Electroencephalographic and dichotic indices of cerebral laterality in stutterers

To test the hypothesis that stuttering is the product of faulty cerebral laterality four experiments were performed on each of five adult stutterers and five fluent speakers. These tests were: (1) dichotic listening with consonant-vowel pairs, (2) alpha recording over both hemispheres during the performance of cognitive tasks intended to engage preferentially the left or right hemispheres, (3) contingent negative variation with either an articulatory or bilaterally symmetrical response, and (4) readiness potential with the same responses. The results fail to disconfirm the null hypothesis regarding stutterers and their fluent peers. All subjects showed consistent patterns of cerebral laterality indicative of localization of speech function in the left hemisphere. Suggestions are made regarding a possible contribution of deficient sensorimotor integration in stuttering.     

The understanding of young children and adults of the deictic adequacy of communications

When a communication is used in a discourse context, the deictic information in the communication may be important in achieving a successful speech act. This information includes the temporal and spatial coordinates of the speech act that locate the communication in a context. In the present study, first- and fourth-grade children (6 and 9 years of age) and college adults were read short stories and asked to evaluate the adequacy of deictically ambiguous or informative communications (Experiment 1) or situations (Experiment 2). The results showed that subjects in all the grades discriminated among the deictically adequate and inadequate communications and situations, though the first graders made fewer correct judgments than did the other subjects of the adequacy of the informative communications and situations.     

Bilingualism and brain functional asymmetry

The task of the neural organization of the native language, acquired by a direct method and of another language, studied at school, performed correspondingly by the left and the right hemispheres, was studied in the bilingual patient after unilateral electroconvulsive therapy used in psychiatry. It was established that in such a bilingual type the right hemisphere is concerned with the formation of deep semantic structures of the native language while the left hemisphere is responsible for the formation of second language deep structures and of surface structures of both languages. The effect of language learning method on cerebral organization of bilingualism is postulated.     

The roles of event contingencies and reinforcement in human autoshaping and omission responding

Four experiments were conducted to test those features deemed to play an important role in the acquisition and/or maintenance of autoshaping and omission responding with human subjects, viz., event contingencies, reinforcement, stimulus generalization, the type of CS employed, conditioned reinforcement, and response topography. One important aspect of these studies is that the boundary conditions were made to resemble those pertaining to the majority of nonhuman animal studies, i.e., magazine training followed by paired CS-US presentations. The results demonstrated the importance of CS-UR or, alternatively, CS-US contiguity together with generalization and a response-reinforcer contingency for autoshaped response initiation and maintenance, respectively. The conditioned reinforcing effect of CS offset appears to play a part in generating and maintaining some responding during omission training, especially during a response-terminated CS procedure. Similar response topography was observed when the form of the UR was compared to that of the CR or autoshaped response. Taken as a whole the results of these experiments with humans are directly comparable to results previously reported using a wide variety of nonhuman animals.     

Effectiveness of social reinforcement as a function of contingent and noncontingent satiation

The social satiation effect is the inverse relation between the availability of a social stimulus and its subsequent efficacy in a reinforcing role. According to a suggested cognitive-interactive theory, the satiation effect is mediated by children's attributions of contingency between their own behavior and the experimenter's actions in the satiation treatments. Perceived contingencies depend, at least to an extent, on actual contingencies, and it was therefore predicted that a satiation effect would be observed only for groups presented in the satiation treatment with noncontingent social stimuli but not for groups presented with contingent stimuli. Middle-class 5- and 7-year-old children were subjected to a 10-min waiting period in which the stimulus word “Yafeh” (“good” in English) was presented 2 or 20 times, contingently or noncontingently. They were then given a 75-trial binary discrimination test: correct responses were reinforced with “Yafeh”. The hypothesis was confirmed in the analysis of variance. However, the predicted difference between the slopes of the contingency and noncontingency conditions was found clearly only in the older sample, while the younger children were more influenced by the number of social stimuli presented in the treatment (satiation) and less influenced by the method of stimulus presentation.     

Recognition and discrimination of emotional faces and pictures

In order to learn whether patients with right-hemisphere disease (RHD) had a deficit in their ability to discriminate and comprehend emotional faces and pictures, we studied nine patients with RHD, nine patients with left-hemisphere disease (LHD), and nine controls. The subjects were presented with six picture tests that comprised either emotional faces or emotional scenes. Their task was either to denote (name or choose) an emotion or to discriminate (same, different) between two faces or emotions. Patients with RHD performed significantly worse than subjects with LHD when asked to discriminate between faces, to discriminate between emotional faces, and to name emotional scenes. There was also a trend for the RHD group to be more impaired than the LHD group when asked to name the emotional face or choose the emotional face. Except for the facial and emotional discrimination tests, the LHD patients also performed worse than controls.     

