Stimulation of the anterior thalamus modulates behavior in multiple cognitive domains

Deep Brain Stimulation (DBS) of the ATN (Anterior Thalamic Nuclei) has been used to treat refractory epilepsy. Despite the fact that the ATN plays a crucial role in various cognitive functions, including emotional processing, memory, and spatial navigation, there is limited understanding of the effects of ATN-DBS across multiple cognitive domains.

In order to gain insight into the variability in the cognitive outcome of DBS across tasks and individuals, we investigated effects of ATN-DBS on multiple cognitive functions within the same patients and stimulation parameters.

Eleven patients with refractory epilepsy performed four cognitive behavioral tasks: Emotional Attention Network, Emotional Face Categorization, Word Recognition, and Head Direction. In each task, reaction time, emotional response, or accuracy was measured under on- and off-DBS conditions. Volumes of tissue activated (VTA) were also estimated to investigate target-specific effects on cognition.

ATN-DBS facilitated attention following the presentation of a negative visual stimulus and increased the inclination to perceive a face as expressing an emotion. Furthermore, ATN-DBS disrupted the precision of head direction in the absence of visual cues. Although overall word recognition memory appeared unaffected by ATN-DBS, individual performance changes depended on the location of VTAs. Interestingly, modulation in one cognitive domain did not consistently result in changes in other domains.

ATN-DBS can influence human behavior across multiple cognitive domains, but with varying degrees of individual difference across tasks. The findings emphasize the complexity of the ATN in its involvement in human cognition and provide novel insight into individualized methods for neuromodulation.