Spoken Recall Reveals Lexical and Mnemonic Function Differences in Temporal Lobe Epilepsy Patients

In a study investigating the differences in lexical and mnemonic function between Temporal Lobe Epilepsy (TLE) patients and healthy controls, researchers examined spoken recall during a Famous Faces biographical memory task. The results revealed that while lexical output did not distinguish TLE patients from healthy controls, other speech features were linked to language and memory performance.

The study involved 81 adults, with 51 having TLE and 30 serving as healthy controls. Lexical measures, including word counts and the lexical index (which compares rare to common words), did not differ between the groups. However, in TLE patients, the lexical index correlated with performance on the Boston Naming Test (BNT) and the Montreal Cognitive Assessment (MoCA) scores.

Compared to healthy controls, TLE patients produced shorter utterances (5.54 ± 2.50 vs. 6.59 ± 2.63 words), shorter pauses (0.61 ± 0.21 vs. 0.67 ± 0.22 seconds), and more frequent pauses (10.81 ± 3.30 vs. 9.29 ± 3.59 times). Additionally, higher education levels were associated with longer utterances, longer pauses, and lower pause frequency in TLE patients, but no evidence of a diagnosis-by-education interaction was found.

Interestingly, faster utterance rates were associated with better biographical recall in both groups, while higher pause rates were linked to worse recall specifically in TLE patients. These findings suggest that automated speech analysis could serve as a digital behavioral biomarker for word-finding difficulty in neurologic populations, including TLE patients.