Causal Role of Brain Networks in Internal Attention

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Which parts of the brain are critical for internal attention? Studies have consistently implicated the default network and fronto-parietal control network in internal attention functions. Our prior work demonstrated that damage to the lateral prefrontal cortex, a core component of the fronto-parietal control network, leads to the dysregulation of both external and internal attention. Following these findings, we aim to investigate the causal role of other networks in their corresponding internal attention functions using the neuropsychological approach involving patients with focalized permanent lesions in their brains.

Neural mechanisms underlying internal attention


How does our brain enable us to pay attention to our thoughts? Using intracranial EEG, we revealed that enhanced connectivity in the theta band between the default network and fronto-parietal control network underlies internal attention. Moving forward, a major focus of our lab is to uncover the electrophysiological interactions between large-scale brain networks subserving internal attention, and the differential patterns that emerge as a function of specific types of internal attention. We use both scalp EEG (for whole brain coverage) and intracranial EEG (for superior spatial resolution) to address these questions.

Predicting attention states in real time


Our prior work established the electrophysiological signatures of internal attention in healthy individuals using thought sampling, in which subjects report their attention state. To circumvent the need for subjective self-reports, recent studies have used machine-learning classifiers to predict internal attention without having to rely on thought sampling. Building on this work, we can now examine whether machine learning using these electrophysiological correlates can successfully predict off-line when an individual is attending internally, and whether the best performing model can reliably predict internal attention in real time.

Internal attention in pathologies

Image by Steve Halama

Establishing the electrophysiological signatures of internal attention in healthy young adults prompted the question of whether and how certain populations deviate from these patterns. We previously found that breast cancer survivors who reported cognitive problems after chemotherapy engaged in internal attention more frequently. Moreover, we revealed notable differences in resting EEG power and coherence between patients with bipolar disorder and schizophrenia. These projects highlight the value of using internal attention measures to examine malfunctions in neurological, medical and psychiatric pathologies. Future work in the lab will continue to leverage our knowledge of internal attention in advancing our understanding of neural processes in different pathologies.