Jolly fat rats? The effects of diet-induced obesity on territorial fighting

In experiment 1, pairs of young male rats became obese on a palatable and complex diet high in fat, sucrose, and protein. The obese pairs exhibited greater within-group weight variability and, when tested as adults, were significantly more aggressive toward an unfamiliar conspecific than chow-fed controls. The increased aggressivity of obese males was not due to the relatively larger resident-intruder weight disparities in these pairs, since weight-matched pairs of unfamiliar animals were as aggressive toward each other as pairs not matched in body weight (experiment 2). The complex and calorically dense diet may have accelerated the development of the experimental animals, producing subjects whose aggressivity was comparable to that of much older animals.     

Putting phonetic context effects into context: a commentary on Fowler (2006)

On the basis of a review of the literature and three new experiments, Fowler (2006) concludes that a contrast account for phonetic context effects is not tenable and is inferior to a gestural account. We believe that this conclusion is premature and that it is based on a restricted set of assumptions about a general perceptual account. Here, we briefly address the criticisms of Fowler (2006), with the intent of clarifying what a general auditory and learning approach to speech perception entails.     

Implicit and explicit processing in deep dyslexia: Semantic blocking as a test for failure of inhibition in the phonological output lexicon

The failure of inhibition hypothesis posits a theoretical distinction between implicit and explicit access in deep dyslexia. Specifically, the effects of failure of inhibition are assumed only in conditions that have an explicit selection requirement in the context of production (i.e., aloud reading). In contrast, the failure of inhibition hypothesis proposes that implicit processing and explicit access to semantic information without production demands are intact in deep dyslexia. Evidence for intact implicit and explicit access requires that performance in deep dyslexia parallels that observed in neurologically intact participants on tasks based on implicit and explicit processes. In other words, deep dyslexics should produce normal effects in conditions with implicit task demands (i.e., lexical decision) and on tasks based on explicit access without production (i.e., forced choice semantic decisions) because failure of inhibition does not impact the availability of lexical information, only explicit retrieval in the context of production. This research examined the distinction between implicit and explicit processes in deep dyslexia using semantic blocking in lexical decision and forced choice semantic decisions as a test for the failure of inhibition hypothesis. The results of the semantic blocking paradigm support the distinction between implicit and explicit processing and provide evidence for failure of inhibition as an explanation for semantic errors in deep dyslexia.     

Impaired discourse gist and working memory in children after brain injury

Emerging evidence suggests that a traumatic brain injury (TBI) in childhood may disrupt the ability to abstract the central meaning or gist-based memory from connected language (discourse). The current study adopts a novel approach to elucidate the role of immediate and working memory processes in producing a cohesive and coherent gist-based text in the form of a summary in children with mild and severe TBI as compared to typically developing children, ages 8-14 years at test. Both TBI groups showed decreased performance on a summary production task as well as retrieval of specific content from a long narrative. Working memory on n-back tasks was also impaired in children with severe TBI, whereas immediate memory performance for recall of a simple word list in both TBI groups was comparable to controls. Interestingly, working memory, but not simple immediate memory for a word list, was significantly correlated with summarization ability and ability to recall discourse content.     

Repetition-based credibility enhancement of unfamiliar faces

This experiment demonstrated that rating the credibility of nonfamous faces results in a significant increase in rated credibility on a subsequent encounter relative to new nonfamous faces. The degree of credibility enhancement is comparable for both honesty and sincerity ratings and at both short (2-day) and long (14-day) interrating intervals. Furthermore, credibility enhancement was independent of recognition; ratings were significantly higher for repeated faces, regardless of whether they were remembered. Although female faces were rated more credible than male faces, there was no gender difference in the degree of credibility enhancement with repetition. Conditional analyses revealed that actual, rather than perceived, repetition formed the basis of credibility enhancement. Future research should compare repetition effects on both credibility and affect as well as the durability of such effects over time.     

Weathering a political storm. A contextual perspective on a psychological research controversy

In the spring of 1999, a storm of controversy arose at the local, state, and national levels surrounding an article on the effects of child sexual abuse published in 1998 in Psychological Bulletin. The article was vehemently denounced by various media outlets, conservative grassroots organizations, members of the general public, state legislatures, and ultimately by the United States Congress. The authors chronicle these unprecedented events and related challenges faced by the American Psychological Association. The authors also describe the Association's efforts to resolve the crisis, while staunchly upholding academic freedom and scientific integrity, and review the lessons learned for the field of psychology.     

Young adult follow-up of hyperactive children: self-reported psychiatric disorders,comorbidity, and the role of childhood conduct problems and teen CD

We report on the psychiatric disorders present at young adult follow-up (Mean age 20–21 years; 13 + year follow-up) and the comorbidity among them for a large sample of hyperactive (H; N = 147) and community control (CC; N = 71) children. The H group had a significantly higher risk for any nondrug psychiatric disorders than the CC group (59% vs. 36%). More of the H group met criteria for ADHD (5%); major depressive disorder (26%); and histrionic (12%), antisocial (21%), passive–aggressive (18%), and borderline personality disorders (14%) at follow-up than the CC group. Severity of childhood conduct problems contributed to the risk for passive–aggressive, borderline, and antisocial personality disorders. But it only affected risk for antisocial personality after controlling for severity of teen conduct disorder (CD), which also contributed to the risk for these same 3 disorders. Examination for comorbidity among these disorders indicated that presence of either borderline or antisocial personality disorder significantly increased the risk for major depression and the other significant personality disorders. More of the hyperactive group had received various forms of mental health treatment during and since leaving high school than the control group. Results suggest that hyperactive children are at significant risk for at least 1 nondrug disorder in young adulthood, principally major depression and several personality disorders, and that this risk is largely mediated by severity of CD at adolescence.     

The probability of the least likely non-length-controlled bigram affects lexical decision reaction times

The frequency effect, by which high frequency words are recognized with more ease than low frequency words, is one of the most robust effects in cognitive psychology. Frequency interacts with many word-level variables, to the extent that most effects reported in word recognition literature have an impact only on low frequency words. This has been taken as evidence that high frequency words are accessed in a special way, via either an addressed pathway as in the dual-route model or an assembled pathway as in a PDP model. Under either model, sublexical effects should have no bearing on the ease with which representations for high frequency words are accessed. In this article, however, we describe a series of studies that examine a sublexical effect (namely nonlength controlled minimal bigram frequency) that is only found for high frequency words, suggesting that sublexical processing must play a role in the recognition of even high frequency words.