chp 2. Flashcards
Neuroimaging Techniques
– Two techniques are used most often:
set of techniques in which pictures of the brain are taken in various ways to provide understanding of both normal and abnormal congnitity of aging
▪ Structural neuroimaging: provides highly detailed images of anatomical features of the brain
o Includes X-rays, CT, and MRI
▪ Functional neuroimaging: provides an indication of brain
activity
o Includes SPECT, PET, fMRI, and NIRSI
o In general, fMRI is the most commonly used technique.
Neuroscience Perspectives
– Neuropsychological approach
▪ Compares healthy older adults with those with pathological disorders of the brain (ex: damaged frontal lobe->dopamine, healthy adult-> dopamine)
– Neurocorrelational approach
▪ Links measures of cognitive performance to measures of brain structure or functioning(ex:cognitive tests and look at brain activity while doing test
– Activation imaging approach
▪ Links functional brain activity with cognitive behavioral data
▪ Compensatory changes(ex: children use on side of the brain with task, older adults use both sides of the brain.)
• How Is the Brain Organized Structurally?
Brain is made up of
Neurotransmitters travel across the
– Brain is made up of neurons.
• Neurons consist of
-dendrites(antennas to receive signals from other nearby neurons),
-axon- transmits information from the cell body to terminal branches.
-neuro-fibers
and terminal branches-releases chemical neurotransmitters so that Information passes on to other neurons
• Neurotransmitters travel across the synapse-are received by dentures of nest neuron.
Neuroanatomy:
The study of the structure of the brain
Neuronamoty involves the study of the structure of the brain including the
-cereberal cortex-outermost part of the brain consists of two hemispheres left and right
-corpus callous-thick bundle of neurons that connect left and right hemisphere
-prefrontal and frontal cortex-important for executive functions-carry out plans, switch between tasks and maintain attention and focus
-cerebellum-controlls equilibrium and coordination of fine motor movements
-hippocampous-located in the middle of the brain-memory
limbic system-emotion, motivation, long-term memory, balance
amygdala-emotion
• Age-Related Changes in Neurons Neurons Dentrites Axon fibers Proteins Synapses Diseases
– Number of neurons declines – Number and size of dendrites decreases – Tangles develop in axon fibers – Increases in deposits of proteins – Number of synapses decreases – These changes occur in greater numbers in diseases such as Alzheimer’s disease
Age-Related Changes in Neurotransmitters
– Dopamine is associated with higher-level cognitive functioning, so declines are related to poorer:
-working memory-memory for information tasks performed actively
• episodic memory(short-term memory)
• tasks that require higher-level cognitive functioning like inhibiting thoughts, attention, and planning.
– Other neurotransmitters
• Abnormal processing of serotonin has been shown to be related to cognitive decline.
• Damage to structures that use acetylcholine is associated with memory declines.
dopamine
serotonin
acetylcholine
- inhibit thoughts, attention, planning, emotion, movement, pleasure and pain
- memory, mood, appetite, sleep
- arousal, sensory perception, sustaining attention
dopaminergic system
neurons that use dopamine
white matter-
neurons that are converted by Myles that transmit info from one part of the cerebral cortex to another or other parts of the brain
Age-Related Changes in Brain Structures
Shrink
Wmh
Dti
– Considerable shrinkage occurs in the brain
• Especially in prefrontal cortex, hippocampus, and cerebellum
– White matter hyperintensities (WMH)-bright spotty appearance on images
• Indicates myelin loss or neural atrophy
– Diffusion tensor imaging (DTI)
-asses the rate and direction that water diffuses through the white matter
• Provides index of density or structural health of the white matter
What Structural Brain Changes Mean And ToM, executive functioning
– Theory of Mind (ToM) is the ability to understand that others have beliefs, desires, and viewpoints different from our own
• Research shows age-related decline in ToM
– Executive Functioning
• Difficulty focusing solely on relevant information
• Due to WMH and reduced volume of prefrontal cortex
memory and emotion changes
– Memory
• Specific structural changes (e.g., the hippocampus) result in memory decline
– Emotion
• Increased processing of positive emotional information with age but decreasing processing of negative emotional info
• Better emotion regulation with age-want meaningful relationships
-age-related increase in connections
social-emotional cognition and prefrontal cortex change
– Social-Emotional Cognition
• Older adults may rely more on automatic judgment processes than reflective processing.
– Prefrontal Cortex
• The Positivity Effect: Older adults are more motivated to derive emotional meaning from life and to maintain positive feelings than younger adults.-> explains why memory detritus and emotion does not
• The Parieto-Frontal Integration Theory
– Also known as P-FIT
– Proposes that intelligence comes from a distributed and integrated network of neurons in the parietal and frontal areas of the brain
