Working Memory Performance under a Negative Affect Is More Susceptible to Higher Cognitive Workloads with Different...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychophysiology

Background:

• Stress significantly impacts cognitive functions, including working memory performance.
• Both task difficulty and external emotional factors act as distinct stressors.
• Neuroimaging reveals that mood influences working memory via hemodynamic activity changes in the prefrontal cortex (PFC).

Purpose of the Study:

• To investigate the interactive effects of affective states and working memory load (WML) on task performance and PFC hemodynamic activity.
• To differentiate hemodynamic responses to workload-induced stress versus situational stress from affective distraction.
• To understand how affective states modulate hemodynamic activity under varying WML.

Main Methods:

• Utilized functional near-infrared spectroscopy (fNIRS) neuroimaging on the PFC of healthy participants.
• Employed n-back tasks to manipulate working memory load (WML).
• Assessed task performance and recorded hemodynamic responses under different affective states and WML conditions.

Main Results:

• Affective stressors induced dominant hemodynamic changes in the medial PFC, while workload-induced stress showed effects in the lateral PFC.
• Increasing WML, particularly under negative affective states, correlated with decreased working memory performance.
• Hemodynamic activity exhibited distinct temporal, spatial, and strength modulations with increasing WML, influenced by affective states.

Conclusions:

• Affective states and WML interact to modulate PFC hemodynamic activity and working memory performance.
• Distinct patterns of hemodynamic activity can differentiate between workload-related and situational affective stress.
• Negative affective states exacerbate performance decrements at higher WML, with corresponding changes in PFC hemodynamic responses.