Differences between target and non-target probe processing--combined evidence from fMRI, EEG and fMRI-constrained...

Area of Science:

• Cognitive Neuroscience
• Neuroimaging

Background:

• Working memory research shows varied results for target recognition versus non-target rejection.
• Understanding neural dynamics in these tasks is crucial for cognitive function research.

Purpose of the Study:

• To investigate the spatio-temporal neural dynamics of working memory probe processing.
• To differentiate brain activity between target and non-target recognition using fMRI-constrained source analysis.

Main Methods:

• Functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) were employed.
• A delayed match-to-sample task was administered to 20 participants.
• fMRI-constrained source analysis was used to examine neural activity patterns.

Main Results:

• Neural activity initiated in occipital/temporal regions, then involved parietal/frontal areas, and finally pre-SMA (supplementary motor area).
• Left fusiform gyrus showed increased activity for non-targets, potentially for mental imagery.
• Anterior cingulate and pre-SMA were differentially involved in target processing and response execution, linked to conflict management.

Conclusions:

• Working memory probe processing involves a dynamic spatio-temporal network across brain regions.
• Specific brain areas like the left fusiform gyrus, anterior cingulate, and pre-SMA play distinct roles in target/non-target discrimination and response.
• Neural activity patterns are modulated by stimulus position and frequency, impacting conflict management strategies.