Abstracts

New episodic memory or the ability to retain new information has been the primary focus of memory research with temporal lobe epilepsy (TLE) patients. Semantic memory has received less attention. Semantic memory refers to culturally shared information and factual knowledge that has no specific temporal-spatial context. This study of TLE patients and controls assessed memory for news events reported in the United States during the 1990s. The goal of the investigation was to further elucidate the status of semantic memory ability in patients with TLE. The participants were 27 healthy controls and 14 temporal lobe epilepsy (TLE) patients. Individuals with left, right or bilateral TLE were included. The two groups did not differ in mean age or level of education. Because there was a significant between group difference in IQ, this variable was used as a covariate in the statistical analyses (see Results).
The Transient News Events Test (O[apos]Connor, M. G. et al., 2000) was administered to both groups. Because the majority of the participants were relatively young, only data for news events from the 1990s will be reported here. A question was asked about six news events that occurred between 1991 and 1998. For each event, a participant received one point for each of the two critical aspects that was correctly identified. If necessary, one or two recognition questions were presented in a forced choice format. A participant received one point for each recognition question answered correctly. Thus, the maximum score was 12 for the free recall and recognition components of the test. All participants were at least 15 years old in 1991. Assessment of the participants began in late 2002. With IQ as a covariate, there was a significant group difference for both the free recall and recognition TNET scores ([italic]p[/italic] [lt] .05). The TLE goup scored lower on both components of the test. The relationship between the TNET and demographic, seizure history, and cognitive test variables was examined. This analysis revealed that the Boston Naming Test (BNT) and a new Famous Faces Naming Test were the measures that correlated best with TNET recall and recognition performance. TLE patients have not often been assessed on measures of semantic memory or culturally shared knowledge. In this study, TLE patients performed worse than controls on both the recall and recognition components of a news events test covering widely reported stories from the 1990s. Interestingly, TNET performance correlated more strongly with other tests of semantic memory (BNT, Famous Faces Naming) compared to measures of episodic memory (WMS-III), IQ and other cognitive abilities and demographic and seizure history variables. Semantic memory and its association with episodic memory and mesial versus lateral temporal lobe pathology merits further study in TLE patients. (Supported by K23 NS42251, NS 37738, and MO1 RR03186 (GCRC))