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