Dissociable mechanisms underlying individual differences in visual working memory capacity

• Published in: NeuroImage (Orlando, Fla.) Fla.), 2014-10, Vol.99, p.197-206
• Main Authors: Gulbinaite, Rasa, Johnson, Addie, de Jong, Ritske, Morey, Candice C., van Rijn, Hedderik
• Format: Article
• Language: English
• Subjects: Attention - physiology; Biological and medical sciences; Brain; Cognitive ability; Conflict (Psychology); Electroencephalography; Evoked Potentials, Visual - physiology; Female; Fundamental and applied biological sciences. Psychology; Humans; Individuality; Male; Memory; Memory, Short-Term - physiology; Psychomotor Performance - physiology; Reaction Time - physiology; Theta Rhythm - physiology; Vertebrates: nervous system and sense organs; Visual Perception - physiology; Visual task performance; Young Adult
• ISSN: 1053-8119; 1095-9572
• DOI: 10.1016/j.neuroimage.2014.05.060

Individuals scoring relatively high on measures of working memory tend to be more proficient at controlling attention to minimize the effect of distracting information. It is currently unknown whether such superior attention control abilities are mediated by stronger suppression of irrelevant information, enhancement of relevant information, or both. Here we used steady-state visual evoked potentials (SSVEPs) with the Eriksen flanker task to track simultaneously the attention to relevant and irrelevant information by tagging target and distractors with different frequencies. This design allowed us to dissociate attentional biasing of perceptual processing (via SSVEPs) and stimulus processing in the frontal cognitive control network (via time–frequency analyses of EEG data). We show that while preparing for the upcoming stimulus, high- and low-WMC individuals use different strategies: High-WMC individuals show attentional suppression of the irrelevant stimuli, whereas low-WMC individuals demonstrate attentional enhancement of the relevant stimuli. Moreover, behavioral performance was predicted by trial-to-trial fluctuations in strength of distractor-suppression for high-WMC participants. We found no evidence for WMC-related differences in cognitive control network functioning, as measured by midfrontal theta-band power. Taken together, these findings suggest that early suppression of irrelevant information is a key underlying neural mechanism by which superior attention control abilities are implemented. •High working memory capacity (WMC) is associated with better attention control.•Mechanisms behind WMC-related differences in attentional control remain unknown.•We used EEG frequency tagging to track attention for relevant and distracting information.•Suppression of distractors is a key underlying mechanism for efficient attention control.