Investigating the interaction between schizotypy, divergent thinking and cannabis use

Cannabis acutely increases schizotypy and chronic use is associated with elevated rates of psychosis. Creative individuals have higher levels of schizotypy, however links between cannabis use, schizotypy and creativity have not been investigated. We investigated the effects of cannabis smoked naturalistically on schizotypy and divergent thinking, a measure of creativity. One hundred and sixty cannabis users were tested on 1 day when sober and another day when intoxicated with cannabis. State and trait measures of both schizotypy and creativity were administered. Quartile splits compared those lowest (n=47) and highest (n=43) in trait creativity. Cannabis increased verbal fluency in low creatives to the same level as that of high creatives. Cannabis increased state psychosis-like symptoms in both groups and the high creativity group were significantly higher in trait schizotypy, but this does not appear to be linked to the verbal fluency change. Acute cannabis use increases divergent thinking as indexed by verbal fluency in low creatives.     

Are mothers of stutterers different? An investigation of social-communicative integration

Many speech-language pathologists assume that parent-child communicative interactions are critical precipitating or maintaining factors in the onset and development of stuttering. Although parents are frequently counseled to alter their attitudes or behaviors, no studies have pinpointed specific parental behaviors as increasing children's disfluency. The purpose of this study was to analyze differences between 12 mothers of stutterers and 12 mothers of nonstutterers in their social-communicative interactions with their own child, an unfamiliar stutterer, and an unfamiliar nonstutterer. Ten minutes of free-play interaction between each mother and child were video recorded from behind a one-way mirror. Results indicate that the two groups of mothers differed significantly only in their use of routine statements. Other findings indicate that stuttering children used significantly more positive and imperative statements than nonstuttering children. All children asked significantly more questions of their own mothers than of unfamiliar mothers.     

Ontogenetic changes in the neural mechanisms of eyeblink conditioning

The rodent eyeblink conditioning paradigm is an ideal model system for examining the relationship between neural maturation and the ontogeny of associative learning. Elucidation of the neural mechanisms underlying the ontogeny of learning is tractable using eyeblink conditioning because the necessary neural circuitry (cerebellum and interconnected brainstem nuclei) underlying the acquisition and retention of the conditioned response (CR) has been identified in adult organisms. Moreover, the cerebellum exhibits substantial postnatal anatomical and physiological maturation in rats. The eyeblink CR emerges developmentally between postnatal day (PND) 17 and 24 in rats. A series of experiments found that the ontogenetic emergence of eyeblink conditioning is related to the development of associative learning and not related to changes in performance. More recent studies have examined the relationship between the development of eyeblink conditioning and the physiological maturation of the cerebellum, a brain structure that is necessary for eyeblink conditioning in adult organisms. Disrupting cerebellar development with lesions or antimitotic treatments impairs the ontogeny of eyeblink conditioning. Studies of the development of physiological processes within the cerebellum have revealed striking ontogenetic changes in stimulus-elicited and learning-related neuronal activity. Neurons in the interpositus nucleus and Purkinje cells in the cortex exhibit developmental increases in neuronal discharges following the unconditioned stimulus (US) and in neuronal discharges that model the amplitude and time-course of the eyeblink CR. The developmental changes in CR-related neuronal activity in the cerebellum suggest that the ontogeny of eyeblink conditioning depends on the development of mechanisms that estavlish cerebellar plasticity. Learning and the induction of neural plasticity depend on the magnitude of the US input to the cerebellum. The role of developmental changes in the efficacy of the US pathway has been investigated by monitoring neuronal activity in the inferior olive and with stimulation techniques. The results of these experiments indicate that the development of the conditioned eyeblink response may depend on dynamic interactions between multiple developmental processes within the eyeblink neural circuitry.     

Clients Changing Counselors: An Inspirational Journey

Clients are a major source of influence and serve as primary teachers in the process of counselor development (T. M. Skovholt & M. H. Ronnestad, 1992). This article examines the dynamic of how counselors change as a result of their experiences with clients. Two case studies are presented as examples of counselor change.     

Book reviews

Thomassen, A., Keuss, P. and van Galen, G. (Eds.). Motor aspects of handwiriting. Amsterdam: North-Holland. 1984. Pp 354. ISBN 0444-86774-0. $50.

Klatskyk, R. L. Memory and awareness. New York: W. H. Freeman. 1984. Pp. 155. ISBN 0-7167-1600-3. £9.95.

Longman Dictionary of Psychology and Psychiatry. New York: Longman. 1984. ISBN 0-582-28257, pp 816, £46.00.

Kintsch, W., Miller, J. R., and Polson, P. G. Methods and tactics in cognitive seience. Hilisadale, N.J.: Lawrence Erlbaum Associates. 1984. Pp. xii+324. ISBN 0-89859-372-1. £27.50.

Dubery, F. and Williats, J. Perspective and other drawing systems. London: The Herbert Press. 1983. Pp. 128. ISBN 0-906969 -25-5. £4.95.

Morris, P. E. and Hampson, P. J. Imagery and consciousness. London: Academic Press. 1983. Pp. 341. ISBN 0-12-507680-0. $36.50.

Bundy, A. The computer modelling of mathematical reasoning. London: Academic Press. 1983. Pp. 322. ISBN 0-12-141252-0. $15.00.

Jeeves, M. A. and Greer, G. B. Analysis of structural learning. London: Academic Press. 1983. Pp. 265. ISBN 0-12-382080-4. $40.00.

Taylor, I. and Taylor, M. M. The psychology of reading. New York: Academic Press, 1983. Pp. 511. ISBN 0-12-684080-6 $29.50.

Wade, N. J. (Ed.). Brewster and Wheatstone on vision. London: Academic Press. 1984. Pp. 358. ISBN 0-12-729550-X. $39.00.

Harre, R. and Lamb, R. The encyclopedic dictionary of psychology. Oxford: Blackwell. 1983. ISBN 0-631-12663-5. £55.00.

Kail, R. and Spear, N. E. (Eds.). Comparative perspectives on the development of memory. Hillsdale, N. J.: Lawrence Erlbaum Associates. 1984. Pp. x+ 374. ISBN 0-89859-317-4. £37.50.

R. Hockey (Ed.). Stress and fatigue in human performance. London: Wiley. 1983. ISBN 0-471 10-265-2. £16.50.

Sarris, V. and Parducci, A. (Eds.). Perspectives in psychological experimentation: Toward the year 2000. Hillsdale, N. J.: Lawrence Erlbaum Associates. 1984. Pp. 370. ISBN 0-89859-272-9. £33.30.     

The interference of a baseline with children's orientation judgement need not entirely mask their contextual responsiveness

Children below the age of seven are very influenced by the orientation of the external frame of reference when they attempt to lay down a stimulus to match that of a tilted target. If, however, the target be set upon a baseline the children seem unable to benefit from salient parallel alignment cues. By modifying the usual design it is shown that children can remain able to take their bearings from contextual alignment even when setting a pointer upon a baseline; but the effect is only revealed in a complex three-way interaction. Contextual sensitivity is thus not abolished, but masked; and its re-emergence is in an apparently anomalous form.