Emotions : A Neuro-Psychological Introduction Sumitava Mukherjee [email_address]
Scope of this presentation What is IN? Brief idea on what is emotion Gross functional level neuroscience of emotions Peek into theorizations about emotions and what is meant by ‘Feeling’ an emotion What is NOT IN ? Cellular level explorations of specific (emotional) stimulus Philosophical arguments related to feelings and emotions Computational approches to emotional processing (Called Emotional/Affective Computing) Evolutionary psychological perspectives on emotions
WHAT IS emotions ? Emotions(or emotional systems) are distinct, integrated psychophysiological response systems … An emotion contains three differentiable response systems: (1) a prototypic form of expression (typically facial), (2) a pattern of consistent autonomic changes, and (3) a distinct subjective feeling state -- Watson and Clark (1994) A state in which a monitoring mechanism acquires a tendency (i.e. a disposition, possibly suppressed) to abort, redirect, or modulate some other process or collection of processes. --- Aaron Sloman A mental state that arises spontaneously rather than through conscious effort and is often accompanied by physiological changes; a feeling: the emotions of joy, sorrow, reverence, hate, and love. -- Thesaurus
Wetting our hands in emotional research .. We need uniformity to study emotions-- so, researchers suggest 2 approaches.. We have a few BASIC emotions > * Happiness * Anger * Sadness * Fear * Surprise * Disgust (From the study of universality of facial expressions-) Ekman&Friesen (1971) <ul><li>Dimensions of Emotions > </li></ul><ul><li>Not discrete states but reactions that vary along a continuum- Emotional reactions (to stimuli and events) can be characterized by VALENCE (Good/Bad) and AROUSAL (how much) </li></ul><ul><li>Characterize by the actions / goals they motivate (drive) – Approach ? OR Withdraw ? </li></ul>
How can we STUDY emotions ? We need to MANIPULATE and MEASURE emotions.. Techniques to elicit emotions >> Mood induction Presentation of emotionally evocative stimuli Reward and Punishment Techniques to measure emotions >> Self report – Direct assessment Indirect Assessment Choose among possible actions Facilitation and Inhibition of a response Psycho-physiological variables
zeroing on the structures..responsible for Emotional processing Friedrich Goltz (1890) – If animals were decerebrate (diencephalon removed) they were unemotional. Papez (1937) – Limbic lobe forms the anatomical basis for emotions [Cortex mostly ignored] Kluver-Bucy syndrome (1939) – Bilateral removal of amygdala and inferior temporal cortex [Tameness and loss of fear, sexual polarity change, orality..] Voo..Hoo.. GOTCHA ?? !! ?? Prefrontal and paralimbic lesions – non human primates > Orbitofrontal lesions -> Socially withdrawn, no fear (attack unknown males) Frontal lesions + Anterior temporal lesions -> abandon facial expressions (visual association cortex seem to have no effect) Amygdalectomy > Does not respond to species specific aversive stimuli any more Disconnecting amygdala from temporal lobe = Problem to perceive [Superior temporal sulcus needed for motion preception-- body language]
The LIMBIC System is suggested to be the primary region in our brain that is responsible for emotional processing along with the Orbitofrontal cortex Limbic System : recap STRUCTURAL POSITIONS
As an integral part of the limbic system. Also, executive control needed to suppress inappropriate unconscious priming Anterior thalamic nuclei: These nuclei are thought to play a role in the modulation of alertness and are involved in learning and memory. Hypothalamus : Many functions including production of hormones for sexual and emotional behavior.. Hippocampus: Integration, Memory, Space Limbic System : recap FUNCTIONS AMYGDALA * Send info to hypothalamus (sympathetic nervous sys) *to the thalamic reticular nucleus for increased attention (relay) * to the nuclei of the trigeminal nerve and facial nerve for facial expressions
An interconnection of the structures that forms the basis for Emotional processing Brain circuit for emotion – contemporary view Fig source : Fundamentals of NeuroPsychology; Kolb, Wishaw; p.527
Schematic of brain circuit for emotions Contemporary view – Schematic circuit
Emotion and Cognition Started from the days of Aristotle – Emotion (sensitive soul) | Cognition (rational soul) Robert Zajonc (Stanford) ~ Affective judgments occur before and independently of cog. Lazarus (Berkeley) ~ emotional response depends on the reason we believe. Work in Neuroscience of Emotions has provided a benefit – Specialized systems (like Amygdala) that respond early -( ? Zajonc ) But these specialized systems interact with other ‘more cognitive’ systems (?Lazarus). SO, Emotion is both interdependent and dependent on Cognition! EMOTIONAL DECISION MAKING-Online Reinforcement evaluation (Edmund Rolls,Oxford) As we interact with the environment, reinforcement properties of a stimulus (or potential output from environment) change. This online and rapid ability to evaluate the reinforcement properties of a stimuli --> ORBITOFRONTAL CORTEX!!
Recent View- Shows Cognitive-Emotional Interactions Mostly from studies by Le Doux(2001) and others on stress/fear employed classical conditioning experiments Block level emotion circuit (recent view) showing Emotion-Cognition Interconnections Where is the Brain Stem ?
FEELING emotions EVENT (Environmental/internal) BRAIN [Feedback produces FEELING of emotion] BEHAVIOR AUTONOMIC RESPONSE ENDOCRINE RESPONSE MUSCLES AUTONOMIC NERVOUS SYSTEM ENDOCRINE SYSTEM James – Lange theory of feeling emotions Emotions are experienced DIRECTLY, INTERNALLY and physiological manifestations are secondary??
FEELING emotions : More recent work <ul><li>Damasio – Somatic marker hypothesis </li></ul><ul><li>Key features... </li></ul><ul><li>Emotion fundamental to survival </li></ul><ul><li>Emotions engage those Neural structures that represent the changes in the body (somatic markers) and those neural structures link the perception to the somatic states. </li></ul><ul><li>Neural control of emotions includes.. </li></ul><ul><li>Limbic system and prefrontal cortex </li></ul><ul><li>Somatosensory cortex and basal ganglia </li></ul><ul><li>Emotions necessary to make rational decisions </li></ul>Need to find : Neural underpinnings of social emotions like jealousy
Few Current ongoing work on Emotions <ul><li>The Cognition and Brain Sciences Unit, University of Cambridge </li></ul><ul><li>The representation, elicitation, maintenance and control of emotion in healthy individuals </li></ul><ul><li>How emotion relates to attention, memory and executive function </li></ul><ul><li>Affective sciences, Swiss national center of competence in Research </li></ul><ul><li>Cross cultural emotion research , emotions offer an interesting perspective for studying culture. </li></ul><ul><li>Computational Emotion Group , University of Southern California </li></ul><ul><li>Studies the processes underlying behavior that people interpret as emotional: </li></ul><ul><li>what is the information processing that underlies this behavior </li></ul><ul><li>how is it physically and mentally manifested </li></ul><ul><li>what features of this behavior drives an observers interpretation </li></ul><ul><li>Cognition and affect project, Aaron Sloman , University of Birmingham </li></ul><ul><li>Edmund Rolls , Oxford center for computational Neuroscience, University of Oxford </li></ul><ul><li>How cognitive states can modulate emotions , and in turn, how emotions can influence cognitive states. It considers the role of sexual selection in the evolution of affective behavior. </li></ul>
Wrap Up.. How can we define and go ahead to study emotions.. What are the brain circuits for emotions.. Emotion- Cognition interactions.. Some idea about studies by Zajonc, Lazarus, Rolls, James-Lange, Damasio Thanks :) ??Queries ??