Interpretation And Understanding

To understand a term or other symbol, I argue that it is generally neither necessary nor sufficient to assign it a unique determinate reference. Independent of and prior to investigation, it is frequently indeterminate not only whether a sentence is true, but also what its truth conditions are. Nelson Goodman's discussions of likeness of meaning are deployed to explain how this can be so.     

Revisiting Sartre on the question of religion

Jean-Paul Sartre's position on religion has traditionally been reduced to variations of his well-known atheism. This is a result of collapsing the distinction between religion and theism, as both critics and supporters of Sartre have commonly done. Consequently, attention to Sartre's persistent and pervasive concern with religious ideas, symbols, and experiences has been neglected. While the religious implications of Sartre's thought have mostly been considered in relation to Christian theology, other newer areas of religious studies suggest additional avenues for considering Sartre. Sartre's possible connections to four such areas are discussed: 1) Eastern religions; 2) Jewish studies; 3) feminist theology, and 4) the psychoanalysis of religion.     

Enrichment versus exercise effects on motor impairments following cortical removals in rats

Groups of rats were exposed to an enriched environment, given access to an activity wheel, or individually housed in wire mesh cages, impoverished. Rats were exposed in groups of four to the enriched environment or placed individually in the activity wheel for 2 h per day for 25 days preoperatively. Within each exposure group, rats sustained bilateral removals of sensorimotor cortex, or were sham-operated controls. Animals were trained preoperatively to locomote across a narrow elevated runway. Postoperatively, locomotor testing was initiated 17 days after surgery throughout which time all animals were maintained under impoverished conditions. Locomotor deficits following cortical damage were a function of preoperative exposure: enriched rats were least impaired; impoverished rats were most impaired. Rats allowed running wheel activity initially showed the same marked deficits as impoverished animals but recovered more rapidly. The opportunity for physical exercise afforded wheel animals preoperatively may have enhanced motor capabilities that aided recovery. However, physical activity alone did not yield the same protective effects from initial impairment as enrichment. Greater elaboration of neural structures associated with perceptual-motor enrichment probably accounted for the initial sparing of the enriched group.     

The behavioral effects of depletions of brain serotonin induced by 5,7-dihydroxytryptamine vary with time after administration

Ether-anesthetized Sprague-Dawley rats were depleted of brain serotonin (5HT) by intraventricular injections of 50 micrograms 5,7-dihydroxtryptamine (57DHT). Oral pretreatment with 25 mg/kg desmethylimipramine was used to protect brain noradrenergic neurons from 57DHT. Liquid chromatographic assays revealed that this treatment did not significantly alter catecholamine levels but depleted hippocampal 5HT by 92% and striatal 5HT by 45%. Three or eleven days after lesioning, locomotor and exploratory behavior was characterized in separate groups of animals with a behavioral pattern monitor (BPM). On Days 4 and 12, the animals were retested following saline or 1.0 mg/kg amphetamine. Three days after depletion, lesioned rats exhibited a decrease rate of habituation of locomotor activity relative to controls. When challenged with amphetamine (1.0 mg/kg), 5HT-depleted rats exhibited increased corner and decreased center activity, as well as stereotyped patterns of locomotion. Eleven days following lesion, 5HT-depleted rats exhibited habituation rates greater than controls; amphetamine challenge yielded patterns of activity similar to those of control animals. These results show that central serotonergic pathways play an important role in modulating both spontaneous and amphetamine-elicited activity in rats, and that compensatory mechanisms operate over time to alter the behavioral effects of 57DHT-induced depletions of brain 5HT.     

On the effect of selection performed on some coordinates of a multi-dimensional population

Samples are often obtained under circumstances which make it less likely to draw individuals from some parts of a population than from others. In this paper a method is presented which makes it possible, under certain assumptions, to correct for the resulting bias and thus reconstruct the means, standard deviations, and correlation coefficients of the original population.Research done under the sponsorship of the Office of Naval Research.