Hot Thought: Mechanisms of Emotional Cognition Paul Thagard pthagard@uwaterloo.ca 1 Thanks to: • Tom Ward and Lisa Neal • Collaborators: – – – – – – Chris Eliasmith Fred Kroon Abninder Litt Baljinder Sahdra Cameron Shelley Brandon Wagar, and others. • Natural Sciences and Engineering Council of Canada 2 Outline 1. 2. 3. 4. 5. 6. 7. Emotional cognition Mechanisms Cognitive model Social model Neural models Integrations Conclusions 3 Individual Decisions 4 Decision Making is Emotional • • • • • Slovic et al: Affect heuristic. Loewenstein et al: Risk as feelings. Damasio: Somatic markers. Mellers: Emotion-based choice. Etc. 5 Emotion in Science • 1953 DNA • 1968 Watson publishes The Double Helix • 143 pages • 235 emotion words 6 Watson’s Emotions 70 60 50 40 30 20 10 0 er g n A ty u a Be ar e F ss e in p ap H e p o H In st e r te S ss e n d a r u S se i pr s r e th O 7 Emotions in Scientific Thinking interest curiosity wonder Generate questions avoid boredom happiness hope Try to answer questions fear anger frustration happiness surprise beauty happiness Generate answers Evaluate answers worry disappointment 8 Emotion in Law • 1994: Nicole Brown Simpson and Ron Goldman murdered. • 1995: O. J. Simpson found not guilty. • 1996: civil trial finds O. J. guilty. • Acquittal result of emotional coherence. 9 Mechanistic Explanations Mechanism Parts Relations Changes Social people associate, communicate influence, decisions Cognitive mental implications, representations associations mental processes Neural neurons excitation, inhibition activations, synaptic Molecular proteins physical connections chemical reactions 10 Cognitive Mechanism: HOTCO • Beliefs and goals are represented by nodes in a connectionist network. • Nodes have activations representing degree of acceptance, but also valences representing emotional value. • Activations and valences spread through the network until a stable conclusion is reached. 11 Why O.J. Was Acquitted Solid lines are excitatory links; dotted lines are inhibitory. 12 Applications of HOTCO • OJ • Experiment by Sinclair & Kunda on motivated stereotypes. • Experiments by Westen et al. on motivated inference in politics. • For details see Thagard in Cognition and Emotion, 2003. 13 Social Mechanism: HOTCO 3 • Group decisions are sometimes based on emotional consensus. • Consensus arises in part from emotional communication: – – – – – Contagion (includes attachment) Altruism (includes compassion) Means-ends Empathy Analogy 14 HOTCO 3 • Individuals are HOTCO 2 processes. • Emotional communication takes place by transfer of emotions between individuals. • Consensus sometimes reached: – Couple deciding on movie. – Academic department hiring decision. • Thagard and Kroon, Mind and Society, forthcoming. 15 Neural Mechanism • GAGE model: Wagar & Thagard, Psychological Review, 2004. • Brain areas: amygdala, hippocampus, nucleus accumbens, ventromedial prefrontal cortex. VMPFC Amg Somatic state HC VTA To Action/ Overt NAc 16 Applications of GAGE • Phineas Gage. • Behavior of Damasio’s patients with VMPFC damage on the Iowa gambling task. • Effects of context on emotion in Schacter & Singer. 17 Relation of GAGE and HOTCO • GAGE is more neurologically realistic: – Spiking neurons. – Anatomically organized. • But HOTCO can be viewed as an approximation to GAGE: – Units encoded by neuronal groups. – Activations encoded by spiking behavior of groups of neurons. – Valences encoded by spiking in emotional brain areas such as the amygdala. 18 New Neural Model • Litt, Eliasmith, and Thagard: “Why Losses Loom Larger than Gains”, in progress. • Uses Neural Engineering framework. • Models loss aversion in decision making. • Adds more brain areas relevant to emotional cognition. • Future applications: – other neuroeconomics applications. – social cognitive neuroscience. 19 DLPFC AMYG 5-HTRD VS DAmid OFC ACC Abbreviations: 5-HTRD, raphe dorsalis serotonergic neurons; ACC, anterior cingulate cortex; AMYG, amygdala; DAmid, midbrain dopaminergic neurons; DLPFC, dorsolateral prefrontal cortex; OFC, orbitofrontal cortex; VS, ventral striatum. 20 Molecular Mechanisms • • • • • Happiness: dopamine. Sadness: serotonin. Fear: cortisol. Love: oxytocin, vasopressin. Thagard: “How molecules matter to mental computation”, Philosophy of Science, 2002. • Lower level mechanisms? - no. See Litt et al., “Is the brain a quantum computer?”, Cognitive Science, forthcoming. 21 Research Strategy • Develop models of mechanisms at all relevant levels. • Integrate models by relating – parts: decompose from higher to lower. – relations: decompose if possible. – changes: show how higher changes result in part from lower changes, but go in other direction too. • Full reduction is rarely possible: pluralistic reductionism. 22 Normative Philosophical Issues • HOTCO explains motivated inference. • GAGE models explains weakness of will. • Normative claim: Rationality requires removal of emotion from cognition. But: – Removal is neurologically impossible. – Not desirable: lose motivation for science, etc. • Need other strategies for ensuring that emotion influences cognition positively. – Informed intuition; social constraints. 23 Conclusions 1. 2. 3. 4. 5. Cognition is emotional. Mechanisms operate at four levels: social, cognitive, neural, molecular. Mechanisms can be integrated and evaluated. Web: cogsci.uwaterloo.ca Book: Hot Thought, MIT Press, 2006. 24