Second-order ‘fear’ conditioning in humans: Persistence of CR2 following extinction of CR1

Two groups of subjects were given pairings of a slide of a triangle (CS₁) with an aversive loud noise (US). After first-order conditioning a different figure (CS₂⁺) was paired with CS₁, whilst a third figure acted as a non-paired control (CS₂⁰). Conditioned second-order skin conductance responses (SCRs) were established to CS₂⁺ for all subjects who had undergone first-order conditioning. Following second-order conditioning, SCRs to CS₁ were extinguished and CS₂⁺ was subsequently tested for retention of its SCR evoking properties. For the group of subjects who believed they had an avoidance response available during the second-order conditioning phase, CR₂ failed to survive extinction of CR₁. However, for the group of subjects who had no perceived control over US presentation, extinction of cr₁ did not eliminate CR₂. This latter finding is consistent with associative analyses of second-order conditioning in animals and has clinical implications for the treatment of fear-related problems.     

MENTAL ARITHMETIC IN AFRICA AND AMERICA: STRATEGIES,PRINCIPLES, AND EXPLANATIONS*

Mental arithmetic abilities were studied among unschooled African adults and American college students. A set of problems tested the use of the four basic arithmetic operations. Performance was analyzed for: strategies, implicit arithmetic principles, and explicit explanations of the principles. Both groups showed accurate mental arithmetic strategies related to the base ten structure of their native counting systems. The American students' mental strategies additionally made use of algorithms based on written place values. Several principles were implicit in the calculation strategies of both groups, and both used these principles to short-cut calculations. Though the African subjects did not, the American subjects did describe these abstract principles in explicit common language or algebraic expressions. Relationships between schooling and cognition are discussed.     

Acquisition and extended retention of a conditioned taste aversion in preweanling rats

The time course of memory decay for infant rats may shed light on the processes responsible for infantile amnesia. A taste aversion conditioning procedure appropriate for both neonatal and adult rats was employed in four experiments to investigate the ontogeny of extended retention. In Experiment 1, rats trained at 1, 10, 20, or 60 days of age were tested for retention of the taste aversion 25 days later. At testing, only those rats conditioned when 20 or 60 days old demonstrated significant taste aversions. Experiments 2 and 3 established that rats 14-15 days old and older were able to retain significant taste aversions following a 25-day retention interval. Younger rats did, however, acquire and retain the aversion for several days and showed a gradual retention loss over progressively longer retention intervals (Experiment 4). These findings suggest that preweanling rats demonstrate initial consolidation, storage, and retrieval of conditioned taste aversions. It is only after this initial period that retention deficits become evident.     

Cortical substrates of taste aversion learning: dorsal prepiriform (insular) lesions disrupt taste aversion learning

The functional relation between restricted damage to ventral primary somatosensory neocortex and the ability of rats to acquire conditioned taste aversion (CTA( was examined by a combination of behavioral and neurohistological techniques. Lesions confined exclusively to the established gustatory neocortex (GN) did not disrupt CTA acquisition, nor did lesions confined to suprarhinal cortical areas ventral to the GN. Lesions that encroached on dorsal prepiriform and insular cortices produced CTA acquisition deficits and damaged a large proportion of efferent projections to the prefrontal and precentral neocortex. In a second experiment, lesions of dorsal prepiriform and insular cortices did not modify taste preference-aversion threshold to any of the four taste modalities. It is concluded tha ventral somatosensory neocortical fields, including the established GN, do not mediate CTA acquisition and that rhinal cortices ventral and posterior to the GN are preferentially involved in associative learning for tastes and illness.     

The religious physician

In order to understand what it means to be a physician, we must, according to Dr. Edmund Pellegrino, analyze four words that capture the essence of the medical enterprise: profession, patient, compassion, and consent. The resultant model provides a rational and secular basis upon which the Jewish or Christian physician can then build an understanding of medicine in its peculiarly religious form. This religious form is likewise characterized by four words: vocation, neighbor, love, and covenant. An analysis of these words provides a model of and for the religious physician.     

Instructional planning: information collected by school psychologists vs. information considered useful by teachers

A limited national sample of 49 school psychologists and 30 regular education teachers provided information on assessment for the purpose of instructional planning. School psychologists listed the types of information they most often collected for this purpose and teachers listed the types of information considered most useful for this purpose. While some indications of agreement were found between school psychologists and teachers, there were also several inconsistencies in the views of the two groups regarding assessment procedures for instructional planning. The findings are discussed in light of empirical evidence on the contribution of various types of assessment data to instructional planning.