Failure to produce conditioning with low-dose trimethylthiazoline or cat feces as unconditioned stimuli.

Trimethylthiazoline (TMT), a derivative of fox feces, has been reported to fail to produce aversive conditioning as an unconditioned stimulus (UCS) when presented in large amounts. Experiment 1 evaluated very low TMT levels that nonetheless produced defensive behaviors in rats during exposure. Although each level (0.01, 0.05, and 0.10 μl TMT) produced significant change in defensiveness, none resulted in significant changes the following day in the absence of TMT. Experiment 2 evaluated cat urine, cat feces, and cat fur/skin odor against a no-odor control. Urine produced no significant changes, but feces and fur/skin odors elicited virtually identical changes in defensive behaviors during exposure. When tested the next day in the absence of odor, the fur/skin odor-exposed group showed significant differences on the same behaviors as during exposure, but the feces-exposed group showed no differences on any measure. Results suggest that lack of conditioning to TMT may relate to the type of predator odor rather than the amount, predator species, or possible lack of odor components in TMT that are present in natural feces. Predator feces may also be less effective as a UCS because they are poorly predictive of the actual presence of the predator. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral Changes Induced in Rats by Exposure to Trimethylthiazoline, a Component of Fox Odor.

Trimethylthiazoline (TMT), a component of fox feces, has been used in various studies as a natural predator stimulus to induce autonomic and behavioral signs of fear (e.g., higher levels of stress hormones, freezing, and risk assessment). The present study investigated whether 2 further behavioral signs of fear are induced in rats by TMT exposure: potentiation of the acoustic startle response and inhibition of appetitive behavior. In addition, the authors tested the rats for dose dependency of TMT-induced freezing behavior. The study confirmed that behavioral changes observed during TMT exposure are caused by TMT-induced fear and are dose dependent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparative behavioral effects between synthetic 2,4,5-trimethylthiazoline (TMT) and the odor of natural fox (Vulpes vulpes) feces in mice.

Synthetic 2,4,5-trimethylthiazoline (TMT)--a component of red fox (Vulpes vulpes) feces--is frequently used to induce unconditioned fear in rodents. Surprisingly, direct comparison between TMT and natural fox feces odor is almost nonexistent. In this study, Experiment 1 compared the avoidance in relation to TMT concentration, natural fox feces, and gender of fox and mice. Results show that the avoidance is (a) higher with either pure or 50% TMT as compared to natural fox feces, whereas the difference is slight with 10% TMT, and (b) significantly higher for the female mouse group compared to the male mouse group with TMT as well as natural fox feces. In addition, no clear difference in effect was observed between male and female fox feces. Experiment 2 compared behavioral parameters recorded as an index of fear and anxiety, general activity, and avoidance in elevated plus-maze and open-field chamber between 10% TMT and natural fox feces in relation to the estrus cycle of the mice. Results show no cycle period effect--except for the avoidance parameter "distance to odorant"--and no different effects between 10% TMT and natural fox feces except for freezing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hippocampal formation supports conditioning to memory of a context.

It has been proposed that contextual fear conditioning depends on 2 processes: (a) construction of a conjunctive representation of the features that make up the context and (b) association of the representation with shock. Support for this view comes from studies indicating that prior exposure to the conditioning context facilitates contextual fear conditioning supported by immediate shock. Thus, conditioning produced by immediate shock is to the memory representation of the preexposed context, which is activated by retrieval cues associated with this context. The authors' experiments support this interpretation and indicate that this process depends on an intact hippocampal formation. These results support the hypothesis that the hippocampal formation supports contextual fear conditioning by storing a conjunctive representation of context. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Not all rat strains are equal: Differential unconditioned fear responses to the synthetic fox odor 2,4,5-trimethylthiazoline in three outbred rat strains.

