Stimulus conditions influencing the development of tolerance to repeated cold exposure in rats

Tolerance to an environmental cold challenge in rats is eliminated when cold exposure occurs in a context different from the adaptation context, indicating that learning mechanisms play a role in thermoregulation (Riccio, MacArdy, & Kissinger, 1991). This finding, analogous to outcomes obtained with drug tolerance, was investigated in the present study. Experiment 1 demonstrated that a change in both proximal and distal contextual cues disrupts an established cold adaptation, an outcome consistent with the view that associative processes contribute to the tolerance. In Experiment 2, although cold tolerance persisted over a 7-day retention interval, the disruption of tolerance by a shift in context was attenuated with the delay of testing. This finding suggests that the precise stimulus attributes of the context were forgotten over the interval. Experiment 3 demonstrated that cold-tolerance disruption is due to the actual change in context and not to novelty of the test context. Experiment 4 showed that changing the context associated with each cold exposure impaired the development of tolerance. The results of these experiments provide additional evidence that cold tolerance is regulated at least partially by associative learning processes.     

Amnesia induced by hypothermia as a function of treatment-test interval and recooling in rats

In Experiment I, a repeated tests procedure was employed to assess hypothermia-induced amnesia of a footshock experience. Rats tested 4 h after training treatment showed no memory loss, but amnesia was present at 24 h. Although recovery of memory was obtained when the same animals were cooled 2 h prior to a 50-h test, repeated testing also tended to attenuate amnesia. In Experiment II, independent groups were tested at 6 or 50 h after training treatment. Again, memory of the footshock was present at the short, but not at the long, interval. Recooling shortly prior to the 50-h test eliminated amnesia. Experiment III indicated that the return of memory produced by recooling did not persist if testing was delayed. These findings suggested that hypothermia may function as an important contextual cue for memory retrieval.     

SAIL: A School Where the Arts Connect with Real Learning

Increasing numbers of educators and parents are recognizing that traditional educational models can be unsupportive and, at times, alienating to children, particularly those with special needs. SAIL, a public charter* school in Washington, DC, for children 5–12 years old (often labelled as having special needs), has used an innovative education model that infuses the arts in learning experiences. Providing a unique physical and social environment, an arts‐based curriculum, and authentic assessment methods, SAIL is steadily achieving or exceeding its goals after two years of operation. This paper describes the work of SAIL. ^* A charter school is an autonomously governed public school designed to educate students in non‐traditional ways and obligated by its charter to monitor and record its performance.     

Counterconditioning of memory in rats

Two experiments examined the counterconditioning of an aversively motivated response in rats. Presentation of a highly palatable sugar solution (maltose in Experiment 1; sucrose in Experiment 2) to thirsty rats was used as the counterconditioning treatment. In Experiment 1, the counterconditioning procedure was found to be effective in modifying both a newly acquired and a cue-reactivated fear memory. In Experiment 2, the counterconditioning effect was shown to occur when the fear memory was reactivated with a noncontingent exposure to the unconditioned stimulus rather than the conditioned stimulus. This outcome supports the interpretation of counterconditioning as a modification of some central representation of the original training memory, rather than the acquisition of a competing peripheral response. The methodological implications of the present approach to counterconditioning are considered.