the mellow years?: neural basis of improving emotional stability over age williams et al. (2006)...
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The Mellow Years?: Neural Basis of Improving Emotional Stability
over Age
Williams et al. (2006)
Amir Shams Tabrizi
IntroductionBehavioral studies have reported that
emotional functions improve with age:- Less negativity- Easing of emotional intensity- Reduction in trait neuroticism
Older adults show a shift in the ratio of positive-to-negative emotion - in the experience, memory, and recognition
of negative emotion- for positive emotion
Why? Possibilities
- Environmental effects, i.e. retirement
- Motivational priorities change with age: ‘knowledge acquisition finding emotional satisfaction’
Purpose of StudyWe know how behavior changes, but how
exactly does the brain change?
How does brain function/activity change over the lifespan with respect to emotional processing?
Regions of Interest
Medial Prefrontal Cortex implicated in governing emotional functions
+
Sub cortical circuits associated with emotional processing
Materials & MethodsParticipants:
242 healthy individualsDivided into 4 age bands:
Teens (12-19)Young (20-29) Middle (30-49)Older (50-79)
Materials & Methods
Behavioral task
- Blocks of 8 facial expressions representing:fear (negative emotion) happy (positive) neutral
- Brain activity recorded using FMRI + ERP
Materials & Methods
FMRIN = 80Regions of Interest:
- Medial Prefrontal cortex- Amygdala- Basal ganglia
Functional maps constructed for activated voxels
within each ROI for contrasts between ‘fear vs.
neutral’ and ‘happiness vs. neutral’
Variables
Independent Variable: age
Dependent Variable: ROI activation
Results
Increasing age = decrease in MPFC response to happiness, but increase in MPFC responses to fear- Brain has to work harder to register fear
Happy Fear
Results
Linear + significant decline of neuroticism over 12-79 years of age
Older = less accurately recognize fear and more accurately recognize happiness
No significant differences in Amygdala + Basal Ganglia activation due to age - 20-29 years = greatest activation for fear and
happiness
DiscussionHow?
Step 1 - as age increases, the following things happen:
Life experiences accumulateMotivational goals changeBecome aware of mortalityDesire to maximize meaningfulness of eventsChose quality over quantity
So this causes greater selectivity in perception of positive emotions
Step 2 selectivity for positive emotions in life
experiences = selectivity for positive emotions in the underlying medial prefrontal systems- MPFC learns (neural plasticity) from experience
Result = better emotional well being
Implications
Emotional brain function is one of the few things that improve with age. So it provides a platform to intervene other cognitive impairments
Strengths & Limitations
- N = 242- Wide spectrum of lifespan (12-79 years)- Brilliant methods section- Very very detailed and well written
- Repetitive results and discussion- Integration of FMRI, RPE, MRI data made
discussion very hard to understand