Neuroanatomy of the human affective system

We provide a brief overview of the structures associated with the limbic system using fixed human material. Although the review is by no means intended to be exhaustive, its purpose is to provide a tutorial on the primary structures that are involved in the experience, expression, and regulation of emotion and their anatomical location so that the reader can use this as a "pedagogical guide" for orientation and understanding of the many papers that appear in this Special Issue.     

Associative processes in repetition priming

Three experiments that investigated alternative accounts of repetition priming are reported. All 3 experiments used semantic comparison tasks and included trials in which each of the 2 words being compared had previously occurred on separate trials. In the re-pair match condition, the response required matched that on the 2 previous trials in which the words had occured. In there-pair mismatch condition, the response required was opposite to that on the previous trials containing the words forming the critical pair. In all 3 experiments, responses were faster and more accurate in the re-pair match condition than in the re-pair mismatch condition. Possible accounts of this effect within the frameworks of instance theory and of transfer appropriate processing are considered.     

Engagement and outcome in the treatment of bulimia nervosa: first phase of a sequential design comparing motivation enhancement therapy and cognitive behavioural therapy

Despite the major advances in the development of treatments for bulimia nervosa, drop-outs and a lack of engagement in treatment, continue to be problems. Recent studies suggest that the transtheoretical model of change may be applicable to bulimia nervosa. The aim of this study was to examine the roles of readiness to change and therapeutic alliance in determining engagement and outcome in the first phase of treatment. One hundred and twenty five consecutive female patients meeting DSM-IV criteria for bulimia nervosa took part in a randomised controlled treatment trial. The first phase of the sequential treatment compared four sessions of either cognitive behavioural therapy (CBT) or motivational enhancement therapy (MET) in engaging patients in treatment and reducing symptoms. Patients in the action stage showed greater improvement in symptoms of binge eating than did patients in the contemplation stage. Higher pretreatment scores on action were also related to the development of a better therapeutic alliance (as perceived by patients) after four weeks. However, pretreatment stage of change did not predict who dropped out of treatment. There were no differences between MET and CBT in terms of reducing bulimic symptoms or in terms of developing a therapeutic alliance or increasing readiness to change. The results suggest that the transtheoretical model of change may have some validity in the treatment of bulimia nervosa although current measures of readiness to change may require modification. Overall, readiness to change is more strongly related to improvement and the development of a therapeutic alliance than the specific type of treatment.     

Visual perception of the relative phasing of human limb movements

Studies of bimanual coordination have found that only two stable relative phases (0 degree and 180 degrees) are produced when a participant rhythmically moves two joints in different limbs at the same frequency. Increasing the frequency of oscillation causes an increase in relative phase variability in both of these phase modes. However, relative phasing at 180 degrees is more variable than relative phasing at 0 degree, and when the frequency of oscillation reaches a critical frequency, a transition to 0 degree occurs. These results have been replicated when 2 people have coordinated their respective limb movements using vision. This inspired us to investigate the visual perception of relative phase. In Experiment 1, recordings of human interlimb oscillations exhibiting different frequencies, mean relative phases, and different amounts of phase variability were used to generate computer displays of spheres oscillating either side to side in a frontoparallel plane or in depth. Participants judged the stability of relative phase. Judgments covaried with phase variability only when the mean phase was 0 degree or 180 degrees. Otherwise, judgments covaried with mean relative phase, even after extensive instruction and demonstration. In Experiment 2, mean relative phase and phase variability were manipulated independently via simulations, and participants were trained to perceive phase variability in testing sessions in which mean phase was held constant. The results of Experiment 1 were replicated. The HKB model was fitted to mean judgment standard deviations.     

Frontal Brain Electrical Activity in Shyness and Sociability

A number of studies have shown that shyness and sociability may be two independent personality traits that are distinguishable across a variety of measures and cultures. Utilizing recent frontal activation–emotion models as a theoretical framework, this study examined the pattern of resting frontal electroencephalographic (EEG) activity in undergraduates who self-reported high and low shyness and sociability. Analyses revealed that shyness was associated with greater relative right frontal EEG activity, whereas sociability was associated with greater relative left frontal EEG activity. Also, different combinations of shyness and sociability were distinguishable on the basis of resting frontal EEG power. Although high-shy/high-social and high-shy/low-social subjects both exhibited greater relative right frontal EEG activity, they differed significantly on EEG power in the left, but not right, frontal lead. High-shy/high-social subjects exhibited significantly less EEG power (i.e., more activity) in the left frontal lead compared with the high-shy/low-social subjects. These findings suggest that in distinguishing individual differences in personality and personality subtypes, it is important to consider not only frontal EEG asymmetry measures, but also the pattern of absolute EEG power in each frontal hemisphere.     

Flanker recall and the flanker validity effect may reflect different attentional processes

High flanker recall in the correlated flanker task suggests a failure of selective attention. We used a dissociation approach to examine the role of attentional processing of the flankers’ identities in the flanker validity effect (FVE). In three experiments, flanker recall decreased as flanker duration decreased, but the FVE was not affected by flanker duration. Masking also produced a dissociation, in that masking decreased flanker recall but the FVE was not affected. Examination of on-line flanker identification suggested that flanker recall was an adequate measure of attentional processing of the flankers’ identities on most trials. The results suggest that attentional processing of the flankers’ identities is not related to the magnitude of the FVE and is not necessary for it to obtain. Because there is a failure of selective attention, the dissociations suggest that flanker recall and the FVE may reflect different attentional processes.     

Homesickness in preadolescent and adolescent girls: risk factors, behavioral correlates, and sequelae.

Examined homesickness in 117 girls ages 8 to 16 during a 2-week stay at summer camp. (Homesickness is the distress or impairment caused by an actual or anticipated separation from home. It is characterized by acute longing and preoccupying thoughts of home and attachment objects.) Elevated preseparation levels of homesickness, high expectations of homesickness, negative separation attitudes, low decision control, and little previous separation experience predicted in-camp levels of homesickness. During the separation, homesickness was associated with insecure interpersonal attitudes, negative initial impressions of the novel environment, high perceived distance from home, and low perceived control. Female surrogate caregivers rated homesick girls as having lower social status and more somatic complaints, social problems, and externalizing behavior than less homesick girls. Although the prevalence, intensity, and longitudinal course of homesickness in girls did not differ from analogous samples of boys, girls' profile of risk factors, correlates, and sequelae is unique in its mixed behavioral presentation and small correlations with age and experience.     

Physiological hyperarousal: construct validity of a central aspect of the tripartite model of depression and anxiety.

Physiological hyperarousal (PH) is an understudied component of the tripartite model of depression and anxiety. This study contributes to the literature on PH, the tripartite model, and anxiety and its disorders, using data from psychotherapy outpatients (n = 2,448), air force cadets (n = 1,335), and undergraduates (n = 284). Psychometrics and exploratory and confirmatory factor analyses showed that PH is a reliable, cohesive, discriminable, and valid construct. Compared with subjective anxiety, PH was more associated to panic versus mood disordered status, and to panic versus generalized anxiety disordered status. As hypothesized, an aspect of anxiety sensitivity (i.e., fear of body sensations) was particularly related to subjective anxiety in the presence of PH. Results support the PH construct as replicable, valid, and clinically important and support the utility of the tripartite and related models for understanding the relation of depressive and anxious syndromes.