Effects of speaking upon the rate and variability of concurrent finger tapping in children

Tapping rate and variability were measured as 73 normal, right-handed children in Grades 1–4 engaged in speeded unimanual finger tapping with and without concurrent recitation. Speaking reduced the rate of tapping and increased its variability to a greater extent in younger children than in older children. Developmental changes in variability but not rate were attributable to a greater number of lengthy (>500 ms) pauses in the tapping of younger children. Speaking slowed the right hand more than the left, and the degree of this asymmetry was constant across grade levels. The right-hand effect for tapping rate was not attributable to lengthy pauses. In contrast, asymmetric increases in tapping variability occurred only among children in Grade 1 and only when lengthy pauses were included in the data. The results implicate three mechanisms of intertask interference: one involving capacity limitations, a second involving cross-talk between motor control mechanisms for speech and finger movement, respectively, and a third factor involving occasional diversion of attention from tapping to speaking. These mechanisms are discussed in relation to developmental changes in mental capacity.     

Clustering of skills and occupations: A generic skills approach to occupational training

A report on the process and procedures of determining generic occupational skills and clusters of occupations for optimal occupational training needs is presented. Four hundred and ninety workers and their supervisors representing 37 different occupations were interviewed using a structured questionnaire consisting of items on mathematics, communication, reasoning, and interpersonal and manipulative skills. Respondents were asked to indicate whether a specific skill was a prerequisite to enter a job and also whether that specific skill was required on the job. Six, three, and two hierarchical skill factors and nine occupational clusters were identified. Training and curricular implications were explored.     

An ecological study of the reliability of clinical judgment in executive appraisal

This research was a study of the reliability of clinical judgment findings (multitrait) across three different information sources (psychometric tests, structured interview, and psychometric tests and interview). Subjects (N = 74) were middle and senior executives of Western Canadian technical companies; clinicians (N = 3) were trained and experienced industrial psychologists. The study investigated the similarity of clinical evaluation of personological characteristics (based on an 18-factor multitrait paradigm) across the three different information sources. Subjects were independently rated by a single clinician on 18 criterion factors in each of the three information source categories. Test information source categories required the administration of approximately 12 hrs of standardized psychological assessment questionnaires to each of the 74 subjects. Interview source category involved a 1.5-hr structured interview per subject. Combined condition pooled both test and interview conditions. Generalizability of the findings was maximized by the undertaking of the experiment in a natural situation thus increasing ecological validity. Statistical treatments used were designed to assess the similarity of a clinician's evaluation of a subject based on the different category of information available about that client. Convergence (intrarater reliability) indexes range from a high of .64 to a low of .05. Results indicate a varying degree of convergence of multitrait clinical ratings dependent on clinician and trait being rated. Results are discussed in terms of implications for practitioners involved in executive personnel selection.     

Differential cerebral involvement in perceiving Chinese characters: levels of processing approach

Three experiments were designed to determine the accuracy and latency with which right-handed Chinese university students (12 females and 12 males) recognized Chinese characters in the left and right visual half-fields (VHFs). The experiments varied in the "depth" of processing required. Experiment 1 was a lexical decision task in which the configuration of the stimulus (a real Chinese character or the mirror image of a real character) determined whether the grapheme was an actual character. Experiment 2 required phonological processing; i.e., subjects had to decide whether a character (or a foil) matched the sound of an orally presented Chinese character. Experiment 3 required semantic processing; i.e., subjects had to decide if a character (or a foil) belonged to a particular semantic category. In each experiment, single characters were presented unilaterally for 150 msec. There was a significant right VHF superiority for accuracy scores for Experiments 2 and 3 but not for Experiment 1. None of the experiments yielded significant visual asymmetries in reaction time. The results do not support previous claims of orthography-specific laterality, but instead show that laterality effects for morphemic stimuli vary with the orthographic, phonological, and semantic processing demands of the task.     

Traits attributed to stuttering and nonstuttering children by their mothers

Traits attributed to 34 stuttering and 34 nonstuttering male children by their mothers using an adjective checklist were studied. Mothers of school-aged male stutterers were found to perceive their children as being more insecure, sensitive, anxious, withdrawn, fearful, and introverted than did mothers of nonstutterers. It was concluded that although research has not demonstrated a characteristic stuttering personality, stutterers continue to be perceived as having characteristic personality patterns.     

Coordinate systems in the long-term memory representation of three-dimensional shapes

Visual information can be stored relative to a particular point of view or independently of any particular point of view. Research on mental rotation has shown that people can store and use viewer-centered visual representations of objects and scenes. Some theories of object recognition posit that object-centered representations are also stored and used to represent the shape of three-dimensional objects. In this paper a series of experiments provides evidence that people can store and use both viewer-centered and object-centered representations of three-dimensional objects.     

Effects of eye movements on the recognition and localization of dichotic stimuli

Three experiments examined the effect of gaze shifts on overall performance and ear differences in dichotic listening. In the first two experiments, lights were switched on and off so as to induce rightward, leftward, or upward gaze during dichotic stimulation. The dichotic material consisted of musical passages in Experiment 1 and two kinds of verbal material in Experiment 2. Vertical eye movements enhanced the accuracy of identification of music but not verbal material. The lateral direction of eye movements affected subjects' ability to localize targets in Experiment 1: localization was more accurate in the direction toward which subjects were looking. In the third experiment it was found that optokinetic nystagmus (OKN) influenced the asymmetry of performance on a dichotic consonant-vowel (CV) test. The right-ear advantage was greatest when the OKN drum rotated from left to right and least when it rotated from right to left. The effect was due to corresponding variation in left-ear scores. Possible mechanisms through which shifts of gaze affect auditory identification and localization are proposed.     

Verbal-manual time sharing in children as a function of task priority

Eighty-three normal, right-handed children performed (a) unimanual finger tapping, (b) recitation of a tongue twister, and (c) both tasks concurrently. Tradeoffs in dual-task performance were measured as the priority assigned to each task was manipulated. Irrespective of task priority, speaking interfered to a greater degree with right-hand tapping than with left-hand tapping, but the effect of tapping upon verbal production and speech errors was not lateralized. The asymmetric effect of speech upon tapping, which was seen in 85.5% of the children, cannot be attributed to the disparity between hands in baseline tapping rate. The findings suggest that time-sharing asymmetry reflects cerebral lateralization of speech, but only some of the results would be predicted on the basis of a functional distance principle of cerebral organization.