Roles of Visual Information for Control of Reaching Movements in Children

What visual information do children normally require for the control of reaching movements? How is performance affected when children do not have access to the preferred mode of perceptual information? These questions were studied in 28 children who were tested on 3 occasions: at 6, 7, and 8 years of age. The task was to pick beads, 1 at a time, from 1 cup and carry them to another cup. With the aid of a mirror arrangement and a curtain, the amount of visual information was manipulated with regard to both the target and the performing hand. The movements were monitored with an optoelectronic device (SELSPOT II) and analyzed in terms of transport and object-handling phases. Results showed that object handling required visual information on both hand and target. For the transport phase of the movement, visual information on the spatial location of the target was sufficient, and sight of the hand did not improve performance. In contrast to adult subjects, when children did not have access to the required visual information, their performances deteriorated markedly. These results indicate that from the age of 6, children use visual information for control of arm movements in a manner like that of adults, although with less accuracy and speed. However, even 8-year-old children are limited in their ability to use alternative perceptual strategies for movement control, and they therefore become less flexible and more dependent on visual information.     

Irrational Beliefs, Interpersonal Perception and Marital Adjustment

To test the hypothesis that the major evaluative beliefs postulated by Rational-Emotive Behaviour Therapy are related to marital adjustment, 50 married couples completed the Dyadic Adjustment Scale (DAS) and the Survey of Personal Beliefs (SPB). Significant correlations were found between DAS scores and three subscales (Other directed shoulds, Low frustration tolerance and Self worth) of the SPB. On the interpersonal dimension of assumed similarity, females in the high dyadic adjustment group were better able to predict their spouses' awfulizing, low frustration tolerance and self-worth beliefs than were females in the low adjustment group. However, the present study offers only limited support for the hypothesis that interpersonal perception of irrational evaluative beliefs is related to marital adjustment.     

Spontaneous Imitation of Fundamental Frequency and Speech Rate by Nonstutterers and Stutterers

Speech can be described either in terms of acoustics, as a perceptual outcome, or as a motor event. Central to theories of speech perception and production is an attempt to describe how these aspects of speech are interrelated. The present experiment investigated how the nonstutterers' and stutterers' reproductions of acoustically presented interrogative sentences were influenced by experimental variations of intonation (sentence initial vs. sentence final) and speech rate (normal vs. time compressed). We studied the effects of these stimulus manipulations on the speech rate and fundamental frequency (F₀ ) of 10 adult German-speaking nonstutterers and seven stutterers. Experimental manipulations of intonation and speech rate significantly influenced the syllable duration and speech rate of both normal speakers and stutterers. The fundamental frequency of the subjects' responses were also significantly influenced by the intonation of the stimulus. But the stutterers' increase in F₀ for stressed syllables was generally less pronounced than that of nonstutterers. These results imply that (a) the subjects not only extract linguistic meaning from intonation but that they also store extragrammatical speech rate information, and (b) the speakers adopt these speech rate variations for their own productions. Generally, these results demonstrate that speech perception is not limited to extracting linguistically invariant information. The results show that speakers actively generate their own prosody and that this generative process is influenced by the prosodic structure of another speaker's antecedent speech. The implications of these results for theories of speech production are discussed.     

Arm-tracking performance with and without visual feedback in children and adults: developmental changes

Tracking performance was investigated in children (aged 6-7 and 10-11) and in adult subjects. Target signals, moving unpredictably along a straight line, were tracked with the preferred arm, alternately with and without visual feedback. Qualitative observations indicate that tracking is based on continuous adjustments of the ongoing response to the continuously changing target position. No step-and-hold strategy could be detected in any of the three age groups. Tracking performance was described with four simple parameters, derived from linear systems analysis: (a) the delay between target signal and tracking movement (DL); (b) performance at the low-frequency range (LF), (c) performance at the high-frequency range (HF); and (d) a measure of tracking quality or overall similarity in the shape of target signal and tracking movement (Q). There was a considerable improvement in tracking performance with age, even after the age of 10-11, which was mainly demonstrated by a decrease in DL and increases in HF and Q. Tracking performance decreased only to a small extent when visual feedback was withdrawn. Age-related differences in the contribution of visual feedback to tracking performance could not be demonstrated.     

A cross-cultural comparison using the act frequency approach (AFA) in West Germany and the United States

Two studies were conducted in West Germany and the United States to investigate cultural similarities and differences on features of personality assessed through act frequency methods. The first study analysed the acts considered to be central and peripheral to each of six dispositional categories: dominance, quarrelsomeness, gregariousness, submissiveness, agreeableness, and aloofness. The results indicated moderate to strong similarity between the cultures in the prototypicality structure for all categories except agreeableness, which showed little concordance. The second study examined the manifested structure of act performance as assessed through retrospective act reports. The results indicated greater similarity of act endorsements between the two sexes within each culture than between cultures within each sex. Generally, the Americans showed higher base rates than the Germans. Furthermore, over all samples, females showed lower base rates than males. The correlations between relative base rates within each of the six different categories were moderately strong between the cultures (0.56, p < 0.001). Analyses of the relations between the prototypicality structure and the manifested structure yielded a complex picture that was highly dependent on dispositional category. For quarrelsome acts, for example, the more central acts were reported to be performed less frequently in both cultures, while other categories showed positive correlations between base rates and prototypicality. The limitations of these studies are described, and future research directions regarding expanding the range of act frequency methods and the number of nations in the search for personality functioning across cultures are suggested.     

Conversations on contexts and meanings: On understanding therapeutic change from a contextual viewpoint

Recent developments within family therapy theory, often referred to as the Post-Milan Movement, have once again stressed the therapeutic encounter'squality of conversation. When therapy is looked upon as conversation, attention is not only paid to the fact that most of what happens in a session is talking. Rather, a more fundamental stance towardshuman life as basically meaning- making is taken. This is one of the essential premises of the contextualist approach to the social sciences.When applied to human problems this approach claims that symptoms evolve when (1) a person gives meaning to and performs a social act within a context inappropriate to the socially shared meaning of that act, and (2) the behavior of the person is accepted as a symptom by him/herself and the observing community. The therapeutic conversation establishes an exclusive context within which the domains of discourse of the client's life can be accounted for and renegotiated. With the acceptance of these accounts, changes evolve in the context-act relationships (i.e. meanings) construed by the client. This appears to be the basis for the self-healing aspects of psychotherapy.