Place learning in scopolamine-treated rats: the roles of distal cues and catecholaminergic mediation

Experiments 1 and 2 tested the hypothesis that cholinergic receptor antagonists impair place learning in a water maze by interfering with the processing of distal, visual cues. Extramaze cues were offered to rats in the form of geometrical patterns arranged on the inner circumference of a curtain surrounding the water maze. In Experiment 1 the animals were offered both the distal cues and proximal cues in the form of pingpong balls in fixed positions on the surface of the water while only distal cues were present in Experiment 2. Animals were injected with either scopolamine (0.5 mg/kg body wt) or saline 20 min prior to the daily place learning sessions. Upon reaching criterion level performance the animals were tested on "rotation" sessions on which the distal cues were displaced. The outcome of such "rotations" demonstrated that-regardless of the presence or absence of proximal cues-scopolamine-treated rats relied at least as much as normal animals on the distal cues. The acquisition phase of both Experiments 1 and 2 demonstrated an almost complete lack of scopolamine-associated impairment in acquisition and performance of the place learning task. In Experiment 3 (when scopolamine was no longer administered) the subjects of Experiment 2 were exposed to a series of pharmacological "challenges" of their place learning performance and eventually to surgical ablation of the anteromedial prefrontal cortex. The outcome of the pharmacological challenges and the postoperative test of task performance demonstrated that the place learning performance of animals which had acquired the task under scopolamine was mediated by a neural substrate dissimilar to the substrate of task performance in normal animals. Rats acquiring the task while deprived of the cholinergic system demonstrated above-normal contributions to task mediation from catecholaminergic-probably dopaminergic-mechanisms and tentative results pointed to a "shift" toward prefrontal task mediation.     

Retrieval improvement is induced by water shortage through angiotensin II

Angiotensin II (ANGII) has an evolutionary preserved role in determining adaptative responses to water-shortages. In addition, it has been shown to modulate diverse phases of memory. Still, it is not clear whether ANGII improves or spoils memory. We demonstrated that endogenous angiotensins enhance consolidation of a long-term associative memory in the crab Chasmagnathus and that water shortage improves memory consolidation through brain ANGII actions. Here, we show that weakly trained crabs, when water-deprived, exhibit enhanced retrieval. Subsequently, memory retention is indistinguishable from that of strongly trained crabs. ANGII, but not angiotensin IV, is a necessary and sufficient condition for such enhancing effect. We conclude that ANGII released due to water shortage leads to enhanced memory retrieval. Thus, it seems that ANGII has an evolutionary preserved role as a multifunction coordinator that enables an adaptative response to water-shortage. The facilitation of memory consolidation and retrieval would be among those coordinated functions.     

Relationship between short- and long-term memory and short- and long-term extinction

Both the acquisition and the extinction of memories leave short- and long-term mnemonic traces. Here, we show that in male Wistar rats, the short-term memory for a step-down inhibitory avoidance task (IA) is resistant to extinction, and that its expression does not influence retrieval or extinction of long-term memory. It has been known for some time that short- and long-term inhibitory avoidance memory involve separate and parallel processes. Here we show that, instead, short-term extinction of IA long-term memory is the first step towards its long-term extinction, and that this link requires functional NMDA receptors and protein synthesis in the CA1 region of the dorsal hippocampus at the time of the first CS-no US presentation.     

Comparative evaluations of reward dimensions in honey bees: evidence from two-alternative forced choice proboscis-extension conditioning

