Stress or no stress: mineralocorticoid receptors in the forebrain regulate behavioral adaptation

Corticosteroid effects on cognitive abilities during behavioral adaptation to stress are mediated by two types of receptors. While the glucocorticoid receptor (GR) is mainly involved in the consolidation of memory, the mineralocorticoid receptor (MR) mediates appraisal and initial responses to novelty. Recent findings in humans and mice suggest that under stress, the MR might be involved in the use of different learning strategies. Here, we used male mice lacking the MR in the forebrain (MR(CaMKCre)), which were subjected to 5-10 min acute restraint stress, followed 30 min later by training trials on the circular hole board. Mice had to locate an exit hole using extra- and intra-maze cues. We assessed performance and the use of spatial and stimulus-response strategies. Non-stressed MR(CaMKCre) mice showed delayed learning as compared to control littermates. Prior stress impaired performance in controls, but did not further deteriorate learning in MR(CaMKCre) mice. When stressed, 20-30% of both MR(CaMKCre) and control mice switched from a spatial to a stimulus-response strategy, which rescued performance in MR(CaMKCre) mice. Furthermore, MR(CaMKCre) mice showed increased GR mRNA expression in all CA areas of the hippocampus and an altered basal and stress-induced corticosterone secretion, which supports their role in the modulation of neuroendocrine activity. In conclusion, our data provide evidence for the critical role of MR in the fast formation of spatial memory. In the absence of forebrain MR spatial learning performance was under basal circumstances impaired, while after stress further deterioration of performance was rescued by switching behavior increasingly to a stimulus-response strategy.     

Item selection by means of a maximizing function

A new item selection technique is presented which takes into account the intercorrelations of the items as well as their correlations with the criterion. The technique is regarded as superior to comparable techniques in that it is considered to achieve greater economy of time, greater objectivity of procedure, higher validity, and higher reliability. The mathematical theory underlying the method is developed. An approximate solution of the mathematical equations is suggested. An approximation procedure for the complete item selection technique is presented, based on the mathematical solution, but much simpler in procedure. The clerical operations involved in the approximation procedure are outlined and illustrated on a sample worksheet.     

What's new? Children prefer novelty in referent selection

Determining the referent of a novel name is a critical task for young language learners. The majority of studies on children’s referent selection focus on manipulating the sources of information (linguistic, contextual and pragmatic) that children can use to solve the referent mapping problem. Here, we take a step back and explore how children’s endogenous biases towards novelty and their own familiarity with novel objects influence their performance in such a task. We familiarized 2-year-old children with previously novel objects. Then, on novel name referent selection trials children were asked to select the referent from three novel objects: two previously seen and one completely novel object. Children demonstrated a clear bias to select the most novel object. A second experiment controls for pragmatic responding and replicates this finding. We conclude, therefore, that children’s referent selection is biased by previous exposure and children’s endogenous bias to novelty.     

Optimal test length for maximum absolute prediction

The concepts of multiple differential prediction and multiple absolute prediction are developed in earlier papers (2, 3). The problem of determining the optimal distribution of testing time for multiple differential prediction has been previously considered (4). This paper develops an analogous procedure for multiple absolute prediction. A numerical example illustrating the procedure is presented. The mathematical rationale underlying the procedure is given.This research was carried out under Contract Nonr-477(08) between the University of Washington and the Office of Naval Research. The computations were carried out by Robert Dear and Donald Mills. Much credit is due the typist, Elizabeth Cross. Supervision of both computational and editorial activities was provided by William Clemans. To each of these able contributors we are deeply grateful.     

Contextual repetition facilitates word learning via fast mapping

The current study explores whether contextual repetition during fast mapping facilitates word learning. Three-year-old children completed fast mapping and test trials using a touchscreen computer. For half of the children, the non-targets (competitors) repeated across learning trials and for other children there was no repetition. All children received the same test trials. Children who experienced contextual repetition, that is, children for whom the competitors repeated during the initial fast mapping task, demonstrated word learning. These data demonstrate that children's word learning is facilitated by the presence of extraneous yet predictable information in the initial fast mapping task.     

Loneliness in Infancy: Harry Harlow, John Bowlby and Issues of Separation

In this contribution, the authors give an overview of the different studies on the effect of separation and deprivation that drew the attention of many in the 1940s and 1950s. Both Harlow and Bowlby were exposed to and influenced by these different studies on the so called ‘hospitalization’ effect. The work of Bakwin, Goldfarb, Spitz, and others is discussed and attention is drawn to films that were used to support new ideas on the effects of maternal deprivation.

