Emotional experience

1. Emotional experience December 1, 2004

2. Emotional experience - introduction • Subjective experience – not perception or expression • ‘Qualia’ • Consciousness • On-line nature of consciousness • Language • Symbolic versus sub-symbolic processing • Experience / consciousness and control of action

3. LeDoux’s approach • LeDoux reduces the problem of understanding emotional experience into the more general problem of understanding consciousness • LeDoux’s solution is to treat emotions as involving unconscious processes that sometimes give rise to conscious content. • In other words, a subjective emotional experience occurs when we become aware/conscious that an emotion system in the brain is active. • So, all we have to do is figure out what the neural systems are responsible for consciousness.

4. Working memory and consciousness • Kihlstrom suggested that what we are aware of at any instant reflects the content of our working memory. • Combined with the suggestion (from James) that the hallmark of consciousness is self-reference • Not ‘thoughts and feelings exist’, • but rather: ‘I think’, and ‘I feel’

5. Working memory • Short-term memory storage (e.g., Miller’s 7 +/- 2 items). • The psychological construct of working memory involves more than just the temporary storage of information, but also manipulation of information (e.g. digit span backwards from the WAIS-III). • Baddeley’s model of working memory involved a ‘central executive’ and two ‘slave systems’ (phonological loop and visuospatial scratchpad).

6. Brain mechanisms of working memory • Working memory is most likely localized to the dorsolateral prefrontal cortex • Early investigations by Jacobsen (1930s). • Based on the work of Fuster, Goldman-Rakic, Petrides • Cells in the prefrontal cortex become active during the delay while performing delayed matching to sample tasks. • Cells in the ‘what’ and ‘where’ pathways also show sustained firing during delay periods (Goldman-Rakic; Desimone) • Reciprocal interactions with prefrontal sites.

7. Working memory & the frontal lobes • The frontal lobes support a diversity of higher cognitive abilities: • Examples: Abstraction, foresight, problem solving, ethical behaviour, attention, affect, self-awareness, modulation of reinforcement contingencies, initiation and control of behaviour. • Other areas of the frontal lobes are thought to play a role in working memory: Orbitofrontal cortex and anterior cingulate.

8. LeDoux’s theory of emotional experience • Emotional experience involves the convergence of several types of information in working memory: • stimulus representations from short term buffers • information from long term memory • non-specific cortical arousal • emotional representations from the amygdala • information about somatic state / arousal

9. Sensory buffers, internal representation • Cortical regions specialized for processing of sensory information have feedback loops (recursion) • Provide temporary storage for incoming sensory information. • Allows perceptual representations to be maintained • Representations can be updated on the basis of new stimulus information that arrives (bottom-up influences) • Influence of contextual information from higher processing centres (top-down influences)

10. Arousal systems of the brain • There are at least five arousal systems in the brain that project diffusely to the cerebral cortex and have an activating effect. • Most are localized in the brainstem and use different neurotransmitters, but one is particularly important for emotion (because it has connections with the amygdala) • is localized in the in the nucleus basalis (and uses acetylcholine). • Arousal causes cells in the cortex and thalamic regions to become more sensitive to input. • Thus, arousal helps ‘lock you in’ to the emotional state that you are in. Significance?

11. Symbolic and sub-symbolic processing • Working memory is a limited capacity serial processor that creates and manipulates representations in a high-level symbolic form (e.g., language) • Working memory / consciousness receives the results of computations from sub-symbolic processors that operate in codes that are undecipherable to consciousness • Integrates the output from these various specialized processors in high-level symbolic form • Emotional representations represent the output from the amygdala to working memory.

12. Result: Emotional experience • Result: an affectively charged conscious experience about the personal significance of an object • Can happen centrally, without peripheral contribution • However, peripheral feedback probably contributes: • A ‘second chance’ when central processing fails to generate such an experience. • For example, if stimulus representations do not reach working memory then feedback via NTS to the amygdala may ‘boost’ activity to send an affective representation to working memory.

13. Relationship to other phenomena • Zajonc’s mere exposure effect • Damasio’s theory and results from gambling task • Cognitive labeling versus appraisal theories • Damasio’s somatic marker hypothesis • Oatley and Johnson-Laird’s communicative theory

14. Rolls and emotional experience • Two levels of consciousness (reflexive): • A basic level at which stimulus representations and their motivational significance are processed • A higher level of processing at which syntactic and semantic elements of the first stage can be manipulated for goal-directed behaviour • Correction of erroneous associations generated by level one

15. Reflexive consciousness • This is a basic tenet of many theories of consciousness • Existential philosophers of the 1950s (e.g., Sartre) • Consciousness involves the awareness of processing that occurs at a more basic level of complexity. • According to Rolls, qualia are a natural consequence of this process.

16. Emotional experience: Why? • Now that we have some idea about how subjective emotional experiences are derived, we need to speculate about its function • Consciousness as a complex symbol manipulating system. Natural language. • Control over sub-symbolic processing. • Connections from the cortex to the amygdala are becoming more extensive throughout the course of evolution.