Influence of Delay Period Duration on Inhibitory Processes for Response Preparation

Cereb Cortex. 2016 Jun;26(6):2461-70. doi: 10.1093/cercor/bhv069. Epub 2015 Apr 16.


In this study, we examined the dynamics of inhibitory preparatory processes, using a delayed response task in which a cue signaled a left or right index finger (Experiment 1) or hand (Experiment 2) movement in advance of an imperative signal. In Experiment 1, we varied the duration of the delay period (200, 500, and 900 ms). When transcranial magnetic stimulation (TMS) was applied 100 ms before the imperative, motor evoked potentials (MEPs) elicited in the first dorsal interosseous were strongly inhibited. For delays of 500 ms or longer, this inhibition was greater when the targeted muscle was selected compared with when it was not selected. In contrast, the magnitude of inhibition just after the cue was inversely related to the duration of the delay period, and the difference between the selected and nonselected conditions was attenuated. In Experiment 2, TMS and peripheral nerve stimulation procedures were used during a 300-ms delay period. MEPs in the flexor carpi radialis for both selected and nonselected conditions were inhibited, but without any change in the H-reflex. Taken together, these results reveal the dual influence of temporal constraints associated with anticipation and urgency on inhibitory processes recruited during response preparation.

Keywords: H-reflex; MEP; choice task; inhibition; preparation.

Publication types

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

MeSH terms

  • Adult
  • Anticipation, Psychological / physiology
  • Choice Behavior / physiology
  • Electric Stimulation
  • Electromyography
  • Evoked Potentials, Motor / physiology
  • Female
  • Fingers / physiology
  • H-Reflex / physiology
  • Humans
  • Inhibition, Psychological*
  • Male
  • Motor Cortex / physiology*
  • Muscle, Skeletal / physiology
  • Neuropsychological Tests
  • Peripheral Nerves / physiology
  • Psychomotor Performance / physiology*
  • Pyramidal Tracts / physiology*
  • Time Factors
  • Transcranial Magnetic Stimulation
  • Young Adult