Speech Perception Within an Auditory Cognitive Science Framework

ABSTRACT— The complexities of the acoustic speech signal pose many significant challenges for listeners. Although perceiving speech begins with auditory processing, investigation of speech perception has progressed mostly independently of study of the auditory system. Nevertheless, a growing body of evidence demonstrates that cross-fertilization between the two areas of research can be productive. We briefly describe research bridging the study of general auditory processing and speech perception, showing that the latter is constrained and influenced by operating characteristics of the auditory system and that our understanding of the processes involved in speech perception is enhanced by study within a more general framework. The disconnect between the two areas of research has stunted the development of a truly interdisciplinary science, but there is an opportunity for great strides in understanding with the development of an integrated field of auditory cognitive science.     

Individual differences in category learning: sometimes less working memory capacity is better than more

We examined whether individual differences in working memory influence the facility with which individuals learn new categories. Participants learned two different types of category structures: rule-based and information-integration. Successful learning of the former category structure is thought to be based on explicit hypothesis testing that relies heavily on working memory. Successful learning of the latter category structure is believed to be driven by procedural learning processes that operate largely outside of conscious control. Consistent with a widespread literature touting the positive benefits of working memory and attentional control, the higher one’s working memory, the fewer trials one took to learn rule-based categories. The opposite occurred for information-integration categories - the lower one’s working memory, the fewer trials one took to learn this category structure. Thus, the positive relation commonly seen between individual differences in working memory and performance can not only be absent, but reversed. As such, a comprehensive understanding of skill learning - and category learning in particular - requires considering the demands of the tasks being performed and the cognitive abilities of the performer.     

Temporal processing and phonological impairment in dyslexia: effect of phoneme lengthening on order judgment of two consonants

The evidence of supporting phonological deficit as a cause of developmental dyslexia has been accumulating rapidly over the past 2 decades, yet the exact mechanisms underlying this deficit remain controversial. Some authors assume that a temporal processing deficit is the source of the phonological disorder observed in dyslexic children. Others maintain that the phonological deficit in dyslexia is basically linguistic, not acoustic, in nature. Three experiments were conducted and tested the impact of the temporal alteration and the impact of complex syllabic structure on consonant order judgments. Thirteen phonological dyslexics (age 10-13) and 10 controls matched for chronologial age were compared on a Temporal Order Judgment (TOJ) task using the succession of two consonants (/p/ /s/) within a cluster. In order to test the possible relevance of the temporal deficit hypothesis, the task also included two additional conditions where either the two stimuli were artificially slowed or two phonological structures were opposed (CCV and CVCV). As expected, the TOJ performance was significantly poorer in dyslexics than in controls. Moreover, in the "slowed speech" condition dyslexics' performance improved to reach the normal controls' level, whereas manipulating the phonological structure complexity provided no significant improvement. Finally dyslexics' performances, especially on the slowed condition, were found correlated with several tests of phonological processing. These results lend support to the general temporal deficit theory of dyslexia.     

Constructing measures with maximum reliability

The scoring of response vectors to give maximum test-retest correlation is investigated. Simple sufficiency arguments show that the form of the best scores is very restricted. A general method is given for finding the best scores, deriving the best scores for the normal factor model, and showing by calculation of several particular cases that for a standard model for binary response it is easy to approximate the best scores.     

Comparison of extra- and within-stimulus prompting to teach prepositional discriminations to preschool children with developmental disabilities

This study compared extra-stimulus to within-stimulus prompts in teaching children with developmental disabilities to discriminate the prepositional concepts In and On. Five preschool-aged children who had difficulty discriminating verbal instructions participated. Extra-stimulus prompts involved modeling, gestures, positioning, and auditory cues which did not form part of the target discrimination. Within-stimulus prompts manipulated the volume and intonational pattern of the verbal stimuli. Four children did not learn the discrimination with extra-stimulus prompting. All four of these children, plus a fifth child who did not have prior experience with extra-stimulus prompting, reached criterion in the within-stimulus prompting condition. The success of the within-stimulus prompts may be related to their enhancing phonetic differences between the verbal stimuli.     

检验能力对统计显著性检验的影响

利用计算机构造被试总体、模拟实验研究程序进行抽样研究,探讨抽样样本总体达到t检验显著性的数目与统计检验能力之间的一致性。模拟实验结果表明,统计检验能力与样本总体t检验显著性的数目具有很高的一致性,但两者同时受到显著性水平α、样本客量n和总体效果大小δ的影响,从而有可能影响统计推断的可靠性。因此,在进行显著性检验过程中,应对统计检验能力进行估计,这将有利于心理学研究成果的积累。     

Psychological Follow-up of Presymptomatic Genetic Testing for Spinocerebellar Ataxia Type 2 (SCA2) in Cuba

Presymptomatic testing for spinocerebellar ataxia type 2 (SCA2) in Cuba started five years ago. We have now investigated the psychological impact of test results on 150 individuals at 50% risk for SCA2. In a prospective study, psychological instruments were used to evaluate depression, anxiety and family functioning (1) before testing and (2) one year after disclosure of the test result. One year after, anxiety and depression levels decreased both in carriers and non-carriers, but anxiety decreased significantly more in carriers. Pathological levels of anxiety were seen mostly in members of dysfunctional families, but decreased more in them than in other consultands. Presymptomatic testing thus seems to have been especially beneficial for these testees, possibly due to a greater gain from the psychosocial support received. It would be pertinent to evaluate now the impact of other psychosocial variables and perform longer-term longitudinal studies.     

Seemingly Anomalous WISC-IV Full Scale IQ Scores in the American and Canadian Standardization Samples

The American and Canadian standardization samples for the fourth edition of the Wechsler Intelligence Scale for Children were used to ascertain the prevalence of “seemingly anomalous” Full Scale IQ (FSIQ) scores for all possible sums of scaled scores combinations of the Verbal Comprehension Index, Perceptual Reasoning Index, Working Memory Index, and Processing Speed Index. About 1% of FSIQ scores in both samples were anomalous (that is, fell outside the range of the four indices). Interestingly, the prevalence of anomalous scores was higher at the extremes of the FSIQ distribution. Moreover, anomalous FSIQ scores occurring above or below the mean of the FSIQ distribution (that is, 100) were larger or smaller, respectively, than any of the four indices. Furthermore, if the range of the four indices did contain the FSIQ (the non-anomalous case), when the FSIQ was below or above 100 it tended to be located distally in the half-segment of the range furthest below or above 100, respectively. A non-technical intuitive analogy from Olympic sports and a statistical explanation for the findings are provided. Important implications for practitioners are also presented. Portions of this paper were presented March 17, 2006 at the 20th annual Joseph R. Royce Research Conference, Department of Psychology, University of Alberta, Edmonton, Alberta.