Miguel Angel Mañas Rodríguez

Comparison between an acceptance-based and a cognitive-control-based protocol for coping with pain

This study compares specific acceptance-based strategies and cognitive-control-based strategies for coping with experimentally induced pain. Forty participants were randomly assigned to an acceptance-based protocol (ACT), the goal of which was to disconnect pain-related thoughts and feelings from literal actions, or to a control-based protocol (CONT) that focused on changing or controlling pain-related thoughts and feelings. Participants took part in a nonsense-syllables-matching task that involved successive exposures to increasingly painful shocks. In both conditions, the task involved an overall value-oriented context that encouraged the participants to continue with the task despite the exposure to pain. At times throughout the task, participants were asked to choose to continue with the task and be shocked or stop the task and avoid being shocked. Each choice had specific costs and benefits. Participants performed the task twice, both before and after receiving the assigned experimental protocol. Two measures were obtained at pre- and post-intervention: tolerance of the shocks and self-reports of pain. ACT participants showed significantly higher tolerance to pain and lower believability of experienced pain compared to the CONT condition. Conceptual and clinical implications are discussed.

Acquisition of schedule-induced polydipsia by rats in proximity to upcoming food delivery

Food-deprived rats that receive intermittent delivery of small amounts of food develop excessive drinking-specifically, schedule-induced polydipsia (SIP). A main characteristic of SIP is its occurrence at the beginning of interfood intervals. The purpose of this study was to demonstrate that SIP can be developed toward the end of interfood intervals, in closer proximity to upcoming than to preceding food delivery. In Experiment 1, two groups were exposed to a fixed-time (FT) 30-sec food schedule with water available during the first or the last 15 sec of each interfood interval. Two additional groups, which had access to water throughout, were exposed to FT 30-sec or FT 15-sec schedules of food presentation. The FT 30-sec group with free access to water developed the highest level of intake; similar and intermediate levels were induced in all the remaining groups. In Experiment 2, three groups of rats were exposed to an FT 90-sec food schedule with water available during the first, the second, or the last 30 sec of each interfood interval. One additional group with access to water throughout was exposed to the FT 90-sec schedule of food presentation. The group with free access to water developed a higher level of consumption than did the other groups, but by the end of training none of the four groups showed statistical differences in polydipsic drinking. Results show that adjunctive drinking can be developed in proximity to upcoming food delivery even with long interfood intervals.