Stuttering and the valsalva mechanism: A hypothesis in need of investigation

This note presents the hypothesis than the excessively forceful closure of the mouth of larynx associated with certain types of stuttering may involve a neurological confusion between speech and the human body's Valsalva mechanism, which is designed to increase pulmonary pressure by forceful closure of the upper airway to assist in many types of physical effort. It is suggested that such behavior may result from excessive neuromotor tuning of the Valsalva mechanism prior to speech, especially in situations where the stutterer anticipates the need to “try hard” to speak properly. Such tuning may both interfere with phonation and render the Valsalva mechanism overexcitable to triggering stimuli, such as the increase in subglottal pressure that accompanies the start of articulation.     

Clinician attitudes toward stuttering: A decade of change (1973–1983)

The attitudes of 674 speech-language pathologists toward stuttering, stutterers, stuttering therapy, parents of stutterers, and related issues were studied during the years 1973–1983. During that period, clinician attitudes were found to shift away from support of the John-sonian concepts, which suggest parental causality and dangers in early intervention. In addition, clinicians became less likely to perceive stutterers as possessing psychologic disorders and misperceptions of their problem and of their interpersonal relationships. However, a significant number of clinician's were found to continue to hold unsubstantiated beliefs regarding the personality of stutterers, their parents, and the efficacy of early intervention with very young stutterers. The results of the study were interpreted as suggesting the need to educate fluency specialists.     

Clustering of disfluency in nonstuttering childrens' early utterances

The clustering of disfluency within early utterances in the speech of four nonstuttering children was examined. During the developmental period their mean length of utterance was between 2.25 and 3.0 morphemes. The frequency and characteristics of the clustered disfluencies are described and compared with single disfluent moments. Clusters of two disfluencies were analyzed for interactive effects of positional preference and type. Results were similar to those found in older preschool nonstuttering speakers, demonstrating the normal developmental nature of clustering in early sentences. Implications for using this temporal measure to differentially diagnose normal from abnormal disfluency are discussed.     

Vowel duration in stutterers participating in precision fluency shaping

The purpose of this study was to determine the extent to which stutters manipulate vowel duration to achieve fluency after participating in Precision Fluency Shaping. Nine stutterers who read an all-voiced sentence fluently before and after therapy were selected for study. Wide-band spectrograms were made of the initial phrase of the sentences, and vowel durations were computed. Results indicated that extended vowel durations were characteristic of the fluency of stutterers posttherapy. The subject that had the highest rate of disfluency after therapy also had the shortest vowel durations. Clinical implications concerning the importance of speech rate during carryover practice are made.     

Group differences in intelligence and speed of information-processing

Three samples of different levels of mental ability, but each of average or above- average intelligence, were administered a battery of reaction time test which measure the speed with which persons can execute various elementary cognitive processes. Discriminant analyses revealed significant differences between the groups in reaction times and intraindividual standard deviations, and univariate analyses indicated that higher ability groups tended to obtain significantly faster mean reaction times and to show significantly less intraindividual variability than lower ability groups. Groups which differed the most in mental ability differed to the greatest extent on the more complex reaction time tests but this pattern was reversed for groups which were relatively close in mean IQ. Generally, the results support the hypothesis that speed- of-processing is an important factor unferlying intelligence, but a number of puzzling findings indicate the need for continued research in this area.     

THE CREATIONISTS

Abstract. As the crusade to outlaw the teaching of evolution changed to a battle for equal time for creationism, the ideological defenses of that doctrine also shifted from primarily biblical to more scientific grounds. This essay describes the historical development of "scientific creationism" from a variety of late–nineteenth– and early–twentieth–century creationist reactions to Charles Darwin's theory of evolution, through the Scopes trial and the 1960s revival of creationism, to the current spread of strict creationism around the world.     

A measure of agreement for use with the Holland classification system

A measure of agreement for partially ordered data is suggested that makes use of the k categories with the highest ranks, the ranks of the remaining categories being disregarded. The proposed measure is applied to the Self-Directed Search in order to evaluate its agreement with occupational preference. Other forms of agreement in the Holland classification system can also be assessed by the proposed measure. Examples are congruence and husband-wife and counselor-client agreement.     

Concept learning,memory and transfer of dot pattern categories

In the first experiment, subjects rated the similarity of a sample of pairs of random dot patterns generated from 3 prototypes consisting of either 4, 6, or 9 dots. The results of the experiment tended to confirm the structure imposed on the patterns by the construction method. In the second experiment, subjects learned to classify random patterns generated from 2 prototypes with either short or long interprototype distance and consisting of either 4, 6, or 9 dots in a traditional concept identification task. After acquisition, memory for old and new distortions and the prototype, which was not presented during learning, was assessed. The tendency to call a pattern “new” increased with the distance between the pattern and its prototype. In a subsequent transfer test, all subjects saw patterns of either 4, 6, or 9 dots. Performance was above chance and the transfer from larger to smaller patterns tended to be greater than the transfer from smaller to larger patterns. This is consistent with a process of schema formation based on features common to most exemplars of the category. The results are discussed in relation to several theories of concept learning and schema abstraction.     

Critical levels and magnitude of effects

Researchers sometimes report an effect of an experimental manipulation on a dependent variable in terms of the difference between levels of a certain nuisance variable required in the different experimental conditions to reach a given criterion of behavior. This method, however, may yield illusory impressions about magnitude of effects.