Apparent contrast of suprathreshold gratings varies with stimulus orientation

Human contrast sensitivity is known to vary with both stimulus spatial frequency and orientation. Previous research has indicated, however, that the apparent contrast of a sinusoidal grating is independent of spatial frequency at suprathreshold levels. We have found that the apparent contrast of suprathreshold gratings is not independent of its orientation. Observers adjusted the apparent contrasts of vertical and oblique gratings to match a 40% standard. Contrast match deviations were found at a number of spatial frequencies, indicating a lack of contrast constancy with stimulus orientation. The apparent contrast of gratings in different orientations could not be predicted in any simple fashion from either contrast threshold differences or ratios.     

Psychofamilial correlates of school disorders

A model for understanding relationships between family functioning and children's school disorders is presented. The model is based upon the work of Minuchin, Rosman, and Baker (1979) with psychosomatic children and on the author's experience as clinical coordinator of a center for children and adolescents with academic and behavioral disorders. Five transactional patterns are identified as supporting the presence of a school disturbance: enmeshment, overprotectiveness, rigidity, lack of conflict resolution, and child intrusion in marital conflict. Each of these patterns is illustrated with case examples in order to highlight how the child's school symptoms often have an important impact on the family's organization. Some treatment suggestions are provided, with special emphasis made for those practitioners working with Hispanic families.     

Dimensions of metaphor

Two rating studies examined several dimensions of metaphorical sentences. A pool of 260 metaphors was constructed, all in the form “(noun phrase) is/are (noun phrase).” In Study 1 all of the items, and in Study 2, 98 of the items were evaluated on ten scales presumed to be important to the comprehension or interpretation of metaphors: semantic relatedness of the subject and predicate, comprehensibility, imageability, imageability of the subject (topic), imageability of the predicate (vehicle), degree of metaphoricity, metaphor goodness, ease of interpretation, number of alternative interpretations, and felt familiarity of the metaphoric ground. Both experiments revealed the rated dimensions to be highly interrelated, but some analyses allowed evaluation of alternative predictions based on current theoretical approaches to metaphor quality and interpretation. The results indicated consistent but mixed support for the general poisitions under consideration as each appeared to have strong and weak areas of applicability. The interrelationships among the scales are discussed, together with implications of the findings for current theories and future metaphor research.     

Response selection and initiation in speeded reactions: a pupillometric analysis

Three studies are described in which the task-evoked pupillary response is recorded during simple and disjunctive reactions in order to examine its contribution as a measure of the motoric and cognitive aspects of performance in these tasks. In simple reactions a pupillary dilation began about 1.5 sec before the imperative stimulus and peaked about 1 sec after the stimulus. The rate of dilation was inversely related to the interstimulus interval. In disjunctive reactions, both "Go" and "No-Go" responses elicited significant dilations but the No-Go dilation was smaller than the Go dilation. When the response was delayed 2.5 sec after the discrimination stimulus, the dilation to both Go and No-Go responses was much reduced. The pupillary response related to response selection was estimated at 55% of that associated with motor preparation and execution. The probability of responding was found to affect the amplitude of the dilation to No-Go responses but not that to Go responses. The data point to a significant contribution of preparatory motor processing in No-Go reactions and to an overlap between decisional and motoric processing in disjunctive reactions.     

The syllable-length effect in number processing is task-dependent

Two experiments were run in order to investigate the relationship between syllable length of number names and eye-fixation durations during silent reading of one- and two-digit numbers. In Experiment 1, subjects had to read a series of three numbers and recall them orally; in Experiment 2, subjects had to indicate manually whether the value of the middle number was between the values of the outer numbers. The effect of syllable length was controlled for possible confounding effects of number frequency and number magnitude. Findings indicated that fixation duration depended on syllable length of number names in the first task, but not in the second task. The results call into question the claim that phonological encoding is imperative in visual processing; phonological encoding was used only when the numbers had to be recalled, and not when they were coded for computational purposes.     

Stability of performances of individual stutterers on oral reading adaptation tasks

This study aimed to determine whether individual oral reading adaptation task performances are sufficiently reliable to be used as predictive indicators of improvement in stuttering behavior by testing the stability of individual stutterers' adaptation scores. Results demonstrated that all stutterers are not stable in their individual adaptation scores and therefore individual adaptation scores may be insufficiently reliable for predicting and classifying. Theoretical and clinical implications are discussed.     

Bibliography of literature pertaining to the onset,development, and treatment of stuttering during the preschool years

This bibliography consists of clinical, experimental, and theoretical papers pertaining to the onset, development, and treatment of stuttering in children five- years old and younger. It is a downward extension of Silverman, F.H., Bibliography of literature pertaining to stuttering in elementary-school children, Journal of Fluency Disorders, 1978, 3, 87–102.     

An inexpensive 28-V timer circuit using solid state and relay devices

An easily constructed 28-V dc timer circuit is described. The circuit is as precise, reliable, and versatile as some commercially available units, but is much less expensive to construct.