Sample-specific ratio effects in matching to sample

In a symbolic matching-to-sample task, pigeons were trained using sample-specific, fixed-ratio “observing responses.” Subsequently, in a mixed condition, each sample was presented equally often with each ratio requirement, i.e., the ratios were no longer correlated with the samples. In a second experiment, pigeons were trained initially in the mixed condition and subsequently shifted to the sample-specific condition in which the required ratios were correlated with the samples. Results of both experiments suggested joint control of choices by ratio value and by the exteroceptive stimuli. The discriminative properties of the ratios appeared to outweigh absolute ratio-size effects.     

Loglinear multidimensional IRT models for polytomously scored items

A loglinear IRT model is proposed that relates polytomously scored item responses to a multidimensional latent space. The analyst may specify a response function for each response, indicating which latent abilities are necessary to arrive at that response. Each item may have a different number of response categories, so that free response items are more easily analyzed. Conditional maximum likelihood estimates are derived and the models may be tested generally or against alternative loglinear IRT models.Hank Kelderman is currently affiliated with Vrije Universiteit, Amsterdam.We thank Linda Vodegel-Matzen of the Division of Developmental Psychology of the University of Amsterdam for making available the data used in the example in this article.     

Some critical observations of the test information function as a measure of local accuracy in ability estimation

The test information function serves important roles in latent trait models and in their applications. Among others, it has been used as the measure of accuracy in ability estimation. A question arises, however, if the test information function is accurate enough for all meaningful levels of ability relative to the test, especially when the number of test items is relatively small (e.g., less than 50). In the present paper, using the constant information model and constant amounts of test information for a finite interval of ability, simulated data were produced for eight different levels of ability and for twenty different numbers of test items ranging between 10 and 200. Analyses of these data suggest that it is desirable to consider some modification of the test information function when it is used as the measure of accuracy in ability estimation.     

Fear of snakes and facial reactions: A case of rapid emotional responding

The aim of the present study was to explore how rapid emotional responses are manifested as facial electromyographic (EMG) reactions when people with explicit fear of snakes are exposed to their fear relevant stimuli. Fifty-six subjects, high or low in fear of snakes, were exposed to pictures of snakes and flowers while facial EMG activity from the corrugator supercilii and the zygomatic major muscle regions was recorded. Measures of autonomic activity and ratings of the stimuli were also collected. Pictures of snakes evoked a rapid corrugator supercilii muscle reaction which was larger in the High fear group as early as 500ms after stimulus onset. The High fear group also rated snakes as more unpleasant and displayed larger skin conductance responses (SCRs) and increased heart rate (HR) when exposed to snakes. Pictures of flowers tended to evoke increased zygomatic major muscle activity which did not differ among the groups. The present results demonstrate that the facial EMG technique is sensitive enough to detect rapidly evoked negative emotional reactions. The results support the hypothesis that people high in fear of snakes are disposed to react very rapidly with a negative emotional response to their fear relevant stimuli.     

Bipolar control in fixed interfood intervals

The ability of stimuli correlated with successive periods in a fixed interfood interval to support a response that produced or removed them was examined using pigeons. The degree to which those correlated stimuli elicited directed key pecks was also obtained. Stimuli early in the interval functioned as negative reinforcers, and stimuli late in the interval functioned as positive reinforcers. Stimuli correlated with successively later portions of the second half of the interval supported successively higher rates of elicited pecking and, with the exception of the final stimulus, supported successively higher rates of stimulus production. Stimuli in successively earlier portions of the first half of the interval supported successively higher rates of correlated-stimulus removal. This effect occurred in spite of the addition of a conjoint variable-interval dependency for food. An ogive fit to the mean normalized response distributions resulted in r²s demonstrating that most of the variance in the temporal organization of the behavior was accounted for. The findings were taken to indicate that fixed interfood intervals establish bipolar control.     

