Role of visual information in ball catching

The present study is concerned with the perceptual information about the body and space underlying the act of catching a ball. In a series of four experiments, subjects were asked to catch a luminous ball under various visual conditions. In general, catching in a normally illuminated room was contrasted with catching the luminous ball in an otherwise completely dark room. In the third and fourth experiments, intermediate conditions of visual information were included. The results suggest that it is possible to catch a ball with one hand when only the ball is visible, but performance is better when the subject has the benefit of a rich visual environment and two hands. The second experiment indicated that subject performance does improve with practice in the dark, but time spent in the darkened room itself doesn't result in a significant decrement in performance. Results of the third study suggest that vision of one's hand does not aid in the performance of this task whereas the presence of a minimal visual frame appears to aid performance. The final study examined the relation between catching performance and body sway under similar visual conditions. Results of this experiment imply that persons who exhibit relatively little postural sway in full-room lighting performed better at this catching task.     

The role of visual information in control of a constrained locomotor task

The nature of visually guided locomotion was examined in an experiment where subjects had to walk to targets under various conditions. Target distance was manipulated so that subjects had to (a) lengthen their paces in order to hit the target; (b) shorten their paces; (c) make no adjustments to their standard pace length at all. They did this under four visual conditions: (a) normal vision; (b) with vision restricted to a "snapshot" each time the foot that was to be placed on the target was on the ground; (c) with a snapshot each time the foot to be placed was in the swing phase; and (d) no vision after departure fro the target. The results show that the subjects succeed in reaching the target in most cases. However, the smoothness and fluidity of their movements vary significantly between conditions. Under normal vision or where visual snapshots are delivered when the pointing foot is on the ground, locomotion is smoothly regulated as the subjects approach the target. where snapshots are delivered when the pointing foot is in the swing phase, regulation becomes clumsy and ill coordinated. Where no vision is available at all during the approach, adjustments are made, but these are least coordinated of all. The results show that well-coordinated visual regulation does not require continuous visual guidance but depends on intermittent information being available at the appropriate times in the action sequence. Such timing is often more important than the total amount of information that is available for guidance.     

The development of locomotor coordination: longitudinal change and invariance

Developmental sequence, relative timing, center of gravity, and phase-plane analyses were used to study a minimum of 15 years of longitudinal, filmed data on the development of hopping in 7 children. The developmental sequences revealed common, qualitative changes in the movement of the children, although each child progressed through the changes at his/her own rate. The timing analyses showed that, in the advanced hop, the tightest limb relationships were found within the hopping leg, then between contralateral limbs of the same girdle, and then between legs and arms. Relative-timing calculations revealed (a) intralimb, timing invariances that were present in first attempts to perform the skill at age 3 and remained for 15 years across all developmental levels; (b) emergent, interlimb timings that gradually became invariant; and (c) intra- and interlimb timing showing gradual development over the 15 years. One invariant, the time between landing and deepest knee flexion, is also invariant in the walk and the run (Shapiro, Zernicke, Gregor, & Diestel, 1981). Phase plane analyses indicated that the timing of peak and zero velocities may be the coordinative constant accounting for a relative timing invariance between the two legs. Position of the body's center of gravity may explain the invariant relative time between landing and deepest knee flexion, or the explanation could lie in the "equation of constraint" regulating joint equilibrium points. The data suggest that modeling the developing hop as the evolving interaction of four vibratory systems would be promising.     

Specific forms of facial EMG response index emotions during an interview: from Darwin to the continuous flow hypothesis affect-laden information processing

Previous research has demonstrated that mild negative emotional imagery and unpleasant sensory stimuli lead to greater electromyographic activity over the brow muscle region than mild positive imagery and stimuli, even in the absence of significant changes in visceral and general facial EMG activity. Previous research has not addressed whether electromyographic responses over the brow region are a sensitive and specific index of emotions, however, since a multiplicity of events lead to changes in brow activity. In this research, facial electromyographic and audiovisual recordings were obtained while individuals were interviewed about themselves. Afterwards, individuals were asked to describe what they had been thinking of during specific segments of the interview marked by distinctive electromyographic responses over the brow region in the context of ongoing but stable levels of activity elsewhere in the face. The results are interpreted in terms of a continuous flow hypothesis of affect-laden information processing.     

