Elektra Schubert and Matthew Jiwa named Young Investigator Award Recipients at the MDHS Graduate Research Conference 2020

PhD students, Elektra Schubert and Matthew Jiwa, named Young Investigator Award recipients of the Faculty of Medicine, Dentistry, and Health Sciences Graduate Research Conference 2020!

Congratulations to our hub's fantastic rising stars, Elektra Schubert and Matthew Jiwa for being awarded the Young Investigator Award and Runner Up respectively at the recent Faculty of Medicine, Dentistry, and Health Sciences (MDHS) Graduate Research Conference 2020!

Elektra and Matthew are 2nd year PhD students of the Decision Neuroscience Lab within the Decision Science Hub. To find out more about Elektra and Matt's work, please see below for the abstracts of their presentations at the Graduate Research Conference.

Decoding explicit and implicit representations of health and taste attributes in the human brain Introduction: Visual food cues are constantly encountered in everyday life and are closely related to dietary decisions.

Elektra Schubert , Daniel Rosenblatt , Djamila Eliby , Yoshihisa Kashima , Hinze Hogendoorn & Stefan Bode

Introduction: The processing of these cues involves two key attributes: taste and health. Previous studies suggest that taste information is neurally encoded very early, during the first second of viewing a food cue, but it is unclear whether health information is also processed at this stage. This study therefore aimed to examine whether and when health and taste attributes are represented in the brain during the viewing of food images a) while making explicit health/taste judgements, and b) while implicitly considering food attributes for consumption decisions.

Methods: We used multivariate support vector regression to determine whether spatiotemporal patterns of event-related potentials occurring in the first 1200 ms after the presentation of a food image could predict ratings of tastiness and healthiness on a trial-by-trial basis. In Experiment 1, participants (N = 37) were directly instructed to rate the tastiness and healthiness of various food items. In Experiment 2, a different sample of participants (N = 89) viewed images of various foods and rated how strongly they would like to consume them (decision strength), with no explicit instruction to consider tastiness or healthiness. In both experiments, brain activity was recorded using electroencephalography (EEG).

Results: The results of Experiment 1 showed that taste and health ratings could both be predicted significantly above chance, with taste (from 530 ms) becoming decodable slightly earlier than health (from 640 ms). In Experiment 2, using the same analysis approach, we found that taste (from 740 ms) and health (from 530 ms) ratings could again be predicted significantly above chance, as well as decision strength (from 830 ms).

Conclusion: Taken together, our results suggest that taste and health information is decodable from electroencephalography data during dietary decisions, even when participants are not explicitly instructed to consider these attributes. This finding provides an exciting path for future studies to investigate potential alterations of taste and health representations following interventions, such as health warning messages, aimed at improving dietary choices.

Choosing to Know: Agency Increases the Value of Non-Instrumental Information

Matthew Jiwa , Patrick S. Cooper , Trevor T-J. Chong & Stefan Bode

Introduction: From the caloric contents of our favourite snacks, to the misdeeds of unknown celebrities, and our own genetic make-up, we now have more information available at the touch of a button – or swipe of a credit card – than ever before. Therefore, how we decide which information to view or avoid is of increasing personal, social, and commercial relevance. Recent research indicates that the propensity to reduce uncertainty, and the expected hedonic value of outcomes, are both key factors in determining whether information is worth pursuing. How contextual factors, such as the possession of agency, affect the computation of the subjective value of information remains an open question.

Methods: The present study investigated whether agency over choosing a specific but random lottery changed the value participants assigned to information about the lottery’s outcome. This task allowed for the disaggregation of information from reward value because it could not be used to increase the magnitude or probability of future rewards (i.e., the information was “non-instrumental”). Participants completed a series of trials in which they bid proportions of their winnings in order to learn the outcomes of lotteries they had either chosen (lotteries they had agency over) or had been assigned (lotteries they did not have agency over).

Results: Results showed that having agency over which lottery to play significantly increased both the perceived probability of obtaining a winning outcome from the lottery and the subjective value of information about the outcome. Computational modelling indicated that this change in information-seeking behaviour was not due to changes in the subjective probability of winning, but instead reflected an independent effect of agency on the value of resolving uncertainty.

Conclusion: These results demonstrate agency to be an important source of value for the desire to obtain information, even when this information has no utility. The effect of agency on the subjective value of information may be attributable to an overlearning of the association between agency and the instrumentality or cognitive value of information.