Midline and off-midline tongue and right- and left-hand vibrotactile thresholds of stutterers and normal-speaking individuals

Vibrotactile thresholds for 7 male stutterers and 7 normal-speaking men (age range for both groups = 19 to 32 yr.) were obtained from the right, midline, and left sides of the lingual dorsum, and the thenar eminences of both hands. The stutterers showed slightly higher (less sensitive) mean thresholds than the normal speakers for all three lingual test sites. This was not the case for the thresholds obtained from both hands. The preliminary data suggest that oral peripheral sensory integrity might be somewhat different for stutterers than for normal-speaking individuals.     

The Effects of Flavor-Aversion Learning on Instrumental Performance

Two experiments investigated the role of lithium-mediated environmental conditioning on instrumental performance. Experiment 1 demonstrated that a novel taste consumed in one arm of a T maze prior to lithium-induced toxicosis reduced performance in this environment whereas similar aversions conditioned in the home cage failed to alter maze performance. Experiment 2 showed that maze performance in a straight alleyway was decremented during extinction only in a group that actually traversed the alley prior to drinking saccharin and receiving lithium injections. This demonstrated that the instrumental decrement observed in Experiment 1 was due not only to the presence of an unpalatable flavor in the goalbox during the test.

     

Regional cerebral glucose metabolism in aphemia: A case report

Local cerebral metabolism was determined in a patient suffering aphemia following cerebral infarction using the 18FDG-PET technique. The syndrome was characterized by profound ictal nonfluency with sparing of other language functions. Speech subsequently improved so that content and grammar were appropriate but mild dysprosody persisted. Conventional CT showed no lesion of the left hemisphere while PET revealed a discrete focus of hypometabolism on the left which partially resolved on serial studies. The metabolic lesion could be localized to the region of the inferior precentral gyrus and the adjacent subcortical space.     

Lexical contribution to nonword-repetition effects: Evidence from event-related potentials

Two experiments investigated the modulation of event-related potentials (ERPs) by the repetition of orthographically legal and illegal nonwords. In Experiment 1, subjects silently counted occasional words against a background of nonwords, a proportion of which were repetitions of an immediately preceding legal or illegal item. ERPs to repeated legal items showed a sustained, topographically diffuse, positive-going shift. In contrast, repeated illegal nonwords gave rise to ERPs showing a smaller and temporally more restricted positive-going modulation. In an attempt to equalize depth of processing across legal and illegal nonwords, subjects in Experiment 2 were required to count items containing a nonalphabetic character against the same background of nonword items. ERPs to repeated legal items showed a modulation similar to, although smaller than, that found in Experiment I, but no effects of repetition were observed in the ERPs to the illegal nonwords. It was concluded that the effects of repeating nonwords, at least as manifested in concurrently recorded ERPs, differ as a consequence of whether items can access lexical memory, and that this is inconsistent with the attribution of such effects solely to the operation of episodic memory processes.     

The role of structural context in perception: Syntax in the recognition of algebraic expressions

Two character-identification experiments investigated the function of structural context during the processing of briefly exposed algebraic strings. Neither experiment prodded evidence to support the notion of an algebra-superiority effect, a contextually driven enhancement of the recognition of specific algebraic characters. However, the results of Experiment 2 indicate that the structure of algebra does provide information at the level of a character’s categorical denomination. These findings suggest that the parsing of an algebraic string includes a level of processing in which its structural context places restrictions on the denominations of its symbols. A processing model of algebraic perception is proposed that incorporates these syntactic constraints—constraints that appear to be independent of feature-based character identification processes.     

J. M. Keynes' ‘theory of evidential weight’: Its relation to information processing theory and application in The General Theory

The conclusions derived by Keynes in his Treatise on Probability (1921) concerning induction, analogical reasoning, expectations formation and decision making, mirror and foreshadow the main conclusions of cognitive science and psychology.The problem of weight is studied within an economic context by examining the role it played in Keynes' applied philosophy work, The General Theory (1936). Keynes' approach is then reformulated as an optimal control approach to dealing with changes in information evaluation over time. Based on this analysis the problem of inductive justification, from a societal perspective, is not, What can we rationally believe will occur in the economic future, given our past experiences? but Can we make the future so as to attain specific economic goals with practical certainty? An answer requires that restrictions be placed on the methodological individualist approach and the acceptance of a restricted holistic approach.     

Psychotropic drug treatment among learning-disabled,educable mentally retarded,and seriously emotionally disturbed students

Psychotropic drug treatment in learning-disabled (LD), educable mentally retarded (EMR), and seriously emotionally disturbed (ED) children and adolescents receiving public school special education services was examined. The findings indicated that while treatment prevalence rates for EMR and ED groups were comparable, the rate for LD students was much lower. In the LD sample, pharmacotherapy was associated with higher ratings of behavioral deviance, longer placement in special education, less social integration, and greater peer rejection, which suggests that symptom severity is an important determiner of pharmacotherapy in this population.     

The word frequency effect in lexical decision: Finding a frequency-based component

Subjects making lexical decisions are reliably faster in responding to high-frequency words than to low-frequency words. This is known as the word frequency effect. We wished to demonstrate that some portion of this effect was due to frequency differences between words rather than to other dimensions correlated with word frequency. Three groups of subjects (10 engineers, 10 nurses, and I0 law students) made lexical decisions about 720 items, half words and half nonwords, from six different categories (engineering, medical, low-frequency nontechnical, medium-frequency nontechnical, and two groups of high-frequency nontechnical). Results of two analyses of variance revealed a crossover interaction such that engineers were faster in responding to engineering words than to medical words, whereas nurses were faster in responding to medical words than to engineering words. The engineering and medical words were equally long and equally infrequent by standard word counts. We take this as support for a frequency-based component in the word frequency effect. The practical implications of this research for estimating the readability of technical text are discussed.     

Vocal frequency and person perception: Effects of perceptual salience and nonverbal sensitivity

Previous research has demonstrated that changes in vocal frequency (pitch) influence judgments made about a speaker, although there is some question as to the relative importance of frequency to message content in person perception. Moreover, these studies have failed to examine the possible joint effect of frequency and individual differences in nonverbal sensitivity on person perception. The purpose of the present investigation was to examine the independent and joint effects of vocal frequency, perceptual salience, and nonverbal sensitivity (assessed by the Profile of Nonverbal Sensitivity) on person perception. Participants were assigned to one of nine experimental conditions and were asked to rate two male and two female speakers on seven unipolar adjective scales. The nine conditions were produced by factorially combining three levels each of salience (content, voice, control) and vocal frequency (decreased, increased, unmanipulated). The results of hierarchical multiple regression analyses indicated that variations in frequency did influence evaluative judgments of the speakers (competent, honest, persuasive), but that the magnitude of the influence varied as a function of the participants' levels of nonverbal sensitivity. The analyses, however, yielded no significant effects for participants' affective judgments, nor any significant effects involving perceptual salience.