Discrimination of acoustic communication signals by grasshoppers (Chorthippus biguttulus): temporal resolution, temporal integration, and the impact of intrinsic noise

A characteristic feature of hearing systems is their ability to resolve both fast and subtle amplitude modulations of acoustic signals. This applies also to grasshoppers, which for mate identification rely mainly on the characteristic temporal patterns of their communication signals. Usually the signals arriving at a receiver are contaminated by various kinds of noise. In addition to extrinsic noise, intrinsic noise caused by stochastic processes within the nervous system contributes to making signal recognition a difficult task. The authors asked to what degree intrinsic noise affects temporal resolution and, particularly, the discrimination of similar acoustic signals. This study aims at exploring the neuronal basis for sexual selection, which depends on exploiting subtle differences between basically similar signals. Applying a metric, by which the similarities of spike trains can be assessed, the authors investigated how well the communication signals of different individuals of the same species could be discriminated and correctly classified based on the responses of auditory neurons. This spike train metric yields clues to the optimal temporal resolution with which spike trains should be evaluated.     

Combining Exposure and Pharmacotherapy in the Treatment of Social Anxiety Disorder: A Preliminary Study of State Dependent Learning

State dependent learning (SDL) occurs when learning acquired in one context is not retrievable in a different context. Although traditionally SDL is thought of in the context of substance use, the role of SDL should be considered during combined medication and exposure treatment for anxiety disorders. Data are presented from a within-subjects, case-series design of four participants with social anxiety disorder. Participants engaged in a series of situational exposures while taking either alprazolam (0.75 mg), propranolol (40 mg), placebo or no medication. They returned 48 h later and engaged in the same situational exposure in an unmedicated state to determine retention of learning following the shift in drug context. Results suggest that SDL effects are possible when combining pharmacotherapy (alprazolam) with exposure therapy. Future research is needed determine the conditions under which SDL is most likely to occur and ways to facilitate transfer of learning across different contexts.     

Classes of substance abuse relapse situations: a comparison of adolescents and adults

Research in the process of relapse has uncovered important developmental differences in the situations that make adolescents and adults most vulnerable to relapse after substance abuse treatment. This study takes a developmental, person-centered approach to relapse by examining the latent class structure of relapse precursors in adolescents and adults. Adults (N = 160) and adolescents (N = 188) in substance abuse and psychiatric treatment were followed up to 18 months after discharge to gather detailed information about their first relapse after treatment. Both adolescents and adults exhibited a 2-class structure of relapse precursors. Adult classes were labeled social and urges situations (primary precursors: social pressure and urges; 67%) and negative and urges situations (primary precursors: negative affect and urges; 33%), while teen classes were labeled social and positive situations (primary precursors: enhancing a positive emotional state and social pressure; 69%) and complex situations (primary precursors: negative affect, negative interpersonal situations, social pressure, and urges; 31%). Findings are discussed in relation to developmental and clinical considerations in treating clients with substance use disorders and comorbid psychopathology.     

Open hearts build lives: positive emotions, induced through loving-kindness meditation, build consequential personal resources

B. L. Fredrickson's (1998, 2001) broaden-and-build theory of positive emotions asserts that people's daily experiences of positive emotions compound over time to build a variety of consequential personal resources. The authors tested this build hypothesis in a field experiment with working adults (n = 139), half of whom were randomly-assigned to begin a practice of loving-kindness meditation. Results showed that this meditation practice produced increases over time in daily experiences of positive emotions, which, in turn, produced increases in a wide range of personal resources (e.g., increased mindfulness, purpose in life, social support, decreased illness symptoms). In turn, these increments in personal resources predicted increased life satisfaction and reduced depressive symptoms. Discussion centers on how positive emotions are the mechanism of change for the type of mind-training practice studied here and how loving-kindness meditation is an intervention strategy that produces positive emotions in a way that outpaces the hedonic treadmill effect.     

Balancing connectedness and self-protection goals in close relationships: a levels-of-processing perspective on risk regulation

A model of risk regulation is proposed to explain how low and high self-esteem people balance the tension between self-protection and connectedness goals in romantic relationships. This model assumes that interpersonal risk automatically activates connectedness and self-protection goals. The activation of these competing goals then triggers an executive control system that resolves this goal conflict. One correlational study and 8 experiments manipulating risk, goal strength, and executive strength and then measuring implicit and explicit goal activation and execution strongly supported the model. For people high in self-esteem, risk triggers a control system that directs them toward the situations of dependence within their relationship that can fulfill connectedness goals. For people low in self-esteem, however, the activation of connectedness goals triggers a control system that prioritizes self-protection goals and directs them away from situations where they need to trust or depend on their partner.     

Cross-cultural perspectives on pitch memory

We examined effects of age and culture on children's memory for the pitch level of familiar music. Canadian 9- and 10-year-olds distinguished the original pitch level of familiar television theme songs from foils that were pitch-shifted by one semitone, whereas 5- to 8-year-olds failed to do so (Experiment 1). In contrast, Japanese 5- and 6-year-olds distinguished the pitch-shifted foils from the originals, performing significantly better than same-age Canadian children (Experiment 2). Moreover, Japanese 6-year-olds were more accurate than their 5-year-old counterparts. These findings challenge the prevailing view of enhanced pitch memory during early life. We consider factors that may account for Japanese children's superior performance such as their use of a pitch accent language (Japanese) rather than a stress accent language (English) and their experience with musical pitch labels.     

Law, Convention and Objectivity: Comments on Kramer

Since I do not disagree with the line of argument taken by Kramer and the distinctions he draws between the different ways rules can be ‘mind-independent’, my comments focus on some of the complexities involved in the application of his distinctions. I suggest that law, properly understood as a system of rules/conventions is both existentially and observationally weakly mind independent, but nonetheless objective.

Taking stock as theories of word learning take shape

In this paper we consider the perceptual and conceptual contributions that shape early word learning, using research on the shape bias as a case in point. In our view, conceptual, linguistic, social-pragmatic, and perceptual sources of information influence one another powerfully and continuously in the service of word learning throughout infancy and early childhood. We articulate several key points of convergence and divergence between our theoretical perspective and that of the attentional learning account. Finally, we consider the broader implications of this debate for clarifying the forces that constrain development.     

Latent Trait Modeling with the Common beliefs Survey III: Using Item Response Theory to Evaluate an Irrational Beliefs Inventory

Assessment of irrational beliefs by such measures as the Common Beliefs Survey III (CBS) has traditionally relied upon classical test theory assumptions, in which the properties of specific test items are less important than the total test score as the aggregate of all item responses. An alternative approach using item response theory (IRT) methodology allows one to specify the parameters of difficulty and discrimination for each test item. Difficulty levels of CBS items range along a continuum of irrationality, the implied latent trait measured by responses to the questionnaire as a whole. We evaluated the CBS responses of 605 individuals from clinical and college settings, drawing from current and archival data. The original Likert scale ratings were recoded into dichotomous scores. Fourteen of the 54 items were highly or very highly discriminating in distinguishing respondents with high and low irrationality levels. However, discriminating items exhibited a very narrow range of difficulty; most functioned at a point a little above the halfway mark on the continuum of irrationality. Item characteristic curves and test information curves were very similar for female (n = 424) and male (n = 179) respondents. We derived a 4-item screening test for irrationality from our IRT analyses of the 54 CBS items. Further test development, focused on the selection and scaling of items with a much broader range of difficulty, would facilitate evaluation of the hierarchical structure of irrational beliefs. Portions of this paper were presented at the 39th Annual Convention of the Association for Behavioral and Cognitive Therapies, Washington, DC, November, 2005.