Bidirectional modulation of human emotional conflict resolution using intracranial stimulation

Abstract

The ability to regulate emotions in the service of meeting ongoing goals and task demands is a key aspect of adaptive human behavior in our volatile social world. Consequently, difficulties in processing and responding to emotional stimuli underlie many psychiatric diseases ranging from depression to anxiety, the common thread being effects on behavior. Behavior, which is made up of shifting, difficult to measure hidden states such as attention and emotion reactivity, is a product of integrating external input and latent mental processes. Directly measuring, and differentiating, separable hidden cognitive, emotional, and attentional states contributing to emotion conflict resolution, however, is challenging, particularly when only using task-relevant behavioral measures such as reaction time. State-space representations are a powerful method for investigating hidden states underlying complex systems. Using state-space modeling of behavior, we identified relevant hidden cognitive states and predicted behavior in a standardized emotion regulation task. After identifying and validating models which best fit the behavior and narrowing our focus to one model, we used targeted intracranial stimulation of the emotion regulation-relevant neurocircuitry, including prefrontal structures and the amygdala, to causally modulate separable states. Finally, we focused on this one validated state-space model to perform real-time, bidirectional closed-loop adaptive stimulation in a subset of participants. These approaches enable an improved understanding of how to sample and understand emotional processing in a way which could be leveraged in neuromodulatory therapy for disorders of emotional regulation.

CLoSES: A platform for closed-loop intracranial stimulation in humans

“…An encoder/decoder model based on theta band coherence input features across regions was used to estimate hidden state. Details on the implementation of ECR can be found else where ( Paulk et al, 2020 ). During ECR CLoSES-SEM was configured on the following way: Theta band filter, coherence, detection if boundary of state estimates were above/below respective thresholds, and stimulation on the following trial (following image onset).…”

“…If another computer is calculating an important feature, e.g. a task performance variable estimated directly from behavior ( Paulk et al, 2020 ) can be connected to another AINP for si-multaneous real-time visualization of neuronal and behavioral state es-timates.…”

Closed loop enhancement and neural decoding of human cognitive control

“…The same framework could also be applied to other cognitive/emotional problems, e.g. monitoring and enhancement of learning 57,58 or emotion dysregulation 59,60 . Although substantial challenges remain before these results can be directly applied in the clinic, they could be the basis of a novel and highly specific approach for intervention in human neuro-psychiatric disease.…”

“…We did not test any other stimulation sites for their effects on MSIT performance, because we had a specific hypothesis regarding the internal capsule. Other sEEG electrodes were stimulated in separate experiments in these same participants, but those are reported elsewhere 59,68,69 and the outcomes of those experiments did not influence the present study.…”