image: Participants performed a gambling task in the presence of a human observer, choosing between a safe (certain) option and a gamble (probabilistic) option. They were instructed to look at the observer’s face, which was presented either as an avatar or as a real human. Participants were informed that the avatar’s facial expressions and movements mirrored those of the real human observer. The authors found that participants made more gambling choices in the avatar condition than in the human condition.
Credit: Toshiko Tanaka (CC-BY 4.0, https://creativecommons.org/licenses/by/4.0/)
Expecting feedback from an avatar compared to a real human facilitates risk-taking behavior in a gambling task, and a brain region called the amygdala is central to this facilitation, according to a study published April 22nd in the open-access journal PLOS Biology by Toshiko Tanaka and Masahiko Haruno from the National Institute of Information and Communications Technology, Japan.
In virtual-reality environments, individuals can adopt various forms of avatars, projecting their behaviors into a virtual realm where their interaction partners also appear as avatars. With this shift in communication style, it is essential to understand how the use of avatars influences our behavior and brain functions. While the behavioral effects of using avatars for oneself have been extensively investigated, fewer studies have focused on behavioral changes caused by the communication partner’s avatar. Given the gap between the current scientific understanding of avatars and growing commercial applications of avatar-based communication, there is a need for a systematic investigation of how an interaction partner’s avatar affects behavior and brain function, particularly in risk-taking scenarios.
To address this need, Tanaka and Haruno designed a task to examine how risk-taking behaviors and underlying neural computations change when a human communication partner's appearance alternates between an avatar and a real person. Specifically, the participants received dynamic facial-expression feedback from either a human observer presented as an avatar or a real human face based on the outcome (win or no-win) of each gambling trial. A total of 28 individuals participated in the behavioral experiments, and 51 individuals underwent functional magnetic resonance imaging (fMRI) scanning.
The results showed that expecting avatar feedback increased gambling behavior in both behavioral and fMRI settings. The computational model-based analysis revealed that the increased gambling rate in the avatar condition was driven by increased valuation of uncertainty regarding facial-expression feedback. Notably, a negative amygdala response to feedback uncertainty contributed to increased risk-taking behavior in both the avatar and human conditions.
In addition, individual differences in behavioral and neural sensitivity to feedback uncertainty were linked to a personality trait score that reflects emotional consideration for others. Taken together, these findings suggest that the amygdala’s response to feedback uncertainty plays a key role in driving increased risk-taking behavior in the avatar condition and that this function is closely linked to individual differences in interpersonal (emotional) reactivity. According to the authors, the results provide valuable insights into human communications and social interactions using avatars that are becoming increasingly more common in our world.
Coauthor Masahiko Haruno adds, “We found that people tend to take more risks when their partner responds through an avatar rather than showing their real face. This seems to be driven by a change in how they process uncertainty—and interestingly, that change is reflected in the amygdala.”
Coauthor Toshiko Tanaka adds, “Using the same confederate and having them pass as just another participant every time wasn’t easy—it took a lot of effort to keep things feeling real for each new person.”
In your coverage, please use this URL to provide access to the freely available paper in PLOS Biology: https://plos.io/43MGr63
Citation: Tanaka T, Haruno M (2025) Feedback from an avatar facilitates risk-taking by modulating the amygdala response to feedback uncertainty. PLoS Biol 23(4): e3003122. https://doi.org/10.1371/journal.pbio.3003122
Author countries: Japan
Funding: This work was supported by JST Moonshot R&D (JPMJMS2011, https://projectdb.jst.go.jp/grant/JST-PROJECT-20339237/), JST CREST (JPMJCR22P4, https://projectdb.jst.go.jp/grant/JST-PROJECT-22712882/), and KAKENNHI (22H05155, https://kaken.nii.ac.jp/ja/grant/KAKENHI-PLANNED-22H05155/) to MH. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.
Journal
PLOS Biology
Method of Research
Experimental study
Subject of Research
People
COI Statement
Competing interests: The authors have declared that no competing interests exist.