Caffeine does not modulate inhibitory control.

Area of Science:

• Cognitive Neuroscience
• Psychopharmacology

Background:

• Caffeine is a widely consumed psychoactive substance with known effects on cognitive function.
• Understanding caffeine's impact on inhibitory control is crucial for its application in cognitive enhancement and understanding its neural mechanisms.

Purpose of the Study:

• To investigate the effects of a 3mg/kg body weight (BW) dose of caffeine on behavioral indices of response inhibition.
• To differentiate caffeine's effects on response inhibition from other cognitive processes like attention and processing speed.

Main Methods:

• Three double-blind, placebo-controlled, within-subjects experiments were conducted.
• Participants completed a modified AX version of the Continuous Performance Test (AX-CPT), the stop task, and the flanker task.
• Behavioral data were analyzed to assess response inhibition and related cognitive functions.

Main Results:

• The AX-CPT suggested potential improvements in response inhibition, but these could be attributed to attentional changes.
• The stop task and flanker task showed negligible effects of caffeine on selective response suppression and overall performance.
• A global effect on processing speed was observed in the stop task, not specific to response inhibition.

Conclusions:

• Caffeine at a 3mg/kg BW dose did not significantly modulate either active or reactive inhibitory control in healthy participants.
• The findings suggest that caffeine's cognitive effects may not directly target inhibitory control mechanisms but could influence broader cognitive processes.
• Results are discussed in relation to neural circuits of inhibitory control and potential caffeine-induced strategic adjustments.