Ezzyat, Y., et al. (2023).
Cerebral Cortex, 34(1).
Abstract
Closed-loop direct brain stimulation is a promising tool for modulating neural activity and behavior. However, it remains unclear how to optimally target stimulation to modulate brain activity in particular brain networks that underlie particular cognitive functions. Here, we test the hypothesis that stimulation’s behavioral and physiological effects depend on the stimulation target’s anatomical and functional network properties. We delivered closed-loop stimulation as 47 neurosurgical patients studied and recalled word lists. Multivariate classifiers, trained to predict momentary lapses in memory function, triggered the stimulation of the lateral temporal cortex (LTC) during the study phase of the task. We found that LTC stimulation specifically improved memory when delivered to targets near white matter pathways. Memory improvement was largest for targets near white matter that also showed high functional connectivity to the brain’s memory network. These targets also reduced low-frequency activity in this network, an established marker of successful memory encoding. These data reveal how anatomical and functional networks mediate stimulation’s behavioral and physiological effects, provide further evidence that closed-loop LTC stimulation can improve episodic memory, and suggest a method for optimizing neuromodulation through improved stimulation targeting.
Here are some thoughts:
This article is important to psychologists for several reasons. It moves beyond simply correlating brain activity with mental states by demonstrating a causal pathway, showing that targeted self-regulation of a specific brain area directly alters an otherwise automatic cognitive process like mind-wandering. This challenges purely psychological or environmental explanations for attentional failures and firmly grounds them in modifiable neural processes. For clinical psychology, the significance is profound; many disorders, from ADHD to depression and anxiety, involve dysregulation of the default mode network and intrusive, off-task thoughts. This neurofeedback protocol offers a proof-of-concept for a non-pharmacological intervention that targets a core neural mechanism of these symptoms rather than just their surface manifestations. It also enriches cognitive theory by providing a mechanistic account of how the brain's large-scale networks compete during attention. The finding that individuals can learn to apply an implicit cognitive strategy to control their brain activity, which then changes their conscious experience, opens new avenues for understanding volitional control and developing treatments that blend cognitive training with real-time neural monitoring.








