Serotonergic and opiate interactions in the modulation of drug- and environmental-induced analgesia in the neonatal rat pup

Serotonergic and opiate interactions in the modulation of drug- and environmental-induced analgesia were assessed in 6-day-old Sprague-Dawley-derived rat pups using tail-flick testing procedures. In these experiments the serotonergic antagonist metergoline was observed to attenuate both the analgesia induced by the opiate agonist morphine and the analgesia induced by isolation from siblings and the dam, an environmental manipulation which has previously been shown to be associated with increases in opiate activity. In contrast, the opiate antagonist naloxone was observed to be ineffective in blocking not only analgesia induced by the serotonergic agonist quipazine, but also analgesia induced by long-term deprivation from the dam and food, a manipulation that has been previously reported to induce increases in serotonergic utilization. These results suggest that in the neonate, as in the adult, the serotonergic modulation of nociception appears to occur "downstream" from the opiate systems serving to regulate nociception following both drug- and environmental-induced alterations in pain sensitivity. Analgesia induced by long-term deprivation from food and the dam appears to be strongly related to increases in serotonergic activity and relatively unaffected by opiate antagonism, whereas analgesia induced by isolation from siblings and the dam may be related to increases in opiate activity, but modulated by serotonergic systems serving to regulate pain responsivity. Thus alterations in the environment, mediated at least in part by alterations in opiate and serotonergic activity, appear to play an important role in influencing the sensitivity of the neonate to pain stimuli.     

Developmental change in the understanding of affective meaning in music

The development of the understanding of affective meaning in music was investigated. Subjects aged 4, 5, 6, and 19 assigned verbal labels to musical segments previously determined by adults to be representative of one of four affects (happy, sad, angry, afraid). Analysis of correct interpretations and errors revealed a pattern of interactions among age, sex, and affect indicating that the ability to verbalize an understanding of affective meaning in music consistent with that of adult subjects is present during the preschool years. Age-related similarities in performance, as well as differences favoring both younger and older subjects, were observed and were discussed in relation to recent research in, and theories of, affective development and communication.The authors thank H. Julia Hannay, Edward Kemery, Shiela MacDonald, and Robert McGrath for their assistance in this research. The conceptual inspiration of Joseph Intrieri is gratefully acknowledged. We also thank Leslie Brody, Robin Hornik, and several anonymous reviewers for their comments on an earlier draft of the paper. Portions of this research were presented at the Southeastern Conference on Human Development, Baltimore, April 1982.     

Developmental dyslexia and word retrieval deficits

Developmental dyslexics, selected on the basis of very slow naming rates on the Rapid Automatic Naming Tasks (RAN), were compared to normal readers on oral language, picture categorization, and reading tasks. Findings indicated that the dyslexics' word retrieval deficits were one symptom of a more generalized, however subtle, oral language deficit which involved both receptive and expressive oral language functioning. The dyslexics' word retrieval problem also seemed chiefly related to language processing and not to deficits in semantic memory as there were no significant differences between dyslexics and controls on a nonverbal semantic memory task (picture categorization). In naming and identifying printed words, the dyslexics appeared to rely considerably upon the "indirect" or "assembly-of-phonology" route; they were slower in naming irregularly spelled words compared to regularly spelled words and on a lexical decision task, the dyslexics were slower in making negative decisions for "pseudohomophones" (e.g., "braik") than for other matched nonwords. Results are discussed in terms of the logogen model with some consideration of a developmental model as well.     

A developmental study of the auditory Stroop effect

A pediatric auditory version of the Stroop procedure was developed and administered to 48 normal children from 3 to 6 years of age. Our purpose was to define the developmental course characterizing interaction between auditory and semantic speech dimensions in young children. The procedure was a reaction time (RT) task that required children to respond as quickly and as accurately as possible to words spoken by a male or a female voice. Children were instructed to ignore what was said and to push the "Mommy" button if Mommy was talking or the "Daddy" button if Daddy was talking. Performance was obtained for words with neutral, congruent, and conflicting semantic content. Preschool children manifested processing dependencies that were similar to those observed in adults on the visual Stroop procedure. Conflict between semantic and auditory dimensions significantly increased RT and congruence between the two dimensions significantly decreased RT relative to the neutral condition. The pattern of results indicated that the meaning of words was processed automatically in the normal children. The magnitude of the Stroop effect reflected developmental change with increasing age.     

Memory and awareness in a patient with multiple personality disorder

We studied an individual with multiple personality disorder in whom each of several personalities claimed to have no direct awareness of the others and to be unable to consciously remember the experiences of other personalities. A broad selection of implicit and explicit memory tests was used to determine the extent to which one personality had access to knowledge acquired by another and the circumstances in which that knowledge would be expressed. The implicit assessment of memory was a necessary but not sufficient condition for demonstrating interpersonality access. The degree of compartmentalization of knowledge in this patient depended largely on whether the interpretation of presented information was likely to differ across personalities.     

Knowledge and beliefs regarding the consequences of cigarette smoking and their relationships to smoking status in a biracial sample

The purpose of this investigation was to evaluate carefully smoking-related knowledge and beliefs and their relationships to smoking status in a large, heterogeneous sample of smokers and nonsmokers in two settings: (a) a large, biracial southern city and (b) a small midwestern community. Participants were 611 (198 male, 413 female) adult respondents to a random-dialing telephone survey in Fargo, North Dakota (n = 200), and Memphis, Tennessee (n = 411). Each participant was given the Smoking Attitudes Survey, which assesses generalized health beliefs as well as health-related problems associated with smoking. Participants' knowledge of smoking-associated diseases (e.g., lung cancer) and of diseases not associated with smoking (e.g., kidney stones) was assessed. Stepwise regression analysis of composite knowledge scores revealed four independent predictors of the health consequences of smoking: education, race, smoking status, and income. Smokers, compared to nonsmokers, reported less knowledge related to the health consequences of smoking, were more likely to be male, were less concerned with the health consequences of smoking, and were more concerned about the health consequences of cholesterol. The best predictor of smokers who had never attempted cessation was their greater concern over weight control when compared to smokers with a history of smoking cessation attempts. The results are discussed in terms of smoking prevention and intervention efforts.