Nontarget detectability and interference with parafoveal target identification

A target and a flanking nontarget which shared no primary feature were exposed simultaneously in the parafoveal region of the left or right visual field. The presentation terminated with one of two metacontrast masks, one of which masked the nontarget significantly better than the other. One group of 8 subjects received nontargets which were detected better with one of the metacontrast masks, while another group of 8 subjects received nontargets which were detected better with the other mask. Target identification was significantly better when the nontarget appeared on its foveal side rather than on its peripheral side, and this superiority was independent of accuracy in detecting the nontarget. The lack of consistency of this result with models explaining the parafoveal identification asymmetry in terms of feature perturbations is emphasized. Asymmetric lateral inhibition is suggested as an explanation.     

Effects of initial limb position on the accuracy, reaction time and electromyographic patterns of rapid movements

An experiment was performed to determine the effects of initial limb condition on final accuracy of rapid, elbow flexion movements in the horizontal plane. Electromyographic (EMG) recordings were also taken from an agonist (biceps) and antagonist (triceps) muscle by means of bipolar surface electrodes. In the experiment the subject's forearm was passively oscillated by means of an electric motor, and when an auditory buzzer sounded, the subject was required to react as quickly as possible and rapidly move to the previously learned target angle. Thus, movements could be initiated from either static or moving starting positions. The results indicated that general accuracy was not greatly affected by these manipulations, however, constant error and pre-motor reaction time suggested that subjects may have been utilizing initial limb condition information contrary to a mass-spring view. EMG data showed that the timing characteristics of the agonist and antagonist muscles were modulated, depending on the type of movement produced, supporting an impulse-timing model (Wallace 1981).     

Children's understanding of food and its functions: A preliminary study of the development of concepts of nutrition

Children's developing conceptions of how the body functions nutritionally were examined. Two different tasks provided converging findings. One task asked children to judge the causes of certain end states (e.g., why X is fat). The second task asked children to judge the result of certain contrasting diets (e.g., twin-1 eats twice as much candy as twin-2). The results evidenced; (a) systematic misconceptions on the part of kindergarteners that were overcome by sixth grade; and (b) other fairly sophisticated conceptions present even at the youngest ages tested. The research provides a needed first step toward describing the naive theories of nutrition possessed by children at different ages. Knowledge of childrens' theories of nutrition are essential for optimal planning of curricula and methods in nutrition education.     

Effects of listener feedback on the messages of kindergarten children in a referential communication task

A referential communication paradigm was employed with kindergarten children to determine the effects of systematically varied feedback following inadequate message production. Feedback conditions included three levels of verbal specificity presented either alone or in combination with visual feedback. Results indicated that kindergarten children formulated more adequate referential messages when provided with either highly specific verbal feedback or a chance to view the listener's incorrect choice of referent. The differential effectiveness of various types of feedback was discussed in terms of the role of comparison activities in the referential communication process, and implications for the communicative competency of kindergarten children were considered.     

Stress management for teachers: A cognitive-behavioral program

Urban secondary school teachers participated in a cognitive-behavioral stress management program. Assessment data were also collected from a waiting list control group. Dependent measures included self-reported anxiety and stress, and observations of teacher classroom behavior. Results showed that the training program significantly decreased self-reported stress and anxiety. Follow-up data indicated further decrease six weeks after termination of the training program. Results also indicated decreases in motoric manifestations of anxiety in the classroom as a result of the training.     

Rate reduction strategies used by normally fluent and stuttering children and adults

Speech rate can be reduced by prolonging the duration of phonetic units, by pausing between words, or through a combination of these approaches. Child and adult normally fluent speakers and stutterers were tested in basal and modified speaking rate conditions. Subjects' utterances in both conditions were converted to spectrographic displays so that measures of phonetic and pause durations could be made. Comparisons of these measures across conditions revealed that all four groups of subjects spontaneously extended pause and phonetic durations, the former more than the latter, when instructed to voluntarily reduce speech rate.     

Issues to consider in the differential diagnosis of normal childhood nonfluencies and stuttering

Historically more attention has been focused on the adult stutterer than on the young stutterer. This article discusses three key issues in the differential diagnosis of normal childhood nonfluencies and childhood stuttering. The three issues are (1) whether early childhood disfluencies are heterogeneous or homogeneous phenomena, (2) whether the relationship between normal childhood nonfluencies and early stuttering is continuous or dichotomous, and (3) whether normal nonfluencies and stuttering differ quantitatively or qualitatively. Theoretical research as well as clinical implications of these issues are discussed.     

Speech timing skills of normally fluent and stuttering children and adults

This study was designed to explore the speech timing skills of normally fluent and stuttering children and adults producing two sentences, ten consecutive times at basal and modified speaking rates. Spectrographic displays of subjects' utterances in both conditions were made in order to obtain consonant, vowel, pause, and utterance duration measures. Results showed that (1) the two groups of children produced speech durational values similar to those of the two adult groups and (3) there were no consistent between- and within-group differences in the basal and modified rate conditions. Findings are discussed in terms of methodological and sampling differences that exist between the present study and past research on stutterers' speech production abilities.     

Visual attention at three months as a predictor of cognitive functioning at two years of age

The purpose of the present study was to examine the predictive power of various cognitive skills at 3 months of age in terms of later cognitive functioning. Habituating to redundant and recovering to novel stimuli at 3 months of age were found to predict later intellectual functioning at 24 months better than 3-month global intelligence or object permanence scores. In terms of information processing skills, recovery predicted later intelligence test scores better than habituation. It is suggested that changes in cognitive functioning may be viewed as a transformation of skills from one age to another rather than as a continuum of the same skills. With regard to the cognitive abilities of the 3-month-old, it is suggested that information processing may be central to cognitive functioning at this age.