Reaction time to threat stimuli in panic disorder and social phobia

Two studies assessed response time among clinically anxious subjects and normal controls when presented with threat, positive and neutral stimuli under perceptual (lexical decision) and semantic (category decision) task conditions. In Study 1, panic disorder subjects' (n = 14) performance was compared to that of matched normal controls (n = 14) while in Study 2 social phobic subjects (n = 24) were compared to matched normal controls (n = 24). Relative to matched normal controls, panic disorder subjects but not social phobics tended to show greater slowing in performance on the more cognitively complex (category) task. A second finding, consistent across both studies was that, compared to the normal control groups, both panic and social phobic groups showed significantly slowed responses to threat words in both the perceptual and semantic tasks. Such findings are directly counter to the predictions of a mood congruence hypothesis. This apparent contradiction is resolved by a review of the literature which indicates that mood-related facilitation effects are obtained only in tasks which tap awareness of threat information rather than speed of response. It is suggested that while anxiety may produce enhanced awareness of threat, it may inhibit responsiveness to it. The results of these studies are seen as consistent with ethological theories of inhibited motoric responses under certain threat conditions. Furthermore, the findings suggest that caution is indicated in interpreting slowed reaction time to threat stimuli in tasks such as the Stroop color naming task as purely the result of attentional processes.     

Age differences in rereading

Younger and older adults read a series of expository and narrative passages twice in order to answer comprehension questions. Reading time was used to index attentional allocation to word, textbase, and situation model processing and to assess shifts in the allocation policy from the first to the second reading. Older readers' comprehension was at least as good as that of younger readers. Analysis of reading times suggested that for both genres, older adults allocated more attention to situation model features than younger adults did on the first reading, whereas young and old allocated attention similarly to this level of representation on the second reading, suggesting that mature readers may give greater priority to situation model construction when first encountering text. Also, for both genres, older adults showed relatively less facilitation than the young in word-level processing in rereading, suggesting that representation at this level is not as firmly established during reading or decays more quickly for older readers. For narrative texts only, this pattern also obtained for textbase processing. Collectively, these data show that age equivalence in text comprehension at the molar level may be accomplished through different processing routes at the molecular level.     

Aging,memory load,and resource allocation during reading

To test the notion that aging brings an inability to self-initiate processing, the authors investigated the effects of memory load on online sentence understanding. Younger and older adults read a series of short passages with or without a simultaneous updating task, which would be expected to deplete resources by consuming memory capacity. Regression analyses of word-by-word reading times onto text variables within each condition were used to decompose reading times into resources allocated to the array of word-level and textbase-level processes needed for comprehension. Among neither the young nor the old were word-level processes disrupted by a simultaneous memory load. However, older readers showed relatively greater levels of resource allocation to conceptual integration than the younger adults when under load, regardless of working-memory span or task priority. These results suggest that the ability to self-initiate the allocation of processing resources during reading is preserved among older readers.     

Pursuing Academic Interests: The Role of Implicit Theories

Students can believe that their academic interests are fixed (entity theory) or malleable (incremental theory). A measure of implicit theories of academic interests was developed to examine how such theories influence students' decisions to retain or change their majors. As hypothesized, entity theorists who believed that they were not doing well in their majors were more likely to choose a new major than were all other groups. This result is consistent with previous findings that entity theorists tend to give up in the face of adversity.     

Should We Agree to Disagree? The Multilevel Moderated Relationship Between Safety Climate Strength And Individual Safety Motivation

Organisational research investigating climate perceptions often use constructs reflecting dispersion and disagreement, termed ‘climate strength’, to investigate situational pressures on behaviour expression. Within safety-specific contexts, research has tended to emphasise the prediction of climate strength rather than an examination of its effects on behaviour. The present paper investigates the important first pathway in the prediction of safety behaviour by investigating the influence of safety climate strength on the relationship between safety climate perceptions and individual safety motivation in a safety critical context using multilevel analyses. Contrary to expectations, results initially indicated that safety climate strength negatively influenced the relationship between safety climate perceptions and safety motivation, such that greater variability was associated with greater motivation. Post hoc analysis re-grouping responses into broader functional levels found support for an interaction, suggesting a difference in the scope of influence for safety climate strength between the two levels of analysis. These findings are discussed in light of self-determination theory, and suggestions for future research and practice made.

     

Brief Report: Symptoms of PTSD,Coping Strategies,and Social Adjustment among Survivors of Early Life Interpersonal Trauma

Dysphoria symptoms of posttraumatic stress disorder (PTSD) have been associated with impairments in social functioning; however, this relationship has been unexamined among interpersonal trauma populations. A sample of 303 women with a history of early life interpersonal trauma completed measures of PTSD severity, coping, and social functioning. Results revealed that dysphoria symptoms had a strong and unique association with total social adjustment and social functioning (i.e., social activities). Active coping significantly mediated the relationship between dysphoria symptoms and total social adjustment, and active coping and seeking emotional support significantly mediated the relationship between dysphoria symptoms and social functioning. Findings elucidate variants of coping that might compound impaired social functioning and highlight the value of integrating coping skills into PTSD interventions.     

Characteristics of implicit chaining in cotton-top tamarins (Saguinus oedipus)

In human cognition there has been considerable interest in observing the conditions under which subjects learn material without explicit instructions to learn. In the present experiments, we adapted this issue to nonhumans by asking what subjects learn in the absence of explicit reinforcement for correct responses. Two experiments examined the acquisition of sequence information by cotton-top tamarins (Saguinus oedipus) when such learning was not demanded by the experimental contingencies. An implicit chaining procedure was used in which visual stimuli were presented serially on a touchscreen. Subjects were required to touch one stimulus to advance to the next stimulus. Stimulus presentations followed a pattern, but learning the pattern was not necessary for reinforcement. In Experiment 1 the chain consisted of five different visual stimuli that were presented in the same order on each trial. Each stimulus could occur at any one of six touchscreen positions. In Experiment 2 the same visual element was presented serially in the same five locations on each trial, thereby allowing a behavioral pattern to be correlated with the visual pattern. In this experiment two new tests, a Wild-Card test and a Running-Start test, were used to assess what was learned in this procedure. Results from both experiments indicated that tamarins acquired more information from an implicit chain than was required by the contingencies of reinforcement. These results contribute to the developing literature on nonhuman analogs of implicit learning.     

Performance on patterned string problems by common marmosets (Callithrix jacchus)

This experiment examined the performance of common marmosets (Callithrix jacchus) on a series of patterned string problems to assess the marmosets’ understanding of means–ends relationships. One marmoset, Jet, was exposed to a series of problems that were ordered in terms of perceived difficulty during two testings that were separated by 1 year. In the second testing, Jet received problems that had been used during the first testing along with three new problems. Each of the new problems was designed to be an exemplar of the type of problem that Jet had experienced difficulty with in the first testing. A second marmoset, Peaches, was tested on the same set of problems given to Jet in the second testing. Results indicated that the marmosets’ performance on these problems fell into three categories. In one category, some problems were solved without evidence of trial-and-error learning. In a second category, there were problems in which the marmosets responded at chance levels initially but evidenced improvement as a function of extended testing. In a third category, some problems appeared to be virtually unsolvable even with extended testing. Taken together, these results indicate that the marmosets were able to learn the means–ends connection between pulling a string and obtaining food. This learning was best characterized as a trial-and-error process for some problem forms, while for others there appeared to be rapid learning that did not require extensive practice. The instances of rapid learning may be the result of the application of a simple spatial proximity rule in which the marmosets chose the string that was closest to an imaginary line drawn between the marmoset and the reinforcer.