Working Memory Load Selectively Influences Response Inhibition in a Stop Signal Task

Area of Science:

• Cognitive Neuroscience
• Psychology

Background:

• Inhibitory control is a crucial executive function.
• The stop signal task and race model are used to measure inhibitory control via stop signal reaction time (SSRT).
• Executive functions, including inhibitory control and working memory, are vital for goal-directed behavior.

Purpose of the Study:

• To investigate the impact of working memory load on inhibitory control.
• To determine if working memory influences the speed of response inhibition (STOP process).
• To examine the relationship between working memory capacity and SSRT under varying cognitive loads.

Main Methods:

• Participants performed a stop signal task under low and high working memory load conditions.
• A dual-task paradigm was employed, combining the stop signal task with working memory challenges.
• Working memory capacity was assessed independently.

Main Results:

• Stop signal reaction time (SSRT) was significantly longer under high working memory load compared to low load.
• The GO process, responsible for response initiation, remained unaffected by working memory load.
• Individual differences in working memory capacity did not explain the observed changes in SSRT across load conditions.

Conclusions:

• Increased demands on working memory impair inhibitory control.
• The STOP process, but not the GO process, is sensitive to working memory load.
• These findings highlight the interplay between working memory and inhibitory control within executive functions.