Reflex responses of human lip muscles to mechanical stimulation during speech

The role played by reflex pathways in the production of movement has been a significant issue for motor control theorists interested in a wide variety of motor behaviors. From studies of locomotion and chewing, it appears that gains in reflex pathways can be altered so that activity in these pathways does not produce destabilizing responses during movement. In speech production, recent experimental evidence has been interpreted to suggest that autogenetic lip reflexes (perioral reflexes) are suppressed during sustained phonation or speech production. The present study was conducted to assess the effects of phonation, direction of movement, and ongoing speech production on reflex responses of lip muscles. The present results suggest, in contrast to earlier work, that this reflex pathway is not suppressed or absent because the amplitude of the observed response depends upon the activation levels of the various muscles of the lower lip and, therefore, indirectly on the nature of the gesture the subject is instructed to produce.     

Electrophysiological correlates of semantic features

Analyses of averaged auditory evoked responses to a list of 10 positive and 10 negative words led to the identification of a restricted region in the brain response which reliably discriminated between words differing in the semantic features positive and negative. These data support the view that word meanings are composed of more basic components or features and are not stored simply as dictionary items in the brain.     

Book Reviews

The Psychological Record -     

Observers’ sensitivity to dynamic anomalies in collisions

The present study examined observers’ ability to discriminate canonical and dynamically anomalous collisions that were presented in either frictionless or frictional systems. Whereas previous research has provided qualitative demonstrations that dynamic information can be extracted from visual events, the current study provides a parametric assessment of observers’ sensitivity to dynamic invariants. Our findings indicate that observers are competent when viewing both familiar, terrestrial (frictional) systems and unfamiliar but computationally simpler, 0-G (frictionless) systems. Thus, our sensitivity to these dynamic invariants in visual events is robust in natural systems whose dynamic properties differ from those of the environment in which we evolved and developed.     

Prevalence of DSM-III conduct and adjustment disorders for adolescent psychiatric inpatients

The prevalence of DSM-III conduct and adjustment disorders in two adolescent psychiatric facilities, both located near large U.S. cities, was investigated. Overall, 31.6% of the adolescent inpatients were conduct disordered while 12.5% were adjustment disordered. The conduct disorders were primarily "aggressive" subtypes suggesting that this characteristic may influence hospitalization and diagnostic decisions. Such data on prevalence assists future treatment planning, allowing anticipation of case loads.     

Type A behavior,anger expression,and reactions to anger imagery

The experiment investigated the effects of Type A behavior, anger expression, and gender on perceptions of control and heart rate. Jenkins Activity Survey defined Type A and B subjects, categorized as either high or low in anger expression, were asked to recall, image, and generate self-referent statements about angry situations. State anger and heart rate were measured during all of the anger induction conditions, and ratings of imagery vividness and perceptions of control for self and others were taken following the recalled and imaged anger conditions. The results, with both the heart rate and self-report measures, indicated that the effects of the independent variables were interactive and situationally dependent. Type A behavior was associated with increased heart rate in two experimental conditions (mood anger and recalled anger), and, in one instance, this effect was amplified in male subjects (recalled anger). The self-report results yielded interactional effects that most commonly took the form of high anger expression, with male Type A's providing higher ratings of state anger, more vivid anger imagery, and lower perceived self-control ratings than did other categories of subjects. Taken together, these results suggest that anger expressiveness, particularly among males, amplifies the usual reactions attributed to Type A's, and that such effects are mediated by the threat of loss of control. Further, the observed interactive relationships limit the generalizability of A/B differences and raise definitional questions about Type A behavior.