Reaction time to threat stimuli in panic disorder and social phobia

Two studies assessed response time among clinically anxious subjects and normal controls when presented with threat, positive and neutral stimuli under perceptual (lexical decision) and semantic (category decision) task conditions. In Study 1, panic disorder subjects' (n = 14) performance was compared to that of matched normal controls (n = 14) while in Study 2 social phobic subjects (n = 24) were compared to matched normal controls (n = 24). Relative to matched normal controls, panic disorder subjects but not social phobics tended to show greater slowing in performance on the more cognitively complex (category) task. A second finding, consistent across both studies was that, compared to the normal control groups, both panic and social phobic groups showed significantly slowed responses to threat words in both the perceptual and semantic tasks. Such findings are directly counter to the predictions of a mood congruence hypothesis. This apparent contradiction is resolved by a review of the literature which indicates that mood-related facilitation effects are obtained only in tasks which tap awareness of threat information rather than speed of response. It is suggested that while anxiety may produce enhanced awareness of threat, it may inhibit responsiveness to it. The results of these studies are seen as consistent with ethological theories of inhibited motoric responses under certain threat conditions. Furthermore, the findings suggest that caution is indicated in interpreting slowed reaction time to threat stimuli in tasks such as the Stroop color naming task as purely the result of attentional processes.     

Avoidant personality disorder and the generalized subtype of social phobia.

Social phobia and avoidant personality disorder (APD) may be given as comorbid diagnoses. However, it is not known if the labels provide independent, useful diagnostic information. We classified social phobics by social phobia subtype and presence of APD. Generalized social phobics with and without APD (ns = 10 and 10) and nongeneralized social phobics without APD (n = 10) were distinguished on measures of phobic severity. The generalized groups also showed earlier age at onset and higher scores on measures of depression, fear of negative evaluation, and social anxiety and avoidance than did the nongeneralized group. APD criteria of general timidity and risk aversion were more frequently endorsed by social phobics with APD. The data suggest that both the generalized subtype of social phobia and the presence of APD do provide useful diagnostic information but the additional diagnosis of APD may simply identify a severe subgroup of social phobics.     

Modification of preschool sex-typed behaviors by participation in adult-structured activities

Earlier studies have shown the girls spend more time than boys in activities that are highly structured by adults. Structured activities may encourage feminine sex-typed behaviors such as compliance to adults; low-structure activities may encourage masculine sex-typed behaviors such as independence and assertiveness. In the present study the effects of high or low levels of adult structuring on children's social behavior during preschool free-play activities were tested in a field experiment carried out during an entire semester in one preschool classroom. For the first 15 minutes of free play, children were assigned to high- or low-structure activities. As predicted, when children were in high-structure activities, they exhibited high rates of bids for recognition and compliance to adults; in low-structure activities, they exhibited peer-directed leadership, bids for recognition, and compliance. There were no generalized effects of these treatments on their subsequent free choice of activities or social behavior. The study demonstrates powerful effects of naturally occurring variations in children's play activities on sex-typed social behaviors.     

Influences of Destructive Personality Information on Decision Making1

This study examined the effects of information about a landlord's personality on juror judgments for a landlord-tenant civil trial. The personality information manipulated was specifically relevant to destructive acts. Alternative versions of witness testimony were used to describe a landlord either high or low on need for power. treating people as objects, and negative life themes. This information strongly influenced aspects of the schema for this case constructed by the individual mock jurors. Destructive personality information caused dislike of the landlord and lowered the credibility of his story. If the landlord treated people as objects, the credibility of the tenant's story and positive evaluations of the tenant increased. Juror judgments about relative fault were strongly shifted by destructive personality information. An empirical model for juror decisions indicated a dynamic interplay of story components and fault judgments.     

