The effects of encoding task on age-related differences in the functional neuroanatomy of face memory

Age-related differences in brain activity mediating face recognition were examined using positron emission tomography. Participants encoded faces using a pleasant-unpleasant judgment, a right-left orientation task, and intentional learning. Scans also were obtained during recognition. Both young and old groups showed signficant effects of encoding task on recognition accuracy, but older adults showed reduced accuracy overall. Increased brain activity in older adults was similar to that seen in young adults during conditions associated with deeper processing, but was reduced during the shallow encoding and recognition conditions. Left prefrontal activity was less in older adults during encoding, but greater during recognition. Differential correlations of brain activity and behavior were found that suggest older adults use unique neural systems to facilitate face memory.     

Regression periods in infancy: a case study from Catalonia

Based on Rijt-Plooij and Plooij's (1992) research on emergence of regression periods in the first two years of life, the presence of such periods in a group of 18 babies (10 boys and 8 girls, aged between 3 weeks and 14 months) from a Catalonian population was analyzed. The measurements were a questionnaire filled in by the infants' mothers, a semi-structured weekly tape-recorded interview, and observations in their homes. The procedure and the instruments used in the project follow those proposed by Rijt-Plooij and Plooij. Our results confirm the existence of the regression periods in the first year of children's life. Inter-coder agreement for trained coders was 78.2% and within-coder agreement was 90.1%. In the discussion, the possible meaning and relevance of regression periods in order to understand development from a psychobiological and social framework is commented upon.     

Speech perception without hearing

In this study of visual phonetic speech perception without accompanying auditory speech stimuli, adults with normal hearing (NH; n = 96) and with severely to profoundly impaired hearing (IH; n = 72) identified consonant-vowel (CV) nonsense syllables and words in isolation and in sentences. The measures of phonetic perception were the proportion of phonemes correct and the proportion of transmitted feature information for CVs, the proportion of phonemes correct for words, and the proportion of phonemes correct and the amount of phoneme substitution entropy for sentences. The results demonstrated greater sensitivity to phonetic information in the IH group. Transmitted feature information was related to isolated word scores for the IH group, but not for the NH group. Phoneme errors in sentences were more systematic in the IH than in the NH group. Individual differences in phonetic perception for CVs were more highly associated with word and sentence performance for the IH than for the NH group. The results suggest that the necessity to perceive speech without hearing can be associated with enhanced visual phonetic perception in some individuals.     

Taxonicity of anxiety sensitivity: an empirical test among youth

Taxometric coherent cut kinetic analyses were used to test the latent structure of anxiety sensitivity (AS) among 371 youth. Anxiety sensitivity was indexed by the 18-item Childhood Anxiety Sensitivity Index (CASI; Silverman et al., J. Clin. Child Psychol. (1991), 20, 162-168). Two sets of manifest indicators of AS were constructed using the CASI: (1) three item-parcel manifest indicators: disease concerns, unsteady concerns, and mental illness concerns; and (2) nine single-item indicators representing each of these three facets of AS. Results from standard and short-scale MAXCOV procedures, internal consistency tests, analyses of simulated Monte Carlo data, and MAMBAC external consistency tests indicated that the latent structure of anxiety sensitivity among youth was taxonic. Estimated base rate of the observed AS taxon ranged between 13.6 and 16.5%. The present findings are discussed in terms of theoretical implications for the study of AS and vulnerability for anxiety psychopathology.     

Body checking and avoidance and the core features of eating disorders among obese men and women seeking bariatric surgery

This study examined two aspects of body checking and avoidance, and their relations to the core psychopathology of eating disorders (EDs), in severely obese men and women seeking bariatric surgery. A consecutive series of 260 (44 male and 216 female) gastric bypass candidates were administered measures to assess body checking and avoidance, binge eating, restraint, and overevaluation of weight and shape. The majority of patients reported regularly pinching areas of their body to check for fatness and avoided wearing clothing that made them particularly aware of their body. Significant associations were observed between checking and restraint, and between avoidance and binge eating. Both checking and avoidance behaviors were significantly associated with overevaluation of weight and shape. The positive associations between each of the two behaviors (body checking and avoidance) with overevaluation of weight/shape remained significant even after controlling for the effects of avoidance on body checking and vice versa. Stepwise multiple regression analyses revealed that binge eating, body checking, and avoidance behaviors made significant unique contributions and jointly accounted for 22-25% of the variance in overevaluation of weight and shape, respectively. This study documents the presence of eating disorder psychopathology among severely obese patients seeking bariatric surgery. The findings support the view that body checking and avoidance behaviors are manifestations of overevaluation of weight and shape and disordered eating.     

DSM-oriented scales and statistically based syndromes for ages 18 to 59: linking taxonomic paradigms to facilitate multitaxonomic approaches

We used behavioral and emotional problem items to construct (a) nosologically based Diagnostic and Statistical Manual of Mental Disorders (DSM) oriented scales from experts' ratings of the items' consistency with DSM-IV (4th ed.; American Psychiatric Association, 1994) diagnostic categories, and (b) statistically based syndromes from factor analyses of adults' self-ratings and ratings of adults by people who knew them (N = 4,628). Quantified, operationally defined, and normed DSM-oriented scales and statistically based syndromes facilitate multitaxonomic approaches to the assessment of adult psychopathology. Psychometric properties and cross-informant correlations were similar for DSM-oriented scales and statistically derived syndromes. Statistical associations between phenotypically similar DSM-oriented scales and statistically based syndromes were moderate to strong. Multitaxonomic approaches can avoid reification of provisional taxa that may result from excessive reliance on a single taxonomic paradigm.     

