About

Brian Knutson is a Professor of Psychology at Stanford University, holding a Ph.D. in Psychology from Stanford University obtained in 1993. His research focuses on elucidating the neural basis of emotion through affective neuroscience, and exploring its implications for decision-making, neuroeconomics, and psychopathology, specifically neurophenomics. He is a member of several affiliated groups including the Bio-X Faculty, the Institute for Human-Centered Artificial Intelligence (HAI), the Wu Tsai Human Performance Alliance, the Stanford Woods Institute for the Environment, and the Wu Tsai Neurosciences Institute. His lab aims to advance understanding of how emotional processes are represented in the brain and how these processes influence behavior and mental health.

Research topics

• Psychology
• Social psychology
• Social Science
• Sociology
• Economics
• Epistemology
• Cognitive psychology
• Communication

Selected publications

• Females have shorter scalp-to-cortex distances and receive stronger TMS electrical fields: Implications for clinical treatment

  Neuropsychopharmacology · 2025-12-16

  articleOpen access
  PublisherOA PDFDOI

• Effects of intermittent theta burst to the left dorsolateral prefrontal cortex on brain volumes and neurometabolites in people with alcohol use disorder: a preliminary investigation

  Frontiers in Human Neuroscience · 2025-07-22

  articleOpen access

  Background: Randomized, placebo-controlled clinical trials (RCTs) employing repetitive transcranial magnetic stimulation (TMS) in the treatment of alcohol use disorder (AUD) have shown promising results. However, the mechanism(s) by which TMS produces improved outcomes in AUD are not established. The goal of these secondary analyses was to assess for longitudinal changes in brain volumes and neurometabolites in the left dorsolateral prefrontal cortex (DLPFC)-the stimulation site-across two published RCTs evaluating intermittent theta burst (iTBS) as an adjunct treatment for AUD. Materials and methods: = 44) were recruited from a residential treatment program at the VA Palo Alto Health Care System. Participants in this report were in RCTs evaluating the efficacy of iTBS for the treatment of AUD. Across studies, 21 participants were randomized to active iTBS and 23 to sham iTBS (2-3 iTBS active or sham sessions/day), delivered over approximately 2 weeks. Bilateral volumes of the rostral and caudal middle frontal and superior frontal gyri left DLPFC neurometabolites were quantitated pre- and post-iTBS sessions. Results: Over the 2-week assessment interval, significant volume increases were observed, collapsed across groups, in the bilateral rostral and caudal middle frontal and superior frontal gyri, as well as in the left DLPFC choline-containing compounds. No group (active vs. sham) × time (2-week assessment interval) interactions were apparent for any measure. Preliminary simple effect tests for volumes indicated that the active group demonstrated significant increases in the bilateral rostral and caudal middle frontal and superior frontal gyri, while the sham group only showed significantly increased left superior frontal volume. Preliminary simple effect tests for metabolites indicated that the active group had significant increases in left DLPFC choline-containing and creatine-containing compounds, and sham showed no significant metabolite changes. In the active group, a higher number of iTBS pulses delivered at the target treatment level was significantly associated with greater increases in left DLPFC n-acetylaspartate, glutamate, and gamma-aminobutyric acid. Conclusion: This study provided novel preliminary indications that iTBS promoted adaptive structural and neurometabolic changes in the left DLPFC site of stimulation in those with AUD. Replication of these findings in a larger sample and examination of other neuroimaging-based markers of TMS-induced neurobiological changes are critical to informing modifications of existing TMS protocols to maximize durable positive treatment outcomes in those with AUD.