Social contagion of binge eating

A social psychological account of the acquisition of binge eating, analogous to the classic social psychological work, "Social Pressures in Informal Groups" (Festinger, Schachter, & Back, 1950), is suggested and tested in two college sororities. In these sororities, clear evidence of group norms about appropriate binge-eating behavior was found; in one sorority, the more one binged, the more popular one was. In the other, popularity was associated with binging the right amount: Those who binged too much or too little were less popular than those who binged at the mean. Evidence of social pressures to binge eat were found as well. By the end of the academic year, a sorority member's binge eating could be predicted from the binge-eating level of her friends (average r = .31). As friendship groups grew more cohesive, a sorority member's binge eating grew more and more like that of her friends (average r = .35). The parsimony of a social psychological account of the acquisition of binge eating behavior is shown. I argue that there is no great mystery to how bulimia has become such a serious problem for today's women. Binge eating seems to be an acquired pattern of behavior, perhaps through modeling, and appears to be learned much like any other set of behaviors. Like other behaviors, it is under substantial social control.     

The Effect of Job Level and Amount of Information on the Evaluation of Male and Female Job Applicants

The addition of job-related information regarding an applicant's leadership ability reduced bias against female applicants applying for a managerial position.     

Prosodic aspects of motherese: effects on gaze and responsiveness in developmentally disabled children

This study was conducted to examine the effectiveness of using voice tones (prosody) typical of "motherese" (O. K. Garnica, 1977, in C. E. Snow & C. A. Ferguson (Eds.), Talking to Children: Language Input and Acquisition, pp. 63-88, Cambridge: Cambridge Univ. Press) on responsiveness and eye gaze in children with severe handicaps. Specifically, two conditions, "motherese" and "conversational" voice tones, were compared. The current study presents data from naturalistic observations of six children, and controlled experimental manipulations with four children. The results of the naturalistic observations in Study 1 suggested a positive relationship between the use of voice tones typical of "motherese" and responsiveness and eye gaze. Further analysis using an alternating treatments design in Study 2 revealed similar results. Specifically, the use of prosody associated with "motherese" showed increased levels of eye gaze when compared to the use of "conversational tones." The results suggest the importance of considering normal development in analyzing social and teaching interactions between teachers and severely handicapped children.     

Children's perception of certain musical properties: scale and contour

Children's perception of scale and contour in melodies was investigated in five studies. Experimental tasks included judging transposed renditions of melodies (Studies 1 and 3), discriminating between transposed renditions of a melody (Study 2), judging contour-preserving transformations of melodies (Study 4), and judging similarity to a familiar target melody of transformations preserving rhythm or rhythm and contour (Study 5). The first and second studies showed that young children detect key transposition changes even in familiar melodies and they perceive similarity over key transpositions even in unfamiliar melodies. Young children also are sensitive to melodic contour over transformations that preserve it (Study 5), yet they distinguish spontaneously between melodies with the same contour and different intervals (Study 4). The key distance effect reported in the literature did not occur in the tasks of this investigation (Studies 1 and 3), and it may be apparent only for melodies shorter or more impoverished than those used here.     

Developmental changes in attentional skills: the effect of irrelevant variations on encoding and response selection

The present experiments examine how irrelevant variations within a stimulus set interfere with performance in a selective attention task. Second graders, fifth graders, and adults were administered a discrete trial version of a selective attention task in which they were required to search for an object that matched the prime on the targeted dimension. The stimuli in the first experiment were constructed from spatially integrated dimensions whereas the second experiment used spatially separated dimensions. The results indicated that while the spatially separated dimensions were perceived independently by all age groups, developmental differences in perceived structure were evident with the spatially integrated dimensions. Problems associated with response selection were a major source of interference with both types of stimuli, but the severity of the interference varied with the age of the perceiver and the nature of the stimuli. The developmental implications of these findings were considered.