The formalin test and the opioid nature of stress-induced analgesia

Exposure to electric shock produces an analgesic reaction (SIA) that is reversed by opiate antagonists ("opioid" SIA) under some conditions but not under other conditions ("nonopioid" SIA). A number of studies using tail-flick to radiant heat as the measure of pain sensitivity have found that a small number of shocks lead to nonopioid SIA, while a large number of shocks produce opioid SIA. In contrast, a small number of shocks have been reported to produce opioid SIA when the Formalin test was used to measure pain reactivity. However, the Formalin test involves administering a chronic pain stimulus (injection of Formalin into the paw) for an extended period before the shocks. Here it is reported that this "preexperimental" stress is sufficient to convert the SIA after a small number of shocks measured by tail-flick to the opioid form.     

Beyond the Apophatic Circle: Rethinking the Debate Between Jean-Luc Marion and Jacques Derrida

This study offers a new perspective on the much-discussed debate between French phenomenologist Jean-Luc Marion and postructuralist theorist Jacques Derrida on the question of ‘negative theology’ and the Christian mystical tradition. It argues that Marion's critique of Derrida betrays a fundamental misunderstanding, specifically, that it fails to recognise that Derrida is not interested in negative theology qua theology, but rather as a discursive practice with certain resources for the performative ‘unsaying’ of logocentric systems. It continues to show that Derrida's principal object is not the God of apophatic theology, but the broader, juridico-political implications of all ‘transcendental signifieds’. Finally, it suggests that Marion's oversight of these facts in his defence of the apophatic tradition unwittingly legitimates Derrida's critique, to the extent that it insulates the Christian tradition from external criticism, and thereby limits the responsiveness of that tradition to the demands of justice.     

On the role of experience versus motivation in predicting the own-race effect

The other-race effect (ORE) is a longstanding phenomenon in experimental psychology, where recognition for same-race faces is superior than for other-race faces. The present research pits two competing theories of perceptual expertise and social motivation against each other to see which is the more robust predictor of the ORE. In Study 1, we measured Black and White participants' prior contact with individuals from the other-race (i.e. expertise) as well as their expected level of future interaction with other-race individuals (i.e. motivation). Of the two theories, anticipated interaction (i.e. motivation) emerged as a significant predictor of the ORE. Study 2 followed the same design, measuring motivation with a self-report assessment of how much participants are willing to have cross-race friendships. Here, neither experience nor motivation predicted the ORE, though an ORE was established. Differences in measures that assess motivation and the experience versus motivation debate are discussed.     

Further evaluation of prompt density,rate of reinforcement,and the persistence of manding

Previous research has evaluated the effects of prompt rates on the rate of communicative behavior. More recent research has suggested that dense prompting can result in communicative behavior that is more resistant to change. However, existing research has not considered the impact that higher response rates had on reinforcement rate, a variable known to impact response persistence. The current study systematically replicated previous research by evaluating communicative responding in contexts associated with dense- and lean-prompt schedules and extended existing research by (a) holding reinforcement rates similar across the two prompting schedules (lean and dense), and (b) evaluating the persistence of communicative responding in the contexts associated with each prompting schedule. The results for Experiment 1 clearly replicated and extended previous research. The results for Experiment 2 were equivocal and suggested that previous reinforcement history and response class size impacted outcomes.     

Grouping and short-term memory: Different means and patterns of grouping

Two experiments, concerned with the improving effects of grouping on auditory short-term memory, are described. In the first, temporal grouping was found to improve recall considerably, but non-temporal grouping had a much smaller effect. Temporal grouping reduced the order errors more than other errors; it also changed the pattern of the order errors. Further, it altered the shape of the serial position curve of all errors. In the second experiment, irregular patterns of temporal grouping were found to be inferior to a regular pattern. The results are discussed in terms of the time available for processing previous items during the presentation of a sequence, and the form that this processing may take.     

Direct quantitative judgments of sums and a two-stage model for psychophysical judgments

Judged magnitudes of differences between stimuli have previously been shown to support a two-stage interpretation of magnitude estimation, in which input transformations and output transformations are each describable as power functions. In an effort to provide support for the model independent of the difference estimation procedure. the present investigation employed two additional judgment tasks. We obtained magnitude judgments and category judgments of the combined magnitudes (sums) of paired weights from two groups of Ss. Values of the inferred input exponent k calculated from the two sets of data were very similar and were also remarkably similar to the exponent previously calculated from magnitude estimations of differences between weights. The output exponent calculated from magnitude judgments of sums described a concave upward function; however. the similar function describing category judgments was essentially linear. These results show that the inferred input exponent is not the result of the difference estimation task, and in addition provides support for the contention that the interval scale may be a less biased sensory measure than the magnitude scale. The introduction of an additive constant to the model improved its fit to the data but the rule by which it was introduced made very little difference.     

Child and adolescent psychopathology research: Problems and prospects for the 1990s

In November 1990 the National Institute of Mental Health (NIMH) convened a special conference of over 100 scientists and leaders to outline specific strategies and research initiatives that should be developed to implement the recently released National Plan for Research on Child and Adolescent Mental Disorders.Participants included journal editors, educators from psychology and psychiatry, representatives from private foundations, and leaders of research program areas in public funding agencies. Critical knowledge gaps were identified in five areas of child and adolescent psychopathology, including depression, attention deficit hyperactivity disorder, conduct disorder, the anxiety disorders, and the developmental disorders. For each of these areas, special emphasis was placed on developing new ideas and obtaining critical input from other areas of investigation. This report summarizes the identified research gaps and recommends research initiatives to implement the National Plan, as outlined by the conference participants.     

Mathematica: A flexible design environment for neural networks

Several neural networks were developed inMathematica in order to explore the role of “spiky” neurons in neural network memory simulations. UsingMathematica for this task confirmed its value as a powerful tool for neural network development: It exhibited distinct advantages over other environments in programming ease, flexibility of data structures, and the graphical assessment of network performance.