Nicotine Produces a Within-Subject Enhancement of Contextual Fear Conditioning in C57BL/6 Mice Independent of Sex

Nicotine enhances learning including contextual fear conditioning. The present study extends previous work on nicotine and conditioned fear to examine the nature of nicotine's enhancement of contextual fear conditioning and sex differences in contextual fear conditioning in C57BL/6 mice using a within-subjects design. Mice were trained by pairing of an auditory stimulus of 80 dB, 6 cps train of broad-band clicks conditioned stimulus (CS) with a 2 sec., 0.35 mA shock unconditioned stimulus (US). Twenty-four hours later mice were tested for freezing in the original context, and one hour later mice were retested in the same context. A 0.5 mg/kg dose of nicotine was given either for three conditions: (1) before training, testing, and retesting; (2) before training and retesting; and (3) before retesting only. The use of a within-subjects design allowed for testing if nicotine would produce state-dependent deficits in contextual fear conditioning. Nicotine did enhance contextual fear conditioning in the groups that received nicotine for both training and testing. Nicotine, however, did not alter freezing when given on training but not testing or testing but not training. No sex differences, however, existed for conditioning or for nicotine's effects on conditioning. These results suggest that nicotine enhanced acquisition and retrieval processes but did not produce state-dependent deficits when administered just for training or just for testing.     

Repentance and forgiveness: the undoing of time

Mass death resulting from war, starvation, and disease as well as the vicissitudes of extreme poverty and enforced sexual servitude are recognizably pandemic ills of the contemporary world. In light of their magnitude, are repentance, regret for the harms inflicted upon others or oneself, and forgiveness, proferring the erasure of the guilt of those who have inflicted these harms, rendered nugatory? Jacques Derrida claims that forgiveness is intrinsically rather than circumstantially or historically impossible. Forgiveness, trapped in a paradox, is possible only if there is such a thing as the unforgivable. “Thus, forgiveness, if there is such a thing,” can only exist as exempt from the law of the possible. Does this claim not open the way for hopelessness and despair? More troubling for Derrida is his concession that forgiveness may be necessary in the realm of the political and juridical. If so, is not the purity of the impossibility of forgiveness so crucial for him, contaminated? In pointing to some of the difficulties in Derrida’s position, I shall appeal to Vladimir Jankelevitch’s distinction between the unforgivable and the inexcusable. I shall also consider the significance of repentance in the theological ethics of Emmanuel Levinas and Max Scheler. Forgiveness, I conclude, is vacuous without expiation, a position that can be helpfully understood in the context of Judaism’s analysis of purification and acquittal in the Day of Atonement liturgy. I argue that what disappears is Derrida’s assurance of the impossibility of forgiveness, a disappearance that allows for hope.     

Stress on the dance floor: the cortisol stress response to social-evaluative threat in competitive ballroom dancers

The social self-preservation theory states that humans have a fundamental motivation to preserve the social self and that threats to the social self perturb biological markers such as cortisol. Five studies were designed to examine the cortisol response to competitive ballroom dancing as a paradigm for real-life social-evaluative threat. Competitive dancing produced substantial increases in cortisol compared to a control day. These increases were not due to the physical strain of dancing and were greater than those found during social-evaluative laboratory stressors. Responses did not habituate across competitions and were mostly elevated under highly focused conditions of threat (couple vs. group competition). These findings support the notion of a social self-preservation system that is physiologically responsive to threats to the social self.     

Pattern recognition and eye-movement parameters

Pattern perception was studied by recording eye movements while Ss visually scanned nine simultaneously presented patterns of asterisks for target patterns. Pattern parameters studied were: similarity of target patterns to non-target patterns (absolute difference in the number of elements), number of target elements, and frequency of targets. Systematic correlation between the first two pattern parameters and eyemovement parameters were found. Mean duration and mean number of fixations on targets and also on non-targets increased with increased similarity. Mean duration and mean number of fixations increased on targets with an increase in the number of target elements. Non-target patterns were perceived more auicfely than targets. Fixations of longer duration were required to perceive the original target than to identify the other target patterns subsequently. The eye-movement results provide the basis for developing inferences about higher order processing of visual stimuli.