Selective inactivation of adenosine A(2A) receptors in striatal neurons enhances working memory and reversal learning

The adenosine A(2A) receptor (A(2A)R) is highly enriched in the striatum where it is uniquely positioned to integrate dopaminergic, glutamatergic, and other signals to modulate cognition. Although previous studies support the hypothesis that A(2A)R inactivation can be pro-cognitive, analyses of A(2A)R's effects on cognitive functions have been restricted to a small subset of cognitive domains. Furthermore, the relative contribution of A(2A)Rs in distinct brain regions remains largely unknown. Here, we studied the regulation of multiple memory processes by brain region-specific populations of A(2A)Rs. Specifically, we evaluated the cognitive impacts of conditional A(2A)R deletion restricted to either the entire forebrain (i.e., cerebral cortex, hippocampus, and striatum, fb-A(2A)R KO) or to striatum alone (st-A(2A)R KO) in recognition memory, working memory, reference memory, and reversal learning. This comprehensive, comparative analysis showed for the first time that depletion of A(2A)R-dependent signaling in either the entire forebrain or striatum alone is associated with two specific phenotypes indicative of cognitive flexibility-enhanced working memory and enhanced reversal learning. These selective pro-cognitive phenotypes seemed largely attributed to inactivation of striatal A(2A)Rs as they were captured by A(2A)R deletion restricted to striatal neurons. Neither spatial reference memory acquisition nor spatial recognition memory were grossly affected, and no evidence for compensatory changes in striatal or cortical D(1), D(2), or A(1) receptor expression was found. This study provides the first direct demonstration that targeting striatal A(2A)Rs may be an effective, novel strategy to facilitate cognitive flexibility under normal and pathologic conditions.     

An experimental investigation of the cognitive vulnerability to depression

The present study employed an experimental design, to examine the role of metacognitive processing in the prevention of relapse to depression. Eighty remitted depressed participants were randomly allocated to receive training in the metacognitive style of rumination, distraction, acceptance or no training control prior to a negative mood induction. Rumination prolonged the intensity of the negative mood consistent with no training, whereas both distraction and acceptance reduced the intensity of the negative mood. Changes in attitudes were only found in the acceptance condition, as participants in this condition reduced negative attitudes towards negative experiences. These results are consistent with information processing theory, and imply that acceptance-based preventative interventions may operate by both reducing the intensity of sad moods and altering one's attitudes towards temporary moments of sadness.     

Decomposition can harm the accuracy of behavioural frequency reports

In survey research, the use of decomposition can lead to pronounced reporting errors as seen by overreporting and overall reporting error. A total of 87 subjects answered either decomposed or undecomposed questions concerning telephone calls made by them while at work. The questionnaire conditions varied the length of the reference period (1 week or 6 months), and the type of call (local or long‐distance). Decomposition conditions introduced either spatial or temporal cues. In all comparisons, decomposed questions increased overreporting bias relative to undecomposed questions. In addition, undecomposed questions with a 1‐week reference period led to increased overreporting bias in comparison to undecomposed/6‐month questions. Results are consistent with a category split estimation model in which smaller categories are predicted to lead to overreporting, and larger categories to underreporting. Decomposition is not recommended for gaining retrospective reports of non‐distinctive, frequent events. Copyright © 2000 John Wiley & Sons, Ltd.     

Robust inference processes in expository text comprehension

Expository text offers particular challenges to the reader because of the abstract and unfamiliar concepts that it presents and its distinctive structure. The present study had three interrelated aims: (1) It examined the impact of appropriate connectives on the reader's derivation of causal bridging inferences from expository text. (2) It scrutinised texts longer than the ones that we had previously examined (Singer, Harkness, & Stewart, 1997), which in turn made it possible to (3) evaluate the impact of position in the text on inference processing. In Experiments 1a and 1b, a joint profile of target reading times and inference answer times indicated that the inspected inferences reliably accompanied reading only in the presence of appropriate causal connectives. The connective-present conditions of Experiment 1 replicated our previous findings using shorter texts (Singer et al., 1997). Experiment 2 indicated that these inference processes are unaffected by text position. We interpreted these findings with reference to the inference validation model (Singer, Halldorson, Lear, & Andrusiak, 1992).     

‘It's not supposed to be this way’: Psychological aspects of a premature menopause

Background: Premature menopause (menopause diagnosed at 40 years or under) is a challenging condition with no prevention or cure. Causes can be the result of surgical intervention or spontaneous and largely unknown. It affects 1–6% of women aged 14–40. Aim: This study investigated women's experience of diagnosis, perception of cause, treatment received, main concerns, perceived long‐term consequences and impact on psychological wellbeing. Method: A cross‐sectional single group design questionnaire study that included both quantitative and qualitative measures was used. It was distributed to women on the database of two specialist London clinics and an internet‐based patient support group. A thematic analysis was undertaken. Findings: The response rate was 62%. Women's experiences varied but showed common themes regardless of timing of diagnosis and services accessed. Improved understanding by health professionals could help this group accept and adjust to the condition more effectively as could psychological support. Fertility was a primary concern regardless of parity and there were several secondary impacts both physiological and psychological. Discussion: A clear need for the offer of emotional support was indicated for all, but particularly for teenage girls and single women who tended not to access support from their own social network. Conclusion: Young women with this diagnosis could benefit from the offer of counselling, though uptake may be influenced by individual factors and vary according to age and circumstances. A good understanding of the physical aspects of this condition is important in the counselling of this group.     

The empathic brain: how, when and why?

Recent imaging results suggest that individuals automatically share the emotions of others when exposed to their emotions. We question the assumption of the automaticity and propose a contextual approach, suggesting several modulatory factors that might influence empathic brain responses. Contextual appraisal could occur early in emotional cue evaluation, which then might or might not lead to an empathic brain response, or not until after an empathic brain response is automatically elicited. We propose two major roles for empathy; its epistemological role is to provide information about the future actions of other people, and important environmental properties. Its social role is to serve as the origin of the motivation for cooperative and prosocial behavior, as well as help for effective social communication.     

From children's hands to adults' ears: gesture's role in the learning process

Children can express thoughts in gesture that they do not express in speech--they produce gesture-speech mismatches. Moreover, children who produce mismatches on a given task are particularly ready to learn that task. Gesture, then, is a tool that researchers can use to predict who will profit from instruction. But is gesture also useful to adults who must decide how to instruct a particular child? We asked 8 adults to instruct 38 third- and fourth-grade children individually in a math problem. We found that the adults offered more variable instruction to children who produced mismatches than to children who produced no mismatches--more different types of instructional strategies and more instructions that contained two different strategies, one in speech and the other in gesture. The children thus appeared to be shaping their own learning environments just by moving their hands. Gesture not only reflects a child's understanding but can play a role in eliciting input that could shape that understanding. As such, it may be part of the mechanism of cognitive change.