Progressive dysfluency associated with right hemisphere disease

A late onset progressive dysfluency following a right hemisphere stroke occurred in a 62-year-old male. Dysfluency was characterized by pronounced word and phrase reiterations, and sound and syllable reiterations to a lesser degree. Spontaneous speech was significantly more dysfluent than oral reading and repetition. Recitation and singing were minimally dysfluent. Reiterations were accompanied by reduced vocal loudness and increased rate of speech. Reiterations occurred in initial, medial, and final sentence position. Secondary symptoms such as facial grimacing were absent. In contrast to acquired cortical stuttering which is characterized by a preponderance of sound and syllable sentence initial repetitions, dysfluency was more closely characteristic of palilalia. The dysfluency occurred as a symptom of a diffuse nonspecific subcortical projection system defect related to massive infarction in the right middle cerebral artery distribution with associated atrophy.     

Nonverbal communication of couples in conflict

This article examined the rates, contextual meanings, and attributional meanings of nonverbal behavior occurring during role-played conflict between dating couples. Eighty couples reported perceptions of their own behaviors and their partners' behaviors and were observed in a laboratory setting by trained raters. The nonverbal channel was used significantly more by females than by males and to express approval rather than disapproval. However, the nonverbal-disapproval summary category demonstrated weak validity. Eye contact had the most complex, unexpected contextual meanings. Reduced eye contact appeared to variously convey disapproval, cues of lower interpersonal power, and a reduction of intimacy to compensate for accompanying increases in other approval behaviors. Despite significant correlations between nonverbal and verbal behaviors, dating partners rarely based their perceptions of their behavior or their partners' behavior upon their rates of nonverbal behaviors.     

Social metrics of song learning

Five metrics of song learning are described for brown-headed cowbirds (Molothrus ater). The intent of these metrics is to capture not only the behavior of the song learner but the social context in which song learning occurs. Playback procedures, observations of mating, and acoustic and functional assessment of song content are combined to yield measures of song potency, functional validity, social dynamics, vocal flexibility, and social reactivity. Taken as a whole, the results revealed by these metrics indicate that males learn to be effective singers by attending to the social consequences of their behavior.     

Comparison of stimulus control and reinforcement control effects on imitative behavior

An attempt was made to evaluate reinforcement and stimulus control of imitative and non-imitative behavior. The imitative response required the subject to duplicate the experimenter's response by matching blocks that varied in color. The factor designed to evaluate stimulus control was fading, a procedure that systematically varies the differences between the imitative and non-imitative stimuli. The topography and duration of the non-imitative stimuli were faded in. The factors designed to evaluate reinforcement control were differential reinforcement of non-imitative behavior and time out from positive reinforcement. The results showed stimulus control of non-imitation to be more important than reinforcement control, and that reinforcing events were not sufficient to control non-imitation; while the arrangement of stimulus events was sufficient to control non-imitation. These results were related to studies providing evidence for the processes of discrimination and generalization.     

The effects of verbal and behavioral noncompliance on third party instigation of aggression

Females, assigned to one of four conditions defined in terms of a confederate's behavior, suggested which shock intensity the confederate ought to set for an opponent during a reaction time competition, should the opponent lose the trial (had slower reaction time). Confederates either verbally complied or disagreed with suggestions to set high shock, while either actually setting the intensity suggested or setting a lower intensity. Over trials, the opponent became increasingly provocative. Results revealed the main effects and interaction of confederate's verbal and actual behaviors, as well as provocativeness of the opponent, significantly influenced the level of shock subjects suggested. Subjects with verbally and behaviorally compliant confederates suggested more intense shock than subjects who encountered any noncompliance.     

A comparison of dichotic and visuo-acoustic competition in hemispherectomized patients

Following hemispherectomy, patients performing dichotic listening tasks have great difficulty reporting items presented to the ear ipsilateral to their intact hemisphere. One possible cause is an attentional imbalance which, when competing inputs are received from both sides of space, restricts the patient's attention to the stimulus contralateral to his remaining hemisphere. If this explanation is true, then a similar ipsilateral ear decrement should occur when a competing visual stimulus is presented in the contralateral field. In the present study, however, hemispherectomy patients easily reported a digit presented to the ear ipsilateral to their intact hemisphere despite the concurrent presentation of a visual digit to their contralateral field.