Baseline activity predicts working memory load of preceding task condition.

Area of Science:

• Neuroscience
• Cognitive Neuroscience

Background:

• The traditional view of brain resting state is challenged by evidence of cognitive processes influencing subsequent rest.
• Activity in posterior parietal and medial prefrontal cortex is known to be modulated by prior experimental conditions.

Purpose of the Study:

• To identify brain areas exhibiting working memory-dependent patterns during subsequent baseline periods.
• To determine the specificity of these patterns to the preceding experimental condition.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used with 94 subjects performing a 0-back and a 2-back n-back task.
• Univariate analysis examined activity changes between baseline conditions following each task.
• Multivariate analysis employed Gaussian process classifiers to recognize task conditions from baseline fMRI data.

Main Results:

• Differential activity was observed in the thalamus, putamen, and postcentral gyrus, in addition to expected changes in precuneus and medial prefrontal cortex.
• Task-related patterns were detected in baseline fMRI data, achieving a 70% recognition rate for the preceding condition.
• These findings indicate that the impact of cognitive tasks on brain rest is significant and regionally specific.

Conclusions:

• Cognitive tasks exert a strong and specific influence on subsequent brain baseline activity in various regions.
• This influence is not confined to the default mode network, suggesting broader neural effects.
• The brain retains task-specific information even during passive rest periods.