Occupational Stressors, Stress Responses, and Alcohol Consumption Among Professional Firefighters: A Prospective, Longitudinal Analysis

This dual-site longitudinal prospective study monitored and measured change in self-reported occupational stressors, emotional trauma, symptoms of stress, and alcohol consumption in urban firefighters. Study participants were 188 firefighters employed by two urban fire departments. The results showed that of 19 occupational stressors examined, only 5 (26%) changed significantly over time, and of those 5, only two—job skill concerns and concerns regarding reduction in force and benefits—decreased, reflecting less bothersome subjective ratings. Of the 12 measures of posttraumatic and other symptoms of stress, 9 (75%) increased significantly over time and none decreased significantly, whereas alcohol consumption was stable over time. Job stressors, trauma caseness, and stress response symptoms at baseline were strongly and significantly associated with the same measures at the two-year follow-up. The implications of the findings for prevention and remediation of stress disorders in fire service personnel are considered. It can be concluded that the stressful nature of urban firefighting is significantly associated with negative health outcomes, including the potential overreliance on alcohol use.     

Maternal Care and Individual Differences in Defensive Responses

Abstract— Familial transmission of mental illness is common. Recent studies in behavioral neuroscience and biological psychiatry reveal the importance of epigenetic mechanisms of transmission that center on the developmental consequences of variations in parental care. Studies with rats suggest that environmental adversity results in patterns of parent–offspring interactions that increase stress reactivity through sustained effects on gene expression in brain regions known to regulate behavioral, endocrine, and autonomic responses to stress. While such effects might be adaptive, the associated cost involves an increased risk for stress-related illness.     

Nothing Matters in Survival

Do I have a special reason to care about my future, as opposed to yours? We reject the common belief that I do. Putting our thesis paradoxically, we say that nothing matters in survival: nothing in our continued existence justifies any special self-concern. Such an “extreme” view is standardly tied to ideas about the metaphysics of persons, but not by us. After rejecting various arguments against our thesis, we conclude that simplicity decides in its favor. Throughout the essay we honor Jim Rachels, whose final days exemplified his own unselfish morality as well as the “neutralist” ideal we espouse. As an appendix, we include the last original work to be published by James Rachels, in which he criticizes Sidgwick’s most famous defense of egoism.     

Postponing trauma: The dangers of telling

Surviving a major historical trauma has consequences that are difficult to live with. Survivors who remain silent are often condemned to a desiccated existence, a dried‐out life, a death in life. Survivors who speak out run an even greater risk. Telling their ghastly tale may trigger somatic consequences, psychotic episodes, or even suicide. As to the psychoanalytic cure, the free association it requires carries its own danger: negative therapeutic reaction in sometimes extreme forms. Avoidance of horror may turn into avoidance of life itself. Awful as it may seem, this avoidance of life may represent a victory over a menacing chaos. Should we as analysts accept the risk of endangering such a victory, no matter how unsatisfactory? The psychoanalytical injunction to speak out may trigger an upsurge of shame and terror. Is subjectivation always possible? This paper is about what happens when denial and splitting strategies are suspended, when ‘crypts’ are opened. Is there an analytic ‘poros’ allowing for a controlled return of affects? Is there a therapeutic solution to the problem of telling a wreckage without being caught in it? The dangers of ‘telling’ will be discussed in regard to new analytic strategies and new interpretive registers. When the ‘silent psychic sharing’ proves insufficient, some analysts go so far as to take part in the shame, share the grief, ‘lend their own psyche’, become a ‘double’ of the analysand, accept the existence of ‘sanctuaries’. To what effect?     

Physiological markers of challenge and threat mediate the effects of performance-based goals on performance

We predicted that adopting a performance-approach vs. performance-avoidance goal would lead to physiological responses characteristic of psychological states of challenge vs. threat appraisals, respectively. Furthermore, we predicted that these states would mediate the effects of goals on performance. Twenty-seven undergraduate females performed a task described as identifying either exceptionally strong performers (performance-approach goal) or exceptionally weak performers (performance-avoidance goal). Participants’ cardiovascular reactivity (CVR) was recorded while they performed the task. As predicted, participants in the performance-approach goal condition performed better on the task than did those in the performance-avoidance goal condition. Also as predicted, those in the former condition exhibited a challenge pattern of CVR whereas those in the latter condition exhibited a threat pattern of CVR. Furthermore, physiological responses mediated the effects of performance-based goals on performance.