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Social Lecture 9 Flashcards
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- 1The Self II: Optimism and the human brain- 85% ranked self in top 50th percentile for leadership.
- 25% rated themselves as getting along with others in 1st percentile.
- 93% ranked self in top 50th percentile for driving ability.
Isn't possible - most people cannot be better than 'most people' - 2Define: Optimism biasThe difference between a person's expectation and the outcome that follows. If expectations are better than reality, the bias is optimistic.
There is evidence of differing optimism bias across a range of age groups and it's also prevalent in race and socioeconomic status. - 3What we want to find:If neurobiology adds additional support for the view that we have an unrealistically optimistic view of ourselves.
How the brain may play a part in mediating OB.
Why we continue to show UO even when reality tells us we are mad to do so!
Possible role of dopamine in enhancing OB. - 4Sharot et al (2007)Wanted to see if: brain studies shed light on how we think about future positive and negative events.
Do optimists and pessimists show different patterns of brain activity when imagining such events?
If so -what does this mean? - 5Sharot et al (2007) - method.Used an fMRI scanner. Asked pps to imagine future positive or negative events. There are limitations to fMRI - can't talk when inside scanner so pps were asked to press button when started thinking of event, and press again when memory had formed. Also asked pps to fill in LOT-R ( Life Orientation Test-Revised) which measures trait optimism.
The researchers measured things such as how emotionally arousing and vivid it was. - 6Sharot et al (2007) - findingsFuture positive events rated as more positive than future negative ones, and were imagined to be closer in temporal proximity than future negative ones.
Negative future events less strongly experienced than positive future events.
The more optimistic pps were (LOT-R score) more likely to expect positive stuff to happen to them sooner than negative events, and to experience them more strongly. - 7Sharot et al (2007) - fMRI findingsSeveral regions of interest (ROI's) were identified. These were: rostral anterior cingulate cortex (rACC), ventral medial prefrontal cortex, posterior cingulate cortex, dorsal medial prefrontal corex - *important bit* - these play key role in retrieval of autobiographical memory and imagining future events and amygdala is important for emotions in autobiographical memory.
- 8Sharot et al (2007) - what they wanted to see nextDo changes in any of these areas correlate with LOT-R scores? (do more optimistic people's brains show different patterns of activation?)
Some evidence of a relationship between LOT-R scores and rACC (but not others)
Correlation between rACC and amygdala activity when imagining future positive events (weaker for neg events).
However these are all correlational and don't determine causality. - 9Sharot et al (2007) - what does this mean?We can't do much about the past, but we can flexibly interpret the future. Specifically, evidence that we can distance ourselves from negative events and move closer towards positive ones.
Especially so for those higher in trait optimism. - 10Possible mechanism underlying optimism bias.Reduced BOLD signal observed in the amygdala and rACC during imagination of negative future events (in comparison to positive ones) - suggesting that the optimism bias may be related to reduction in negative future thought.
BOLD is what fMRI measures, and depressed people have reduced activity in rACC, suggesting link between optimism bias and mental well-being. - 11SpeculationsrACC activity when thinking of future events suggests self-regulatory focus that underpins bias in attention and vigilance towards positive events and away from negative ones.
Possible link with mechanisms underlying depression (do depressed person imagine future differently? Does brain activity show this?) - 12Sharot et al (2011)Combined learning procedure with fMRI.
fMRI data obtained while pps estimated likelihood of experiencing adverse life events.
After each trial told average probability of individual experiencing that event.
Allowed researchers to see how much pps adjusted beliefs following new info. - 13Sharot et al (2011): findings.Selective updating: pps learned to greater extent from info offering a chance to adopt more optimistic expectations than from info that challenged their rosy outlook.
Overall: more likely to update beliefs when average probability of experiencing negative event was lower than their own probability - found in 79% of pps. - 14Sharot et al (2011): criticismsWas it down to weighting desirable info more strongly in memory? (no- equal memory for pos and neg items)
Was it down to differences in emotional arousal? (no)
Was it down to differences in underlying base rates of events? (no) - 15Sharot et al (2011): conclusionBehavioural findings suggest a likely computational principle that mediates unrealistic optimism. Specifically, this indicates that estimation errors provide a learning signal whose impact depends on whether new information calls for an update in an optimistic or pessimistic direction.
In the brain:
Looked at brain activity when desirable (probability less likely than thought) and undesirable (probability more likely) updates were provided.
Brain activity was greater when probability was more desirable than estimates- even more so for those scoring high on LOT-R. - 16SummaryFindings show mechanistic account of how unrealistic optimism persists in face of challenging information. Optimism was related to decreased coding of undesirable future info, in the frontal cortex - this area has also been found to be sensitive to negative estimation errors. Pps with high scores on trait optimism were worse at tracking undesirable errors in this region than those with low scores (Sharot et al, 2011).
- 17Dopamine - Sharot et al (2012)Thought enhancing dopamine function would influence how healthy individuals process info about probabilities of future events, increasing OB.
- 18Dopamine - Sharot et al (2012): methosDouble-blind placebo-controlled intervention study.
Tested on 2 days, one week apart - in 1 pps got L-DOPA, and other placebo.
Similar life events task at each time.
And then told average probability of experiencing them.
Assessed if they used this info to update estimates (memory test).
Also tested other neuromodulator used to treat depression (citalopram, SSRI) to see if it worked in the same way. - 19Dopamine - Sharot et al (2012): findingsEnhancing pps dopamine function increased optimistic prediction bias.
Not much effect from citalopram.
Also found different behavioural updating for dopamine pps - L-DOPA impaired updating in response to undesirable info about future. - 20Dopamine - Sharot et al (2012): conclusionsHave found a tendency to incorporate undesirable info into our predictions for the future, is associated with increase dopamine levels. This leads to an underestimation of the likelihood of neg events, a fundamental characteristic of UO.
Implication for treatment of depressed individuals? -wider reading
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- Flashcards on Social Lecture 9 Flashcards, created by Hanna Bourne on 19/11/2016.
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