Lecture 3 Flashcards
Joe LeDoux
Joe LeDoux & his team published many influential studies on fear learning and fear circuits in rodents (he’s famous for his studies on the amygdala). More recently he has stopped using the word ‘fear’ or ‘emotion’ to describe his findings with non-human animals. He now talks about “survival behaviors” and “survival circuits”. It was a conscious deicision to avoid the usual sloppiness in how scientists use the term “emotion”.
Questions to ask about emotions
- What do emotions do?
- What causes emotions?
- What is caused by emotions?
These questions try to help define emotion in terms of its functions. We need to be intentional in the way we define emotion.
Emotions are functional states
Emotions are states of the brain (in that they can be implemented in the brain). But if we define emotions literally by their brain state, we need different definitions for humans, flies, octopus because they have completely different nervous systems. Emotion is a functional state but it’s still separable from the brain states associated with the emotion. A more abstract definition can be more useful and broadly applicable.
How to define emotions functionnally?
We need a functional account of emotions that defines emotions in terms of the stimuli that cause the brain state and the behaviours, etc., that are caused by the brain state. Functional definitions identify states by their causal relations (i.e. what does it do?) NOT by how they are constituted (i.e. what is it made of?). Functional definitions describe causal effects in an abstract manner that is independent of the physical way that that the state is implemented. Functional definitions are generalizable
How to define a clock?
“A device that measures time”. By defining a clock by its function (measuring time) we have a definition that is broadly applicable to a category. The definition we use influences how we categorize and differentiate things. Is a broken clock a clock? Is a computer clock (on which you can’t directly read the time, but makes your computer indicate the time) a clock?
Functional definition of mental states
We can define mental states in terms of their causal relations to inputs and outputs
* Emotions are functional states that are caused by sensory inputs and cause behavioural outputs
* Emotions can also be caused by and cause changes in other mental states (e.g. memory, perception, attention etc.)
Architecture for emotions as functional states (Fan-in, fan-out structure)
Stimuli influence the central emotional state, which influences:
- Observed behavior (not always conscious)
- Subjective reports (always conscious)
- Psychophysiology
- Cognitive changes
- Somatic responses
Context and volitional control both have a moderating effect on the emotional state and the resulting behavior. This architecture provides foundation for neuroscientific research
Generalization (in the architecture for emotions as functional states)
A single emotional state can be elicited by many stimuli, and can elicit many different behaviors. Stimuli and behavior are indirect evidence of the emotional state. Stimuli can be external and/or internal: behavior can become a stimulus that influences the emotional state.
The role of context in emotions
Context has a moderating effect on emotions. It can influence the stimuli we encounter and the effects of thos stimuli. This is proof of that emotion is not a reflex: a reflex will stay the same across contexts.
Volitional control of emotion
Volitional control can inhibit emotion. We can influence our own emotional response. Volitional control can intervene in several different places/times of the process. It is conscious by nature, but there could also be some unconscious influences on emotional states.
Architecture for emotions as functional states: example of fear research
Scientists will use a frightening stimulus (ex. a spider), and see the resulting processes (fear, survival behavior, etc.). Context is important: seeing a spider in an insectarium and in a bed will elicit different emotional states. Other cognitive states can also influence emotional states - for example knowing that the spider is harmless. Finally, volitional control can happen: you can try to control your fear response, and overcome the feeling of fear itself.
What does an emotion “do”? What is its function?
We can also have a functional account in evolutionary terms that explains why an emotion is adaptive and what purpose it served in the evolutionary environment. Anything that evolved via natural selection is selected based on its functional effect for an organism in its given environment. The adpative functions of emotions may not be immediately clear. Ultimately, we need a fucntional explanation of emotion at the level of the entire organism and how it interacts with its environment
The use of functional definitions
Functional definitions of emotion states are useful because they can generalizet, theoretically (e.g. to different animals, to robots). However, it is an empirical question whether emotions can be embodied in all brains or even in systems that are not brains is an empirical question. It may turn out that there are limits on the kinds of systems that can instantiate emotion, even once emotion is more fully understood. We don’t know the answer to this yet.
Type identity
When you experience an instance of emotion e.g. joy, this corresponds to a pattern of brain activity and this is different from the pattern of activity when you experience another emotion e.g. fear
Questions about type identity (ex. of fear)
- Is the brain activity when you feel fear today the same as when you experienced fear last week?
- Is it the same as when your friend experiences fear?
- Is it similar to when your cat experiences fear?
- How similar at the neurobiological level are different instances of fear?
- How can we measure this similarity?