Looking at threat-relevant stimuli: The role of anxiety and coping style

Abstract Results of numerous studies demonstrate that anxious subjects selectively attend to threat-related rather than to neutral stimuli. It has been argued that, as a result of this, anxious individuals more easily perceive and misattribute threatening stimuli in their environment, thereby creating a vicious circle of attention and anxiety. The evidence for this anxiety-linked attentional bias, however, is largely based on studies using subliminal or dichotic presentation of verbal stimuli. The present study sought to replicate these results by examining the relationship between anxiety and visual attention during prolonged exposure to threat-relevant (pictures of situations in a dental practice) and neutral (pictures of situations at a hairdresser salon) material with 45 women. No significant relationship emerged between dental trait anxiety and duration subjects directed gaze to the threat-relevant pictures. Neither self-reported state anxiety nor habitual coping style appeared to be significantly related to duration of visual attention for the threat-relevant pictures. Hence, no evidence was found supporting the hypothesis that high anxiety leads to a bias in attention towards emotionally threatening information. It is suggested that hypervigilance occurs in the early stages of the appraisal process.     

The effects of fading,feedback, and feedback plus instruction on the perfomance of institutionalized retarded children in number retention exercises

Summary Three feedback training procedures, fading, feedback and feedback plus instruction, were used in conjunction with reinforcement contingencies to assess the performance of 12 mentally retarded boys in number rentention exercises. The fading and the feedback plus instruction procedures were the only ones to yield highly significant effects: none of the procedures led to any substantially improved performance in transfer exercises. Advantages of fading over the more traditional procedure (less errors, ability to learn difficult exercises) are discussed, as are the problems arising in the application of this method. Analysis of the exercises showed that premature removal of the additional colour cues in the fading procedure resulted in a substantial reduction of the number of correct responses, especially in the difficult exercises, and that the feedback procedure was particularly unsuccessful in difficult exercises. Methodological problems encountered in previous retention studies were indicated and an attempt made to overcome them.

---

Zusammenfassung Kombiniert mit Belohnungen, die nur für richtige Antworten erfolgten, wurden drei Rückmelde-Trainingsverfahren: Fading, Feedback und Feedback plus Instruction angewandt, um 12 geistig retardierte Jungen an Zahlen-Konservations-Aufgaben zu trainieren. Nur die Fading- und Feedback plus Instruction-Techniken zeigten hoch signifikante Trainingsgewinne, doch keine der Techniken führte zu bedeutenden Verbesserungen bei Transferaufgaben. Die Vorteile der Fading-Technik gegenüber mehr traditionellen Verfahren (weniger Fehler, Erlernen schwierigerer Aufgaben) wurde ebenso erörtert wie Probleme ihrer Anwendung. Aufgabenanalysen zeigten, daß erstens verfrühtes Ausblenden der zusätzlichen Farben bei der Fading-Technik zu einem starken Absinken der Anzahl der richtigen Antworten besonders bei schwierigen Aufgaben führt; und daß zweitens die Feedback-Technik beim Erlernen schwieriger Aufgaben besonders geringen Erfolg hat. Methodologische Probleme bei vorausgegangenen Konservationsexperimenten wurden aufgezeigt, und es wurde versucht, diese methodologischen Probleme zu lösen.

---

---

This paper is based on a thesis submitted by the author to the University Mannheim as partial fulfillmant of the requirements for the degree of Master of Science (Diplom). The writer is greatly indebted to Dr. Norman H. Stein for his guidance throughout the planning and execution of the study and to his helpful suggestions and criticisms. The writer is also indebted to Dr. Byron J. Ward for making subjects available at Syracuse State School, and to the teachers of the Association for Retarded Children in Syracuse, New York. The study was conducted during a one year stay at Syracuse University. The financial support of the Studentenwerk Mannheim for tuitions and living expenses and a travel grant of the Fulbright Commission is gratefully acknowledged.     

Eliminativism and the ambiguity of ‘belief’

It has recently been claimed (1) that mental states such as beliefs are theoretical entities and (2) that they are therefore, in principle, subject to theoretical elimination if intentional psychology were to be supplanted by a psychology not employing mentalistic notions. Debate over these two issues is seriously hampered by the fact that the key terms theoretical and belief are ambiguous. This article argues that there is only one sense of theoretical that is of use to the eliminativist, and in this sense some kinds of belief (dispositional states, infra-conscious states and the Freudian unconscious) are indeed theoretical and hence possible candidates for elimination, while others (consciously occurring thoughts like judgements and perceptualGestalten) are not theoretical and hence not candidates for elimination.