  PublisherOA PDFDOI

• Neuroforecasting reveals generalizable components of choice

  PNAS Nexus · 2025-02-01 · 3 citations

  articleOpen accessSenior author

  Accurate forecasts of population-level behavior critically inform institutional choices and public policy. While neuroforecasting research suggests that measurements of group brain activity can improve forecasting accuracy relative to behavior, less is known about how and when brain activity can effectively improve out-of-sample forecasts. We analyzed neural and behavioral data collected in two experiments to forecast choice in more vs. less demographically representative aggregate internet markets in order to test when forecasts based on brain activity generalize better than behavior. In both experiments, while the accuracy of market forecasts based on behavior varied as a function of sample representativeness, market forecasts based on brain activity remained significant regardless of sample representativeness. These findings are consistent with the notion that brain activity associated with early affective responses can generalize across individuals to index aggregate choice more broadly than downstream behavior. Thus, brain activity from limited samples may reveal generalizable components of choice that can improve market forecasts. These findings inform theory regarding which components of individual choice generalize to improve market forecasts and provide insights into mechanisms that underlie the effective application of neuroforecasting.

  PublisherDOI

• How we stumbled upon the rat play vocalizations: A recollection

  Behavioural Brain Research · 2025-08-07

  articleOpen access1st authorCorresponding

  Over a quarter of a century later, most rodent researchers know that specific types of rat Ultrasonic Vocalizations (USVs) appear to index distinct affective states endowed with arousal, value, and motivational force. Few know the story, however, of how we accidentally stumbled upon 50 kilohertz (50 kHz) USVs in the context of rat play by turning the wrong dial on a bat detector, which I recollect here. The tale of that mistake highlights the critical roles of serendipity, preparation, openness, persistence, and a supportive environment in scientific discovery. • A mistaken misdial revealed that young rats produce 50 kHz USVs while playing. • Reward anticipation increases 50 kHz USVs, which predict approach and are modulated by dopamine. • Researchers now use USVs to index affective states and model psychiatric symptoms in rats. • Hindsight bias notwithstanding, serendipity paired with preparation can promote scientific progress.

  PublisherDOI

• Mapping the cellular etiology of schizophrenia and complex brain phenotypes

  Nature Neuroscience · 2025-01-20 · 43 citations

  articleOpen access

  Psychiatric disorders are multifactorial and effective treatments are lacking. Probable contributing factors to the challenges in therapeutic development include the complexity of the human brain and the high polygenicity of psychiatric disorders. Combining well-powered genome-wide and brain-wide genetics and transcriptomics analyses can deepen our understanding of the etiology of psychiatric disorders. Here, we leverage two landmark resources to infer the cell types involved in the etiology of schizophrenia, other psychiatric disorders and informative comparison of brain phenotypes. We found both cortical and subcortical neuronal associations for schizophrenia, bipolar disorder and depression. These cell types included somatostatin interneurons, excitatory neurons from the retrosplenial cortex and eccentric medium spiny-like neurons from the amygdala. In contrast we found T cell and B cell associations with multiple sclerosis and microglial associations with Alzheimer's disease. We provide a framework for a cell-type-based classification system that can lead to drug repurposing or development opportunities and personalized treatments. This work formalizes a data-driven, cellular and molecular model of complex brain disorders.

  PublisherOA PDFDOI

• Brain activity explains message effectiveness: A mega-analysis of 16 neuroimaging studies

  PNAS Nexus · 2025-10-31 · 4 citations

  articleOpen access

  Persuasive communication in marketing, political, and health domains influences sales, elections, and public health. We present a mega-analysis (a pooled analysis of raw data) of 16 functional MRI datasets (572 participants, 739 messages, and 21,688 experimental trials) assessing the neural correlates of the effectiveness of messages in individual message receivers and at scale (in large groups of message receivers who did not undergo neuroimaging). Existing theories suggest that decision-making is driven by expected rewards and perceived social relevance associated with the expected outcomes of a given choice. Consistent with these theories, we find that (i) brain activity implicated in reward and social processing is associated with message effectiveness in individuals and at scale across diverse domains (e.g. marketing and health campaigns); (ii) exploratory analysis further suggests language, emotion, and sensorimotor processes as pertinent to message effectiveness; and (iii) brain activity provides complementary information on message effectiveness at scale beyond self-reports provided by the same neuroimaging participants. This study offers novel insights into the neurocognitive mechanisms underlying effective messaging, highlights a path toward greater unity and efficiency in persuasion research, and suggests practical intervention targets for message design.

