Alterations of P300 wave in occipital lobe in depressive patients

Actas Esp Psiquiatr. Jul-Aug 2007;35(4):243-8.

Abstract

Introduction: The objective of this work is to assess neurofunctional alterations in patients with depression, analyzing the neurophysiological activity of P300 wave in bilateral occipital areas during visual attention and visual memory cognitive tasks.

Method: The study was made up of a group of 40 individuals, 21 in the control group and 19 in the group with depression. Visual stimulation was made by means of Cognistin system (ATI). The person is placed at one meter from the screen and remains seated, with no external visual stimulus if possible. All individuals were subjected to two different tasks: visual <<oddball>> paradigm and visual memory.

Results: A delay exists in latency of the P300 wave, in a global manner, both in visual task discrimination and memory task in patients with depression in the occipital areas. There is negative correlation between the P300 amplitude and severity of the depression, so that greater amplitude in the P300 component implies reduced severity of depression and vice versa. The reaction time in visual discrimination task correlates significantly with severity of depression; greater reaction time reveals greater severity in the depression.

Conclusions: The conclusions of this study reveal neurofunctional alterations in the occipital lobe during visual discrimination and memory task in patients with depression.

MeSH terms

  • Adult
  • Cognition Disorders / diagnosis
  • Cognition Disorders / etiology
  • Cognition Disorders / physiopathology
  • Depressive Disorder / diagnosis
  • Depressive Disorder / physiopathology*
  • Depressive Disorder / psychology*
  • Diagnostic and Statistical Manual of Mental Disorders
  • Electroencephalography
  • Electromyography
  • Event-Related Potentials, P300 / physiology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • Occipital Lobe / physiopathology*
  • Severity of Illness Index