Use of visual, acoustic, and olfactory information during embedded invertebrate foraging in brown capuchins (Cebus apella)

Experiments were conducted to investigate which sensory cues are used by brown capuchins (Cebus apella) in embedded invertebrate foraging. The importance of visual, olfactory, and acoustic cues in such foraging was determined by presenting subjects with a stimulus log modified to block out given sensory cues. Experiment 1 was designed to investigate whether subjects could locate an invertebrate embedded in wood when only visual, acoustic, or olfactory information was available. Experiments 2 and 3 were designed to investigate extractive foraging behavior when two sensory cues were provided. It was hypothesized that the combination of visual and acoustic information would be necessary for subjects to successfully locate embedded invertebrates. Results indicated that subjects' performance was most successful when both visual and acoustic information was available.     

Validation of the Wisconsin Personality Disorders Inventory-IV with the SCID-II

The Wisconsin Personality Disorders Inventory (WISPI-IV; Klein & Benjamin, 1996) is the latest version of a self-report measure of DSM-IV personality disorders (PDs) derived from an interpersonal perspective. When categorical diagnoses derived from the WISPI-IV were compared with independent SCID-II diagnoses, the majority of the kappas were poor (>.40). However, all but one of the effect sizes for the differences in WISPI-IV means between groups with and without SCID-II diagnoses were large (>.80). When SCID-II and WISPI-IV dimensional scores were considered, the average r between profiles was .61 (median = .58) and correlations between corresponding PD scales (mean diagonal r = .48; mean off-diagonal r = .18) indicated good convergent and discriminant validity for five of the WISPI-IV scales. These results add to the cumulating evidence suggesting greater reliability and validity of dimensional over categorical scores for PDs. Researchers and clinicians interested in having an efficient method of assessing PDs may consider using a dimensional approach such as the WISPI-IV as an alternative to diagnostic interview.     

Electrophysiological responses to errors and feedback in the process of action regulation

The anterior cingulate cortex (ACC) is believed to be involved in the executive control of actions, such as in monitoring conflicting response demands, detecting errors, and evaluating the emotional significance of events. In this study, participants performed a task in which evaluative feedback was delayed, so that it was irrelevant to immediate response control but retained its emotional value as a performance indicator. We found that a medial frontal feedback-related negativity similar to the error-related negativity (ERN) tracked affective response to the feedback and predicted subsequent performance. Source analysis of the feedback-related negativity and ERN revealed a common dorsomedial ACC source and a rostromedial ACC source specific to the ERN. The oscillatory nature of these sources provides further evidence that the ERN reflects ongoing theta activity generated in the mediofrontal regions. These results suggest that action regulation by the cingulate gyrus may require the entrainment of multiple structures of the Papez corticolimbic circuit.     

Eating disorder and obsessive–compulsive symptoms in a sample of bulimic women: Perfectionism as a mediating factor

The present study aimed to investigate whether perfectionism mediates the association between obsessive–compulsive (OC) and eating disorder (ED) symptoms. Analyses were conducted using data collected among a national sample of eating disordered women diagnosed with BN or a subclinical variant of BN (N = 204). Each participant completed a series of self-report inventories on perfectionism, as well as OC, ED, and depressive symptoms. Higher ED symptoms were significantly associated with greater levels of perfectionism (p < .01) and OC symptoms (p < .05). As hypothesized, perfectionism significantly mediated the relationship between ED and OC symptoms, controlling for depression. Findings indicate that perfectionism may be considered a shared etiological or phenomenological factor in ED and OC symptoms.     

Multi-Couple Group and Self-Directed PREP Formats Enhance Relationship Satisfaction and Improve Anger Management Skills in Air Force Couples

This study examined the effectiveness of delivering the Prevention and Relationship Enhancement Program (PREP) to volunteer couples in the U.S. Air Force in either a six-week instructional multi-couple group condition or a self-directed book condition. A standardized pre/post protocol was employed and outcomes included relationship satisfaction and anger management skills, two known risk factors for partner maltreatment. Significant improvement was found for the group condition in both relationship satisfaction and anger management skills, but only for anger management skills in the self-directed book condition. Finally, the group condition reported greater program satisfaction. Implications are discussed.     

Developmental Changes in the Consideration of Sample Diversity in Inductive Reasoning

Determining whether a sample provides a good basis for broader generalizations is a basic challenge of inductive reasoning. Adults apply a diversity-based strategy to this challenge, expecting diverse samples to be a better basis for generalization than homogeneous samples. For example, adults expect that a property shared by two diverse mammals (e.g., a lion and a mouse) is more likely to be shared by all mammals than a property that is shared by two more similar mammals (e.g., a lion and a tiger). Across four studies, we document a developmental progression in children's understanding that diverse samples provide a strong basis for generalizations, such that young children (grade 1) consistently failed to consider sample diversity within their inductive reasoning, but older children (grade 5) preferred to create diverse samples on which to base inferences about basic-level categories. These results suggest that recognizing the value of a diverse sample for inductive reasoning emerges slowly across the elementary school years.     

The Development of Compensatory Stepping Skills in Children

The development of the ability to use the step for balance recovery was studied among twenty-five 9- to 19-month-old children. The children were grouped according to walking experience (4 levels) and exposed to backward support surface translations, 8 cm in amplitude, under 3 velocity conditions: 15, 20, and 25 cm/s. New walkers (up to 2 weeks' walking experience) used the step infrequently and ineffectively in response to threats to balance. Intermediate walkers (1-3 months' walking experience) showed an increasing use of the step and significant improvement in step execution compared with new walkers. Advanced walkers (> 3 months' walking experience) experienced no falls throughout the protocol, capturing balance with feet-in-place or step responses under all perturbation conditions. A significant developmental transition in the emergence of the compensatory step occurred between the new walker and the intermediate walker experience levels, that is, within the first 3 months of walking experience. Three to 6 months' experience was required for the development of an effective stepping response. A concomitant change in mediolateral stability paralleled the emergence of compensatory stepping.     

Visual discrimination of species in dogs (Canis familiaris)

In most social interactions, an animal has to determine whether the other animal belongs to its own species. This perception may be visual and may involve several cognitive processes such as discrimination and categorization. Perceptual categorization is likely to be involved in species characterized by a great phenotypic diversity. As a consequence of intensive artificial selection, domestic dogs, Canis familiaris, present the largest phenotypic diversity among domestic mammals. The goal of our study was to determine whether dogs can discriminate any type of dog from other species and can group all dogs whatever their phenotypes within the same category. Nine pet dogs were successfully trained through instrumental conditioning using a clicker and food rewards to choose a rewarded image, S+, out of two images displayed on computer screens. The generalization step consisted in the presentation of a large sample of paired images of heads of dogs from different breeds and cross-breeds with those of other mammal species, included humans. A reversal phase followed the generalization step. Each of the nine subjects was able to group all the images of dogs within the same category. Thus, the dogs have the capacity of species discrimination despite their great phenotypic variability, based only on visual images of heads.