The frontal cortex is crucial to sound decision-making, and the activity of frontal neurons correlates with many aspects of a choice, including the reward value of options and outcomes. However, rewards are of high motivational significance and have widespread effects on neural activity. As such, many neural signals not directly involved in the decision process can correlate with reward value. With correlative techniques such as electrophysiological recording or functional neuroimaging, it can be challenging to distinguish neural signals underlying value-based decision-making from other perceptual, cognitive, and motor processes. In the first part of the paper, we examine how different value-related computations can potentially be confused. In particular, error-related signals in the anterior cingulate cortex, generated when one discovers the consequences of an action, might actually represent violations of outcome expectation, rather than errors per se. Also, signals generated at the time of choice are typically interpreted as reflecting predictions regarding the outcomes associated with the different choice alternatives. However, these signals could instead reflect comparisons between the presented choice options and previously presented choice alternatives. In the second part of the paper, we examine how value signals have been successfully dissociated from saliency-related signals, such as attention, arousal, and motor preparation in studies employing outcomes with both positive and negative valence. We hope that highlighting these issues will prove useful for future studies aimed at disambiguating the contribution of different neuronal populations to choice behavior.
Keywords: value, reward, choice, decision-making, prediction error, valence, orbitofrontal, anterior cingulate
Citation: Wallis JD and Rich EL (2011) Challenges of interpreting frontal neurons during value-based decision-making. Front. Neurosci. 5:124. doi: 10.3389/fnins.2011.00124
Received: 10 May 2011; Paper pending published: 08 June 2011;
Accepted: 28 September 2011; Published online: 22 November 2011.
Edited by:Tobias Kalenscher, Heinrich-Heine University Duesseldorf, Germany
Reviewed by:Earl K. Miller, Massachusetts Institute of Technology, USA
Copyright: © 2011 Wallis and Rich. This is an open-access article subject to a non-exclusive license between the authors and Frontiers Media SA, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and other Frontiers conditions are complied with.
*Correspondence: Erin L. Rich, Helen Wills Neuroscience Institute, University of California Berkeley, 132 Barker Hall, Berkeley, CA, USA. e-mail: email@example.com