The effect of strategy training and stimulus saliency on attention and recognition in preschoolers

Observing behavior and short-term recognition were studied in a training and test design. Preschoolers matched pictures from memory with training of a selective attending strategy or placebo practice. Both groups were then tested for retention of the strategies attained during training. For one-third of the subjects in each condition the relevant portions of the stimuli were made perceptually salient, for another third the irrelevant portions were salient, and for the rest no portions were salient. Strategy training enhanced relevant observing behavior and facilitated recognition accuracy in both training and test. The salient irrelevant cues interfered in training for the Placebo subjects. A second study examined the effect of three components of the strategy training procedure; verbal instructions, modeling, and fading. Verbal instructions, and to a lesser extent, modeling and fading, enhanced relevant observing behavior in both training and test but facilitated recognition accuracy only in training.     

Effects of question type and experimenter position on bilateral differences in electrodermal activity and conjugate lateral eye movements

28 dextral males participated in a within-subjects experiment which tasted for the effects of question type (verbal versus spatial) and experimenter-position (in front of or behind the subject) on direction of conjugate lateral eye movements (LEMs) and bilateral differences in skin conductance responses (SCRs). Question dependent asymmetries were observed for LEM direction but not for SCR magnitude. Experimenter-position had no significant effect. The results for LEM direction are consistent with the hypothesis linking eye movements to the left or right with activation of the cerebral hemisphere contralateral to the direction of gaze. The results for SCR magnitude, given certain assumptions, can be reconciled with a hemispheric model of contralateral excitatory control of that system.     

Latency and accuracy characteristics of saccades and corrective saccades in children and adults

Accuracy and latency characteristics of the first saccade to a target together with the frequency and latency of corrective saccades were studied in children (mean age = 8.5) and adults. The independent variables manipulated were fixation-light offset to target-light onset warning interval (0 and 300 msec) and the presence and location of nontarget stimuli. Although saccade accuracy was significantly affected by nontarget lights, children could respond as accurately as adults and, in replication of previous findings, as quickly when a 300 msec warning interval was given. No speed-accuracy trade off was found for either group as a function of the warning signal condition. Children were as likely to make corrective saccades as adults, but did so with a significantly longer latency. Corrective saccade latencies were greater when a change in direction was required but this effect did not interact with age.     

Effects of long- and variable-duration signals for food on activity,instrumental responding,and eating

Incentive-motivation theories typically assume that the conditioning of appetitive motivation involves the same parameters as Pavlovian salivary conditioning. In contrast, the Soltysik-Konorski model asserts that drive is inhibited by stimuli closely associated with food (salivary CSs) and augmented by stimuli more loosely associated with food (long and variable CS-US interval). Experiment 1 examined this latter proposition. Sixty-four rats were given extensive exposure to each of four environmental CSs, two while hungry and two while satiated. Within each deprivation condition, food was given 30–300 sec after placement of the rats in one environment, and was not given in the other environment. Performance on three separate measures—activity, lever-pressing, and food consumption—was higher in the environments previously associated with food. Experiment 2 examined the effects of discrete stimuli presented in advance of eating; in accord with the results of Experiment 1, food consumption was greater after a stimulus (1- to 9-min duration) previously paired with food than after no stimulus or after a stimulus unpaired with food. The overall results indicate (a) that stimuli associated with food become capable of facilitating a variety of food-directed behaviors, possibly via the conditioning of a common appetitive system, and (b) that a close association between the stimuli and food is not essential for such conditing to occur.     

Measures of timed performance and intelligence

The question of an association between IQ and measures of timed performance derived from inspection time and reaction time was examined in a sample of 182 adults and by reanalyzing data involving 48 adults from a previously published study. Multiple regression analysis found that measures of timed performance accounted for as much as 25% of IQ variance in the normal population, but that the inclusion of borderline and mildly retarded subjects resulted in much higher correlation coefficients because of the markedly less efficient performance of these persons in tasks of this kind. This outcome raised doubts about the validity of combining data from retarded and nonretarded subjects. Results ran counter to claims that tasks of the kind used are largely uninfluenced by cognitive variables, so that findings are not necessarily explained satisfactorily in terms of a mental speed factor. It was concluded that these measures of timed performance do not, at this time, provide a basis from which a reliable culture-fair measure of intelligence might be devised.     

Discrete dynamic choice: An extension of the choice models of thurstone and luce

The present paper deals with the extension of two well-known static discrete choice theories to the dynamic situation in which individuals make choices at several points in (continuous) time. A dynamic version of Luce's Axiom, “independence from irrelevant alternatives”, is proposed and some of its implications are derived. In the static case Yellott (J. Math. Psych. 1977, 15, 109–146) and others have demonstrated that an independent random utility model generated from the extreme value distribution exp(?e^?ax?b) becomes equivalent to Luce's Axiom. Yellott also introduced an axiom called “invariance under uniform expansions of the choice set”, and he proved that within the class of random utility models with independent identically distributed utilities (apart from a location shift) this axiom is equivalent to Luce's Axiom. These results are extended to the dynamic situation and it is shown that if the utility processes are expressed by so-called extremal processes the corresponding choice model is Markovian. A nonstationary generalization is proposed which is a substantial interest in applications where the parameters of the choice process are influenced by previous choice experience or by time-varying exogenous variables. In particular, it is demonstrated that the nonstationary model is Markovian if and only if the joint choice probabilities at two points in time have a particular form. Thus, the paper provides a rationale for applying a specific class of Markov models as the point of departure when modelling mobility processes that involve individual discrete decisions over time.     

