Neocortical disconnectivity disrupts sensory integration in Alzheimer's disease

Neuropsychology. 2005 Nov;19(6):728-38. doi: 10.1037/0894-4105.19.6.728.


The cortical pathology in Alzheimer's disease (AD) should lead to the loss of effective interaction between distinct neocortical areas. This study compared 2 conditions within a single sensory integration task that differed in the demands placed on effective cross-cortical interaction. AD patients were impaired in their ability to bind distinct visual features of a stimulus when this binding placed greater demands on cross-cortical interaction (i.e., motion and color) but were not impaired when this binding placed lesser demands on such interaction (i.e., motion and luminance). In contrast, neurologically intact individuals and patients with Huntington's disease were able to effectively bind features under both conditions. These results provide psychophysical support for the presence of functional disconnectivity in AD and demonstrate the utility of AD for investigating the neurocognitive substrates of sensory integration.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / physiopathology*
  • Case-Control Studies
  • Cues
  • Female
  • Humans
  • Huntington Disease / physiopathology
  • Male
  • Neocortex / physiopathology*
  • Neuropsychological Tests / statistics & numerical data
  • Perceptual Disorders / physiopathology*
  • Photic Stimulation / methods
  • Sensation / physiology*
  • Sensory Thresholds / physiology
  • Visual Perception / physiology*