Reasoning about update logic

Logical frameworks for analysing the dynamics of information processing abound [4, 5, 8, 10, 12, 14, 20, 22]. Some of these frameworks focus on the dynamics of the interpretation process, some on the dynamics of the process of drawing inferences, and some do both of these. Formalisms galore, so it is felt that some conceptual streamlining would pay off.This paper is part of a larger scale enterprise to pursue the obvious parallel between information processing and imperative programming. We demonstrate that logical tools from theoretical computer science are relevant for the logic of information flow. More specifically, we show that the perspective of Hoare logic [13, 18] can fruitfully be applied to the conceptual simplification of information flow logics.     

Social categorization as a function of priming

The present study investigates the effect of priming on the use of social categorizations. Using sex and race as stimulus categorizations, previous studies failed to confirm the hypothesis that priming one of the two available categorizations would enhance the use of the primed categorization relation to the not-primed categorization. As suggested by Stangor, Lynch, Duan and Glass (1992). a momentary increase in accessibility may be insufficient to further enhance the use of highly accessible categorizations like race and sex, but it may be expected that priming will increase the use of categorizations which are less habitually used in daily life. The results of the present experiment support the hypothesis that, when the stimulus categorizations are weakly accessible (university major, university town), the relative use of the previously primed categorizations does indeed increase, compared to the alternative, not-primed, categorization.     

Irrational Beliefs, Interpersonal Perception and Marital Adjustment

To test the hypothesis that the major evaluative beliefs postulated by Rational-Emotive Behaviour Therapy are related to marital adjustment, 50 married couples completed the Dyadic Adjustment Scale (DAS) and the Survey of Personal Beliefs (SPB). Significant correlations were found between DAS scores and three subscales (Other directed shoulds, Low frustration tolerance and Self worth) of the SPB. On the interpersonal dimension of assumed similarity, females in the high dyadic adjustment group were better able to predict their spouses' awfulizing, low frustration tolerance and self-worth beliefs than were females in the low adjustment group. However, the present study offers only limited support for the hypothesis that interpersonal perception of irrational evaluative beliefs is related to marital adjustment.     

Suppression of emotional and neutral material

Previous studies have indicated that suppression of a thought results in an immediate increase of the frequency of this thought and/or in a rebound effect, i.e. in a heightened frequency of this thought later on. The present study (n = 53) examined the relationship between suppression and emotionality of the to-be-suppressed material. More specifically, it was investigated whether suppression of an emotional story results in stronger immediate enhancement or thought rebounds than suppression of a neutral story. There was a clear initial enhancement effect in the group suppressing a neutral story: subjects who tried to suppress experienced more target thoughts than subjects who did not try to suppress. In the neutral-story conditions, no rebound effect occurred. In the groups exposed to an emotional story, there was neither evidence of initial enhancement nor of a rebound. As most obsessions are related to emotional themes, the present findings cast doubt on the claim that the rebound phenomenon represents a valid laboratory model for clinical obsessions.     

Effects of matches and mismatches in agoraphobic and neutral situations

An experiment was conducted to investigate the generalizability of Rachman's match/mismatch model and to explore if environmental conditions affect the consequences of an underprediction. Twenty subjects walked around in agoraphobic, and 15 did so in neutral, situations. Both groups carried a walkman and 7 aversive human screams were administered to them at random times. The results gave strong support to previous investigations on matches and mismatches, but no differences were shown between agoraphobic and neutral situations. Possible explanations are discussed.     

Phonological and motoric demands in handwriting: evidence for discrete transmission of information

In an experiment with handwriting tasks effects of phonological and motoric task factors upon reaction time and movement time were measured to test implications of a discrete information processing account of the task. The model is built up of serially organized stages, each of which monitors one specific type of operation, necessary to generate a message. The serial structure of the model is defined as the limitation that higher levels of the model provide their output to the next lower processor in the hierarchy, and receive their input from the next higher stage. The parallel character of the model is exemplified through the assumption that all processors are active at the same time and concurrently with the real time production of writing movements. The study adds evidence that a serial architecture of processors can be compatible with the parallel processing of a message as long as more abstract operations are prepared more in advance to real-time movements than operations lower in the hierarchy. In the experiment the prediction was tested that the time course of the manifestation of phonological and motoric task demands reflects the discrete and serial structure of the model.     

Arm-tracking performance with and without visual feedback in children and adults: developmental changes

Tracking performance was investigated in children (aged 6-7 and 10-11) and in adult subjects. Target signals, moving unpredictably along a straight line, were tracked with the preferred arm, alternately with and without visual feedback. Qualitative observations indicate that tracking is based on continuous adjustments of the ongoing response to the continuously changing target position. No step-and-hold strategy could be detected in any of the three age groups. Tracking performance was described with four simple parameters, derived from linear systems analysis: (a) the delay between target signal and tracking movement (DL); (b) performance at the low-frequency range (LF), (c) performance at the high-frequency range (HF); and (d) a measure of tracking quality or overall similarity in the shape of target signal and tracking movement (Q). There was a considerable improvement in tracking performance with age, even after the age of 10-11, which was mainly demonstrated by a decrease in DL and increases in HF and Q. Tracking performance decreased only to a small extent when visual feedback was withdrawn. Age-related differences in the contribution of visual feedback to tracking performance could not be demonstrated.