Thyroid hormones,psychophysiological reactivity,and anxiety

Thirty-eight adults were assigned to three groups: posttreatment hyperthyroid (n=13), low euthyroid (n=12), and high euthyroid (n=13). Physiological and subjective responses to three anxiety-induction procedures—public speaking, personally distressing imagery, and threat of shock—were compared across groups. Although there were differences across stressors for physiological and subjective measures, group differences were not detected. Results are discussed with regard to the risk for residual anxiety following treatment for hyperthyroidism and the possible influence of thyroid function on the etiology or maintenance of anxiety.     

Charles “Erik” Eriksen (1923-2018)

A towering figure in experimental psychology, Charles W. Eriksen, passed away in February this year. “Erik” made extensive original and lasting contributions to both research methods and theories in several areas of psychology, especially involving visual information processing. His research exhibited consistent concerns with experimental methods for distinguishing among alternative explanations and distinguishing perception from behavior. Erik pioneered many research methods now in common use—including converging operations, visual search, rapid serial presentations, the stop-signal paradigm, temporal integration in form perception, spatial cues for guiding selective attention, and the flankers task. He also introduced and tested many theories of selective attention. Erik was the founding editor of Perception & Psychophysics, and served for 23 years as its principal editor. An impressive and unforgettable person, Erik was a compelling personification of “the greatest generation.”     

Priming or executive control? Associative priming of cue encoding increases “switch costs” in the explicit task-cuing procedure

The explicit task-cuing procedure involves presenting a cue that indicates which task to perform on a target. Responses are typically faster when tasks repeat than when they alternate, and this difference is often interpreted as a measure of the time required for executive control processes to change task set. This article suggests that the difference reflects priming of cue encoding when successive cues are identical or associatively related. Subjects responded to task repetitions more quickly when the cue on the current trial was associatively related to the cue on the previous trial (e.g., day --> night) than when the cues were unrelated (e.g., verb --> night). Models applied to the time course function--generated by manipulating the interval between the onsets of the cue and the target--showed that the facilitation was due to cue encoding, a process that does not require online executive control.     

Inhibitory control in mind and brain: an interactive race model of countermanding saccades

The stop-signal task has been used to study normal cognitive control and clinical dysfunction. Its utility is derived from a race model that accounts for performance and provides an estimate of the time it takes to stop a movement. This model posits a race between go and stop processes with stochastically independent finish times. However, neurophysiological studies demonstrate that the neural correlates of the go and stop processes produce movements through a network of interacting neurons. The juxtaposition of the computational model with the neural data exposes a paradox-how can a network of interacting units produce behavior that appears to be the outcome of an independent race? The authors report how a simple, competitive network can solve this paradox and provide an account of what is measured by stop-signal reaction time.     

Effects of methylphenidate on inhibitory control in hyperactive children

This study investigated the effects of methylphenidate (MPH) on inhibitory control in hyperactive children. A double-blind, placebo-control, within-subject (crossover) design was used in which 12 children, between 6 and 11 years of age, were each tested four times in each drug condition: 0.3 mg/kg and 1.0 mg/kg of methylphenidate, and placebo. Dependent measures included (a) the probability of inhibiting responses to a primary choice reaction time task given a stop signal, on the Stopping Task, and (b) response latency and errors on the Matching Familiar Figures Test (MFFT). MPH improved the efficiency of the central inhibitory mechanism by speeding the inhibitory process, thereby affording the children greater control over their actions and enabling them to increase the probability with which they inhibited responses given a stop signal. MPH increased response latency but did not reduce errors on the MFFT, and observation of the children's task performance highlighted the interpretive problems associated with this task. Performance on both tasks was better at a dosage of 1.0 mg/kg than at 0.3 mg/kg.     

Induction and activity-dependent reversal of persistent LTP and LTD in lateral perforant path synapses in vivo

The reversibility of long-term potentiation (LTP) and heterosynaptic long-term depression (LTD) lasting weeks was examined in the lateral perforant path of freely moving adult Sprague-Dawley rats. LTP lasting weeks was rapidly reversed within minutes by high-frequency heterosynaptic stimulation of the medial perforant path, in an N-methyl-D-aspartate receptor-dependent manner. LTP reversal also occurred, albeit more slowly and to a lesser extent, when animals were given 1-3 weeks of overnight exposure to an enriched environment (EE). LTD likewise was reversed upon repeated EE exposure. A covert similarity between the degrees of LTP and LTD reversal was revealed when the small potentiation effect of EE treatment by itself on lateral path responses was taken into account. Despite its ability to reverse previously acquired synaptic plasticity, two weeks of EE treatment had no effect on animals' retention of the platform location in a spatial watermaze task, although it did facilitate new learning. These data are in agreement with the hypothesis that hippocampal synapses retain the capacity for rapid synaptic change even when otherwise relatively stable plasticity has previously been induced. Slow reversal of such plasticity did not correlate with a loss of memory retention, possibly because either slow changes permit reorganization of representations such that both old and new information can be accommodated, or else the new information is synaptically represented in orthogonal fashion to the old information.     

The Legacy of Adolf Meyer''s Comparative Approach: Worcester Rats and the Strange Birth of the Animal Model

The breeding of albino rats had an enormous impact on experimental psychology in the twentieth century. Rats were, and for many questions still remain, the "standard animal" for laboratory research in neurology, psychology, and physiology. Albert Meyer was one of the figures most responsible for developing the albino rat as an experimental model. Despite Meyer's pioneering work with albino rats, his rat research has received only sparse attention. Little is known about the way in which the animal served Meyer's more famous psychiatric program. In this article, the author discusses the role that albino rats played in Meyer's animal research. He then turn to the contrast between the way in which Meyer viewed the animal's role in research and the way rats were later used as a laboratory "standard" to assure scientific generality. This comparison highlights the changes that occurred in comparative psychology in the twentieth century, and it further clarifies some of the concerns associated with the use of animal models today.     

What language shall I borrow? The poetry of Rainer Maria Rilke and the care of souls

This article suggests that the reality of the world is socially constructed through the words and narratives chosen and used. These social constructions may be from science and technology, business and economics, or poetry and metaphors, and as such each shapes a different world. The work of the poet Rainer Maria Rilke is used to illustrate how the power of words and images shape and form the world. The implications of the use of language for the care of souls are discussed.