Decision Making and the Brain Flashcards
Understanding what influences our decisions and the neural mechanisms behind it
What is a Decision?
A decision is a deliberate process that results in the commitment to a categorical proposition/ committing to one or the other.
We make decisions small or big all the time in our daily lives.
- what to say, where, when will i eat breakfast, go to uni, what will i do after uni etc
The impact of subjective value and emotions may effect decisions.
Why decision making?
Our decisions can balance certainties against risks. They can balance short-term gratification against long-term benefits.
They can be right or not quite.
What are the different kinds of decision making?
Perceptual decision making and Higher cognitive decision making.
The impact of subjective value and emotions may effect decisions.
How can decision making be studied?
At different levels, ranging from simple perceptual decisions, to complex and emotive value-based decisions.
Investigating decision-making in the context of simple sensory-motor tasks has the advantage that motor output can be accurately measured during the course of precise manipulation of sensory input, and while activity in the brain is recorded.
I.E. investigating it by producing a stimuli and record motor-output behaviour
What is a perceptual decision?
It emphasises the role of sensory information in directing behaviour.
A perceptual decision is a decision-making process based on interpreting sensory information. It involves choosing between different options or actions by analyzing and understanding what you see, hear, or feel. For example, deciding whether a light is red or green at a traffic signal or identifying a distant object as a bird or a plane are examples of perceptual decisions.
eg: Signal detection theory:
Asks and measures how well can the patient detect the signal: in this case, there’s a blurred picture of a face, and of a house.
- we’re trying to get a peak/high point of clarity in the decision to reduce noise. we try to make the signal clearer/ tighten the signal.
- we compute visual, auditory, taste, sensory info etc etc in our experiences. We detect these signals and workout whats good or bad.
What is a simple explanation of perceptual decision making and how can we become good at it?
- Gather more evidence to separate one perceptual signal from another
- Reduce the noise (the variability) interfering with the spread (how much can fluctuate or vary) of signal
- Exposure and learning lots of perceptual characteristics through our experiences is best
- However, all this gathered info may still be inaccurate technologically
What are reward expectations?
This translates to the expected value of the outcome, which helps guide the decisions we make.
i.e Expected Value Theory is a form of subjective value
- where what you’re expected to gain must be multiplied by the probability of receiving that gain/ i.e what is valuable to us influences our decision
This choice is also influenced by risk and loss aversion.
Explain subjective value
Our own subjective ideas of value/ desirability that influence our decision-making.
eg: economic choice
Which pair of shoes will we choose? Which cake? How many pieces? 2, but if you’ve already had a piece then you probably wouldn’t care for another.
Which variables come in-between decision making?
- Physiological Factors
-Emotional Factors
-Survival Factors
-Risk Factors
-Expected Value Factors
-Peer-pressure Factors - Cultural Factors
How does reward value change over time? And which areas of the brain are involved?
- There is a study with animals and humans where the Orbitofrontal Cortex (OFC) lesions impair tasks in which the value of objects change, as well as tasks, in which the value of rewards associated with objects change.
So, when this part of the brain is damaged, we can have problems with:
- Making decisions about value: Difficulty in evaluating and deciding the worth or benefit of different options.
- Instrumental extinction (a particular task): Trouble with learning that a previously rewarded behavior is no longer reinforced, leading to challenges in stopping that behavior.
- Object rehearsal learning: Problems with remembering and practicing how to use or interact with objects.
- Reinforcer devaluation: Difficulty in adjusting behaviors when a previously rewarding outcome is no longer desirable or valuable.
Reinforcer devaluation decision making in monkeys encompassed what?
They are presented with 2 images via a touch screen - they learn to associate one with a reward. peanuts or m&ms.
They normally discriminate correctly after 10-15 days or 60 pairs, with 90% accuracy.
Next, the images associated with peanuts or m&ms are paired side and side and the monkey must choose its preference. Before the testing, one of those rewards is fed until satiety.
The correct score in this experiment is when the monkey chooses the reward that they aren’t satiated with.
- Control/normal monkeys are good at this.
- Monkeys with Orbitofrontal cortex (OFC) lesions aren’t - they struggle to decide their next move as they can’t make sense of the previous lessons.
- Magnocellular Mediodorsal Leison also impairs this task
How do Risk and Emotions also guide the decisions that we make? (basics)
Reward or outcome value and probabilities of outcome are crucial, as well as the subjective level or risk.
eg: gambling decisions may depend on how rich you are or if your wife will divorce you when spending over a certain amount
- Our brain deciding these things can be based on :
- levels of education
- access to socio-economic status
- our friends/ family
These things that shape us have created some type of level of risk that influences our decision making.
We don’t always make rational decisions: due to the framing effect and heuristics (mental shortcuts)
Explain the influence of risk in decision-making through the framing effect. How does this effect the brain?
- The framing effect is the context and phrasing of a problem that can influence a person’s choice.
- For risks, the idea that ‘looses loom larger than gains’ is important for decisions involving risks. This is tricky because many decisions involve an element of risk/ uncertainty.
- There are two main frames, a gain frame and a loss frame.
- A study looked at how our brain reacts when you’re interpreting a gain or loss frame.
- Participants who were most susceptible to the framing effect/ i.e, who chose the loss frame despite the examples being the same, showed heightened activity in the Orbitofrontal Cortex (OFC)
- This shows that emotional biases can influence decision making
Explain the influence of Emotion on Decision-making through the Somatic Marker Theory. How does this effect the brain?
The Somatic Marker Theory:
is an emotional mechanism, based on bodily states, that can generate feelings that rapidly signal the prospective consequence of actions, AND SO, can influence or bias decision making./
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- This theory suggests that our body’s physical reactions to emotions can help us quickly understand the potential outcomes of our actions. These bodily feelings influence our decisions by giving us a “gut feeling” about what might happen.
- When we make emotional decisions we have bodily changes going on - making an influence
- heart rate, increased breathing, goose bumps, irritation
EXPERIMENT:
- a card game/ gambling.
- they measured peoples risky choices when the players realised they may have a good/bad deck
- found that bad decks elicited stress
BRAIN DAMAGE:
- people with Ventromedial Pre-frontal Cortex (PFC) damage has different responses in the sae experiment
- they couldn’t recognise whether they had a good/bad deck,
I.E. no representation of Value.
Do network structures throughout the brain work together to optimise decision making processes?
YA
