The extinction of within-compound flavor associations

Three experiments studied extinction of the associations which are formed between two flavors presented in a simultaneous compound. In Experiment 1 those associations were identified by a sensory preconditioning procedure in which the poisoning of one element of the compound led to the rejection of the other element. Separate presentation of either element between their joint occurence and the poisoning of one element sharply attenuated the rejection of the other element. That attenuation was interpreted in terms of the extinction of within-compound associations. Experiment 2 obtained similar results with an alternative extinction procedure in which the elements of the original compound were presented in other compounds. Experiment 3 obtained similar results when the existence of the within-compound associations was determined by an alternative assessment procedure in which one element of the compound was made more attractive by the induction of a specific hunger. These experiments suggest that within-compound associations can be extinguished when the elements are separately presented outside of the compound. Experiments 2 and 3 make less plausible an alternative interpretation of the effects of separate element presentation in terms of reduction of the novelty of the element. The findings may be taken as implying that the elements of a simultaneously presented compound are joined by a single symmetrical association which acts at various points during a sensory preconditioning experiment.     

Electromyographic indications of laryngeal-area activity during stuttering expectancy

Using surface electrodes, mean microvolt values of laryngeal-area muscle activity were determined for 13 male and 6 female stutterers during 10-sec periods in which single words were silently read and stuttering expectancy was indicated. No significant differences in levels of laryngeal-area muscle activity were found between periods of fluency expectancy and stuttering expectancy preceding both fluent and stuttered speech. The results were interpreted as being nonsupportive of the hypothesis that a breakdown in stutterers' laryngeal-area muscle activity occurs during moments of stuttering expectancy. In addition, the results suggest that the most common rationale for the utilization of laryngeal biofeedback procedures to enhance fluency should be questioned.     

Communicative stress and stuttering frequency during normal,whispered, and articulation-without-phonation speech modes

The effect of communicative stress on the frequency of stuttered syllables in 12 adult stutterers reading six different but equivalent passages using normal voicing, whispering, and articulation-without-phonation speech under a stress and a non-stress condition was studied. Although the frequency of stuttering was significantly greater in the normal voicing mode than in the whispering mode and greater in the whispering mode than in the articulation-without-phonation mode, no differences were found between the stress and the nonstress conditions with respect to stuttering.     

Do the mentally retarded have poor memory?

The hypothesis that mentally retarded persons have a short-term memory deficit whixh is due to inadequate rehearsal strategies is reexamined. A reevaluation of results of a number of experiments suggests that normal and retarded persons differ on short-term memory tasks, and the superiority of normals is present from the time of initial stimulus exposure. While some evidence for slope differences in retention curves is found in a few tasks, it is not strong support for memory differences. The hypothesis that “memory” differences are due to differential encoding as a result of more adequate rehearsal by the normal subjects is unacceptable. If this were the case, some differences in slope of retention curves could be expected unless rehearsal beyond the encoding stage was totally precluded. The review points to a need for an empirical reevaluation of the issue with a full recognition that deficits in particular processes may characterize some retarded persons and not others.     

Selective attention and changes in clinical state

Thirty inpatients of a psychiatric unit were given the Mini-Mult and a series of auditory selective attention tasks in order to test the hypotheses that (1) impaired attention is related to degree of pathology, and (2) improvement in clinical state leads to improved ability to selectively attend. The results showed that the relationship between the Mini-Mult and the listening tasks is significant only when the subjects had to exclude irrelevant stimuli (interference condition). The results also indicated that the relationship between clinical changes and changes in attentional performance is significant. The findings were discussed in terms of a quantitative theory of attention.     

Sex differences in realization of individual potential for achievement

Data from 4035 participants in Project TALENT were analyzed to examine the extent to which known sex differences in achievement held up when early potential for achievement was contolled. Original TALENT data, consisting of information on socioeconomic background, cognitive abilities, and educational and occupational aspirations, were collected in 1960 when members of the study sample were in Grade 9. Follow-up surveys measuring participants' educational and occupational attainment were conducted at 1, 5, and 11 years after the date of participants' expected graduation from high school. Women had higher high school grades and scored higher on a composite of academic ability tests taken in Grade 9 than did men. However, by 11 years after high school, men had acquired more education and were earning more money on the job. Sex differences in realization of achievement potential were found across all socioeconomic levels. At least part of the reason behind women's relative failure to translate potential into achievement may lie in the greater conflict, for women, between the roles of spouse/parent and the roles of student/worker: variables measuring the onset, duration, and extent of family-related commitments were more strongly related to female than to male realization of potential. Sex differences in achievement grew larger between the 5- and 11-year follow-ups as a greater proportion of women in the study sample became wives and mothers. The widening of the sex gap in achievement during this period was particularly pronounced among the subgroup of individuals who were in the top quartile of potential in Grade 9.     

The response of day and night wetting children and children who wet only at night to retention control training and the enuresis alarm

Forty-five children with night wetting only (NW) and 30 children with day and night wetting (DNW) were randomly assigned to 2 treatment groups: alarm only and alarm preceded by 4 weeks of retention control training (R.C.T.). Fewer children became dry at night in the DNW group than the NW group and DNW children relapsed earlier following treatment. The enuresis alarm was far superior to R.C.T. in reducing night wetting in both enuretic groups. It also reduced day wetting in some of the DNW children. Children who became dry in the NW group did not show significant changes in functional bladder capacity. Although changes in functional bladder capacity were seen in the DNW children who became dry, changes were only noticeable once dryness had been achieved.     

Statistical significance tests for binormal ROC curves

Statistical significance tests are derived and evaluated for measuring apparent differences between an obtained and an expected binormal ROC curve, between two independent binormal ROC curves, and among groups of independent binormal ROC curves. A binormal ROC curve is described by two parameters which represent the spread of the means and the ratio of the standard deviations of the two underlying Gaussian decision variable distributions. To test the significance of apparent differences between or among ROC curves, approximate χ² statistics for each of the three tests were constructed from maximum likelihood estimates of the two parameters defining the binormal ROC curve. The performance of each test statistic was evaluated by simulating five-category rating scale data with equal numbers of noise and signal-plus-noise trials (set at 50, 250, and 500) for each of three typical ROC curves. For the significance test involving only one ROC curve, rating scale data were generated from the chance diagonal of the ROC space also. Although test performance was found to be somewhat dependent on the number of trials and on the location of the ROC curve in the ROC space, comparisons of the obtained and expected fractions of (falsely) significant results at various α levels showed the proposed statistical significance tests to be reliable under practical experimental conditions.     

Developmental auditory agnosia in the severely retarded: A further investigation

The hypotheses were investigated that (a) ability to recognize the auditory perceptual stimuli for familiar events is a developmental correlate to language acquisition and (b) the low functioning mentally handicapped suffer from auditory agnosia and are impaired in this ability. The subjects were 42 nonretarded children of ages 3 through 6 and 53 severely and moderately retarded, noninstitutionalized students. The retarded subjects were matched by mental age to the chronological age of the nonretarded children. The stimuli were 49 environmental sounds; the task consisted of sound-and-picture matching-to-sample. Group membership and developmental age were the factors in an analysis of variance design. The results revealed a strong effect of developmental age (p <. 0001). The effect of group was not significant, indicating that auditory agnosia may not be common among the lower functioning retarded. The assumption that agnosia may be a major factor underlying the language disability of the severely retarded was reexamined. It was suggested that the severely retarded achieve the requisite perceptual-semantic knowledge base for language too late, after the critical age for spontaneous and efficient language learning has passed.