Differential effects of forward or simultaneous conditioned stimulus-unconditioned stimulus intervals on the defensive behavior system of the Norway rat (Rattus norvegicus)

To test several predictions derived from a behavior-systems approach, the authors assessed Pavlovian fear conditioning in rats after 30 trials of forward, simultaneous, or unpaired training. Direct evidence of conditioned fear was collected through observation of flight and freezing reactions during presentations of the conditioned stimulus (CS) alone. The authors also tested the CS's potential to reinforce an instrumental escape response in an escape-from-fear paradigm. On the one hand, rats that received forward training showed conditioned freezing, but no conditioned flight was observed. On the other hand, rats that received simultaneous training showed conditioned flight, but no conditioned freezing was observed. Rats that received either forward or simultaneous pairings showed instrumental learning of the escape-from-fear response. Implications for several theories of Pavlovian conditioning are discussed.     

Evaluating research institutions: Lessons from the CGIAR

Investing in research is a long-term, risky proposition. In agriculture, it could take fifteen years or more for a research finding to show an improvement in a farmer’s field. Yet, research institutions, like other organizations it needs to be evaluated. For more than twenty years, independent panels of outside experts have evaluated each of the international research centers that the Consultative Group of International Agricultural Research (CGIAR) supports. This paper examines the evolution of this review system, outlines the key methodological challenges faced, and draws lessons for others engaged in evaluating research institutions. It notes that the scope of the CGIAR reviews have been broadened over time in response to users’ concerns. Reviews now cover four dimensions of performance: research results, quality and relevance of research, vision and strategic directions, and management efficiency. The methodological challenges faced in measurement, valuation, and attribution are reviewed, along with practices found to be helpful in addressing these concerns. The paper concludes that the panel approach to institutional evaluation has served CGIAR’s needs well, and recommends it as an evaluation technique for integrating quantitative and qualitative dimensions of institutional performance. His recent work has concentrated on the governance and management of the CGIAR and the individual research centers it supports, including questions of evaluating management effectiveness. Prior to joining the World Bank in 1979, he was Assistant Professor of Political Science at Bogazici University (Istanbul) and Senior Research Director of Systems Research Incorporated (Lansing, Michigan).     

Exocentric pointing in three-dimensional space

A study is reported of an exocentric pointing task in all three dimensions, in near space, with only two visible luminous objects--a pointer and a target. The task of the subject was to aim a pointer at a target. The results clearly show that visual space is not isotropic, since every set direction appeared to consist of two independent components--one in the projection onto a frontoparallel plane (tilt), the other in depth (slant). The tilt component shows a general trend across subjects, an oblique effect, and can be judged monocularly. The slant component is symmetrical in the mid-sagittal plane, requires the use of binocular information, and shows considerable differences between subjects. These differences seem to depend on the amount of binocular information used by each subject. There was a remarkably high level of consistency in the exocentric pointing, despite the absence of environmental cues. The within-subject consistency in the settings of the pointer corresponds to a consistency of about 1 min of arc in disparity of its tip, even though the pointer and target are separated by more than 5 deg.     

Einstein's theory of theories and types of theoretical explanation

In this paper I draw on Einstein's distinction between “principle” and “constructive” theories to isolate two levels of physical theory that can be found in both classical and (special) relativistic physics. I then argue that when we focus on theoretical explanations in physics, i.e. explanations of physical laws, the two leading views on explanation, Salmon's “bottom‐up” view and Kitcher's “top‐down” view, accurately describe theoretical explanations for a given level of theory. I arrive at this conclusion through an analysis of explanations of mass—energy equivalence in special relativity.     

Piaget and Vygotsky: Many resemblances,and a crucial difference

Piaget and Vygotsky are two influential developmental psychologists. One can even say that their contributions to developmental psychology, albeit different, are similarly remarkable and unique. This article is in four parts. In the first part, I refer briefly to a commonly noticed difference between Vygotsky’s and Piaget’s theories. In the second part, I show that there are many resemblances between Vygotsky and Piaget. In the third part, I argue that in spite of such resemblances, there exists a crucial, and generally unnoticed, difference between Piaget’s and Vygotsky’s theories, and that this difference underlies the way each author addresses the following issues: 1) the origins of development and the motor of development; 2) the relationships among equal peers vs. those based on authorities, as they are sources of development and learning; 3) the more appropriate methods for studying developmental changes; 4) the importance of the distinction between true vs. necessary knowledge; and 5) the role of transformation and personal reconstruction vs. that of transmission and social influence in the phenomena of development and learning. Finally, I summarize the main ideas and arguments which I elaborate throughout this article, and mention what can be gained when the generally ignored aforementioned difference is noticed.     

Counseling and Mental Health Care in Palestine

The authors provide a brief overview of counseling and mental health care in Palestine, including their history and a summary of their current status. Finally, a discussion is presented of future trends in the development of the profession with regard to recent changes in the region.     

The synergy of working memory and inhibitory control: behavioral, pharmacological and neural functional evidences

Concomitant deficits in working memory and behavioral inhibition in several psychiatric disorders like attention-deficit/hyperactivity disorder, addiction or mania, suggest that common brain mechanisms may underlie their etiologies. Based on the theoretical assumption that a continuum exists between health and mental disorders, we explored the relationship between working memory and inhibition in healthy individuals, through spontaneous inter individual differences in behavior, and tested the hypothesis of a functional link through the fronto-striatal dopaminergic system. Rats were classified into three groups, showing good, intermediate and poor working memory and were compared for their inhibitory abilities. These two functions were simultaneously modulated by a dose-effect of d-amphetamine and in situ hybridization was used to quantify dopaminergic receptor (RD1) mRNAs in prefrontal cortex and striatal areas. A functional relationship between working memory and inhibition abilities was revealed. Both functions were similarly modulated by d-amphetamine according to an inverted-U shaped relationship and depending on initial individual performances. D-amphetamine selectively improved working memory and inhibition of poor and intermediate performers at low doses whereas it impaired both processes in good performers at a higher dose. D1 receptors were less expressed in prelimbic, infralimbic and anterior cingulate cortices of good compared to intermediate and poor performers, whereas no difference was observed between groups in striatal areas. The synergy of working memory and inhibitory abilities, observed in both healthy and psychiatric populations, may originate from endogenous variability in dopaminergic prefrontal cortex activity. Such findings confirm the validity of a dimensional approach, based on the concept of continuity between health and mental disorders for identifying endophenotypes of mental disorders.     

Acoustic markers associated with impairment in language processing in Alzheimer's Disease

This study broaches in a novel way the analysis of cognitive impairment characteristic of the early stages of Alzheimer's Disease (AD). Specifically, we attempt to determine the acoustic speech parameters that are sensitive to the onset of the disease, and their association with the language deficit characteristic of AD. Speech analysis was carried out on 21 elderly patients with AD using Praat software, which analyzes the acoustic components of speech. The data obtained were subjected to stepwise regression, using the overall scores obtained in the test as the criterion variable, and the scores on the frequency, amplitude and periodicity variables as predictors of performance. We found that the percentage of voiceless segments explains a significant portion of the variance in the overall scores obtained in the neuropsychological test. This component seems to be related mainly to the patient's ability in phonological fluency. This finding could permit the creation of a diagnostic test for AD through analysis of the acoustic speech parameters at very low cost in terms of both time and resources.