The use of perceptual features in categorization by orangutans (<Emphasis Type="Italic">Pongo abelli</Emphasis>)

The extent to which categorization of natural classes in animals reflects a generalization based on perceptual similarity versus an abstract conceptual representation remains unclear. Here, two experiments were conducted to identify the perceptual features used by orangutans when categorizing pictures. In Experiment 1, subjects were trained and tested for transfer on a concrete discrimination (gorillas or orangutans vs. other primates). Analysis of performance on both positive and negative exemplars revealed that performance was best on photos with faces, particularly close-ups. Moreover, error trials did not seem to reflect instances of mistaken identity, but rather, exemplars that may have been distracting for other reasons, such as novel coloration or morphology. In Experiment 2, photos were modified to test the effects of various features. Color modifications caused the biggest decrease in performance, and eye modifications also affected performance deleteriously. Therefore, two perceptual features, namely eye regions and color, played a key role in subjects' ability to categorize. However, performance based on an underlying concept cannot be ruled out, because both of these features are highly relevant in terms of defining category membership. Although a subset of features was identified as playing a key role in categorization, these features differed depending on whether feature-use was studied indirectly, as in Experiment 1, or directly, as in Experiment 2.     

Sensory-specific satiety is intact in amnesics who eat multiple meals

What is the relationship between memory and appetite? We explored this question by examining preferences for recently consumed food in patients with amnesia. Although the patients were unable to remember having eaten, and were inclined to eat multiple meals, we found that sensory-specific satiety was intact in these patients. The data suggest that sensory-specific satiety can occur in the absence of explicit memory for having eaten and that impaired sensory-specific satiety does not underlie the phenomenon of multiple-meal eating in amnesia. Overeating in amnesia may be due to disruption of learned control by physiological aftereffects of a recent meal or to problems utilizing internal cues relating to nutritional state.     

“What It Means To Be a Woman:” Ambivalent Sexism in Female College Students’ Experiences and Attitudes

This study used content analysis to examine if themes related to ambivalent sexism (Glick and Fiske 1996) emerged when female students wrote an essay answering the question “What does it mean to be a woman?” and examined the relationship between Ambivalent Sexism Inventory (ASI) scores (Glick and Fiske 1996) and content analysis. Participants were 78 female undergraduate students in the Southeastern U.S. Findings revealed themes related to ambivalent sexism were present in 99% of essays, indicating that ambivalent sexism is highly relevant to women’s gendered experiences. Furthermore participants’ ASI scores were positively correlated with a sexism score created from coded essay content. The discussion addresses theoretical and contextual implications of the findings.     

Analyzing aphasia data in a multidimensional symptom space

The utility of single-case vs. group studies has been debated in neuropsychology for many years. The purpose of the present study is to illustrate an alternative approach to group studies of aphasia, in which the same symptom dimensions that are commonly used to assign patients to classical taxonomies (fluency, naming, repetition, and comprehension) are used as independent and continuous predictors in a multivariate design, without assigning patients to syndromes. One hundred twenty-six Italian-speaking patients with aphasia were first classified into seven classic aphasia categories, based on fluency, naming, auditory comprehension, and repetition scales. There were two goals: (1) compare group analyses based on aphasia types with multivariate analyses that sidestep classification and treat aphasic symptoms as continuous variables; (2) present correlation-based outlier analyses that can be used to identify individuals who occupy unusual positions in the multivariate "symptom space." In the service of the first goal, group performance on an external validation measure (the Token Test) was assessed in three steps: analyses of variance based on aphasia type, regressions using the same cut-offs for fluency, naming, comprehension and repetition as independent but dichotomous predictors, and regressions using the same subscales as continuous predictors (with no cut-offs). More variance in Token Test performance was accounted for when symptoms were treated as continuous predictors than with the other two methods, though use of independent but dichotomous predictors accounted for more variance than aphasia taxonomies. Thus, if we by-pass classical taxonomies and treat patients as points in a multidimensional symptom space, better predictions are obtained. Outlier analyses show that group results depend on heterogeneity among patients, which can be used as a search tool to identify potentially interesting dissociations. Hence this multivariate group approach is complementary to and compatible with single-case methods.     

