Thinking can cause forgetting: memory dynamics in creative problem solving

Research on retrieval-induced forgetting has shown that retrieval can cause the forgetting of related or competing items in memory (Anderson, Bjork, & Bjork, 1994). In the present research, we examined whether an analogous phenomenon occurs in the context of creative problem solving. Using the Remote Associates Test (RAT; Mednick, 1962), we found that attempting to generate a novel common associate to 3 cue words caused the forgetting of other strong associates related to those cue words. This problem-solving-induced forgetting effect occurred even when participants failed to generate a viable solution, increased in magnitude when participants spent additional time problem solving, and was positively correlated with problem-solving success on a separate set of RAT problems. These results implicate a role for forgetting in overcoming fixation in creative problem solving.     

Weight-Related Abuse: Impact of Perpetrator-Victim Relationship on Binge Eating and Internalizing Symptoms

Disordered eating and weight problems are associated with experiencing childhood abuse. While weight-related abuse (WRA; teasing and verbal abuse specific to one’s weight) uniquely predicts disordered eating and mood problems in adulthood, the link between WRA and adult outcomes is largely unexplored. Relationships between perpetrators and victims (e.g., family member vs. stranger) have demonstrated an impact on outcomes in research on sexual abuse, and may elucidate important aspects of the relationship between psychopathology and abuse. Thus, we investigated the effect of the perpetrator’s relationship to the victim on disordered eating symptoms in a population of young adults (N = 371) oversampled for current overweight and obesity. Parent perpetration of WRA was the strongest predictor of both depression and abuse-related emotional impact ratings. In contrast, friend and classmate perpetration of WRA were the sole predictors of binge eating and anxiety symptoms, respectively. Results highlight the importance of investigating the impact of multiple types of perpetrators of WRA, as well as the need to examine family and other close relationships in the treatment of disordered eating and internalizing symptoms.     

Effects of electric-shock delivery on schedule-induced water intake: delay of shock, shock intensity, and body-weight loss.

In each of four experiments, schedule-induced water intake in the rat was studied under fixed-time 40-sec food delivery. Experiments I and II studied the temporal relationship between response-independent electric-shock delivery and licking. Shock was delivered under a variable-time 60-sec schedule. A lick-dependent delay was imposed so that licking and shock delivery were systematically separated in time by a minimum of 1 to 15 sec. Over a wide range of shock intensities the data failed to reveal a consistent delay-of-shock effect. Similar shock intensities led to similar reduction of water intake at each delay of shock interval. Experiments III and IV studied the effects of body-weight loss on water intake during independent shock delivery. In Experiment III, shock was delivered under variable-time 60-sec with a minimum separation between shock and licking of 5 sec. In Experiment IV, shock was delivered under variable-time 180-sec. The minimum separation between shock and licking was 10 sec. In each study, the resistance of water intake to suppression by shock delivery increased as the degree of body-weight loss increased. Schedule-induced water intake was affected more by shock when the animal was maintained at 90% of free-feeding weight than at 70%.     

Comparisons between variable-interval and fixed-interval schedules of electric shock delivery

Responding maintained in rats under a variable-interval 35-sec food schedule was suppressed more by 60-sec and 240-sec fixed-interval schedules of shock delivery than by 60-sec and 240-sec variable-interval schedules of shock delivery. When the delivery of shock was preceded by a 5-sec visual stimulus, little overall response suppression was found with either fixed-interval or variable-interval schedules. In a third experiment, the percentage of occasions on which a cue preceded each shock delivery was varied from 0% to 100%. For the fixed-interval shock condition, the most suppression occurred with the 0% treatment, the least with 100%, and an intermediate amount with the 50% treatment. For the variable-interval groups, the most suppression occurred in the 50% condition, the least in the 100% group, and an intermediate amount with 0%.     

Effects of diazepam on schedule-controlled and schedule-induced behavior under signaled and unsignaled shock.

Schedule-controlled lever pressing and schedule-induced licking were studied in rats under a multiple fixed-interval fixed-interval schedule of food reinforcement upon which was superimposed a multiple variable-time variable-time schedule of electric-shock delivery. Shocks were signaled in one component of the multiple schedule and unsignaled in the other. The effects of diazepam upon the suppression of behavior during the signal (conditioned suppression) and during signaled and unsignaled shock (differential suppression) were studied under several shock intensities (Experiment 1) and at increased body weight (Experiment 2). In each study, diazepam led to dose-dependent increases in the rate of pressing and licking during signaled and unsignaled shock, but had little effect on conditioned suppression. the rate-enhancing effects of diazepam depended upon the intensity of shock, nature of the response, and whether or not shocks were signaled. The data was discussed in terms of (1) implications for understanding the effects of signaled and unsignaled shock on behavior, (2) the effects of diazepam on behavior suppressed by response-independent shock, and (3) comparison between operant and schedule-induced behavior.     

Multilevel modeling of two cyclical processes: extending differential structural equation modeling to nonlinear coupled systems

The authors present a dynamical multilevel model that captures changes over time in the bidirectional, potentially asymmetric influence of 2 cyclical processes. S. M. Boker and J. Graham's (1998) differential structural equation modeling approach was expanded to the case of a nonlinear coupled oscillator that is common in bimanual coordination studies in which participants swing hand-held pendulums but is also applicable to social systems in general. The authors' nonlinear coupled oscillator model decomposed the fluctuations into a competitive component, unique to each individual variable, and a cooperative component that captured bidirectional influence. The authors' model also generated an index of the symmetry/asymmetry of bidirectional influence. Together, the models are useful quantitative tools for the study of interacting, changing processes.