Discrimination Reversal Conditioning of an Eyeblink Response is Impaired by NMDA Receptor Blockade

In the present study we examined the effects of the specific NMDA receptor antagonist CPP on discrimination reversal learning in rabbits. We report two primary findings. First, the institution of NMDA receptor blockade had no effect on a learned discrimination. Second, after stimulus reversal, CPP treatment impaired acquisition of the discrimination reversal. This impairment manifested itself early in training as a retardation in acquisition of a CR to the new CS+ and late in training as an inability to suppress responsiveness to the new CS-. Given the comparability of the present results with previously published results for phenytoin-treated rabbits, we suggest that the effects of phenytoin on learning in this paradigm is at least in part mediated by its effects on NMDA receptors. We further suggest that these findings emphasize the need to better define the role of NMDA receptor activation and hippocampally-mediated circuits in a variety of associative learning paradigms.     

Re-thinking the relationship between theory and practice: Practitioners as map-readers, map-makers—or jazz players?

Theory is a major element in professional knowledge. Doubts about its value reported by practitioners raise questions at a critical juncture in the careers field about the relevance of prevailing theories and how they are approached. The topic of the relationship between theory and practice is a sensitive one in the debate on competencies and an illuminating one in that on post-modernism. As recent studies demonstrate, problems in integrating theory and practice arise in training and may persist, but experienced practitioners achieve 'fusion' between them and become 'practical theorists'. Practice is improvisatory, and is refined by frameworks provided by theory, critical thinking and 'reflective practice'. However, theories are often tardy or irrelevant, and practitioners also need to be able to carry out their own research, including action research. This has implications for initial and in-service training, supervision and policy, and for the relationships between researchers, theorists and practitioners.     

Mental health status among Puerto Ricans,Mexican Americans,and Non-Hispanic whites

Compared mental health characteristics of island Puerto Ricans to three groups from the Los Angeles Epidemiologic Catchment Area Study: Mexican American immigrants, U.S.-born Mexican Americans, and Non-Hispanic whites. The Diagnostic Interview Schedule was used to obtain both diagnostic and symptom scale information about affective disorders, alcohol abuse/dependence, somatization, phobic disorder, and psychotic disorder. Mexican American immigrants had the fewest mental health problems of all groups. Puerto Ricans had more somatization disorder, but less affective and alcohol disorders than U.S-born Mexican Americans or non-Hispanic whites. Results are considered in the light of selection factors, relative disadvantage of groups and methodological problems. This research was supported by grants MH36230 and MH45763 from the National Institute of Mental Health, and made use of data from the Los Angeles site of the Epidemiologic Catchment Area Program, which is a series of five epidemiologic research studies performed by independent research teams in collaboration with staff of the Division of Biometry and Epidemiology of the National Institute of Mental Health. The NIMH principal collaborators were D. Regier, B. Locke, W. Eaton and J. Burke. The NIMH project officers were C. Taube and W. Huber. The principal investigators and coinvestigators from the five sites were Yale University: J. Myers, M. Weissman, G. Tischler; Johns Hopkins University: M. Kramer, E. Gruenberg, S. Shapiro; Washington University: L. Robins, J. Helzer; Duke University: D. Blazer, L. George; University of California at Los Angeles: M. Karno, R. Hough, J. Escobar, A. Burnam, D. Timbers.     

The death and transfiguration of career-and of career guidance?

The predominant understanding of career in the industrial era has focused on progression within hierarchical work organisations. With the move into a post-industrial era, the possibility of such careers is rapidly receding. The concept of career, however, has always been broader than this, and other aspects of it are now claiming increased attention. They focus more upon individual experiences in terms of development in learning and work throughout life. The role of career guidance in relation to such experiences is potentially of much greater social significance. A number of implications for career guidance provision and practice are discussed.     

Career in context

Mainstream career theories have been criticised for their scanty conceptualisation of the environment that influences individuals' careers. There are few foundations upon which to build an appropriate conceptualisation of the dramatically changing environment of career today. The implications of Pepper's contextualist world hypothesis are discussed. Compared with orthodox approaches, the world as seen from this perspective is as different as the Internet is from a library; its understanding of the environment, and indeed career, is also significantly different. The contextualist perspective upon career research, theory and practice is outlined and the possibility of its adoption in the mainstream of the career field is explored     

The coincidence effect in similarity and choice

Medin, Goldstone, and Markman (1995) recently described a series of parallel effects in similarity and choice. They suggested that similarity and choice are related in a nontrivial way such that choice may entail a similarity judgment to an explicit or constructed ideal. In this paper, the correspondences between similarity and choice were investigated with respect to a phenomenon in similarity known as thecoincidence effect. In coincidence (pronounced “coincide-ence”), two items that match on one dimension but have a large difference on another dimension receive a higher similarity rating than do two items that have only modest differences on both dimensions. We conducted five experiments in order to examine commonalities between similarity and choice processes with respect to coincidence. Four types of tasks were given: similarity ratings, desirability ratings, forced choice similarities (which of two items is most similar to a target), and forced choice preferences (which of two items one would prefer, given a target). We found a main effect for ratings as opposed to forced choices, with ratings showing greater coincidence effects than did choices. Similarity measures tended to produce more coincidence than did preference measures. The overall pattern of results suggests the presence of dimensional weighting processes sensitive to task characteristics and operating somewhat differently for similarity and decision making.     

Inductive acuity and the acquisition of language

This study attempted to assess the inductive explanation of language acquisition. It was predicted that inductive acuity, operationally defined by reference to Kagan's concept of Reflection-Impulsivity, would facilitate syntactic and semantic development. Results indicated that children who are superior inductors scored higher on semantic tests, but not on syntactic tests. It was suggested that distinct learning strategies may be involved in the acquisition of syntax and semantics. Various theoretical implications of these findings for models of language encoding were discussed. Suggestions for subsequent research were offered.     

A digital ultrasound recorder

A system that continuously monitors and records rodent ultrasonic vocalizations over the frequency range 10–90 kHz is described. The system records vocal frequency, sound pressure, time, and duration of call. Data are stored digitally. The system was validated by a pilot study in which distress calls of rat pups were selectively activated while they were subjected to a cold environment.     

The effect of social comparison information on learned helpless and mastery-oriented children in achievement settings

The present study investigates the effect of social comparison information on learned helpless and mastery-oriented children's attributions, behaviour, and affect following a failure experience. Ninety-one fifth grade children experienced failure in the context of high consensus or group failure feedback, low consensus or personal failure feedback or no social comparison feedback. The Jindings point to the robustness of the helpless and mastery response patterns: the behaviour of learned helpless children, as compared to mastery-oriented children, deteriorated following failure regardless of the social comparison feedback they recieved. However, the attributions made by the two groups of children differed. Mastery-oriented children appeared to use social comparison information more accurately in that they appropriately made higher task difficulty ratings when receiving group failure feedback than when receiving personal failure feedback. Learned helpless children were more likely to use a self-derogatory bias and made attributions to their low ability, even when presented with social comparison feedback that was contrary to their bias. These findings are discussed in terms of their implications for education and for intervention with learned helpless childrens.