A major challenge in understanding choice behaviour is determining how subjects evaluate alternatives that differ along multiple dimensions. Of particular interest is whether similar dimensions are compared to each other or whether each alternative is assigned an absolute value (utility). We assumed that choice proportions would follow Weber’s effect, according to which discrimination is proportional to relative difference (difference/mean). We tested honey bees in a two-alternative forced choice (2AFC) paradigm of proboscis-extension response (PER) conditioning. Subjects were conditioned over six trials to associate each of two odours with sucrose solution rewards and then tested in a choice trial between the two alternatives. Each group of subjects was tested in one treatment, and there were four treatments in each of six experiments. Rewards differed in delay, duration of feeding, and sucrose concentration. In each treatment, the high-profitability alternative was better than the low-profitability alternative along a single dimension, but between treatments of each experiment values in another dimension monotonically increased. Proboscis-response proportions during the conditioning phase tended to be greater for the high-profitability alternative, and choice proportions for it in the choice phase ranged between 0.72 and 0.89 in the 24 treatments. We show for the first time that harnessed bees are sensitive to reward delay. Preferences did not differ statistically between the different treatments of any of the experiments. The results support comparative evaluation of alternatives and are pertinent to multi-attribute choice, with implications for context-dependent preferences. We also discuss the potential advantages of the 2AFC PER simultaneous choice assay.     

Histamine enhances inhibitory avoidance memory consolidation through a H2 receptor-dependent mechanism

Several evidences suggest that brain histamine is involved in memory consolidation but the actual contribution of the hippocampal histaminergic system to this process remains controversial. Here, we show that when infused into the CA1 region of the dorsal hippocampus immediately after training in an inhibitory avoidance task, but not later, histamine induced a dose-dependent promnesic effect without altering locomotor activity, exploratory behavior, anxiety state or retrieval of the avoidance response. The facilitatory effect of intra-CA1 histamine was mimicked by the histamine N-methyltransferase inhibitor SKF-91844 as well as by the H2 receptor agonist dimaprit and it was blocked completely by the H2 receptor antagonist ranitidine. Conversely, the promnesic action of histamine was unaffected by the H1 receptor antagonist pyrilamine, the H3 receptor antagonist, thioperamide, and the NMDAr polyamine-binding site antagonist ifenprodil. By themselves, ranitidine, pyrilamine, thioperamide, and ifenprodil did not affect IA memory consolidation. Our data indicate that, when given into CA1, histamine enhances memory consolidation through a mechanism that involves activation of H2 receptors; however, endogenous CA1 histamine does not seem to participate in the consolidation of IA memory at least at the post-training times analyzed.     

‘Categories We Share’: Mobilising Common In‐groups in Discourse on Contemporary Immigration in Greece

Prejudice reduction has been an important concern within social psychology both in theory and applied research. According to the premises of Social Identity Theory, redrawing of the category boundaries is often considered a necessary step in order to battle prejudice, because in‐group favouritism when the category boundaries change is diffused to the previously distinct identities. The present paper offers a review of the relevant research, and following a discourse analytic perspective argues that recategorisation can also be viewed as a rhetorical resource that people use in verbal interaction in order to achieve certain rhetorical ends. This point is exemplified using interview data from Greece with Greek participants who mobilise common in‐groups between themselves and the immigrants in Greece. Different common in‐groups were mobilised on the basis of common human nature, common ethnic descent and through the use of the common experience of migration that many Greek people have because Greece has been an emigrant sending country for the biggest part of the 20th century. Occasionally, these category constructions were used to differentiate between immigrants of different ethnic descent claiming that only certain immigrant groups can integrate to Greek society, whereas on other instances, these common in‐groups were used in order to inoculate speakers of accusations of prejudice. Copyright © 2012 John Wiley & Sons, Ltd.     

Relationships Between Need for Cognition,Knowledge, and Verbal Ability

The authors investigated the relationships between need for cognition. knowledge, and verbal ability. Participants completed scales that measured their need for cognition, verbal ability, and knowledge about people and events that occurred during the Vietnam War era. Correlational analyses showed that the participants' need for cognition scores were modestly but positively correlated with verbal ability and knowledge and that verbal ability and knowledge were also positively correlated. The correlation between need for cognition and knowledge was small but significant when verbal ability was controlled. The conclusion drawn from these results is that need for cognition contributes to the acquisition of knowledge beyond the contribution of verbal ability.     

