Adulthood and Aging

CHAPTER TWONeuroscience as a Basis for Adult Development and Aging12 of 23Neuroscience Toolsallow for the study of age related pathologies: AlzheimersParkinsons

Magnetic resonance imaging (MRI) provides static snapshots of the brain

2Neuroscience ToolsFunctional magnetic resonance imaging (fMRI) fMRI monitors blood flow in the brain concurrent with behavioral performance.

3The Nervous SystemNeurons: cells that send and receive messagesDendrites receive messagesCell body keeps the cell alive and decides when to send messageAxon sends messageTerminal buttons release chemical messengers into gapNeurotransmitters are the chemical messengers that allow neurons to communicateSynapse is the space between neurons

4Healthy Neurons& Unhealthy neurons5 of 23

Structural Changes in NeuronsPlasticityNeurofibrillary tanglesAmyloid plaquesBoth considered characteristics of Alzheimers diseaseChanges in communication between the neuronsParkinsons disease

The Nervous System

6Methodological PerspectivesNeuropsychological PerspectiveCompares healthy older adults with those with pathological disorders of the brain

7Methodological PerspectivesCorrelational PerspectiveLinks measures of cognitive performance to measures of brain structure or functioning

89 of 23Methodological PerspectivesActivation imagingLinks functional brain activity with cognitive behavior data

9Anatomy of the Human BrainExecutive functionsAbility to make and carry out plansSwitch between tasksMaintain attention and focus

Brain structures involved:Prefrontal cortexHippocampusCerebellum

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Age-Related Changes in the Structure of the BrainThinning and shrinkage in volume and density are linked to:Lower cognitive test scoresPoor performance of executive functionMemory declineDecline in speed of processing

White matter hyperintensities (WMH)Indicate myelin loss or neural atrophy

1112 of 23Age-Related Changes in Neurochemical PropertiesThe dopaminergic system is associated with:higherlevel cognitive functioning Inhibiting thoughtsAttentionPlanning a decline in functioning as one ages normallyResearch has found a decline in cognitive tasks that involve more effort:Episodic memorySpeed tasksworking memory

12Functional Consequences of Brain DeteriorationAnterior cingulate cortex (ACC) Affiliated with the prefrontal cortex and is also involved in executive controlAs one ages, this area tends to deteriorate, affecting tasks involving working memory

13Compensation and Prefrontal BilateralityWhen presented with similar tasks:younger adults exhibit unilateral activity in left prefrontal regionolder adults exhibit bilateral activity (both left and right prefrontal areas)Perhaps the aging brain makes compensatory changes

1415 of 23Neural Plasticity and the Aging BrainPlasticity involves the interaction between the brain and the environment and is mostly used to describe the effects of experience on the structures and function of the neural system.Neural stem cells (which give rise to new neurons) persist in adult brains and can generate new cells throughout adulthood.Environmental enrichment Experiments with aging mice showed an increase in number of newly generated neurons after sessions in complicated mazes.

1516 of 23Neuroscience and Cognitive AgingDifferent regions of the brain do not deteriorate evenly. Prefrontal area is more prone to decay than, for example, the amygdala (involved in emotional processing).

16Emotional Processing and the BrainInformation with high emotional significanceis more likely to be remembered than information that is emotionally neutral for both older and young adults.Negative high-arousal information is:automatic in naturelinked to activation of the amygdala interacting with the hippocampusNegative low-arousal information:more activation of the prefrontal cortex-hippocampus network is necessaryIf the amygdala is damaged, arousing stimuli are not attended to.

1718 of 23Aging and Emotional ProcessingYounger and older adults process positive and negative information differently.Positivity Effect: Older adults are more motivated to derive emotional meaning from life and to maintain a positive affect.As a result, older adults pay more attention to and remember positive information.Younger adults tend to pay more attention to and remember negative information.

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