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Email geoff.white@otago.ac.nz

Professor Geoff White

Profile

Emeritus Professor White was Head of the Psychology Department at Otago University for 10 years from 1987, and for 5 years from 2004 was the University's Deputy Vice-Chancellor (Research). He joined the Department of Psychology at Otago in 1985, having spent 13 years lecturing at the Victoria University of Wellington and in visiting appointments at Colorado College, University of Colorado, Boulder, and University of California, San Diego. He has been President of the New Zealand Psychological Society and for many years was a member of the New Zealand Psychologists' Registration Board. He edited the New Zealand Journal of Psychology and has been Associate Editor of the Journal of the Experimental Analysis of Behavior.

He has been the recipient of the New Zealand Psychological Society's Hunter Award and Adcock Award, and in 2000 with John Wixted was the recipient of the American Psychological Association's George A Miller Award. He is a Fellow of several national and international organisations, including the Royal Society of New Zealand. He has successfully supervised over 20 PhD students and many Master's students, and in 2003 was the University's inaugural supervisor of the year. In 2009 he was made an Officer of the New Zealand Order of Merit for services to science and psychology.

Geoff retired from the department in July 2014.

Memory and Discrimination Processes

Memory is a window on the past. In this metaphor, the important discriminations are made when we look out. Signs that point out what we are to look for, the retrieval cues, are actually in the present. Remembering, like looking, is direct.

The importance of retention interval as a retrieval cue

Our experiments study the factors that influence short-term memory, and emphasise the importance of the retention interval itself as a retrieval cue. Typically, when the retention interval is lengthened, remembering becomes less accurate. But we have shown that remembering can be more accurate at long retention intervals than at short intervals, even when conditions are introduced in the short intervals that should erase the memory trace, such as retroactive interference or rehearsal prevention.

These results are important because they suggest that the usual monotonically-decreasing forgetting function is not simply the result of time-related processes such as trace decay. Retrieval-cue availability is more important, independently of the duration of the retention interval. Theoretically, our cross-species demonstrations of the dependence of remembering on the time at which retrieval occurs, suggest that episodic memory is an ability of humans and nonhumans alike. Although episodic memory can involve the discrimination of what, where, and when, it doesn't actually matter how long ago the 'when' was, so long as the retrieval conditions are optimal.

Memory as discrimination

These theoretical ideas, and our supporting experimental research, point to the importance of discriminations made at the time of remembering. We have applied these ideas in our many studies of the effects of clinically-relevant drugs on remembering in animals. By examining the effects of the drugs on the intercept and slope of forgetting functions we have been able to establish that the main effect of most drugs is simply to make the discrimination at the time of remembering more or less difficult. At present we are using these ideas in an attempt to understand the sunk cost effect.

Publications

White, K. G. (2018). Direct remembering, mediated remembering, and atypical forgetting functions. Journal of the Experimental Analysis of Behavior, 109(1), 70-86. doi: 10.1002/jeab.298

Magalhães, P., & White, K. G. (2016). The sunk cost effect across species: A review of persistence in a course of action due to prior investment. Journal of the Experimental Analysis of Behavior, 105(3), 339-361. doi: 10.1002/jeab.202

Cowie, S., Bizo, L. A., & White, K. G. (2016). Reinforcer distributions affect timing in the free-operant psychophysical choice procedure. Learning & Motivation, 53, 24-35. doi: 10.1016/j.lmot.2015.10.003

White, K. G., & Sargisson, R. J. (2015). A delay-specific differential outcomes effect in delayed matching to sample. Learning & Behavior, 43(3), 217-227. doi: 10.3758/s13420-015-0174-1

White, K. G., & Magalhães, P. (2015). The sunk cost effect in pigeons and people: A case of within-trials contrast? Behavioural Processes, 112, 22-28. doi: 10.1016/j.beproc.2014.09.035

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