The role of the bereavement group in the face of 9/11: a self-psychology perspective

The sudden traumatic loss of a spouse equates to an assault on self and the loss of both an internal and external self-object. Mourning requires compensatory self-objects to help in the restoration of self and in the creation of new self-structure. The catastrophe of 9/11 not only assaulted thousands with unanticipated traumatic loss, but also devastated the usual networks of support. In this light, the bereavement group became a valuable venue for self-restoration and recovery. In her group work with 9/11 corporate and uniformed service widows, the author applies a self-psychology perspective that considers that empathic immersion not only affords safety and stabilization, but the opportunity to have self-object needs met in a process that restores and develops self-structure. She proposes the bereavement group as a cohesive self-object milieu serving mirroring, twinship, and idealizing needs. Drawing upon clinical examples, she illuminates the capacity of the group to establish safety, regulate affect, reduce isolation and shame, rekindle memory, and foster coping skills. As such, the group affords a restoration of the assaulted self, an integration of the loss, and an emerging redefinition of self.     

The effects of prenatal maternal stress on children's cognitive development: Project Ice Storm

There exists considerable research on the effects of prenatal maternal stress on offspring. Animal studies, using random assignment to experimental and control groups, demonstrate the noxious effects of prenatal maternal stress on physical, behavioural and cognitive development. The generalizability of these results to humans is problematic given that cognitive attributions moderate reactions to stressors. In humans, researchers have relied upon maternal anxiety or exposure to life events as proxies for the stressors used with animals. Yet, the associations between maternal anxiety or potentially non-independent life events and problems in infants are confounded by genetic transmission of temperament from mother to child. We summarize the literature on prenatal maternal stress and infant cognitive development, leading to the conclusion that the human literature lacks the ability to separate the effects of the objective exposure to a stressor and the mother's subjective reaction. We then describe our prospective Project Ice Storm in which we are following 150 children who were exposed in utero to a natural disaster. We demonstrate significant effects of the objective severity of exposure on cognitive and language development at age two years with important moderating effects of the timing during pregnancy. The implications of our findings are discussed.     

Longitudinal Predictors of Alcohol‐Related Harms During the Transition to Adulthood

While a range of factors have been found to increase the likelihood of alcohol‐related harms among young people, little is known about their relative importance. This article aimed to identify the risks for alcohol‐related harms at an age when alcohol use and problems tend to peak in Australia (19–20 years). A wide range of concurrent and antecedent factors from multiple domains were examined using path analysis, including individual characteristics, family environment, and externalising and internalising problems. The sample comprised of 941 individuals from the Australian Temperament Project, a large longitudinal community‐based study. The path model controlled for current risky drinking and revealed a number of variables that were significant longitudinal predictors of alcohol‐related harms within each of the domains, including adolescent antisocial behaviour and drinking behaviour, low agreeableness, impulsivity, and paternal drinking levels. The potential for developmental prevention approaches to reduce alcohol‐related harms by targeting externalising behaviour problems, interpersonal influences, and individual characteristics is discussed.     

The dimensions of change in therapeutic community treatment instrument

In this article, the authors describe the refinement and preliminary evaluation of the Dimensions of Change in Therapeutic Community Treatment Instrument (DCI), a measure of treatment process. In Study 1, a 99-item DCI, administered to a cross-sectional sample of substance abuse clients (N = 990), was shortened to 54 items on the basis of results from confirmatory factor analyses and item response theory invariance tests. In Study 2, confirmatory factor analyses of the 54-item DCI, completed by a longitudinal cohort of 993 clients, established and validated an 8-factor solution across 2 subpopulations (adults and adolescents) and 2 time points (treatment entry and 30-days postentry). The results of the 2 studies are encouraging and support use of the 54-item DCI as a tool to measure treatment process.     

Dopamine D2 receptors mediate reversal learning in male C57BL/6J mice

Dopamine is critical for directing goal-oriented behavior. We investigated dopamine D₂ receptor involvement in reversal learning and reinforcement efficacy in mice lacking functional dopamine D₂ receptors and their heterozygous and wild-type littermates. Mice discriminated between two odors to receive a food reinforcer: One odor signaled a reinforcer (S⁺); the other odor signaled no reinforcer (S⁻). After mice learned the S⁺/S⁻ relationship, we inverted the reinforcement contingencies. The necessary number of trials to relearn the new reinforcement contingencies served as our index of reversal learning. Mice lacking functional dopamine D₂ receptors repeatedly failed to inhibit previously reinforced responses during reversal trials. In a separate experiment, mice responded for reinforcers on a progressive ratio schedule of reinforcement. Mice lacking functional dopamine D₂ receptors earned significantly fewer reinforcers than did heterozygous mice. Our results suggest that dopamine D₂ receptors regulate reversal learning and influence the reinforcing efficacy of natural rewards.