Extinction context as a conditioned inhibitor

Two lick suppression experiments using rats were conducted to determine whether extinction of a punctate excitor in a particular context would result in that context becoming a conditioned inhibitor, as defined by passing both summation and retardation tests. The role of extinction trial spacing was investigated as a possible determinant of whether the extinction context would become inhibitory. Experiment 1 demonstrated that, although inhibition was evident using either massed or spaced extinction trials, spaced trials reduced measurable inhibition as assessed by the summation test, but trial spacing had no influence on retardation test performance. Experiment 2 confirmed Experiment 1’s conclusions while controlling for the influence of latent inhibition on the retardation test. In Experiment 2, the context proved inhibitory only following massed extinction trials. These data suggest that, at least with select parameters, an extinction context can become inhibitory.     

A problem masked

While Ester Aflalo’s conclusions for teaching the nature of science seem uncontentious her analysis of degree of religiosity and its relationship to perceptions of the nature of science among Palestinian Muslim and Jewish Israelis fails to take into account complex affiliations to religion such as history, the nature of identity and resistance to political oppression. My response is that the focus on religion and science, while important, can obscure subtle relationships between worldviews and perceptions of the nature of science. Analysis of this latter relationship may be more fruitful in supporting transformative science teaching.     

Towards a Theoretical Framework for Teaching Controversial Socio‐scientific Issues

This paper develops a conceptual basis for a model on the teaching of socio‐scientific controversial issues for secondary or high school students. I argue that the teaching of controversial issues needs a stronger theoretical base. Drawing on a liberal democratic conception of possible sources of conflict, three strands are developed that provide a framework for teachers when teaching socio‐scientific issues: these are categories of reasonable disagreement, the communicative virtues, and modes of thought. Examples are given to illustrate how the framework can be used by teachers in which the features of controversy are made explicit to students.     

Design‐based science and real‐world problem‐solving

Design‐based science (DBS) is a science pedagogy in which new scientific knowledge and problem‐solving skills are constructed in the context of designing artifacts. This paper examines whether the enactment of a DBS unit supported students’ efforts to construct and transfer new science knowledge and ‘designerly’ problem‐solving skills to the solution of a new real‐world design problem in a real‐world setting. One hundred and forty‐nine students participated in the enactment of a DBS unit. Their understanding of the curricular content was assessed by identical pre‐instructional and post‐instructional written tests. They were then given a new design problem as a transfer task. There was a statistically significant increase on scores from pre‐test to post‐test with an effect size of 1.8. There was a stronger correlation between the scores of the transfer task and those of the post‐test than with those of the pre‐test; we use this finding to suggest that the knowledge that was constructed during the unit enactment supported the solution of the transfer task. This has implications for the development of science curricula that aim to lead to the construction of knowledge and skills that may be useful in extra‐classroom settings. Whether participation in consecutive enactments of different DBS units increases transfer remains to be investigated in more depth.     

Book reviews and notes

SOCIAL‐CULTURAL ASPECTS OF MENTAL RETARDATION edited by H. Carl Haywood. New York: Appleton‐Century‐Crofts, 1970. xvii + 798 pp. $8.00.

LUDVIG HOLBERG'S MEMOIRS: AN EIGHTEENTH CENTURY DANISH CONTRIBUTION TO INTERNATIONAL UNDERSTANDING edited by Stewart E. Fraser. Leiden, The Netherlands: E.J. Brill, 1970. Volume I, 289 pp. Volume II, 33 pp. portfolio containing 33 engravings. $36.50 (Limited supply available at $23.00 from the International Center, George Peabody College for Teachers, Nashville, Tennessee 37203.)

HANDBOOK ON FORMATIVE AND SUMMATIVE EVALUATION OF STUDENT LEARNING by Benjamine S. Bloom, J. Thomas Hastings, and George F. Madaus. New York: McGraw‐Hill Book Company, 1971. xi+923 pp. $11.95.

TEACHING AND LEARNING: AN INTRODUCTION TO NEW METHODS AND RESOURCES IN HIGHER EDUCATION by Norman MacKenzie, Michael Eraut, and Hywel C. Jones. Unesco and the International Association of Universities, 1970, distributed by Unipub. Inc., P.O. Box 433, New York 10016. 209 pp. $3.50.

A CHANCE TO GO TO COLLEGE. New York: College Entrance Examination Board, 1971. A‐46 + 248 pp. $3.00.

PARAMETERS OF LEARNING: PERSPECTIVES IN HIGHER EDUCATION TODAY by William James McKeefery. Carbondale: Southern Illinois University Press, 1970. xix + 169pp. $6.95.     

Associative foundation of causal learning in rats

Are humans unique in their ability to interpret exogenous events as causes? We addressed this question by observing the behavior of rats for indications of causal learning. Within an operant motor–sensory preconditioning paradigm, associative surgical techniques revealed that rats attempted to control an outcome (i.e., a potential effect) by manipulating a potential exogenous cause (i.e., an intervention). Rats were able to generate an innocuous auditory stimulus. This stimulus was then paired with an aversive stimulus. The animals subsequently avoided potential generation of the predictive cue, but not if the aversive stimulus was subsequently devalued or the predictive cue was extinguished (Exp. 1). In Experiment 2, we demonstrated that the aversive stimulus we used was in fact aversive, that it was subject to devaluation, that the cue–aversive stimulus pairings did make the cue a conditioned stimulus, and that the cue was subject to extinction. In Experiments 3 and 4, we established that the decrease in leverpressing observed in Experiment 1 was goal-directed instrumental behavior rather than purely a product of Pavlovian conditioning. To the extent that interventions suggest causal reasoning, it appears that causal reasoning can be based on associations between contiguous exogenous events. Thus, contiguity appears capable of establishing causal relationships between exogenous events. Our results challenge the widely held view that causal learning is uniquely human, and suggest that causal learning is explicable in an associative framework.     

When more is less: Extending training of the blocking association following compound training attenuates the blocking effect

Three conditioned lick suppression experiments with rats were performed to assess the influence, following compound training of two stimuli (A and X) with the same outcome (AX-O trials), of extending training of the blocking association (i.e., A-O) on responding to the target stimulus (X) at test. In Experiment 1, backward blocking was attenuated when the blocking association was extensively trained. Experiment 2 showed that forward blocking was also attenuated by extensive further training of the blocking association following the AX-O trials. Experiment 3 contrasted candidate explanations of the results of Experiments 1 and 2 and demonstrated that these results are consistent with the framework of the extended comparator hypothesis (Denniston, Savastano, & Miller, 2001).