Assessment of distance to potential mates by female barking treefrogs (Hyla gratiosa)

This study investigated the cues used by female barking treefrogs, Hyla gratiosa, to assess distances to potential mates. Eight-speaker playback experiments were used to demonstrate that distance affects female choice in complex acoustic environments and to test 3 possible cues that females might use to assess distance: (a) degradation in spectral and temporal cues of calls, (b) relative call amplitude at the female's location, and (c) the rate at which the amplitude of calls increases as a female approaches a calling male. All 3 hypotheses were refuted, suggesting that females use a more complex mechanism, such as triangulation, to assess distance. Females preferred speakers with greater source amplitudes even when they had to travel further to reach those speakers. Determination of source amplitude is possible only if females can assess independently both the distance to sound sources and the amplitude of calls at the females' location. Hence, anuran amphibians may possess greater cognitive abilities than are generally attributed to them.     

Emergence of an egocentric cue guiding and allocentric inferring strategy that mirrors hippocampal brain-derived neurotrophic factor (BDNF) expression in the Morris water maze

From insects to humans, successful navigation relies on retained representations of spatial relations. These representations are thought to depend on the hippocampal formation, particularly those that are independent of the navigator (allocentric representations). The Morris water maze is a simple and popular task often used to assess spatial navigation. But how animals navigate toward and retain information regarding the location of the goal in this task remains unclear. We provide a comprehensive account of how the water maze is accomplished behaviourally. Our findings suggest that animals solve the task using distal cues via an initial view-matching strategy that is supported by egocentric guidance. Through increased training, however, an emergence of an egocentric-guiding strategy combined with the animal’s greater ability to infer the hidden platform’s location (via allocentric extrapolation) emerges. We also demonstrate that behavioural changes, towards a more allocentric strategy, are reflected in increases in hippocampal brain-derived neurotrophic factor.     

Current status of cannabis treatment of multiple sclerosis with an illustrative case presentation of a patient with MS, complex vocal tics, paroxysmal dystonia, and marijuana dependence treated with dronabinol

Pain, spasticity, tremor, spasms, poor sleep quality, and bladder and bowel dysfunction, among other symptoms, contribute significantly to the disability and impaired quality of life of many patients with multiple sclerosis (MS). Motor symptoms referable to the basal ganglia, especially paroxysmal dystonia, occur rarely and contribute to the experience of distress. A substantial percentage of patients with MS report subjective benefit from what is often illicit abuse of extracts of the Cannabis sativa plant; the main cannabinoids include delta-9-tetrahydrocannabinol (delta9-THC) and cannabidiol. Clinical trials of cannabis plant extracts and synthetic delta9-THC provide support for therapeutic benefit on at least some patient self-report measures. An illustrative case is presented of a 52-year-old woman with MS, paroxysmal dystonia, complex vocal tics, and marijuana dependence. The patient was started on an empirical trial of dronabinol, an encapsulated form of synthetic delta9-THC that is usually prescribed as an adjunctive medication for patients undergoing cancer chemotherapy. The patient reported a dramatic reduction of craving and illicit use; she did not experience the "high" on the prescribed medication. She also reported an improvement in the quality of her sleep with diminished awakenings during the night, decreased vocalizations, and the tension associated with their emission, decreased anxiety and a decreased frequency of paroxysmal dystonia.     

Assessing the automaticity of moral processing: efficient coding of moral information during narrative comprehension

A long-standing theoretical debate concerns the involvement of principled reasoning versus relatively automatic intuitive-emotional processing in moral cognition. To address this, we investigated whether the mental models formed during story comprehension contain a moral dimension and whether this process is affected by cognitive load. A total of 72 participants read stories about fictional characters in a range of moral situations, such as a husband being tempted to commit adultery. Each story concluded with a "moral" or "immoral" target sentence. Consistent with a framework of efficient extraction of moral information, participants took significantly longer to read immoral than moral target sentences. Moreover, the magnitude of this effect was not compromised by cognitive load. Our findings provide evidence of efficient coding of moral dimensions during narrative comprehension and demonstrate that this process does not require cognitively intense forms of principled reasoning.     

Do traumatic events influence the clinical expression of compulsive hoarding?

Traumatic experiences have been posited as one potential catalyst for the abrupt onset of obsessive-compulsive symptoms including compulsive hoarding. To determine whether traumatic life events (TLEs) might influence the expression of compulsive hoarding in obsessive-compulsive disorder (OCD), interview responses to the Posttraumatic Stress Disorder module of the Structured Clinical Interview for DSM-IV (SCID) were examined in 180 individuals with OCD. Compared to individuals with OCD who did not meet criteria for hoarding, participants classified as hoarders (24% of the sample) were significantly more likely to have reported at least one TLE in their lifetime. Patients who met criteria for hoarding and who had also experienced TLEs had significantly greater hoarding symptom severity than those hoarders not exposed to trauma. This association was found to be robust. That is, the relationship between TLEs and hoarding symptom severity was not better accounted for by age, age of OCD onset, depressive symptoms, general OCD symptomatology, or mood and anxiety comorbidity. Closer examination revealed that the clutter factor of compulsive hoarding (and not difficulty discarding or acquisitioning) was most strongly associated with having experienced a traumatic event.     

