Adaptations of motor neural structures' activity to lapses in attention

Cereb Cortex. 2015 Jan;25(1):66-74. doi: 10.1093/cercor/bht206. Epub 2013 Aug 19.


Sustained attention is fundamental for cognition and when impaired, impacts negatively on important contemporary living skills. Degradation in sustained attention is characterized by the time-on-task (TOT) effect, which manifests as a gradual increase in reaction time (RT). The TOT effect is accompanied by changes in relative brain activity patterns in attention-related areas, most noticeably in the prefrontal cortex (PFC) and the right parietal areas. However, activity changes in task-relevant motor structures have not been confirmed to date. This article describes an investigation of such motor-related activity changes as measured with 1) the time course of corticospinal excitability (CSE) through single-pulse transcranial magnetic stimulation; and 2) the changes in activity of premotor (PMC), primary motor (M1), PFC, and right parietal areas by means of near-infrared spectroscopy, during a sustained attention RT task exhibiting the TOT effect. Our results corroborate established findings such as a significant increase (P < 0.05) in lateral prefrontal and right parietal areas activity after the emergence of the TOT effect but also reveal adaptations in the form of motor activity changes--in particular, a significant increase in CSE (P < 0.01) and in primary motor area (M1) activity (P < 0.05).

Keywords: NIRS; motor preparation; sustained attention; time-on-task; transcranial magnetic stimulation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological*
  • Adult
  • Attention / physiology*
  • Electromyography
  • Evoked Potentials, Motor
  • Humans
  • Male
  • Motor Activity / physiology*
  • Motor Cortex / physiology*
  • Muscle, Skeletal / innervation
  • Muscle, Skeletal / physiology
  • Parietal Lobe / physiology*
  • Prefrontal Cortex / physiology*
  • Pyramidal Tracts / physiology*
  • Reaction Time
  • Spectroscopy, Near-Infrared
  • Thumb / innervation
  • Transcranial Magnetic Stimulation
  • Young Adult