Delay of stimulus presentation after the saccade in visual search

Delay of stimulus onset after each saccade in visual search decreased oculomotor and manual reaction times, with a greater effect occurring for the oculomotor response. The saccadic oculomotor reaction might have been facilitated in three ways: by the facilitation of reaction with a foreperiod warning stimulus, by the attenuation of saccadic suppression effects due to the stimulus onset delay, or by the use of a strategy of preprogramming fixation durations. The results support a model of visual search using preprogrammed control of visual fixation durations.     

Dynamic algebras: Examples,constructions, applications

Dynamic algebras combine the classes of Boolean (B 0) and regular (R ; *) algebras into a single finitely axiomatized variety (B R ) resembling an R-module with scalar multiplication . The basic result is that * is reflexive transitive closure, contrary to the intuition that this concept should require quantifiers for its definition. Using this result we give several examples of dynamic algebras arising naturally in connection with additive functions, binary relations, state trajectories, languages, and flowcharts. The main result is that free dynamic algebras are residually finite (i.e. factor as a subdirect product of finite dynamic algebras), important because finite separable dynamic algebras are isomorphic to Kripke structures. Applications include a new completeness proof for the Segerberg axiomatization of prepositional dynamic logic, and yet another notion of regular algebra.Dept. of Computer Science, Stanford, CA 94305 This research was supported by the National Science Foundation under NSF grant no. MCS78-04338. Preparation of the present version was supported by the National Science Foundation under NSF grant number CCR-8814921.This paper originally appeared as Technical Memo #138, Laboratory for Computer Science, MIT, July 1979, and was subsequently revised, shortened, retitled, and published as [Pra80b]. After more than a decade of armtwisting I. Németi and H. Andréka finally persuaded the author to publish TM#138 itself on the ground that it contained a substantial body of interesting material that for the sake of brevity had been deleted from the STOC-80 version. The principal changes here to TM#138 are the addition of footnotes and the sections at the end on retrospective citations and reflections.     

Retrieval processes in perceptual recognition and cued recall: The influence of category size

The purpose of these experiments was to determine whether nonsemantic category size and other variables would influence perceptual recognition as they influence cued recall. Procedures developed by Jacoby and his associates were replicated with words belonging to either small or large nonsemantic categories and with recognition tested under bright-target/patterned-mask conditions. The results indicated that words belonging to larger nonsemantic sets were more difficult to identify. This finding and the results of other manipulations are discussed in relation to the interactive activation model and to the proposal that perceptual recognition performance is dependent on a retrieval process similar to that involved in recall prompted by nonsemantic cues.     

Aging and Inhibition of Unconsciously Processed Information: No Apparent Deficit

Young and older adults were compared on a cued recall task designed to show effects of activation and inhibition of unconsciously processed information. The number of associates related to the target words by prior experience was varied, and the targets were studied either in the absence or the presence of meaningfully related context cues. The number of associates of the target had an effect on recall when context cues were absent during study, suggesting that the associates had been activated and encoded during study. In contrast, when context cues were present during study, no effect of the number of target associates was observed, suggesting that the associates had been inhibited during study. Comparable activation and inhibition effects were obtained for younger and older subjects. The results suggested little or no age-related deficit in inhibition when the to-be-inhibited information was unconsciously processed and not brought to conscious awareness.     

What is free association and what does it measure?

This paper reports the results of a study of free association in which participants were asked to produce the first two words to come to mind. The findings were used to estimate the reliability of indices of strength and set size for different types of items and to model free association as a retrieval task. When confined to first responses, reliability was generally high for both indices, particularly for words with smaller sets of associates and stronger primaries. When second responses were included, reliability declined. A second response added new but weak items to the set, and, when the primary associate was not produced on the first opportunity, it tended not to be produced on the second. Relative to when multiple responses are requested, first-response free association provides more reliable indices of the relative strength and set size for a word's strongest associates. A model of free association assuming that a strength distribution underlies each response provided a good fit to the data.     

The impact of negative moods on self-enhancing cognitions: the role of reflective versus ruminative mood orientations

This research program examined how self-focused attention to feelings affects the relation between mood negativity and self-enhancing thought. The primary hypothesis was that the particular manner in which people focus on their moods (reflective vs. ruminative) determines whether they reveal positive (i.e., mood-incongruent) or negative (i.e., mood-congruent) self-relevant thoughts in response to negative moods. Studies 1-4 revealed that social comparisons, temporal comparisons, and other self-enhancing cognitions (i.e., attributions, disidentification, relationship evaluations) are more likely to be mood incongruent when people adopt a reflective orientation to their negative feelings and more likely to be mood congruent when they adopt a ruminative orientation. Additionally, moods and mood orientations affected self-enhancing thoughts through the mediating influence of mood regulation goals and intentions (Studies 5 and 6).     

Restraint and Cancellation: Multiple Inhibition Deficits in Attention Deficit Hyperactivity Disorder

We used variations of the stop signal task to study two components of motor response inhibition—the ability to withhold a strong response tendency (restraint) and the ability to cancel an ongoing action (cancellation)—in children with a diagnosis of attention deficit hyperactivity disorder (ADHD) and in non-ADHD controls of similar age (ages 7–14 years). The goal was to determine if restraint and cancellation were related and if both were deficient in ADHD. The stop signal task involved a choice reaction time task (go task) which required a rapid response. The demand for inhibitory control was invoked through the presentation of a stop signal on a subset of go trials which required that the ongoing response be suspended. The stop signal was presented either concurrently with the go signal (restraint version) or after a variable delay (cancellation version). In Study 1, we compared ADHD and control children on the cancellation version of the stop task; in Study 2, we compared ADHD and controls on the restraint version. In Study 3, a subset of ADHD and control participants completed both tasks so that we could examine convergence of these dimensions of inhibition. Compared to control participants, ADHD participants showed a deficit both in the ability to cancel and to restrain a speeded motor response. Performance on the restraint version was significantly correlated with performance on the cancellation version in controls, but not in ADHD participants. We conclude that ADHD is associated with deficits in both restraint and cancellation subcomponents of inhibition.     

Self-Esteem Instability and Humor Styles: Does the Stability of Self-Esteem Influence How People Use Humor?

The purpose of the present study was to examine whether self-esteem instability moderated the association between self-esteem level and the use of humor. This was accomplished by examining the associations that humor styles had with self-esteem level and self-esteem instability among 499 undergraduates. The results of the present study show that self-esteem instability moderated the association between self-esteem level and humor styles such that individuals with stable high self-esteem reported the highest levels of affiliative humor as well as the lowest levels of aggressive and self-defeating humor. These results suggest that individuals with stable and unstable forms of self-esteem employ different styles of humor.     

An Examination of Sociotropy and Excessive Reassurance Seeking in the Prediction of Depression

The study was an examination of the relationship between sociotropy and excessive reassurance seeking in the prediction of depression. Although there is an obvious theoretical link between these constructs, little empirical work has been directed at integrating these constructs. Because it was theorized that sociotropic persons would be relatively more likely to engage in excessive reassurance seeking relative to autonomous individuals, it was predicted that sociotropy, and not autonomy, would be positively related to excessive reassurance seeking. In addition, it was predicted that excessive reassurance seeking would mediate effects of sociotropy upon depression. Overall, the results from 167 undergraduates completing measures for all variables supported these predictions. The results suggest that beyond the psychological vulnerabilities hypothesized by A. T. Beck (1983), sociotropic persons might engage in interpersonal behaviors that exacerbate their response to life stress.