An investigation of traumatic life events and obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD), like most other psychiatric disorders, is suspected of being influenced by an interaction between life events and genes, both with regard to onset and course of illness. To date, no specific genes have been identified as playing a frequent role, and only a relatively few empirical studies have assessed the association between stressful life events (SLEs) and OCD. The present study builds on past research by examining the potential contributions from traumatic life events (TLEs) on the severity and symptom features in 265 individuals with Structured Clinical Interview for DSM-IV (SCID)-diagnosed OCD. Of these participants 54% endorsed having experienced at least one TLE in their life time. The presence of one or more TLEs was associated with increased OCD symptom severity. This relationship remained significant despite controlling for key variables including age, OCD age-of-onset, comorbidity, and depressive symptoms. In addition, obsessions/checking and symmetry/ordering were two of four symptom factors that were specifically associated with the occurrence of TLEs. These results are generally supportive of a pathoplastic relationship between TLEs and OCD symptomatology and thus suggest the need for greater systematic consideration of life stresses in research focused on the nature and treatment of OCD.     

Middle school student perceptions of school climate: Examining protective functions on subsequent adjustment problems

The present study examined the roles of student perceptions of four aspects of school climate (friction, cohesion, competition among students, and satisfaction with classes) as moderators of the relations between effortful control and subsequent conduct problems and depressive symptoms. Participants were 488 10-to-14-year old students involved in two waves, with one year between each wave, of a study. Hierarchical regression analyses indicated that high levels of perceived friction predicted more subsequent conduct problems and depressive symptoms, even after baseline levels of these problems were partialled out. Low levels of effortful control also elevated risk for subsequent conduct problems. However, perceptions of the school as high in cohesion offset the risk associated with low levels of effortful control. Perceived satisfaction with classes also offset this risk, but only for females. Contrary to expectations, student perceptions of school climate did not interact with effortful control to predict subsequent depressive symptoms.     

Subtyping as a knowledge preservation strategy in category learning

Subtyping occurs when atypical examples are excluded from consideration in judging a category. In three experiments, we investigated whether subtyping can influence category learning. In each experiment, participants learned about a category where most, but not all, of the exemplars corresponded to a theme. The category structure included a subtyping dimension, which had one value for theme-congruent exemplars and another for exception exemplars. On the basis of work by Hayes, Foster, and Gadd (2003) and studies on social stereotyping, we hypothesized that this subtyping dimension would enable the participants to discount the exception exemplars, thereby facilitating category learning. Contrary to expectations, we did not find a subtyping effect with traditional category-learning procedures. By introducing the theme prior to learning, however, we observed increased effects on typicality ratings (Experiment 1) and facilitated learning of the category (Experiment 2). Experiment 3 provided direct evidence that introducing the theme prior to learning enhanced the subtyping effect and provided support for a knowledge-gating explanation of subtyping. We conclude that subtyping effects are strongest on already-learned concepts and that subtyping is unlikely to aid in the learning of new concepts, except in particular circumstances.     

Combat-related post-traumatic stress disorder: a case report using virtual reality exposure therapy with physiological monitoring.

The current report summarizes a case study from an Office of Naval Research (ONR) funded project to compare the effects of virtual reality graded exposure therapy (VRGET) with cognitive behavioral group therapy in active-duty corpsmen. Details of the collaborative program between the Virtual Reality Medical Center (VRMC) and Naval Medical Center San Diego (NMCSD) will be discussed.     

Relationships Between Attitudes Toward Organizations and Performance Appraisal Systems and Rating Behavior

Data collected in seven separate samples in three countries (the USA, Canada and Israel) were used to examine the relationships between perceptions of one’s organization (climate, commitment), beliefs about appraisal systems (self‐efficacy, uses of appraisal) and raters’ orientations to appraisal systems (confidence and comfort) and specific rating behaviors. We obtained good fits for structural models suggesting that attitudes and beliefs accounted for substantial variance in raters’ likelihood of giving high or low ratings, willingness to discriminate good from poor performers, and willingness to discriminate among various aspects of job performance when completing actual performance ratings. Proximal attitudes and beliefs (i.e., those directly related to the performance appraisal system) appear to have stronger links to rating behavior than do more distal attitudes (i.e., attitudes toward the organization in general).