Dr. Tim Pleskac, Senior Researcher at the Max Planck Institute for Human Development, Berlin, and ex-University of Basel researcher returns to Basel this week. Tim will give a talk at the Social, Economic, and Decision Making Colloquium on post-decisional processing.

Post-decisional processing and its implications for confidence and belief

What happen after people make a choice? I think we would all agree that our judgment and decision processes do not simply shut down after a choice is made. Instead we continue processing. We change our minds. We update our beliefs. In other words, we engage in post-decisional processing. During this talk, I will discuss two critical aspect of post-decisional processing. The first aspect is that people continue to accumulate evidence about the original choice alternatives. I will show that as more time passes between a choice and a confidence judgment this post-decisional evidence accumulation process leads decision makers to be more likely to make confidence judgments under different states of mind: states of mind that are better aligned to the true state of the world. Thus, by taking just a little more time to make a confidence rating, decision makers can make more accurate assessments. A second aspect of post-decisional processing is the choice itself. I will show that the very act of making a choice changes our subsequent beliefs and state of mind as compared to not making a choice at all, an interference effect of sorts. This last result is consistent with the common hypothesis of behavioral decision researchers that choice is a process that constructs beliefs and preferences, which can be formalized in terms of a quantum random walk of choice and judgment.

Dr. Todd Hare, Assistant Professor in Neuroeconomics, University of Zurich, visited our Dept. this week and gave a talk on the neural basis of self-control. Below the title and abstract for his talk.

Acute stress impairs self-control in goal-directed choice by altering multiple functional connections within the brain’s decision circuits

Dietary self-control requires the integration of short-term taste and long-term health aspects into an overall value for a food item. On a neural level, previous work has shown that the ventromedial prefrontal cortex (vmPFC) and ventral striatum, and amygdala are part of a valuation system that represents such values. Little is known, however, about the impact of acute stress on these neural mechanisms and subsequent dietary choices. We examined choice behavior and neural activity with BOLD fMRI after participants were exposed to an acute stressor (Socially Evaluated Cold Pressor). We found differences in choice patterns and neural activity during dietary self-control choices following our stress manipulation. Salivary cortisol and self-report measures indicated a successful stress induction. At the level of choice, both groups generally followed the health goal and chose the healthier item more than 70% of the time. However, further analysis of the choice patterns showed that the stress group put more weight on taste during choice than controls. Paralleling their choice behavior, the stressed group showed stronger representations of taste attributes in the amygdala and ventral striatum compared to controls. Moreover, there was greater connectivity between these limbic regions and areas of vmPFC that reflected the overall value of foods when stressed subjects chose to eat more tasty food options. Lastly, activity in the dorsolateral prefrontal cortex (dlPFC) increased when exercising self-control in both stressed and control subjects. However, the degree of connectivity between dlPFC and vmPFC decreased as a function of stress level. These results suggest that differential patterns of connectivity between vmPFC and both cortical and limbic regions may underlie the more taste-oriented behavior following acute stress.

Today we have Prof. Dr. Ilja van Beest, from Tilburg University, in our SWE colloquium talking on “Ostracism: Financial threats, survival threats, inclusion threats, and religious threats.” Here’s the abstract:

Recently we summarised 10 years of ball tossing in a meta-analysis of ostracism research (Hartgerink et al, PlosOne). We observed that the average effect size of ostracism approaches 1.5 standard deviations. This generalised across structural aspects (number of players, ostracism duration, number of tosses, type of needs scale), sampling aspects (gender, age, country). In the current talk I will provide an overview of the studies on ostracism that inspired us to conduct a meta-analyses. Specifically, I will present research on the relation between ostracism and (1) financial threats, (2) survival threats, (3) inclusion threats, (4) religious threats.

We had Dr. Takao Noguchi, from UCL, giving a talk in the Social, Economic, and Decision Psycholopy Colloquium this week . Takao presented work on an account of context effects using decisions by sampling. Here’s the abstract for his talk:

“The attraction, compromise, and similarity effects in multi-alternative decision making demonstrate that the preference for an alternative is not independent of the other alternatives in the choice set. To explain these context effects, we propose the multi-alternative decision by sampling model. The model has three components: 1) an alternative is evaluated through a series of pair-wise comparisons on single attribute values, 2) similar alternatives are compared more often, and 3) relatively small differences in attribute values are ignored. We discuss empirical evidence for each of these components, and address how multi-alternative decision by sampling explains context effects in multi-alternative choice.”

Today, we had Prof. Dr. Tilmann Betsch from the University of Erfurt telling us about his work on children’s decision making, in particular, their tendency to utilise all available information when making a decision (as opposed to focusing on the most relevant pieces). These findings seem really interesting in suggesting that the ability (or motivation?) to prioritise information develops between late childhood and late adolescence.

Next week, April 7, Tuesday, a few very promising job talks will take place concerning an Assistant Professorship position in Decision Neuroscience.