Lauren Y. Atlas

Research

When we hear a friend or film critic give rave reviews to a new release, we plug our ears, fearing disappointment if the movie fails to live up to expectations. Sometimes we even actively lower our expectations, hoping to be pleasantly surprised later on. But are these the best strategies? Positive expectations can also be profoundly beneficial. In the well-known placebo effect, simply believing in a treatment can lead to changes in the body that mimic the effects of real medications. This phenomenon isn't just limited to expectations about good things - in the "nocebo effect", expecting negative events like side effects causes symptoms to actually worsen. So what determines whether expectations help or hurt us? Do expectations change how we make decisions about our environment, or do they actually change the world we perceive?

To address these questions, I study how expectations affect the human brain, and how the brain in turn shapes our conscious experiences. In my experients, people learn that different arbitrary cues like tones or shapes predict different levels of pain or emotion. This conditioning approach causes people to develop expectations about emotional events simply on the basis of the arbitrary stimulus that preceded it. I also study expectations about treatments by having people experience either real treatments like morphine, or fake treatments like placebo creams or pills. After expectations are firm, I use fMRI to identify the brain regions that respond to expectations, and I test whether brain and behavioral responses to pain and emotion differ as a function of manipulated expectations. Finally, I take advantage of advanced fMRI analysis approaches (e.g. whole-brain multi-level mediation analysis) to isolate the brain mechanisms that give rise to expectancy effects on subjective experience. I take a multi-modal approach to the study of expectancy effects on affective experience, combining fMRI with other methodologies, including psychophysiology, pharmacological interventions, and TMS.

This approach is promising because it can help us determine whether expectations truly change perception and experience, or whether expectations simply influence judgment and decision-making. While I have focused thus far on expectancy effects on pain, future projects will extend this work to other affective domains, and build a stronger picture of the general mechanisms underlying expectancy effects on affective processing. This, in turn, has strong translational implications, allowing us to understand the extent to which clinical outcomes depend on patient beliefs, and building a platform with which to test whether expectancy-based processing is altered in specific affective disorders.

Representative Publications

Atlas, L.Y., Bolger, N., Lindquist, M.A., and Wager, T.D. (2010). Brain mediators of predictive cue effects on perceived pain.  The Journal of Neuroscience 30(39), 12964-12977.[Link to paper]. Additional information.

Atlas, L.Y., Bolger, N., Lindquist, M., & Wager, T.D. (2009). Amygdala activity predicts expectancy effects on pain-processing regions.The Neuroscience of Emotion: From Reaction to Regulation.  Boston, MA, June, 2009.

Atlas, L.Y., Davidson, M., Dahl, K., Lindquist, M., & Wager, T.D. (2008).  Tracing pain pathways from stimulus to report. CNS, San Francisco, CA. April, 2008.

Atlas, L.Y., Wager, T.D., Dahl, K., and Smith, E.E. (In Press). “Placebo Effects” in Handbook of Neuroscience for Behavioral Psychologists. Eds. John T. Cacioppo and Gary Berntson.