The detrimental effects of extrinsic reinforcement on "Intrinsic motivation"

Extrinsic consequences have been criticized on the grounds that they decrease intrinsic motivation or internally initiated behavior. Two popular rationales for this criticism, Lepper's overjustification hypothesis (1981) and Deci's motivational theory (Deci & Ryan, 1985), are reviewed and the criticism is then redefined behaviorally. "Intrinsically controlled" behavior is defined as behavior maintained by response-produced reinforcers, and the question concerning extrinsic consequences is thus restated as follows: When behavior is maintained by response-produced stimuli, does extrinsic reinforcement decrease the reinforcing value of those stimuli? The empirical support for this detrimental effect is summarized briefly, and several possible explanations for the phenomenon are offered. Research results that reflect on the effect's generality and social significance are discussed next, with the conclusion that the effect is transient and not likely to occur at all if extrinsic rewards are reinforcing, noncompetitive, based on reasonable performance standards, and delivered repetitively.     

Induced subject-relative movement: Persistence of apparent movement of a stationary point after removal of inducing stimulus

It was observed by chance that perceived movement of a stationary spot of light in a dark featureless field persists after its induced movement by a moving frame. When the frame was suddenly occluded, apparent movement of the spot persisted in the same direction as prior induced movement. The effect which is compelling and readily reported and referred to as induced subject-relative movement (ISRM) was confirmed and further investigated in four experiments. In the first, the informal observations of ISRM were confirmed using manual tracking to index perceived movement, and in the second, it was shown to occur only very slightly and briefly when the frame merely stopped. In the third experiment, ISRM was shown to occur following two different paths of induced movement, and in the fourth, not to occur following real movement of the spot, which was almost indistinguishable from its induced movement. It is suggested that the effect arises from the absence of a signal for cessation of perceived movement when the frame disappears.     

Book reviews

BODEN, MARGARET A. Artificial Intelligence and Natural Man. Hassocks : Harvester Press Limited, and New York: Basic Books Inc., 1977. Pp. ix+537. £613.50 hardback; £64.95 paperback. ISBN 0 85527 435 2.

ESTES, W. K. (Ed.). Handbook of Learning and Cognitive Processes. Vol. 6. Linguistics. Functions in Cognitive Theory. Hillsdale, N.J. : Erlbaum Associates. 1979. Pp. 331. £12.70. ISBN o 470 26311 3.

O'KEEFE, J. and NADEL, L. The Hippocampus as a Cognitive Map. London: Oxford University Press. 1978. Pp. 543. £25.00. ISBN 0 12 524150 X.

FITZSIMONS, J. T. The Physiology of Thirst and Sodium Appetite. Cambridge: Cambridge University Press. 1979. Pp. 572. £32.50. ISBN 0 521 22292 3.

MURRAY, F. B. and PIKULSKI, J. J. (Eds). The Acquisition of Reading. Baltimore: University Park Press. 1978. Pp. 178. £8.95. ISBN 0 8391 1281 5.

NEWTON, M. J., THOMAS, M. E. and RICHARDS, I. L. Readings in Dyslexia. Wisbech: Benrose Ltd. 1979. Pp. 203. £4.50. ISBN 09 0511 4124.

SENDERS, J. W., FISHER, D. F. and MONTY, R. A. (Eds). Eye Movements and Higher Psychological Processes. Hillsdale, N. J. : Erlbaum. 1978. Pp. 394. £19.95. ISBN 0 470 26489 6.

GRUBER, H. E. and VONECHE, J. J. (Eds). The Essential Piaget. London: Routledge & Kegan Paul. 1977. Pp. 880. £12.95. ISBN 07100 87780.

SIEGEL, L. S. and BRAINERD, C. J. (Eds). Alternatives to Piaget. New York: Academic Press. 1978. Pp. 262. £11.70. ISBN 12 641950 7.

BRANSFORD, J. D. Human Cognition: Learning, Understanding and Remembering. Belmont, California: Wadsworth. 1979. Pp. xii+300. £11.85. ISBN 0 534 00699 X.

VON FIEANDT, K. and MOUSTGAARD, I. K. The Perceptual World. London: Academic Press. 1977. Pp. 680. £32.00. ISBN 0 12 725050 6.

BURTON, A. and RADFORD, J. (Ed.). Thinking in Perspective: Critical Essays in the Study of Thought Processes. London: Methuen. 1978. Pp. xxii+232. £3.95. ISBN 0 416 85840 6.

MAYER, R. E. Thinking and Problem Solving: An Introduction to Human Cognition and Leavning. Glenview, Illinois: Scott, Foresman and Company. 1977. Pp. viii+214. £4.95. ISBN 0 673 15055 0.

BATES, E. Language and Context: The Acquisition of Pragmatics. New York: Academic Press. 1976. Pp. 375. £14.50. ISBN 0 12 081550 8.