Predator odors induce unconditioned fear in rats; however, the synthetic predator odor 2,4,5-trimethylthiazoline (TMT) either elicits robust fear behavior (e.g., freezing) or no fear responses at all. The authors investigated whether this is due to the use of different outbred rat strains. TMT induced robust freezing in Sprague-Dawley and Long-Evans rats but not in Wistar rats. All 3 strains avoided TMT, but Wistar rats were less sensitive to TMT. Wistar rats are capable of freezing; all 3 strains displayed the same amount of odor-cue conditioned freezing. Thus, TMT is a robust unconditioned fear stimulus in rats, and prior negative results from other laboratories were due to the choice of a rat strain (Wistar) that is less responsive to TMT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Two roles of the context in Pavlovian fear conditioning.

At both empirical and theoretical levels, multiple functional roles of contextual information upon memory performance have been proposed without a clear dissociation of these roles. Some theories have assumed that contexts are functionally similar to cues, whereas other views emphasize the retrieval facilitating properties of contextual information. In Experiment 1, we observed that one critical parameter, the spacing of trials, could determine whether the context would function as a conditioned stimulus or as a retrieval cue for memories trained in different phases. Experiments 2 and 3 doubly dissociated these functions by selectively disrupting one role but not the other, and vice versa. Overall, these observations identify one determinant of different functions of contextual information and pose a major challenge to theories of learning that assume exclusively one or the other function of the context. Moreover, these data emphasize the importance of parametric variations on behavioral control, which has critical implications for studies designed to understand the role of the hippocampus in processing of contextual attributes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pretraining Inactivation of the Caudal Pontine Reticular Nucleus Impairs the Acquisition of Conditioned Fear-Potentiated Startle to an Odor, but Not a Light.

Recent data from developing rats suggest that structures downstream from the amygdala are involved in the acquisition of conditioned fear-potentiated startle (FPS). The authors tested this idea in adult rats by temporarily inactivating the structure critical for FPS, the caudal pontine reticular nucleus (PnC), during fear conditioning. When the conditioned stimulus (CS) was an odor, rats displayed freezing, but not FPS, at test. This effect was not due to a decrease in footshock sensitivity. Further, no savings were evident on retraining. When the CS was a light, inactivation of the PnC had no effect on the acquisition of FPS. Thus, the PnC may be crucial for the acquisition of conditioned FPS to an odor, but not a light. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The verbal threat information pathway to fear in children: The longitudinal effects on fear cognitions and the immediate effects on avoidance behavior.

Verbal information has long been assumed to be an indirect pathway to fear. Children (aged 6-8 or 12-13 years) were exposed to threat, positive, or no information about 3 novel animals to see the long-term impact on their fear cognitions and the immediate impact on avoidance behavior. Their directly (self-report) and indirectly (implicit association task) measured attitudes toward the animals changed congruent with the information provided, and the changes persisted up to 6 months later. Verbal threat information also induced behavioral avoidance of the animal. Younger children formed stronger animal- threat and animal-safe associations because of threat and positive verbal information than older children, but there were negligible age effects on self-reported fear beliefs and avoidance behaviors. These results support theories of fear acquisition that suppose that verbal information affects components of the fear emotion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporally graded, context-specific retrograde amnesia and its alleviation by context preexposure: Effects of postconditioning exposures to morphine in the rat.

Five experiments studied retrograde impairments in Pavlovian fear conditioning following prolonged exposure to the opioid receptor agonist morphine. Injections of morphine commencing 1-7 days but not 14 days after conditioning produced amnesia for that conditioning episode. This amnesia was (a) selective such that morphine impaired freezing to the conditioning context but not to the auditory conditioned stimulus, (b) independent of the interval between the last injection of morphine and test, and (c) accompanied by a failure of contextual discrimination. Context preexposure protected context conditioning and discrimination from the amnestic effects of morphine. These results show that retrograde deficits in contextual fear conditioning are mediated by failures to consolidate a contextual representation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maternal care, isolation-induced infant ultrasonic calling, and their relations to adult anxiety-related behavior in the rat.

