Production deficits in aphasia: A voice-onset time analysis

An experimental study was conducted to examine phonetic and phonemic deficits in the speech production of aphasics. Subjects included four Broca's aphasics, four Conduction aphasics, five Wernicke's aphasics, one nonaphasic dysarthric patient, and four normal controls. The subjects read a list of words containing word-initial stop consonants which were subsequently measured acoustically for voice-onset time. The results showed that Broca's aphasics exhibit a more severe production disorder than Conduction aphasics who in turn exhibit a more severe disorder than Wernicke's aphasics, in accord with clinical observations. In addition, although Broca's aphasics produced both phonetic and phonemic errors, the results showed that they have a pervasive phonetic disorder which affects their correct target productions as well as the total number of phonetic errors produced. This deficit however seems to be a speech deficit rather than a low-level motor control problem. In contrast, the Wernicke's aphasics show a deficit characterized by isolated phonemic mistargeting errors. Finally, the pattern of productions for the Conduction aphasics indicates that some patients show a predominantly phonetic disorder similar to the Broca's aphasics and others show predominantly a phonemic disorder similar to the Wernicke's aphasics.     

An olfactory investigation of the compatibility of oddity instructions with the design of a 3-AFC signal detection task

There are two principal differences between the Triangular Method and the 3-Alternative Forced-Choice (3-AFC) procedure originating from the theory of signal detection. These are the instructions given and the types of three-stimulus sets (‘triangles’) presented to the subject.In the Triangular Method the subjects are instructed to select the odd stimulus from each triangle presented, whilst in the 3-AFC task the subject must either select the strongest or identify the weakest stimulus.The triangles presented in the Triangular Method sometimes contain two physically weak stimuli plus one stronger, and at other times two strong stimuli plus one weaker. In contrast, in a 3-AFC experiment all the triangles comprise either two weak plus one stronger, or two strong plus one weaker stimulus.Previous research has shown that the parameter d' is invariant with the two procedures, if the appropriate models are used for conversion of proportions of correct responses into corresponding values of d'.The present experiments provide evidence that the Triangular Method instructions (to select the odd stimulus) used in combination with the 3-AFC task design (using three types of triangles) does not result in biased estimates of d'. In addition, it was shown that even after a large number of presentations the value of d' remained stable, which supports the notion of stability of the decision rule implied by the oddity instructions.     

The dilution effect: Nondiagnostic information weakens the implications of diagnostic information

In a series of studies, subjects were asked to make predictions about target individuals. Some subjects were given information about the target which pretest subjects had judged to be “diagnostic”—that is, had judged to be usefully predictive of the outcome. Other subjects were given a mix of information judged to be diagnostic and information judged to be “nondiagnostic” by pretest subjects—that is, judged to be of little value for predicting the outcome. Subjects given mixed information made much less extreme predictions than did subjects given only diagnostic information. It was argued that this “dilution effect” occurs because people make predictions by making simple similarity judgments. That is, they compare the information they have about the target with their conception of outcome categories. The presence of individuating but nondiagnostic information about the target reduces the similarity between the target and those outcomes that are suggested by the diagnostic information. One of the major implications is that stereotypes and other “social knowledge structures” may be applied primarily to abstract, undifferentiated individuals and groups and may be largely set aside when judgments are made about concrete, individuated people.     

On the problems of being more or less the same

Sixty children aged 2–3 to 5-2 were given four quantity tasks which tested their understanding of more and same. Two tasks involved addition, two involved judgment of static quantities. One of each type of task required a manipulative response, and one of each required a yes/no judgment. The tasks involved judgments of equality and inequality. Tasks involving a manipulative response were significantly easier than those involving a yes/no judgment, indicating that the nature of the response required of the child is crucial. All other differences were negligible, indicating that the other task variables investigated do not affect the child's ability to respond correctly. The ability to make accurate responses was not strongly associated with counting ability. There was a significant difference in the children's counting responses depending on the method used to elicit it.     

The relationship of sex and sex role to trait and situationally specific anxiety types

While considerable research has investigated the relationship of sex and/or sex role to general or trait anxiety, little is known about their relationship to more specific anxiety types. Based on the postulate that sex and sex-role differences may depend on the extent to which an anxiety-producing situation represents a sex-stereotypic domain, the present study compared their relationships to four measures of anxiety: Math anxiety, test anxiety, and two measures of trait anxiety. Subjects were 180 undergraduate students enrolled in introductory psychology courses. Although females reported higher levels of anxiety on all four scales than did males, a discriminant function analysis indicated that math anxiety was the strongest contributor to the separation of the sexes. Significant score differences as a function of sex role were found using the STAI A-Trait scale, and a significant sex × sex-role interaction was found for scores on the S-R Inventory of Anxiousness. Feminine-typed males and undifferentiated females reported highest anxiety levels in comparison to same-sex individuals. Implications for the understanding and treatment of both general and situationally specific anxiety are discussed.     

Are there constraints on childhood disfluency?

Analysis of the spontaneous speech of eight stuttering and eight normally fluent children reveals that (a) the location of both stuttering and normal disfluent moments is constrained by sentential constituent structure, and (b) stuttering children experience fluency breakdown with a particular type of constituent (verb phrase) not usually disfluently produced by normals. A view of early stuttering as a sentence planning and integration disorder is present.     

Portable delayed auditory feedback device: A preliminary report

This writing is a preliminary report describing a prototype of a portable delayed auditory feedback device called the DYSTECH 1000. This writing and our observations are presented to stimulate review and feedback by our colleagues of the DYSTECH 1000 as a clinical and generalization tool.     

Folded additive structures: A nonpolynomial model of some factorial interactions

A nonpolynomial measurement model for representing nonadditive compositions of stimulus dimensions is presented. This representation, which is referred to as a folded additive structure, permits the decomposition of a behavioral ordering into independent factors in some of the cases where the behavior itself does not directly reflect this independence. Psychologically, this representation corresponds to a model of behavior which assumes that (1) the effect stimulus attributes have on behavior is mediated by a single relevent psychological dimension, (2) the behavioral ordering is single-peaked over this mediating dimension and (3) the mediating dimension has a conjoint additive ordering over a set of relevent stimulus dimensions. Necessary and sufficient tests for folded additive structures are given. In addition, five psychological theories which make these assumptions are discussed.     

Blocking acquisition of the rabbit's nictitating membrane response to serial conditioned stimuli

Three experiments demonstrated that prior training with one stimulus (CS1) would block acquisition of the rabbit's nictitating membrane response (NMR) to another stimulus (CS2) which was more contiguous to the US during serial compound training (CS1-CS2-US). Specifically, the CS1-US interval was 800 msec, which produces only a modest rate of CR acquisition, while the CS2-US interval was 400 msec, which is an optimal value for the NMR preparation. Experiment 1 demonstrated blocking when CS1 overlapped CS2, and Experiment 3 demonstrated blocking when CS1 and CS2 were presented in a strictly sequential fashion. Experiment 2 showed that the magnitude of blocking in the serial compound was comparable to that obtained in a simultaneous compound in which both the CS1-US and CS2-US intervals were 800 msec, thus making CS2 less contiguous with the US than in the serial compound. Moreover, the level of responding to CS2 in all serial compound groups (blocking and control) was lower than in the simultaneous compound groups. The present findings provide further evidence that the associative consequences of CS-US contiguity can be highly attenuated by processes of attention or competition for associative strength.