Use of a computer-controlled firearms training simulator in perception response time experiments

This paper describes the use of a custom-configured computer-controlled firearms training simulator to measure perception response (reaction) time (RT) to a stimulus in which the degree of threat presented is a manipulable variable across trials. The computer records the number of frames of videotape traversed between the point of presentation of the threat in the video stimulus and the point at which the subject responds by drawing the firearm. For the purposes of data analysis, these frame-count measures are converted to RT measurements. Example data are presented that capture perception RT at both thedraw-stimulus and thefire-stimulus points in situations for which either only one threat or more than one threat exists. Other elements, such as degree of threat and accuracy of response, provide additional data.     

Gestural beats: The rhythm hypothesis

Gestural beats are typically small up and down or back and forth flicks of one or both hands. It has been assumed by researchers hypothesizing about the interaction of beats and speech that beats coincide with verbal stress. Microanalysis shows that gestural beats are organized in rhythmic patterns and do not necessarily cooccur with stressed syllables as previously assumed. Tone group nuclei appear to function as gestational points for rhythmic groups, which supports the theory that thinking utilizes words as cognitive tools and provides evidence that in some cases entire tone units are formed in advance. Evidence of an interpersonal gestural rhythm is also presented.This research was supported by grants from the National Science Foundation and from the American Association of University Women Educational Foundation.     

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.     

Prevalence of ADHD and comorbid disorders among elementary school children screened for disruptive behavior

In the context of a school-based prevention of conduct disorder program, 7,231 first- through fourth-grade children were screened for cross-setting disruptive behavior. Frequencies of DSM-III-R psychiatric disorders and patterns of comorbidity were assessed. We also examined the association of psychiatric diagnosis with child and parent characteristics to determine differential risk based on diagnostic subgroups. Attention deficit hyperactivity disorder (ADHD) and oppositional-defiant disorder (ODD) were the most frequent diagnoses. Mood and anxiety disorders were infrequent as single diagnoses. Patterns of comorbidity demonstrated that both externalizing and internalizing disorders commonly cooccurred with ADHD. More severe degrees of psychopathology and psychosocial risk accrued to the subgroup of youths with ADHD plus a comorbid externalizing disorder.This study was supported by grant MN-46584 from the National Institute of Mental Health.     

Active and passive avoidance following the administration of systemic DSP4, xylamine, or p-chloroamphetamine

Groups of rats were administered either DSP4 (50 mg/kg, ip), xylamine (50 mg/kg, ip), or p-chloroamphetamine (2 X 10 mg/kg, ip), either 2 weeks or 1 week before the testing of two-way active avoidance. DSP4 and xylamine, the selective noradrenaline (NA) neurotoxins, caused a two-way avoidance impairment but p-chloroamphetamine, the selective 5-hydroxytryptamine (5-HT) neurotoxin, did not do so. Pretreatment with desipramine (20 mg/kg, ip) blocked the avoidance impairment caused by DSP4 and xylamine treatment. Neither DSP4 nor xylamine caused any alteration of passive avoidance retention. The biochemical analyses indicated severe NA, but not 5-HT, depletions in the DSP4 and xylamine conditions and drastic 5-HT, but not NA, depletions in the p-chloroamphetamine conditions. These results confirm and extend earlier findings concerning the role of NA in avoidance behavior.     

Attentiveness of mothers and fathers to their baby's cries

Thirty-two mother-father-infant triads participated in a study to examine whether parents' responsiveness to their own infant's distress was affected by the infant's birth order and gender. After separating from their 10- to 11-month-old baby, one parent from each family (16 mothers and 16 fathers) was selected to hear cries that were attributed to the child. Consistent with previous findings regarding physiological reactions to crying and observations of caretaking behavior, first-time parents gave quicker and more frequent attention to their infants than did multiporous parents. Speedy intervention was related to the amount of caretaking responsibilities that parents reported they assumed and to the age at which parents believed that their infant first recognized them. The results demonstrate the importance of caretaking for promoting parental sensitivity to infant signals.     

Effects of causal belief for prior success or failure on preferences to delay gratification in task contingent versus task noncontingent conditions1

This study investigated how causal belief for prior success or failure affected preferences to delay gratifications in task contingent versus task noncontingent conditions. Success or failure on the Treatment Task and belief about the outcome were experimentally induced to lead fourth-and fifth-grade pupils to perceive task performance as resulting from one of four factors (Ability, Task Difficulty, Effort, or Luck). Thereafter, each subject chose between smaller, noncontingent rewards and delayed, larger rewards that were contingent on waiting only or on successful performance on tasks which varied in similarity to the initial task. As predicted, preferences to delay were not differentially affected by success or failure when subjects believed unstable factors of effort or luck caused the outcome. However, delay was affected by prior success or failure when the belief was that the outcome resulted from stable factors of ability or task difficulty, with subjects delaying more after success than following failure. Furthermore, the outcome predicted delay on tasks identical or similar to the Treatment Task whereas belief about causality predicted delay on the Different Task. Delay was greater by subjects with ability or effort inductions than by subjects with a luck induction.