Eighteen temporal lobectomy patients (9 left, LTL; 9 right, RTL) were administered four verbal tasks, an Affective Implicit Task, a Neutral Implicit Task, an Affective Explicit Task, and a Neutral Explicit Task. For the Affective and Neutral Implicit Tasks, participants were timed while reading aloud passages with affective or neutral content, respectively, as quickly as possible, but not so quickly that they did not understand. A target verbal passage was repeated three times; this target passage was alternated with other previously unread passages, and all passages had the same number of words. The Explicit Affective and Neutral Tasks were administered at the end of testing, and consisted of multiple choice questions regarding passage content.
Verbal priming effects in terms of improved reading speed with repetition for the target but not non-target passages were found for patients with both left and right temporal lobectomies. As in the Burton, Rabin et al. [Burton, L., Rabin, L., Vardy, S.B., Frohlich, J., Wyatt, G., Dimitri, D., Constante, S., Guterman, E. (2004). Gender differences in implicit and explicit memory for affective passages. Brain and Cognition, 54(3), 218–224] normative study, there were no interactions between this priming effect and affective/neutral content. For the explicit tasks, items from the repeated passages were remembered better than the unrepeated passages, and there was a trend for information from the affective passages to be remembered better than the neutral passages, similar to the normative pattern.
The RTL group did not show the normative pattern of slower reading speed for affective compared to neutral passages that the LTL group showed. Thus, the present findings support the idea that intact right medial temporal structures are important for affective content to influence some aspects of verbal processing.
A variety of studies have evaluated material-specific explicit memory effects after temporal lobectomy. These studies generally report that after left temporal lobectomy including removal of the hippocampus and amygdala, there are decrements in verbal memory performance, and after right temporal lobectomy, there are decrements in visual memory performance (reviewed by Jones-Gotman, 1987, Leritz et al., 2006, Naugle, 1991 and Phillips and McGlone, 1995). The verbal memory deficits seen after left temporal lobectomy include impaired memory for prose passages, words, and verbal paired associates, and the visual memory deficits include impaired recall of geometric designs and faces (i.e., Milner, 1967, Novelly et al., 1984, Phillips and McGlone, 1995, Rausch and Crandall, 1982 and Savage et al., 1992).