Does the contextual interference effect last over extended transfer trials?

The contextual interference effect (random practice yields better transfer and retention compared to blocked practice) detected in a study of 24 boys and 33 girls randomly selected (M age = 10.5 yr., SD = .6) performing a linear positioning motor task seemed to dissipate in extended transfer trials.     

The mental representation of living and nonliving things: differential weighting and interactivity of sensorial and non-sensorial features

Warrington and colleagues (Warrington & McCarthy, 1983, 1987; Warrington & Shallice, 1984) claimed that sensorial and functional-associative (FA) features are differentially important in determining the meaning of living things (LT) and nonliving things (NLT). The first aim of the present study was to evaluate this hypothesis through two different access tasks: feature generation (Experiment 1) and cued recall (Experiment 2). The results of both experiments provided consistent empirical support for Warrington and colleagues' assumption. The second aim of the present study was to test a new differential interactivity hypothesis that combines Warrington and colleagueS' assumption with the notion of a higher number of intercorrelations and hence of a stronger connectivity between sensorial and non-sensorial features for LTs than for NLTs. This hypothesis was motivated by previoUs reports of an uncrossed interaction between domain (LTs vs NLTs) and attribute type (sensorial vs FA) in, for example, a feature verification task (Laws, Humber, Ramsey, & McCarthy, 1995): while FA attributes are verified faster than sensorial attributes for NLTs, no difference is observed for LTs. We replicated and generalised this finding using several feature verification tasks on both written words and pictures (Experiment 3), including in conditions aimed at minimising the intervention of priming biases and strategic or mnemonic processes (Experiment 4). The whole set of results suggests that both privileged relations between features and categories, and the differential importance of intercorrelations between features as a function of category, modulate access to semantic features.     

Integrating neurobiology and psychopathology into evidence-based treatment of social anxiety disorder

Social anxiety disorder (SAD) is a common, chronic psychiatric disorder characterized by a persistent fear of social or performance situations in which embarrassment can occur. This disorder typically appears during the mid-adolescent years and is unremitting throughout life if not properly treated. SAD presents as two subtypes: the more common and debilitating generalized form, and the nongeneralized form, which consists predominantly of performance anxiety. The majority of patients with SAD have comorbid mental disorders, including mood, anxiety, and substance abuse. No single development theory has been proposed to account for the origins of SAD, although current understanding of the etiology of SAD posits an interaction between psychological and biological factors. Risk factors include environmental and parenting influences and dysfunctional cognitive and conditioning events in early childhood. The neurobiology of SAD appears to involve neurochemical dysfunction, as evidenced by studies of neuroreceptor imaging, neuroendocrine function, and profiles of response to specific medications. Clinical trials have demonstrated that benzodiazepines and antidepressants are effective in the treatment of SAD. The selective serotonin reuptake inhibitors are emerging as the first-line treatment for SAD, based on their proven safety, tolerability, and efficacy. Goals for ongoing future research include development of approaches to achieve remission, to convert nonresponders and partial responders to full responders, and to prevent relapse and maintain long-term efficacy. This monograph explores the epidemiology, clinical presentation, and differential diagnosis of SAD, with a focus on neural circuitry of social relationships and neurochemical dysfunction. The prevalence, rates of recognition and treatment, patterns of comorbidity, quality-of-life issues, and natural history of SAD are discussed as well as pharmacologic and psychosocial treatment strategies for SAD.     

The influence of NMDA receptors in the dorsomedial striatum on response reversal learning

In mammals, the dorsomedial striatum is one brain area shown to be critical for the flexible shifting of response patterns. At present, the neurochemical mechanisms that underlie learning during a shift in response patterns are unknown. The present study examined the effects of NMDA competitive antagonist, DL-2-amino-5-phosphonopentanoic acid (AP-5), injected into the dorsomedial striatum on the acquisition and reversal of a response discrimination. Male Long-Evans rats were tested across two consecutive days in a modified cross-maze. Rats received an infusion of either saline or AP-5 (5 or 25 nmol) 5 min prior to each test session. In the acquisition phase rats learned to turn in one direction (right or left) to receive a cereal reinforcement. In the reversal learning phase rats learned to turn in the opposite direction as in the acquisition phase. In both phases, criterion was achieved when a rat made 10 consecutive correct trials. Infusions of AP-5 did not impair acquisition, but impaired reversal learning of a response discrimination in a dose-dependent fashion. The reversal learning deficit induced by AP-5 resulted from reversions back to the originally learned response pattern following the initial shift. These results suggest that activation of NMDA receptors in the dorsomedial striatum are critical for the flexible shifting of response patterns by enhancing the reliable execution of a new response pattern under changing task contingencies.