Transfer of training of a new linguistic contrast in voicing

The present study examined the plasticity of the human perceptual system by means of laboratory training procedures designed to modify the perception of the voicing dimension in synthetic speech stimuli. Although the results of earlier laboratory training studies have been ambiguous, recently Pisoni, Aslin, Perey, and Hennessy (1982) have succeeded in altering the perception of labial stop consonants from a two-way contrast in voicing to a three-way contrast. The present study extended these initial results by demonstrating that experience gained from discrimination training on one place of articulation (e.g., labial) can be transferred to another place of articulation (e.g., alveolar) without any additional training on the specific test stimuli. Quantitative analyses of the identification functions showed that the new perceptual categories were stable and displayed well-defined labeling boundaries between categories. Taken together with the earlier findings, these results imply a greater degree of plasticity in the adult speech processing system than has generally been acknowledged in past studies.     

Choice reaction time with a random foreperiod

Choice reaction latencies were measured at three different a priori probabilities for two stimulus alternatives. Unlike the results of some other studies, the mean latency of a given response was nearly the same whether the response was correct or incorrect. The discriminable stimuli were a 1000- or a 1700-Hz tone presented at 70 dB SPL. Latencies and standard deviations, based on about 17,000 observations, are reported for three observers. The data are compared with predictions of the optimum sequential model of Wald and Stone and two modifications of that random-walk model, one proposed by Link and Heath and the other proposed by Laming. Fast-guess analyses were also carried out. The three-parameter version of either the sequential or the modified random-walk models provided reasonably accurate predictions of the mean data for each observer. The parameters estimated by the fast-guess analysis were unrealistic. There are three obvious differences between this experiment and most previous choice reaction-time experiments. First is stimulus modality#x2014;we used an auditory signal, whereas most of the previous studies used a visual signal. Second, the observers practiced more in this experiment than in most previous experiments. Finally, there was a random foreperiod with a heavy penalty for anticipations. One or more of these factors is the probable reason for the discrepancy between our results and those of previous studies.     

An Apple II package for computer-assisted telephone interviewing

This paper describes an Apple II (an Apple-compatible) microcomputer package for a computer-assisted telephone interviewing (CATI) system. This system generates random telephone numbers within any number of exchanges that the user supplies, automatically dials the telephone, prompts the interviewer with each question, and records and permanently saves each response. It also provides a printed copy of the collected data by frequency of response in each question category. The Apple II CATI package is readily available, inexpensive, and easy to program in the BASIC language.     

A generalization of Kristof's theorem on the trace of certain matrix products

Kristof has derived a theorem on the maximum and minimum of the trace of matrix products of the form \(X_1 \hat \Gamma _1 X_2 \hat \Gamma _2 \cdots X_n \hat \Gamma _n\) where the matrices \(\hat \Gamma _i\) are diagonal and fixed and theX _i vary unrestrictedly and independently over the set of orthonormal matrices. The theorem is a useful tool in deriving maxima and minima of matrix trace functions subject to orthogonality constraints. The present paper contains a generalization of Kristof's theorem to the case where theX _i are merely required to be submatrices of orthonormal matrices and to have a specified maximum rank. The generalized theorem contains the Schwarz inequality as a special case. Various examples from the psychometric literature, illustrating the practical use of the generalized theorem, are discussed.     

Acquiring conjunctive concepts: When and why does feature frequency affect feature identification?

According to frequency theories of concept attainment, acquisition of rule-governed concepts depends on discriminating relevant from irrelevant stimulus features on the basis of their respective frequencies of occurrence. Depending on the theorist, the critical frequency counts may be based on occurrence in all stimuli or on occurrence in positive instances only. Experiment 1 held frequency in positive instances constant and varied the frequency of irrelevant features in the negative category. High frequency was associated with impaired performance, but only when concept problems started with a negative instance. Experiment 2 demonstrated that some previous findings in the literature that were thought to support frequency theory also depended on problems starting with a negative instance. These findings are not easily reconciled with existing frequency theories. We attribute our results to high intercategory similarity, which is a correlate of high frequency of irrelevant features. In the context of a hypothesis-testing theory, we propose that a negative start stimulus proactively interferes with memory for information in the initial positive instance and that the extent of the interference depends on how similar negative instances are to positive instances.     

The generalization of the effects of a cognitive-behavioral treatment program for aggressive children

A cognitive-behavioral treatment program for aggressive children was assessed using 12 outcome measures classified into five categories which reflected a continuum of generalization of treatment effects. From a summer daycamp 41 children, ages 7 through 12, were selected based on aggressive behavior displayed during the first week of camp. They were randomly assigned to either a treatment group or a nontreatment control group. Treatment consisted of four weeks of coping-skills training using behavioral rehearsal and self-instruction training. Considering all 12 measures, treatment was found effective (F=2.90, p < .01). The most meaningful results included improved interpersonal problem-solving skills and a decrease in being disciplined for fighting. No changes were found, however, in physical or verbal aggression and in peer rating of aggression. Modest support for the effectiveness of these treatment procedures was identified, although caution is needed in considering their clinical utility. Further research and application appear justified.     

Deep dysphasia: An analog of deep dyslexia in the auditory modality

A right-handed patient, with two left hemisphere lesions, a small one in the prefrontal lobe and a larger one in the temporal, presents an unusual syndrome: a massive deficit for oral language (expression and comprehension) contrasting with a fairly good preservation of written language (expression and comprehension). The processing of isolated words and sentences has been extensively tested with repetition and dictation tasks. The patient performs rather well with nouns, verbs, and adjectives, poorly with adverbs and function words, and completely fails with nonsense words. A remarkable feature of his repetition is the frequency of semantic paraphasias. Thus, this patient exhibits a behavior rather similar to deep dyslexia, hence the possible label "deep dysphasia." The paper presents a "preunderstanding" hypothesis to account for such behaviors.     

Lesions of the basal ganglia, thalamus, and deep white matter: Differential effects on language functions

Forty-five patients with unilateral demarcated vascular lesions in the basal ganglia, the thalamus and the deep white matter were investigated with an "aphasia battery." Patients with basal ganglia lesions performed worse than both other groups in tests of articulation, syntax, and lexical functions. The deficit of patients with basal ganglia lesions on all expressive language modalities was lateralized to the left hemisphere. Patients with left thalamic lesions showed impairments of speech fluency and in the Token Test. Patients with white matter lesions alone showed no effect of laterality in tests of language functions. The results are discussed on the basis of a recent theory of the participation of the deep nuclei in language processing.     

Attentional biases and the right-ear effect in dichotic listening

Most dichotic listening experiments permit subjects to deploy attention in any way they choose. We argue that this adds uncontrolled variance to the observed right-ear advantage. In the first experiment, more robust laterality effects were obtained in an identification task with focused than with divided attention. Such differences were not found in the second experiment, when a detection procedure was used. Virtually all the laterality effect observed in the second study could be attributed to subjects who were biased attenders, in the sense that they exhibited more intrusions from the right ear to the left than vice versa. However, rather than indicating that laterality effects are simply attentional bias, this effect can be attributed to an asymmetry of perceptual discrimination.