The 28th Bartlett Memorial Lecture Causal learning: An associative analysis

The concordance between performance and judgements of the causal effectiveness of an instrumental action suggests that such actions are mediated by causal knowledge. Although causal learning exhibits many associative phenomena—blocking, inhibitory or preventative learning, and super-learning—judgements of the causal status of a cue can be changed retrospectively as a result of learning episodes that do not directly involve the cue. In order to explain retrospective revaluation, a modified associative theory is described in which the learning processes for retrieved cue representations are the opposite to those for presented cues, and this theory is evaluated by studies of the role of within-compound associations in retrospective revaluation and blocking. However, this modified theory only applies when the within-compound association represents a contiguous rather than a causal cue relationship.     

Pavlovian counterconditioning: changing the suppressive properties of shock by association with food.

Two experiments are described in which rats received a series of shock and food presentations in a Pavlovian counterconditioning sequence. Subsequently, the capacity of the shock to act as a reinforcer during conditioned emotional response (CER) training was assessed. In the first experiment, following each shock during counterconditioning by a food presentation was found to retard the development of suppression during CER training relative to control conditions in which different groups of rats received either a sequence of explicitly unpaired shock and food presentations, shock presentations alone, or food presentations alone. The second experiment demonstrated that when the magnitude of the food presentations is held constant, the attenuation of the suppressive properties of shock by pairing with food depends on the magnitude of the shock. The results are interpreted as demonstrations of Pavlovian counterconditioning, which, it is suggested, modifies the general aversiveness of a noxious stimulus.     

Book reviews

MELTON. A. W. and MARTIN, E. (Eds). coding Processes in Human Memory. Wahsington, D. C.: V. H. Winston and Sons. 1973. Pp. xiv + 448. £ 5.54.

ADOLFSON, J. and BERGHAGE, T. E. Peception and Performance Underwater. New york: Wiley Interscience. 1974. Pp. xx + 359. £ 10.60.

SCHWARTZ, M. Psysiological Psychology. New York: Appleton-Century-Crofs. 1973. Pp. 484. $ 7.65.

VALENSTEIN, E. S. Brain Control. New York: Wiley. 1973. Pp. 407. £ 6.40.

GOODMAN, I. J. and SCHEIN, M. W. (Eds). Birds: Brain and Behaviour. New York: Academic Press. 1974. Pp. 457. £ 10.00.

STONE, L. J., SMITH, H. T. and MURPHY, L. B. The Competent Infant. London: Tavi-stock Press. 1974. Pp. 1314. £ 11.00.     

TOWARD A NEW FOCUS FOR CHURCHES' DEVELOPMENT PROJECTS?

“The Church must recognize that she is growing powerless to orient or produce development. The less efficient she is as a power, the more effective she can be as a celebrant of the mystery… The Church will have to renounce progressively the ‘power to do good’ she now has, and see this power pass into the hands of a new type of institution.”     

Short-Term Retention of “Surprising” Events By Pigeons

Terry and Wagner (1975) have suggested that the short-term retention of information about an event is enhanced if the occurrence of the event is made unexpected or surprising. Three experiments tested this idea using delayed conditional position (Experiment I) and colour discriminations (Experiments II and III). The subjects were pigeons and the presentation of food was the target event to be remembered. Choice of one of two simultaneously presented stimuli was reinforced if the retention interval had been initiated by presentation of target food. Contrary to Terry and Wagner's claim, retention was superior on probe test trials in Experiments I and II if the presentation of the target food was preceded by a previously established signal for food (CS+) rather than by a stimulus which had not been paired with food (CS-). Experiment III systematically manipulated the signalling conditions used during initial discrimination training. Retention was better following a CS+ presentation if the target food had been signalled during initial discrimination training but worse if the food presentation had been unsignalled. These results do not favour the idea that retention of an event is directly affected by whether or not the target event is surprising.     

Appetitive-aversive interactions: Superconditioning of fear by an appetitive cs

Four groups of rats received conditioned suppression training in which a tone and light compound was reinforced with shock. If the light had been previously paired with free food, enhanced fear conditioning accrued to the tone during compound training relative to control groups pre-exposed to the light alone, the light semi-randomly associated with food, or the light unpaired with food. The second experiment replicated the difference in aversive conditioning for the groups receiving the light either paired or unpaired with food. The results are discussed in terms of the functional similarity of a conditioned excitor for food and a conditioned inhibitor for shock.     

Book reviews

Ribsbn, A. H. The Developmental Neurqpsychology of Sensory Deprivation. London: Academic Press. 1975. Pp. xiii and 303. £7.90. ISBN 012 588550 4.

Kennedy, A. and Wilkes, A. Studies in Long Term Memory. London: Wiley, 1975. Pp. xiii + 358. £10,00. ISBN 0471 46905 X.

Osherson,D. N. Logical Abilities in Children. Vols. I, Ii and III. Ptomoac, Md: Erlbaum 1974, 1974, 1975. Pp. 162, 272. £5.45, £5.45, £9.20.

Kaufman L., Sight and Mind: an Introduction to Visual Perception. Oxford University Press. 197s. Pp. ix + 580. £8.75.

McCormick,E. J. Human Factors in Engineering and Design. Fourth edition. New York: McGraw-Hill, 1976. Pp. xi + 491. £13.70.

Chapman, T. and Foot, H. (Eds). Humour and Laughter: Theory, Research and Applicatim. London: Wiley. 1976. Pp. 348. £9.50 ISBN 0471 14612 9.

Estes,W. K. (Ed.). Handbook of Learning and Cognitive Processes. Vol. I. Introduction to Concepts and Issues. Hillsdale, N.J.: Erlbaum Associates. 1975. £9.20. ISBN 0470 24585 9.

Markel, J. D. and Gray, Jr., A. H. Linear Prediction of Speech. Berlin: Springer-Verlag. 1976. Pp. 288. $30.00.     

A word-finding computer program with a dynamic lexical-semantic memory for patients with anomia using an intelligent speech prosthesis

A computer program for a portable microprocessor has been developed which aids anomic patients in finding words given clues about the target word. Over time the lexical-semantic memory is reorganized automatically depending on the frequency of word usage by an individual patient. Words can be added or deleted to fit the patient's idiosyncratic lexicon. A clinical example is given. The program is being tested with a variety of aphasic-anomic patients with major word-finding difficulties.