Epilepsia. 2023 Dec 20. doi: 10.1111/epi.17871. Online ahead of print.
ABSTRACT
OBJECTIVE: Statistical learning, the fundamental cognitive ability of humans to extract regularities across experiences over time, engages the medial temporal lobe in the healthy brain. This leads to the hypothesis that statistical learning may be impaired in patients with epilepsy (PWE) involving the temporal lobe, and that this impairment could contribute to their varied memory deficits. In turn, studies done in collaboration with PWE, that evaluate the necessity of medial temporal lobe circuitry through disease and causal perturbations, provide an opportunity to advance basic understanding of statistical learning.
METHODS: We implemented behavioral testing, volumetric analysis of the medial temporal lobe substructures, and direct electrical brain stimulation to examine statistical learning across a cohort of 61 PWE and 28 healthy controls.
RESULTS: We found that behavioral performance in a statistical learning task was negatively associated with seizure frequency irrespective of seizure origin. The volume of hippocampal subfields CA1 and CA2/3 correlated with statistical learning performance, suggesting a more specific role of the hippocampus. Indeed, transient direct electrical stimulation of the hippocampus disrupted statistical learning. Furthermore, the relationship between statistical learning and seizure frequency was selective as behavioral performance in an episodic memory task was not impacted by seizure frequency.
SIGNIFICANCE: Overall, these results suggest that statistical learning may be hippocampally dependent and that the statistical learning task could serve as a clinically useful behavioral assay of seizure frequency that may complement existing approaches such as seizure diaries. Simple and short statistical learning tasks may thus provide patient-centered endpoints for evaluating the efficacy of novel treatments in epilepsy.
PMID:38116686 | DOI:10.1111/epi.17871