Effects of UCS intensity and postpeak acquisition trials on classical conditioning of the SCR

The present study examined the effects of UCS intensity and number of postpeak acquisition trials on classical conditioning and extinction of the SCR. A 2 × 3 design was employed in which subjects received either a 1, 2, or 4 mA shock UCS and either two or 16 acquisition trials beyond the peak CR. While conditioning was demonstrated during acquisition, there was no relationship between strength of conditioning and intensity of UCS. The phenomenon of stronger resistance to extinction following fewer acquisition trials (e.g., two past the peak CR) than with many (e.g., 16 past the peak CR) was demonstrated only for the groups that were conditioned with the 4 mA UCS. Resistance to extinction varied positively with UCS intensity, but only for the subjects who received two postpeak acquisition trials. Sixteen trials beyond the peak CR resulted in the UCS intensity having little or no effect on resistance to extinction.     

Symmetry,scale types,and generalizations of classical physical measurement

A review is presented of a number of recent results concerning fundamental measurement structures with a particular emphasis on generalizations of physical measurement. Relational structures are classified in terms of richness and redundancy of their automorphism groups (i.e., in terms of their symmetries). By means of this classification, the possible types of measurement scales are described, and the possibilities for structures with concatenation operations (either associative or nonassociative and either positive or intensive) and for conjoint structures whose automorphisms factor into component automorphisms are explicitly spelled out. Certain conjoint structures with concatenation operations on components are viewed as generalizations of classical physical measurement and some of their most important algebraic and representational properties are explored.     

Concepts of present self,expected self,and ideal self in vocational preferences and expectations

This study investigated the hypotheses that similarity of ideal self and occupational stereotypes are important in determining the vocational preferences of adolescents, while similarity between expected self and occupational stereotypes is important in determining their occupational expectations. Subjects were 97 male and 88 female high school students. Findings were consistent with the view that ideal self played an important role in determining vocational preferences for males and females. However, contrary to expectations, ideal self was more strongly associated than expected self with vocational expectations for females, though not for males.     

Saccade latency in children and adults: Effects of warning interval and target eccentricity

Saccadic response latency to the onset of an eccentric target was studied in children (mean age = 8.7) and adults. The independent variables investigated were fixation-light offset to target-light onset warning interval (0, 100, 300, and 600 msec) and target eccentricity (5° or 15°). Both children and adults showed shorter saccade latencies under warning-interval conditions. Children were found to have longer latencies than adults with 0 or 100 msec warning intervals but to respond with as short or shorter latencies with 300 or 600 msec warning intervals. Target eccentricity effects did not interact with age, and occurred only with a lower target intensity. Children defined as poor readers could initiate a response as quickly as good readers but were less able to maintain fixation-light fixation prior to target onset.     

Response and associative phase components of elaborative prompt effects in children's noun-pair learning

The effects of aural and pictorial elaborative prompts were estimated separately for response and associative phase components of children's nounpair learning. A 20-item list of noun pairs was administered individually to 200 second- and third-grade children by the method of paired-associates. Indices of response learning (free verbal recall and pictorial identification) revealed equivalent effects among prompt conditions whereas measures of associative learning (multiple-choice pictorial-recognition tests) demonstrated substantial performance facilitation as a function of both aural and pictorial elaborative prompts. This outcome was regarded as an unequivocal identification of the locus of elaborative prompt effects in children's nounpair learning.     

Influence of televised modeling and verbalization on children's delay of gratification

Voluntary delay of gratification in 9-year-old children was assessed 4 weeks prior to, immediately after, and 4 weeks subsequent to exposure to one of four televized films. The modeling group observed an adult female model exemplify high-delay behavior. The persuasion group observed the model verbalize good reasons for waiting. The persuasion-modeling group observed the model exemplify high-delay behavior and verbalize reasons for waiting. Subjects in each of the treatment groups emitted more delay choices on the posttest than control group subjects who observed the model exhibit neutral behavior. The greatest magnitude of change occurred when modeling and persuasive cues were combined. Treatment effects were still in evidence for the modeling and the persuasion-modeling groups after a period of 4 weeks.     

The component awareness and accuracy of dual- and single-jointed actions

The accuracy with which people execute wrist and elbow movements were measured using three main conditions: (i) single-jointed (wrist or elbow) movements to targets, (ii) dual-jointed (wrist and elbow) movements to targets, and (iii) components of dual-jointed movements to targets, when the task for the subject was to perform the elbow or wrist constituent of the action in isolation, without displacing the second joint. Elbow precision was significantly worse under component than dual conditions, which is compatible with the notion that wrist and elbow activity are conjugately, rather than independently, programmed when a dual-jointed action is performed. The pattern of wrist accuracy was divergent, but possible reasons for this were discussed. In all cases, error was measured in terms of deviation from perfect posture; using this index, the hypothesis that incorporating more moving joints into an action serves to increase movement complexity and jeopardise precision was tested, but the results were ambiguous. Discussion also centered on the problems of using performance data to infer changes in motor programming, and the need for rigorous conceptualisation and research in this area.