Sozial-, Wirtschafts- und Entscheidungspsychologie


Social, Economic, and Decision Psychology Blog

Archive for May, 2016

Charles Judd

This week we have Prof Dr. Charles Judd from the University of Colorado Boulder visiting us and giving a talk in the Social, Economic, and Decision Psychology colloquium (Thursday,  May 26, 2016, 13:00, title and abstract follow). We’re looking forward to seeing you there.

Experiments in which samples of participants respond to samples of stimuli: Designs, analytic models, and statistical power

Many psychological experiments ask participants to judge faces, memorize words, or solve analytic problems under different experimental conditions. The interest is in the mean condition differences in participants’ responses. Most typically differences due to the specific stimuli (i.e., faces, words, and problems) are ignored in the analysis of the resulting data. I will show that this can result in serious bias if the goal is to generalize conclusions to other samples of participants and other samples of stimuli that might have been used. I will then provide an introduction of the use of linear mixed models for analyzing data from designs involving two random factors, participants and stimuli. I will briefly discuss a range of such designs and then discuss issues of statistical power. I will argue that many failures to replicate experimental results may be due to the failure to treat stimuli as a random factor in the analysis of data from experiments involving  samples of both participants and stimuli.

Workshop on Sequential Sampling Models of Decision Making

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From May 9 to May 11, the Workshop on Sequential Sampling Models of Decision Making, organized by Jared Hotaling, Sebastian Gluth, Jörg Rieskamp, and Jerome Busemeyer (Indiana University), was held at the Seminarhotel Seeblick in Emmetten. An impressive list of international experts on the topic (including Richard Shiffrin, Roger Ratcliff, Scott Brown, Michael Frank, Rafal Bogacz, Marius Usher, Paul Cisek and many more) were invited and gave talks at the workshop. The presentations were accompanied by some stimulating and intensive discussions about current and future challenges for sequential sampling modeling. About 15 PhD students and post docs from the SWE centers and other universities joined the meeting and presented their work during the poster session. The nice hotel with its impressive view over Lake Lucerne and the adventurous cable car trip to the mountain restaurant Niederbauen also contributed to making this a very successful and enjoyable workshop.

Guillaume Sescousse

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This week we have Guillaume Sescousse from the Donders Institute for Brain, Cognition and Behaviour at Radboud University (Nijmegen, Netherlands) visiting us and giving a talk in the Social, Economic, and Decision Psychology colloquium (Thursday,  May 19, 2016, 13:00, title and abstract follow).

Exploring the links between reward, dopamine and gambling addiction

Despite the pervasive hypothesis that reward sensitivity, dopamine, and gambling addiction are intimately related, the specific nature and direction of these links remain elusive. In this talk I will present a series of recent experiments tackling this question, using a combination of psychopharmacology, neurochemical PET and fMRI in humans. I will show that dopaminergic drugs modulate the relative sensitivity to reward vs punishment, but in opposite directions in healthy participants and gambling addicts. I will provide suggestive evidence that this individual variability in drug effects is related to an underlying variability in baseline dopamine synthesis capacity, which is enhanced in gambling addicts. I will also show that in the context of risky decision-making, dopamine modulates the subjective distortion of winning probabilities. Finally, I will present evidence showing that gambling addicts might not suffer from enhanced brain responses to winning, but to nearly winning (so-called ‘near-misses’). Together, these results shed light on the role of dopamine in reward sensitivity and gambling addiction. They also reinforce the baseline-dependency principle of dopaminergic drug effects, thus demonstrating the importance of a dimensional as opposed to a categorical approach to dopaminergic treatment in psychiatry.

Humans need not apply

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Will bots rule the world? According to Jerry Kaplan, the question is ill posed. In his book, Humans need not apply, Kaplan makes the case that it is a matter of when, not whether artificial intelligence will radically change the way we live and make a living. In fact, the revolution has begun: Algorithms invest side-by-side with humans in the stock market, decide what ads we consume online, and predict the prices we are willing to pay for goods on Amazon. The impact of this trend will be felt most and hardest, argues Kaplan, as more and more jobs are automatised and wealth is accumulated by the lucky few at the top that can capitalise on these advances.

But what does this mean for Psychologists? In a working paper, The future of employment: How susceptible are jobs to computerisation?, Frey and Osborne (2013) estimate the likelihood that over 700 jobs can “be sufficiently specified, conditional on the availability of big data, to be performed by state of the art computer-controlled equipment” and argue that about 50% of today’s employment in the US is at risk due to automatisation. However, their estimates suggest that Psychologists may not be affected by automation: Frey and Osborne establish a ranking of occupations and the Clinical, Counseling, and School Psychologists category ranks 24 out of 702 in the ranking of jobs least likely to be automatised, while Industrial-Organizational Psychologists and Psychologists, All other… rank 57 and 17, respectively.

The title of Kaplan’s book is borrowed from an equally sobering 15-minute video by CGP Grey that illustrates the broader issue of automatisation in the world of work and is available here.