In the rat, variations in maternal care affect the development of stable individual differences in anxiety-related behavior. Here, it was asked whether such experience-dependent differences can be detected already during early life. As a measure for anxiety in pups, isolation-induced ultrasonic vocalizations were used, and their dependency on different maternal behaviors, namely licking, retrieval behavior, and responsiveness to playback of pup calls, was tested. Consistent with reported differences of adult rats with high or low levels of maternal care experienced, the rarely licked offspring appeared to be more anxious, since they emitted more calls when separated from their mother and litter. Based on these findings, it was examined whether infant calling can be used as a predictor of adult anxiety-related behavior. Results show that infant call emission was negatively correlated with immobility and calling during fear conditioning. These relationships seem to be mediated at least partly by maternal care. In total, measuring ultrasonic vocalizations can provide information about an affective trait of infant and adult rats, which gives the opportunity to study the development of emotionality from early life onward. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predicting recidivism with the Personality Assessment Inventory in a sample of sex offenders screened for civil commitment as sexually violent predators.

We examined the ability of scores from the Personality Assessment Inventory (PAI; Morey, 1991) to predict postrelease (M = 4.90 years follow-up) arrests in a sample of 1,412 sex offenders. We focused on scores from 4 PAI measures conceptually relevant to offending, including the Antisocial Features (ANT), Aggression (AGG), and Dominance (DOM) scales, as well as the Violence Potential Index (VPI). Scores from several PAI measures demonstrated small- to medium-sized effects in predicting violent nonsexual recidivism, nonviolent recidivism, and sex offender registry violations, with the AGG scale being the strongest (d = 0.50 for violent nonsexual recidivism, d = 0.55 for sex offender registry violations) and most consistent predictor of recidivism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rapid reacquisition of fear to a completely extinguished context is replaced by transient impairment with additional extinction training.

A series of experiments studied reacquisition of fear reactions to a completely extinguished context. Reacquisition was rapid when reconditioning occurred as soon as the fear reactions were completely extinguished, showing that the original conditioning was intact. However, when reconditioning occurred after massive extinction training, fear reactions were depressed but then recovered across a long retention interval. This recovery was due to reconditioning and was similar to that produced by conditioning a massively preexposed context. These results show that massive extinction converts a potentially dangerous context into one that is merely familiar. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of bed nucleus of the stria terminalis lesions on conditioned anxiety: Aversive conditioning with long-duration conditional stimuli and reinstatement of extinguished fear.

Four experiments investigated the effects of lesions of the bed nucleus of the stria terminalis (BNST) on conditioned fear and anxiety. Though BNST lesions did not disrupt fear conditioning with a short-duration conditional stimulus (CS; Experiments 1 and 3), the lesion attenuated conditioning with a longer duration CS (Experiments 1 and 2). Experiment 3 found that lesions attenuated reinstatement of extinguished fear, which relies on contextual conditioning. Experiment 4 confirmed that the lesion reduced unconditioned anxiety in an elevated zero maze. The authors suggest that long-duration CSs, whether explicit cues or contexts, evoke anxiety conditioned responses, which are dissociable from fear responses to shorter CSs. Results are consistent with behavioral and anatomical distinctions between fear and anxiety and with a behavior-systems view of defensive conditioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exposure to a rhythmic auditory stimulus facilitates memory formation for the passive avoidance task in the day-old chick.

Previous research regarding the beneficial effects of auditory stimuli on learning and memory in humans has been inconsistent. In the current study, day-old chicks were used to reduce the impact of individual differences on responses. Chicks were trained on a passive avoidance task and exposed to various auditory stimuli. Exposure to a complex rhythmic sequence for 1 min strongly facilitated chicks' long-term memory. The optimal time of presentation of the stimulus was between 10 min before and 20 min after training. Moreover, the enhancing effect was not generalized to the other auditory stimuli tested. It is suggested that this effect may be due to arousal because arousal hormones are critical to long-term memory formation. This study indicates that the temporal characteristics and type of stimulus may be important considerations when investigating the effects of auditory stimuli on cognitive functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effectiveness of functional family therapy for youth with behavioral problems in a community practice setting.