Self-Optimization of Walking in Nondisabled Children and Children With Spastic Hemiplegic Cerebral Palsy

Children voluntarily adopt a frequency and movement pattern for walking. The force-driven harmonic oscillator (FDHO) model was used in this study for accurate prediction of the preferred walking frequency of nondisabled children and children with spastic hemiplegic cerebral palsy. Four potential optimality criteria with which the preferred walking pattern was forced to comply were examined: minimization of physiological costs, maximization of mechanical energy conservation, minimization of asymmetry in lower limb movements and minimization of variability of interlimb and intralimb coordination. Age and gender-matched nondisabled children (n = 6) and children with spastic hemiplegic cerebral palsy (n = 6) were tested under six frequency conditions of walking at a constant speed on a treadmill. For the nondisabled children, the results indicated that their preferred walking frequency could be accurately predicted by the FDHO model. They freely adopted a walking pattern that minimized physiological costs, asymmetry, and variability of inter- and intralimb coordination. For the children with spastic hemiplegic cerebral palsy, the prediction of preferred overground walking frequency required that the FDHO model be modified to account for muscle mass and leg length discrepancies between limbs and increased stiffness. Most of the children achieved the same optimality goals as the nondisabled when walking at the preferred frequency. However, the children were found to use different mechanisms to attain these goals: for example, a steeper increase observed in physiological cost at higher frequencies; a lowered center of gravity of the body, which allowed for angular symmetry; and greater variability of between-joint coordination in the nonaffected limb and less variability in the affected limb.     

The role of proprioception in the perception and control of human movement: Toward a theoretical reassessment

The theoretical role of proprioception in the perception and control of human movement is elusive because of the obvious inability to manipulate experimentally the various receptive systems. Individuals who have had the metacarpophalangeal joint and joint capsule removed and replaced with silastic inserts afford a unique opportunity to evaluate a principal source of proprioception, namely, slowly adapting joint afferents. In a set of experiments, we show that such individuals show no deficits in finger localization following joint replacement. We take this and other complementary findings as a preliminary basis for proposing a dynamic rather than kinematic account of movement production. In addition, we provide a reconceptualization of the function of proprioceptive information in the CNS. Our arguments focus on proprioceptive inputs as tuning or modulating interneuronal pools rather than providing dimension-pecific information to the brain, as is commonly assumed.     

Problems in the evaluation of PLATO lessons

The evaluation of the effectiveness of PLATO CAI in both educational and industrial settings is discussed. The evaluation of the PLATO instruction in the educational setting generally supports the effectiveness of PLATO instruction but was hampered by limited control of instructional method for different populations of students. Further difficulties in evaluation were caused by ceiling effects in the measurement instrument. Evaluation of PLATO instruction in the consulting setting was hampered by lack of cooperation by the client institution. Mastery of the content of some areas covered by the PLATO lessons in this setting was high, whereas mastery of other content areas was low. Conclusions address the necessity for at least a minimal amount of cooperation from the client institution and a minimal amount of control of the evaluation setting for adequate evaluation of any CAI instructional method.     

The variable influence of confession inconsistencies: How factual errors (but not contradictions) reduce belief in suspect guilt

Wrongful conviction statistics suggest that jurors pay little heed to the quality of confession evidence when making verdict decisions. However, recent research indicates that confession inconsistencies may sometimes reduce perception of suspect guilt. Drawing on theoretical frameworks of attribution theory, correspondence bias, and the story model of juror decision‐making, we investigated how judgments about likely guilt are affected by different types of inconsistencies: self‐contradictions (Experiment 1) and factual errors (Experiment 2). Crucially, judgments of likely guilt of the suspect were reduced by factual errors in confession evidence, but not by contradictions. Mediation analyses suggest that this effect of factual errors on judgments of guilt is underpinned by the extent to which mock‐jurors generated a plausible, alternative explanation for why the suspect confessed. These results indicate that not all confession inconsistencies are treated equally; factual errors might cause suspicion about the veracity of the confession, but contradictions do not.     

Two- and three-year-olds infer and reason about design intentions in order to categorize broken objects

In naming artifacts, do young children infer and reason about the intended functions of the objects? Participants between the ages of 2 and 4 years were shown two kinds of objects derived from familiar categories. One kind was damaged so as to undermine its usual function. The other kind was also dysfunctional, but made so by adding features that appeared to be intentional. Evidence that 2‐, 3‐ and 4‐year‐olds were more likely to apprehend the broken objects than the intentionally dysfunctional objects as members of the familiar lexical categories favors the conclusion that, in naming, children may spontaneously infer and reason about design intentions from an early age. This is the first evidence that 2‐ and 3‐year‐olds not only take design intentions into account in object categorization, but that they do so even without explicit mention of the objects’ accidental or intentional histories. The results cast doubt on a proposal that young children's lexical categorization is based on automatic, non‐deliberative processes.