Discrimination of auditory temporal patterns

Two same-different discrimination experiments were performed for click patterns having a total duration of about 4 sec and interclick intervals ofn × 250 msec, withn a random integer. In Experiment 1, the influence of the physical click group structure on discrimination performance was investigated. In Experiment 2, the effect of the strength of an induced internal clock on discrimination performance was measured. Performance was poor if the group structure of clicks was maintained during a change in click pattern and also if the induced infernal clack strength was low. The performance of about 70% of the subjects improved significantly if either a change in click grouping structure occurred or a strong internal clock could be induced. These results cannot be accounted for with simple models based an single-interval duration discrimination or between-pattern correlation statistics.     

Relevant implication and the case for a weaker logic

We collect together some misgivings about the logic R of relevant inplication, and then give support to a weak entailment logic DJ^d. The misgivings centre on some recent negative results concerning R, the conceptual vacuousness of relevant implication, and the treatment of classical logic. We then rectify this situation by introducing an entailment logic based on meaning containment, rather than meaning connection, which has a better relationship with classical logic. Soundness and completeness results are proved for DJ^d with respect to a content semantics, which embraces the concept of meaning containment.Dedicated to Robert K. Meyer on the occasion of his 60th birthdayThis paper was presented to the Australasian Association for Logic Conference, A.N.U., Canberra, in July, 1992. This Conference commemorated the 60th birthday of Robert K. Meyer, in recognition of the enormous contribution he has made to Logic, especially to Relevant Logic, and of the general lift he has given to the field in his adopted country, Australia. This paper owes its inspiration to Robert Meyer's Farewell to Entailment [37] and his earlier Why I am not a Relevantist [35]. This paper also owes a great deal to Richard Sylvan who has consistently supported weaker relevant logics at a time when stronger relevant logics were in vogue (see especially [47], Chapter 3). In writing this paper, I have also benefited from conversations with Nuel Belnap, Michael Dunn, Kit Fine and Alasdair Urquhart during a period of study leave in 1991. I also thank Robert Meyer, Michael Dunn, Martin Bunder and John Slaney for useful comments on my conference paper. I would also like to thank the referees of this Journal for their helpful comments, which led me to make substantial improvements to this paper.     

Retest stability of DSM-III-R diagnoses among adolescents using the diagnostic interview schedule for children (DISC-2.1C)

Retest stability of DSM-III-R diagnoses was assessed using the DISC-2.1C with a sample of Anglo, African, and Hispanic American adolescent patients 12 to 17 years of age. Based on the kappa statistic, retest stability was fair for any disorder ( =.50), for any anxiety disorder ( =.44), for any affective disorder ( =.53), for any disruptive behavior disorder ( =.58), and for substance use disorders ( =.46). Although there was a trend for reliability to be somewhat higher for African Americans ( =.58) than for Anglos ( =.42) or Hispanics ( =.49), these differences were not statistically significant. In general, 15- to 17-year-olds had somewhat better reliability ( =.58) than did 12- to 14-year-olds ( =.44). Males had somewhat higher reliability ( =.63) than females ( =.43). These findings are congruent with those reported recently using the DISC-R (Schwab-Stone et al., 1993) and suggest that the DISC appears to be at least as reliable as other available child diagnostic instruments. In view of the fair-to-moderate levels of reliability of these instruments in general, future research should focus on the joint effects of instrument, subject, interviewer, and nomenclature on operating characteristics of diagnostic interview schedules, focusing in particular on factors affecting accurate recall and reporting of symptoms and episodes. This research was supported in part by grants MH44214 and MH44773 from the National Institute of Mental Health, and by the Hogg Foundation for Mental Health. The authors wish to acknowledge the participation and collaboration of A. J. Pumariega, J. W. Swanson, and C. E. Holzer III and staff of the Center for Cross-Cultural Research, directed by F. M. Treviño.     

Saccade latency and warning signals: Effects of auditory and visual stimulus onset and offset

Previous studies have found that a nonspecific visual event occurring at the fovea 50–150 msec after the onset of a peripheral target delayed the initiation of the saccade to that target. The present studies replicated and extended this finding by studying the effects of both visual and auditory warning signals, by examining the effects of onset and offset warning on manual response latency, and by investigating the effects of presenting the warning events in the periphery of the visual field. The results indicated that the interfering effects occur with visual but not auditory stimuli, with saccades but not motor responses, and when the visual warning event occurs either foveally or in the subject’s periphery. Implications for the processes involved are discussed.     

The more,the better?: Number of decisions as a determinant of memorability

Three experiments tested alternative explanations to the Johnson-Laird, Gibbs, and deMowbray (1978) proposal that the number of decisions made about a word is a major determinant of its memorability. The alternatives considered were increased processing time, retrieval aids, and the number of positive decisions. In Experiment 1, subjects made a speeded classification about each word for a category defined by three properties. Though items with more target properties were processed longer and better remembered, within a property level processing time was not associated with better memory. In Experiment 2, subjects received three properties, but different groups responded “Yes” to words with all three properties, words with any of the three properties, or whether words had each of the properties. As predicted by the number-of-decisions hypothesis, but not by the other hypotheses, with an increasing number of target properties, recall generally increased in the ALL group, decreased in the ANY group, and remained constant in the EACH group. In Experiment 3, this recall pattern was replicated with a different set of two target properties. The number-of-decisions notion is contrasted to the elaboration principle, and a simple model is proposed. It is concluded that the number of decisions is a useful technique for investigating within-level encoding differences     

Marital disturbance and child problems: A cautionary note regarding hyperactive children

In previous work, investigators have found a relationship between marital discord and childhood conduct problems (aggression) in clinic samples. Given the wide variability of aggression found among hyperactive children,it would follow from previous work that child aggression may be associated with marital discord in a hyperactive population. This hypothesis was tested in a sample of 23 boys (ages 5 to 8) diagnosed as attention deficit with hyperactivity. Aggressive behaviors were tracked by the children's teachers for 12 school days. Parental and teacher ratings of conduct problems were also obtained. Additionally, the auditory version of the laboratory Continuous Performance Test was administered. Marital adjustment, overt hostility, and conflict tactics, as reported by the mothers, were not significantly correlated with any of the measures of aggression or conduct problems. In other words, marital discord in families with a hyperactive boy did not explain differential rates of aggressive behavior despite definite variability in both the marital and child behavioral measures. Marital discord was marginally related to severity of attentional deficit on the Continuous Performance Test. The results underscore the need for caution in attempting to extend findings from a general population (i.e., undifferentiated clinicreferred children) to a specific diagnostic subgroup (i.e., attention-deficit hyperactive children).