Epub 2011 Jan 15.

Abstract

Many neuropsychological studies demonstrate impairment of working memory in patients with major depressive disorder (MDD). However, there are not enough functional neuroimaging studies of MDD patients seeking for the underlying brain activity relevant to working memory function. The objective of this study is to evaluate prefrontal hemodynamic response related to working memory function in patients with MDD. Twenty-four subjects with MDD and 26 age- and gender-matched healthy subjects were recruited for the present study. We measured hemoglobin concentration changes in the prefrontal and superior temporal cortical surface areas during the execution of working memory task (WM; 2-back, letter version) using 52-channel near-infrared spectroscopy (NIRS), which enables real-time monitoring of task-related changes in cerebral blood volumes in the cortical surface areas. MDD patients showed a smaller increase in lateral prefrontal and superior temporal cortex activation during the 2-back task and associated poorer task performance than healthy controls. The results coincided with previous findings in terms of working memory deficits and prefrontal cortex dysfunction in MDD patients, but contradicted with some previous fMRI studies that suggested increased cortical activity during the working memory task in patients with depression. The contradiction may, in part, be explained by a relatively low level of cognitive demand imposed on the subjects in the present study.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Depressive Disorder, Major / complications
  • Depressive Disorder, Major / drug therapy
  • Depressive Disorder, Major / physiopathology*
  • Female
  • Humans
  • Male
  • Memory Disorders / diagnosis
  • Memory Disorders / etiology
  • Memory Disorders / physiopathology*
  • Memory, Short-Term / drug effects
  • Memory, Short-Term / physiology*
  • Middle Aged
  • Prefrontal Cortex / anatomy & histology
  • Prefrontal Cortex / drug effects
  • Prefrontal Cortex / physiopathology*
  • Spectroscopy, Near-Infrared / methods*