Implicit and explicit memory for affective passages in temporal lobectomy patients.

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.

Affective tasks elicit material-specific memory effects in temporal lobectomy patients.

Eighteen patients who had undergone a right (9) or left (9) temporal lobectomy (RTL, LTL) including removal of the amygdala and hippocampus were evaluated. Sixteen male and sixteen female undergraduate subjects were evaluated for normative comparison. All subjects were administered Verbal (words) and Visual (faces) paired associates tasks. The present study sought to evaluate material-specific memory after temporal lobectomy, and to compare affective versus neutral memory as well. Thus, there were 4 tasks: Verbal Affective, Verbal Neutral, Visual Affective, and Visual Neutral. The material-specific effects of better Verbal memory performance by the RTL subjects compared to the LTL subjects and better Visual memory performance by the LTL subjects than the RTL subjects were only significant for the Affective tasks, and not the Neutral tasks. Perhaps adding an affective dimension to the material-specific memory tasks engaged the amygdala in addition to the other structures known to be important in memory. A strong interpretaion of the present data is made difficult by task differences and the low average IQ and possible reorganization of function that may have occurred in the patient sample.

Gender differences in implicit and explicit memory for affective passages.

Thirty-two participants were administered 4 verbal tasks, an Implicit Affective Task, an Implicit Neutral Task, an Explicit Affective Task, and an Explicit Neutral Task. For the Implicit Tasks, participants were timed while reading passages aloud as quickly as possible, but not so quickly that they did not understand. A target verbal passage was repeated three times, and alternated with other previously unread passages. The Implicit Affective and Neutral passages had strong affective or neutral content, respectively. The Explicit Tasks were administered at the end of testing, and consisted of multiple choice questions regarding the passages. Priming effects in terms of more rapid reading speed for the target compared to non-target passages were seen for both the Implicit Affective Task and the Implicit Neutral Task. Overall reading speed was faster for the passages with neutral compared to affective content, consistent with studies of the emotional Stroop effect. For the Explicit memory tasks, overall performance was better on the items from the repeated passage, and on the Affective compared to Neutral Task. The male subjects showed greater priming for affective material than female subjects, and a greater gain than female subjects in explicit memory for affective compared to neutral material.

Perception and priming of affective faces in temporal lobectomy patients.

Eighteen patients who had undergone standard anterior temporal lobectomy including removal of the amygdala and hippocampus (9 left, LTL; 9 right, RTL) were administered an Affective Task composed of faces depicting negative emotions, and a Neutral Task consisting of faces with different lighting and orientation conditions. Both tasks required judgment of poser identity and indication of decision by pressing a reaction time button. Subjects were shown a set of photos in an Exposure Phase, followed by a Test Phase in which the photos previously seen (primed) were mixed with new photos (unprimed). The LTL subjects performed better than the RTL subjects for both the RT and accuracy data in both the Neutral and Affective Tasks. The performance of the LTL subjects improved when the task had an affective component (Affective vs. Neutral Task), whereas the RTL subjects did not show this benefit. In terms of specific emotions, for the LTL group, pain was responded to most slowly and shock was the emotion responded to most quickly, and significantly more quickly than in the RTL group. Fear was the emotion responded to most slowly by the RTL group and significantly more slowly when compared to the LTL group. The only priming effect was a reverse priming for pain, such that stimuli seen before were respondedto less accurately than new stimuli; this was not related to lesion side.