MILGHAM, N. W., KRAMES, L. and ALLOWAY, T. M. Food Aversion Learning. New York: Plenum Press. 1977. Pp. 263. £27. ISBN 0 306 31040 6.

O'CONNOR, N. and HERMELIN, B. Seeing and Hearing and Space and Time. London: Academic. 1978. Pp. 157+viii. £6.80. ISBN 0 12 524150 X.     

Changing behavior with behavioral techniques

The following report describes how a combination of reward and punishment was used to change the behavior of an acting-out third grade student. Punishment was used to suppress the undesirable behavior and a reward system was used to reinforce the new desirable behavior. The subject dropped from an average of .20 times per day in getting out his seat to an average of 0.12 over a five-week period.     

Re-examination of the role of the instrumental contingency in the sodium-appetite irrelevant incentive effect

Thirsty rats were trained to perform one action—either lever pressing or chain pulling—for a sodium chloride solution and the other for water on a concurrent random interval schedule. When the experimental groups were tested in extinction under a sodium appetite, the instrumental action trained with the sodium solution was not performed at a significantly higher rate than that reinforced by water relative to control groups tested while thirsty. In a second experiment all animals were tested in extinction under a sodium appetite after training with either a sodium solution and water in the experimental condition or a potassium chloride solution and water in the control condition. The experimental animals chain-pulled more rapidly on test than the control rats, irrespective of whether this action was reinforced with the sodium solution or with water. These results confirm the findings of Dickinson and Nicholas (1983a) that the instrumental contingency plays little role in the irrelevant incentive effect based upon a sodium appetite.     

Instrumental performance following reinforcer devaluation depends upon incentive learning

Conditioning an aversion to the reinforcer following instrumental training reduces performance in a subsequent extinction test. Three experiments examined whether this reinforcer-devaluation effect depends upon experience with the devalued reinforcer prior to the extinction test. In Experiments 1 and 2 thirsty rats were trained to press a lever for sucrose solution in a single session. All animals then received an injection of lithium chloride (LiCl) either immediately following the session or after a delay of 6 hr. On the next day either the sucrose solution or water was presented non-contingently either in the operant chamber without the lever present or in a separate drinking cage. In a subsequent extinction test only the animals that had received immediate LiCl and re-exposure to non-contingent sucrose pressed less than those in the delayed-LiCl control groups. Experiment 3 demonstrated that this difference depended, at least in part, on post-conditioning exposure to a contingent reinforcer. Lever pressing and chain pulling were reinforced concurrently with either a sucrose or a sodium chloride solution in a single session immediately before the administration of LiCl. All animals then received non-contingent presentations of one of the reinforcers in the absence of both manipulanda. Finally, performance of both actions was assessed in an extinction test. Re-exposure to a reinforcer produced a relative reduction in the performance of its associated action on test. These results are interpreted as evidence that the instrumental reinforcer devaluation effect depends upon a process of incentive learning.     

Incentive learning following reinforcer devaluation is not conditional upon the motivational state during re-exposure

Three experiments analysed the effect of re-exposure to the reinforcer following aversion conditioning on instrumental performance. In the first experiment, groups of hungry and thirsty rats were trained to press a lever for sucrose, which was then followed by a single injection of lithium chloride (LiCl). On the following day, half the animals in each motivational condition received re-exposure to the sucrose solution; the remaining animals were not re-exposed. In a subsequent extinction test animals that had received re-exposure to the sucrose pressed less than animals that were not re-exposed. Moreover, the effect of re-exposure to the sucrose solution was similar following training under hunger and thirst. In the remaining studies, animals were trained to lever-press for sucrose while either hungry or thirsty. They were then injected with LiCl and re-exposed to the sucrose while either hungry or thirsty, i.e. in the same or different motivational state employed during training, or they were not re-exposed. Lever pressing was then tested in extinction in the training motivational state. As in the first experiment, re-exposure to the reinforcer after aversion conditioning enhanced the magnitude of the reinforcer devaluation effect. More importantly, re-exposure to the sucrose produced a comparable effect on instrumental performance, whether re-exposure was given under the same or different motivational state to that employed during training. These results suggest that the instrumental reinforcer devaluation effect depends upon a process of incentive learning, but that this process is not conditional upon the current motivational state of the animal.     

Book reviews

Commons, M. L., Herrnstein, R. J. and Rachlin, H. (Eds.). Quantitative analyses of behaviour: Matching and maximising accounts. Quantitative analyses of behuviour series, Volume 2. Cambridge, Mass.: Ballinger. 1982. Pp. 616. ISBN 0-88410-739-6

Alkon, D. L. and Farley, J. (1984). Primary neural substrates of learning and behavioural change. Cambridge: Cambridge University Press. Pp. 385. ISBN 0-521-25472-8. £35.00.

Satinoff, E. and Teitelbaum, P. (Eds.) (1983). Handbook of behavioral neurobiology, volume 6: Motivation. New York: Plenum Press. Pp. 592. ISBN 0-306-41068-0.