Fine motor movements while drawing during the encoding phase of a serial verbal recall task reduce working memory...

Area of Science:

• Cognitive Psychology
• Human Factors
• Neuroscience

Background:

• The time-based resource-sharing (TBRS) model posits that tasks demanding sustained attention interfere with working memory.
• Understanding how different motor tasks impact cognitive functions like working memory is crucial for optimizing task design and performance.
• Previous research suggests secondary tasks can interfere with working memory, but the specific effects of movement type remain less understood.

Purpose of the Study:

• To investigate the differential effects of discrete versus continuous fine motor movements on concurrent verbal serial recall.
• To test the hypothesis that continuous movements impose a greater cognitive load, thereby more significantly impairing working memory performance than discrete movements.

Main Methods:

• Participants performed a verbal serial recall task (recalling lists of six spoken words) under three conditions: listening only, drawing a discrete shape (star), and drawing a continuous shape (circle).
• Kinematic data (movement size, speed, duration, pauses) were collected during the drawing conditions.
• Recall performance was analyzed across serial positions and compared between conditions.

Main Results:

• Overall word recall was significantly lower in both drawing conditions compared to the listening-only condition.
• Continuous movement (circle drawing) resulted in significantly worse recall than the listening-only condition, particularly at mid-serial positions (position 5).
• While discrete movements also impaired recall, the effect was less pronounced than with continuous movements. Movement duration and pauses in discrete movements correlated with recall.

Conclusions:

• Fine motor movements, especially continuous ones, impair working memory performance by capturing attentional resources.
• The type of movement is critical; continuous movements appear to divert more cognitive resources than discrete movements, aligning with the TBRS model.
• These findings highlight the importance of considering the nature of concurrent motor tasks when assessing cognitive load and working memory capacity.