The hypothesis that memories are stored as a specific distribution of strengths in a population of modifiable synapses was examined by the bilateral induction of long-term enhancement in synapses of the main afferent fiber system to the hippocampal formation in rats. Brief, high-frequency activation of the perforant pathway in chronically prepared animals resulted in a persistent increase in the field EPSP and population spike, measured extracellularly in fascia dentata. This treatment resulted in a profound and persistent deficit in the acquisition of new spatial information in a task requiring spatial "reference" memory, and disruption of recently acquired spatial information. Well-established spatial memory was completely unaffected, however, as was the acquisition of spatial information into shortterm "working" memory. These results support the hypothesis that, during the formation of "cognitive maps," spatial information must be temporarily stored at modifiable synapses at the input stage to the hippocampal formation, but that this information is not needed once the representation of the environment is well established. Spatial working memory, in a familiar environment, appears not to depend on the distribution of synaptic strengths in this system at all.Most attempts to explain associative learning in the nervous system have invoked long-term changes in the efficacy of cellto-cell communication as the underlying information-storage medium (e.g., Hebb, 1949; Marr, 197 1). The common element of these theories is the assumption that information is stored as a specific distribution of modifiable synaptic weighting functions. These hypotheses predict that a treatment that disrupts such a distribution, by driving the population of modifiable synapses to the maximum strength, will disrupt the information content. This would have two consequences: impaired performance of tasks requiring the integrity of previously stored information, and impaired acquisition of new information. The present experiments were designed to examine this prediction by studying the effects on spatial learning and memory of artificially induced enhancement of synaptic efficacy in a large population of hippocampal synapses.Bliss, Lomo, and Gardner-Medwin first documented that brief episodes of electrical stimulation of perforant path fibers at physiological frequencies resulted in a lasting increase in synaptic transmission to hippocampal target neurons (Bliss and GardnerMedwin, 1973;Bliss and Lomo, 1973). Since this discovery, considerable evidence has accumulated in support of the hypothesis that this experimentally induced phenomenon represents the activation of a physiological process that normally Received Apr. 5, 1985; revised July 15, 1985; accepted July 17, 1985. This work was supported by PHS Grants AGO3376 and NS20331. We thank Seth Sharpless for help with computer software, B. Peterson for secretarial assistance, and P. Sharp and B. Jones Leonard for helpful comments on the manuscript. Lomo (1966) and the term LTP (long-term p...

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Two stepwise multiple regression analyses were performed on the African self-consciousness (ASC) Scale scores of 219 African-American male and female college students utilizing 36 background and 20 Africentric activity factors as the predictor variables. The results revealed that only a very small number of the two sets of predictors were significantly related to the ASC scores. The background factors of parental membership in predominantly Black organizations, exposure to Black studies courses, and prior experiences with racism/racial prejudice significantly predicted ASC scores and accounted for some 34% of the total variance. The activity factors of attending African cultural activities, reading books about Blacks/ African culture, and giving aid/assistance to other Blacks all during the preceding year predicted ASC scores. This latter group of findings, however, accounted for such a nominal portion of the total variance that they must be considered inconclusive. It was concluded that these findings point toward a potentially promising area of African self-consciousness research, but more rigorous and systematic approaches to measurement development in particular, as well as sampling are needed to enhance this general area of prediction.

This research investigated the relationship between social cultural setting and background characteristics to African self-consciousness (ASC) as measured by the ASC Scale. Two hundred fifty Black college students, half from pre dominantly Black Florida A&M University (FAMU) and half from predominantly White Florida State University (FSU), were administered the ASC Scale and a background questionnaire. The findings revealed that: (a) FAMU stu dents obtained significantly higher ASC Scale scores than FSU students; (b) older students obtained significantly higher ASC scores than younger students; (c) upper level students obtained higher ASC scores than lower level stu dents, and this effect was more pronounced for FAMU students than for FSU students; (d) students with Black Studies backgrounds obtained higher ASC Scale scores than did students without this experience, especially for the FSU students; (e) FAMU students with all-Black elementary school backgrounds obtained higher ASC Scale scores than did the other students. It concluded: (a) that the African self-consciousness construct appears to be an important factor in explaining differences in psychological functioning and behavior among Black students in different sociocultural settings; and (b) that Black sociocultural settings and pro- Black experiential emphases are probably facilitative of healthy Black personality functioning.