The Effect of Attributional Retraining on Mastery and Performance Motivation Among First-Year College Students

Motivation can be undermined among first-year college students as they face a multitude of unanticipated challenges during the transition from high school to college (Compas, Wagner, Slavin, &; Vannatta, 1986 Compas , B. E. , Wagner , B. M. , Slavin , L. A. , &; Vannatta , K. ( 1986 ). A prospective study of life events, social support, and psychological symptomatology during the transition from high school to college . American Journal of Community Psychology , 14 , 241 – 257 .[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Perry, Hall, &; Ruthig, 2005 Perry , R. P. , Hall , N. C. , &; Ruthig , J. C. ( 2005 ). Perceived (academic) control and scholastic attainment in higher education . In J. Smart (Ed.), Higher education: Handbook of theory and research ( Vol. 20 , pp. 363 – 436 ). New York : Springer .[Crossref] , [Google Scholar]). As a consequence, approximately 27% of first-year students do not return for the second year of college (Feldman, 2005 Feldman , R. S. ( 2005 ). Improving the first year of college: Research and practice . Mahwah , NJ : Erlbaum . [Google Scholar]). First-year college students (N = 336) participated in a study to examine the efficacy of an Attributional Retraining (AR) treatment designed to increase motivation and enhance academic achievement. Employing a pre–post study design spanning an academic year, we examined the impact of AR on student motivation as operationalized in terms of mastery and performance goals. Findings indicated that AR increased mastery motivation but did not affect performance motivation. Findings also demonstrated that mastery motivation mediated the relationship between AR and grade point average, suggesting that mastery motivation is a key mechanism of AR. Findings are discussed in terms of conceptual contributions to both the AR and achievement motivation literatures, and practical implications are outlined.     

Personal goals as predictors of intended classroom goals: Comparing elementary and secondary school pre‐service teachers

Background and Aims. The literature documents fewer classroom mastery goal structures in secondary school compared to elementary. However, little is known about how personal achievement goals may influence classroom goal structures. This is especially true at the level of pre‐service teachers. Our objective was to investigate if pre‐service teachers’ personal goals predicted their intended classroom goal structures. Sample. Participants were 125 elementary and 175 secondary school pre‐service teachers from two Western Canadian universities. Method. Structural equation modelling was used to examine if the structural relationships and latent means of personal and intended classroom goal structures differed for elementary and secondary school pre‐service teachers. Results. The results revealed that personal goals predicted the goal structures that pre‐service teachers intended to establish; however, the relationships and means differed between elementary and secondary school pre‐service teachers. Specifically, personal mastery‐approach goals positively predicted classroom mastery goals much more strongly at the elementary than the secondary level. Furthermore, elementary pre‐service teachers had significantly higher latent mean scores on personal mastery‐approach goals than their secondary counterparts. Conclusions. It seems possible that the currently documented differences between classroom goal structures noted for elementary compared to secondary school may be based on the personal goals endorsed as pre‐service teachers. The results are further discussed in terms of alignment with research on practising teachers’ personal and classroom goals and implications for teacher education.     

The role of cognitive flexibility and vocabulary abilities of younger and older users in searching for information on the web

The present study investigated the role of cognitive flexibility and vocabulary abilities in explaining age‐related differences in information searching with a search engine. Nineteen older and 20 younger participants had to carry out nine searches and to complete a battery of cognitive tests. Older participants obtained poorer search performance with fewer correct answers, and lower task completion speed. They interacted little with the system, and showed specific difficulties in getting out of impasses and reformulating unfruitful requests. Regression analyses suggested that age differences in the number of requests were moderated by differences in cognitive flexibility and that the older participants did not leverage their increased vocabulary in producing new keywords. The findings suggest that the age‐related decline in cognitive flexibility plays a role in the age‐related differences observed in searching for information, especially in the way users get out of impasses. The results have implications for designing search engine tools. Copyright © 2010 John Wiley & Sons, Ltd.