A comparison of latent inhibition and learned irrelevance pre-exposure effects in rabbit and human eyeblink conditioning

The learning of an association between a CS and a US can be retarded by unreinforced presentations of the CS alone (termed latent inhibition or LI) or by un-correlated presentations of the CS and US (termed learned irrelevance or LIRR). In rabbit eyeblink conditioning, there have been some recent failures to replicate LI. LIRR has been hypothesized as producing a stronger retardation effect than LI based on both empirical studies and computational models. In the work presented here, we examined the relative strength of LI and LIRR in eyeblink conditioning in rabbits and humans. In both species, a number of pre-exposure trials sufficient to produce LIRR failed to produce LI (Experiments 1 & 3). Doubling the number of CS pre-exposures did produce LI in rabbits (Experiment 2), but not in humans (Experiment 4). LI was demonstrated in humans only after manipulations including an increased inter-trial interval or ITI (Experiment 5). Overall, it appears that LIRR is a more easily producible pre-exposure retardation effect than LI for eyeblink conditioning in both rabbits and humans. Several theoretical mechanisms for LI including the conditioned attention theory, stimulus compression, novelty, and the switching theory are discussed as possible explanations for the differences between LIRR and LI. Overall, future work involving testing the neural substrates of pre-exposure effects may benefit from the use of LIRR rather than LI.     

Providing a treatment rationale for PTSD: Does what we say matter?

Little is understood about the factors that influence a woman's preference for a particular type of treatment after an assault. Furthermore, it remains unclear the extent to which providing detailed information such as the mechanism underlying a treatment or its side effects can affect a client's treatment preference for psychotherapy or pharmacotherapy. The current study of 324 women with varying degrees of trauma exposure and posttraumatic stress symptoms experimentally manipulated the content of treatment rationales for two common PTSD treatments: sertraline (SER) and prolonged exposure (PE). Specifically, both information regarding the hypothesized mechanism of the treatment and treatment side effects were manipulated. In general, personal reactions were more positive and credibility was stronger for psychotherapy than pharmacotherapy. This preference for the psychotherapy persisted regardless of specific information presented in the treatment rationale. For those reporting heightened hyperarousal and those of minority status, there was an increased likelihood of more positive reactions to sertraline. The results highlight assessment of treatment-related beliefs and preferences early on in the therapeutic process. Ultimately, understanding the factors that shape treatment preferences may contribute to the development of personalized treatment strategies that integrate preferences and attitudes about treatment as a way of bolstering adherence and outcome.     

Monitoring Online Training Behaviors: Awareness of Electronic Surveillance Hinders E‐Learners1

Web‐based training programs commonly capture data reflecting e‐learners' activities, yet little is known about the effects of this practice. Social facilitation theory suggests that it may adversely affect people by heightening distraction and arousal. This experiment examined the issue by asking volunteers to complete a Web‐based training program designed to teach online search skills. Half of participants were told their training activities would be tracked; the others received no information about monitoring. Results supported the hypothesized effects on satisfaction, performance, and mental workload (measured via heart rate variability). Explicit awareness of monitoring appeared to tax e‐learners mentally during training, thereby hindering performance on a later skills test. Additionally, e‐learners reported less satisfaction with the training when monitoring was made salient.     

Some fear-potentiating effects of fluprazine hydrochloride in mice

The fear-potentiating effects of fluprazine hydrochloride were explored in a series of five experiments. The drug was found to strongly inhibit entry into a novel open field, exploration of a complex maze, or approach to a novel object placed in the animal's home cage. Time sampling techniques were used to assess drug effects on frequencies of immobility, activity, and grooming and rearing responses prior to and for 70 min after footshock. There were no group differences during the 10 min immediately following shock but the groups diverged steadily in immobility, activity, and grooming for the remainder of the observations. Post-shock activity and grooming responses increased steadily towards baseline values among control mice but remained at low levels or declined among drug-treated mice. Immobility responses declined steadily among control mice but increased substantially among the fluprazine-treated mice throughout post-shock observations. Pairs of male mice treated with fluprazine were also found to maintain greater intermouse distances in a novel linear runway than pairs of undrugged adult males, juvenile males, or male-female pairs. It is suggested that fluprazine hydrochloride both potentiates fear and alters its time course in addition to interfering in some way with normal olfactory processes.     

Jolly fat rats? The effects of diet-induced obesity on territorial fighting

In experiment 1, pairs of young male rats became obese on a palatable and complex diet high in fat, sucrose, and protein. The obese pairs exhibited greater within-group weight variability and, when tested as adults, were significantly more aggressive toward an unfamiliar conspecific than chow-fed controls. The increased aggressivity of obese males was not due to the relatively larger resident-intruder weight disparities in these pairs, since weight-matched pairs of unfamiliar animals were as aggressive toward each other as pairs not matched in body weight (experiment 2). The complex and calorically dense diet may have accelerated the development of the experimental animals, producing subjects whose aggressivity was comparable to that of much older animals.     

Prey-dependent effects of fluprazine hydrochloride on predatory aggression in northern grasshopper mice (Onychomys leucogaster) and rats (Rattus norvegicus)

Treatment with the phenylpiperazine DU 27716 (fluprazine hydrochloride) inhibited the predatory killing of albino mice by northern grasshopper mice (Onychomys leucogaster) and of frogs by rats. This treatment had no effect on cricket predation by grasshopper mice or worm predation by rats. The prey-specific effect of fluprazine did not seem to result from a decreased tendency to attack nor was its effect restricted to prey showing characteristic rodent defensive responses. Rather, the drug seemed to increase fearfulness when the prey exhibited vigorous defensive behavior. It is possible that increased fearfulness induced by treatment with this drug may also contribute to its antioffensive effect during conspecific encounters.     

Power,Empowerment, and Equality: Evidence for the Motives of Feminists,Nonfeminists, and Antifeminists

Both feminists and antifeminists claim they do not seek to dominate others, and accuse their ideological opponents of an insidious desire for power. The purpose of this study was to examine the motives of feminists, nonfeminists, and antifeminists by assessing their values in a context in which they would not feel that their motives regarding feminism were being scrutinized. Participants were 126 mostly European-American students. Antifeminist men placed more emphasis on their own power than did other men; but antifeminist, nonfeminist, and feminist women did not differ in emphasis placed on power. Among both men and women, antifeminists placed little importance on equality. Feminist women placed more importance on equality than did nonfeminist women, who in turn placed more importance on equality than did antifeminist women.