  PublisherDOI

• The impact of affective congruence on charitable giving

  Social Cognitive and Affective Neuroscience · 2025-01-01 · 2 citations

  articleOpen accessSenior author

  Although charitable aid requests often include multiple salient affective features, their interactive effects on donation behavior and the neuropsychological mechanisms underlying their combined influence remain unclear. In four studies, including six behavioral experiments and one Functional Magnetic Resonance Imaging (fMRI) experiment, we examine how the affective congruence of request features influences giving decisions. Across studies, requests with affectively congruent features, regardless of valence, elicited greater donations. The impact of affective congruence was mediated by increased positive aroused affect experienced by donors. Convergently, at the neural level, congruent requests elicited greater activity in the Nucleus Accumbens (NAcc), a brain region associated with positive aroused affect. Increased NAcc activity subsequently predicted donation decisions, bridging responses to stimulus input and behavioral output. These findings suggest that both positive and negatively valenced charitable requests can effectively increase donations if their salient affective features are congruent through neuro-affective mechanisms that support positive aroused affect. These results contribute to a deeper understanding of how affective congruence in charitable appeals engage neural reward systems to drive prosocial behavior. By identifying the NAcc as a bridge from request stimulus to giving behavior, these data illustrate the intersection of emotion, decision-making, and prosociality at both behavioral and neural levels.

  PublisherOA PDFDOI

• Deconstructing neural predictors of risky choice

  PNAS Nexus · 2025-06-18 · 1 citations

  articleOpen accessSenior author

  Abstract To survive and thrive, animals must navigate risk by anticipating and avoiding potential losses while approaching potential gains. Although researchers have leveraged neuroimaging to predict risky choices in humans, consensus on unitary versus distinct underlying neural and psychological mechanisms remains elusive. Across four functional magnetic resonance imaging studies (combined n = 230), we tested univariate and multivariate models predicting trial-by-trial risky gambling choices in an original sample, replicated predictive features in an independent sample, and generalized predictive features to samples playing a different gambling task. Prechoice activity in distinct circuits predicted subsequent risky (i.e. nucleus accumbens [NAcc] and medial prefrontal cortex [MPFC]) versus safe (i.e. anterior insula [AIns]) choices. A triple dissociation analysis distinguished these neural predictors of risky choice from neural activity associated with sensory input and motor output. Prechoice NAcc and MPFC activity was further associated with individuals' preferences for risky choices, while AIns activity was associated with individuals' preferences for safe choices. Finally, prechoice AIns activity in response to risky gambles was associated with lower levels of debt in real life (controlling for demographic, behavioral, and self-report measures). Together, these convergent findings reveal distinct and replicable neural predictors of risky choice, which generalize across analyses, tasks, and individuals.

  PublisherOA PDFDOI

• Negative Affect Circuit Subtypes and Neural, Behavioral, and Affective Responses to MDMA

