Working memory load modulates anticipatory postural adjustments during step initiation.

Area of Science:

• Neuroscience
• Biomechanics
• Cognitive Psychology

Background:

• Working memory (WM) influences selective attention.
• Postural standing tasks require attentional resources.
• The impact of WM load on anticipatory postural adjustments (APAs) during step initiation is not well understood.

Purpose of the Study:

• To investigate how WM load affects APAs during step initiation.
• To determine if dual-tasking with a WM task influences postural control during volitional stepping.

Main Methods:

• Sixteen healthy young adults participated in a dual-task study.
• Participants performed stepping tasks (simple/choice reaction time, Flanker task) alone or with a WM task (memorizing 1 or 6 digits).
• APA errors, reaction time (RT), and foot-lift time were measured using force data.

Main Results:

• APA error rates increased significantly under high WM load (6 digits) in incongruent conditions.
• RT and foot-lift time were longer in incongruent conditions compared to congruent ones.
• WM load did not significantly affect RT or foot-lift time.

Conclusions:

• High WM load diminishes cognitive resources available for selective attention and decision-making during step initiation.
• Cognitive load, particularly under demanding attentional conditions, can compromise postural control.
• These findings highlight the interplay between cognitive function and motor control in tasks like stepping.