The study examined the effectiveness of Functional Family Therapy (FFT), as compared to probation services, in a community juvenile justice setting 12 months posttreatment. The study also provides specific insight into the interactive effects of therapist model specific adherence and measures of youth risk and protective factors on behavioral outcomes for a diverse group of adolescents. The findings suggest that FFT was effective in reducing youth behavioral problems, although only when the therapists adhered to the treatment model. High-adherent therapists delivering FFT had a statistically significant reduction of (35%) in felony, a (30%) violent crime, and a marginally significant reduction (21%) in misdemeanor recidivisms, as compared to the control condition. The results represent a significant reduction in serious crimes 1 year after treatment, when delivered by a model adherent therapist. The low-adherent therapists were significantly higher than the control group in recidivism rates. There was an interaction effect between youth risk level and therapist adherence demonstrating that the most difficult families (those with high peer and family risk) had a higher likelihood of successful outcomes when their therapist demonstrated model-specific adherence. These results are discussed within the context of the need and importance of measuring and accounting for model specific adherence in the evaluation of community-based replications of evidence-based family therapy models like FFT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Daily and momentary mood and stress are associated with binge eating and vomiting in bulimia nervosa patients in the natural environment.

The relation of mood and stress to binge eating and vomiting in the natural environments of patients with bulimia nervosa (BN) was examined using real-time data collection. Women (n = 131; mean age = 25.3 years) with BN carried a palmtop computer for 2 weeks and completed ratings of positive affect (PA), negative affect (NA), anger/hostility (AH), and stress (STRS); they also indicated binge or vomit episodes (BN-events) 6 times each day. Mixed models were used to compare mood and STRS between and within days when BN-events occurred. Between-days analyses indicated that binge and vomit days both showed less PA, higher NA, higher AH, and greater STRS than days with no BN-events. Within-day, decreasing PA, and increasing NA and AH, reliably preceded BN-events. Conversely, PA increased, and NA and AH decreased following BN-events. Demonstration of the temporal sequencing of affect, STRS, and BN-events with a large BN sample may help advance theory and clinical practice, and supports the view that binge and purge events hold negatively reinforcing properties for women with BN. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Testing a social-cognitive model of HIV transmission risk behaviors in HIV-infected MSM with and without depression.

Objective: Social-cognitive models have been used to explain health risk behaviors in numerous populations, including people with HIV. However, these models generally do not account for the influence of clinically significant psychological problems such as major depression. Design: This study examined whether a social-cognitive model would explain recent sexual transmission risk behavior among sexually active HIV-infected men who have sex with men (MSM) who meet or do not meet screening criteria for major depression. Main Outcome Measures: Participants (n = 403) completed self-report assessments of negative expectancy, social models, and self-efficacy (SE) related to condom use, as well as recent STRB and a screening measure for major depression. Multiple group modeling was used to examine whether condom use SE explained associations of negative expectancy and social models for condom use with recent STRB among participants who screened positive (n = 47) or negative (n = 356) for major depression. Results: The multiple group model fit the data well (χ2(36) = 30.55, p = .73; CFI = 1.00; RMSEA     

Good citizens to the end? It depends: Empathy and concern with future consequences moderate the impact of a short-term time horizon on organizational citizenship behaviors.

Organizational citizenship behaviors (OCBs) can be viewed as a social dilemma in which short-term employee sacrifice leads to long-term organizational benefits. With 3 studies, the authors evaluated a set of interrelated hypotheses based on a social dilemma analysis of OCBs. In Study 1, participants rated OCBs as costly to an employee in the short run and beneficial to an organization in the long run, indicating that OCBs were viewed as social dilemmas. In Studies 2 and 3, self-reported (Study 2) and supervisor-rated (Study 3) likelihood of engaging in OCBs was higher among those who adopted a long-term horizon within an organization and those high in empathy (M. H. Davis, 1983). Most important, a short-term time horizon led to a steeper decline in OCBs among employees low in empathy and those concerned with the future consequences of their actions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)