Heat and Violence: New Findings from Dallas Field Data, 1980–19811

Research in both laboratory and field settings has suggested a link between thermal stress and violent behavior, and both linear and curvilinear models have been investigated. A dearth of field studies prompted the analysis reported here, which is based on data for some 10,000 aggravated assaults occurring the City of Dallas in 1980 (a summer of severe heat stress) and 1981. This analysis replicates and extends certain aspects of recent work by Anderson and Anderson (1984) relating to the so-called linear and curvilinear hypotheses. Thermal stress is measured in two ways: a Discomfort Index (DI), which takes into account the influence of humidity acting in concert with temperature, and ambient temperature. Regression analyses were performed in two stages. In the first, data for all neighborhoods and all days of the study period were combined into ambient temperature and DI models. At the second stage, models differentiated between the three levels of neighborhood socioeconomic status. With weekend controlled, DI and ambient temperature were significant independent variables in the ‘overall’ model and in medium and low status neighborhoods. However, when linear effects were controlled, the curvilinear measures were never significant. The analysis generally tended to confirm Anderson and Anderson's suggestion that a reduction of aggression with increasing temperature does not appear to occur within the normal range of temperatures. This analysis further suggested that the hypothesized curvilinear effect is weak, if not entirely absent, even during conditions of extreme heat.     

On the varieties of computer experience

An on-line, real-time, high-level experiment control language is described. It is written to run on a PDP/8I with 8K memory, automatic multiply-divide. PT08B and RO-33 Teletype, and a interface hardware system.     

A novel automatic procedure for measuring ocular counterrolling: A computeranalytical method to determine the eye’s roll angle while subjects work on perceptual tasks

In investigations of the perception of space, the consideration of ocular counterrolling-the movement of the eye around its visual axis in response to body movement-is crucially important. The angle of this movement must be known in order for one to determine the precise retinal coordinates of a distal object. Following transformation, this stimulus serves as a reliable cue for visual direction. The otolith organs provide information about body tilt and are responsible for ocular counterrolling. A novel, noninvasive method to measure ocular counterrolling, based on the cross-correlation of digitized video pictures of the eyes, is presented. The resolution attained was ≤ 0.1°. The computer analysis is fully automatic and fast, and it can be performed while subjects work on perceptual tasks. No direct access to the eyeballs is required. Data from 4 subjects showing the counterrolling profile in various body positions are presented.     

Is there implicit memory without attention? A reexamination of task demands in Eich’s (1984) procedure

The relation between memory and attention has been of long-standing interest. Eich (1984) made an important discovery of implicit but not explicit memory for contextually determined homophones (e.g., taxi-FARE) presented in a channel to be ignored within a selective listening procedure. However, his slow rate of presentation of shadowing task materials may have allowed frequent attention shifts to the allegedly ignored channel. With a direct replication of Eich’s timing parameters, we reproduced his results, but when the attended channel was presented twice as fast as Eich’s, implicit memory for the to-be-ignored words vanished. Our results contradict claims of extensive semantic processing of unattended auditory information in this task.     

Varieties of positive and negative priming

Numerous recent investigations have focused on a particular relation between the roles a stimulus plays in successive displays: when a stimulus ignored by a subject on one occasion is to be attended on a succeeding occasion, reaction time to that stimulus is slowed relative to a control condition. But this is but one possible case ofnegative priming. There are other ways in which negative priming might occur, and there are several varieties of positive priming as well. All these possibilities were explored in the present experiment.     

Intuitionistic uniformity principles for propositions and some applications

This note deals with the prepositional uniformity principlep-UP: p x N A (p, x) x N p A (p, x) ( species of all propositions) in intuitionistic mathematics.p-UP is implied by WC and KS. But there are interestingp-UP-cases which require weak KS resp. WC only. UP for number species follows fromp-UP by extended bar-induction (ranging over propositions) and suitable weak continuity. As corollaries we have the disjunction property and the existential definability w.r.t. concrete objects. Other consequences are: there is no non-trivial countable partition of;id is the only injective function from to; there are no many-place injective prepositional functions; card () is incomparable with the cardinality of all metric spaces containing at least three elements.