  JAMA Network Open · 2025-04-30 · 8 citations

  articleOpen access

  Importance: Rapidly acting therapeutics like 3,4-methylenedioxymethamphetamine (MDMA) are promising treatments for disorders such as posttraumatic stress disorder (PTSD). However, understanding who benefits most and the underlying neural mechanisms remains a critical gap. Stratifying individuals by neural circuit profiles could help differentiate neural, behavioral, and affective responses to MDMA, enabling personalized treatment strategies. Objective: To investigate whether baseline stratification of individuals based on negative affect circuit profiles, particularly in response to nonconscious threat stimuli, can differentiate acute responses to MDMA. Design, Setting, and Participants: This randomized clinical trial, implementing a double-blinded, within-participant, placebo- and baseline-controlled design, was conducted at Stanford University School of Medicine between November 2, 2021, and November 9, 2022, for wave 1 data collection. Participants had used MDMA on at least 2 prior occasions, but not in the past 6 months, and had subthreshold PTSD symptoms and early life trauma but no current psychiatric disorders. Data were analyzed from March 1, 2023, to January 1, 2024. Interventions: Participants completed 4 visits: 1 baseline session followed by 1 placebo session and 2 MDMA sessions in a randomized order, totaling 64 visits. Baseline functional magnetic resonance imaging (fMRI) assessed the negative affect circuit using a nonconscious threat processing task (NTN). Main Outcomes and Measures: Primary outcomes included activity and connectivity of amygdala and subgenual anterior cingulate cortex (sgACC) defining the negative affect circuit. Secondary outcomes were behavioral measures of implicit threat bias, likability of threat expressions, and affective assessments. Results: Sixteen participants (10 [63%] female; mean [SD] age, 40.8 [7.6] years) were stratified into subgroups with high and low levels of NTN activity in the amygdala (NTNA+ [n = 8] and NTNA- [n = 8], respectively), based on a median split of baseline nonconscious threat-evoked fMRI responses. Following administration of the 120 mg of MDMA vs placebo, the NTNA+ subgroup showed significant reductions in amygdala (contrast estimate [CE], -1.43; 95% CI, -2.60 to -0.27; Cohen d, -1.22; P = .02) and sgACC activity (CE, -1.48; 95% CI, -2.42 to -0.54; Cohen d, -1.56; P = .004), increased sgACC-amygdala connectivity (CE, 0.65; 95% CI, 0.02-1.28; Cohen d, 1.02; P = .04), and increased likability of threat expressions (CE, 14.38; 95% CI, 1.46-27.29; Cohen d, 0.86; P = .03) compared with the NTNA- subgroup. Conclusions and Relevance: In this randomized clinical trial of MDMA's acute profiles, 120 mg of MDMA acutely normalized negative affect circuit reactivity in participants stratified by heightened amygdala reactivity at baseline, demonstrating the potential of neuroimaging to identify prospective biomarkers and guide personalized MDMA-based therapies. Trial Registration: ClinicalTrials.gov Identifier: NCT04060108.

  PublisherOA PDFDOI

• News source bias and sentiment on social media

  PLoS ONE · 2024-10-23 · 8 citations

  articleOpen access1st authorCorresponding

  As social media becomes a key channel for news consumption and sharing, proliferating partisan and mainstream news sources must increasingly compete for users' attention. While affective qualities of news content may promote engagement, it is not clear whether news source bias influences affective content production or virality, or whether any differences have changed over time. We analyzed the sentiment of ~30 million posts (on twitter.com) from 182 U.S. news sources that ranged from extreme left to right bias over the course of a decade (2011-2020). Biased news sources (on both left and right) produced more high arousal negative affective content than balanced sources. High arousal negative content also increased reposting for biased versus balanced sources. The combination of increased prevalence and virality for high arousal negative affective content was not evident for other types of affective content. Over a decade, the virality of high arousal negative affective content also increased, particularly in balanced news sources, and in posts about politics. Together, these findings reveal that high arousal negative affective content may promote the spread of news from biased sources, and conversely imply that sentiment analysis tools might help social media users to counteract these trends.

  PublisherDOI

Recent grants

• Anticipatory Affect and Financial Risk Taking

  NSF · $415k · 2008–2013

• NIH Grant R21AG030778

  NIH · $493k · 2011

• NIH Grant R03MH066923

  NIH · $77k · 2005

• NIH Grant R03DA020615

  NIH · $234k · 2007

Frequent coauthors

• Claudia B. Padula

  Stanford University

  73 shared

• Kiosses

  Scripps Research Institute

  72 shared

• Steinman

  University of California, San Diego

  72 shared

• Burkart

  Scripps Research Institute

  72 shared

• Gandhi

  VA Palo Alto Health Care System

  72 shared

• Yuri A. Blednov

  The University of Texas at Austin

  72 shared

• Bajo

  Scripps Research Institute

  72 shared

• Pahng

  Scripps Research Institute

  72 shared

Education

• Ph.D., Psychology

  Stanford University

  1993

• B.A. / B.A., Psychology / Comparative Religion

  Trinity University

  1989

Awards & honors

• Glushko Prize for Excellence in Undergraduate Research in Sy…
• Barwise Award for Distinguished Contributions to Symbolic Sy…
• Stanford Honors Thesis Prizes - Symbolic Systems
• Symbolic Systems Distinguished Teaching Award