Cognitive Function and Exercise Flashcards
What percent of total energy does the brain consume at rest
20%
What percent of cardiac output goes to the brain at rest
15%
The developing brain
- Increases 4x in size from birth (95% of adult size at age 6)
- Consumes 50% of body’s energy at rest
- Receives 50% of total cardiac output at rest
- Fully developed by 3rd decade of life (early-mid 20s)
Aspects of brain plasticity
Neurogenesis, synaptogenesis and angiogenesis
Neurogenesis
Growth of new neurons
Synaptogenesis
Creation and strengthening of connections between neurons
Angiogenesis
Growth of new blood vessels to support brain tissue
Def: Cognitive function
The process whereby an individual is able to perceive recognize or understand thoughts and ideas
What processes are included in cognitive function
- Organizing and planning
- Problem solving
- Recognition and memory
- reaction time
What is included in global cognition
Fluid and crystallized cognition
Fluid cognition
- Working memory
- Processing speed
- Learning and decision making
- Attention
- Flexible thinking, task switching
- Visual spatial memeory
Crystallized Cognition
- Language abilities
- Verbal intellect
- reading abilities
- semantic knowledge
How is cognition measured
- Measure specific domains (attention, working memory etc) or global neurocognitive function
- Some approaches use motor tasks to assess cognition
Issues with measuring cognition
- Learning effects
- Language abilities
- Hearing and visual abilities
- Comparisons between tasks
Commonly used cognitive tests
- Montreal cognitive Assessment
- Eriksen Flanker task
- Stroop test
- Trail making test
- Digit-symbol substitution test
Montreal Cognition Assessment
- Screening tool for cognitive impairment
- Visuospatial Abilities
- Language abilities
- memory and delayed recall
- Executive function
Score of test gives cut off for normal> mild cognitive impairment> dementia
Eriksen Flanker Test
Inhibitory control, selective attention, processing speed
- State direction middle arrow points
- Could be congruent condition (all same way), incongruent (other arrows are in opposite way) or neutral (other shapes aren’t arrows)
Stroop Test
- Selective attention, processing speed
- reading is a very automatic process
- must suppress the automatic drive to read word and instead say the color of the ink
Trail Making Test
- Task-switching, visual search, processing speed
- Version A - connect numbers in sequence as fast as possible
- Version B - connect number-letter-number in sequences as fast as possible
- time to completion
Digit-Symbol Substitution Test
- Working memory, attention, visual search abilities, processing speed
- Match symbols to their appropriate number as fast as you can
- # correct in 90 seconds
fMRI
- Measures blood oxygen level dependent response to cognitive testing
- Surrogate for brain activity
- Excellent spatial resolution but cannot measure rapid responses (poor temporal)
Electroencephalography (EEG)
- Measure electrical activity of brain cells in response to cognitive challenges
- Excellent temporal resolution, cannot determine where the brain activity is happening (poor Spatial)
What impacts cognitive function
- Genetics
- In utero exposure
- early-life experiences
- social economic status
- Parental education
- Environmental factors
- daily behaviours
What daily behaviours impact cognitive function
- Diet
- Physical Activity
- Sleep
- Sedentary behaviour
- Drugs
Physical activity and the Developing Brain
Children with higher physical fitness have better cognitive function
- Memory
- Attention
- Self-control
- Decision-making abilities
Kids with higher perform better academically and have larger brain volume (hippocampus - memory, learning and decision making)
Aerobic activity and brain tissue loss in aging humans
Higher cardiorespiratory fitness associated with less brain tissue loss in older adults
Exercise and neurological disease study
- 1700 older adults reported activity time in past month
- divided into genetic risk for alzheimer’s (homo vs heterozygous)
- Measured cognitive function
- Homozygous = increased risk of alzheimer’s
Exercise training and cognition
Following exercise intervention;
- Improved cognition in multiple domains compared to control
- aerobic combined with strength-training or flexibility superior to aerobic alone
Physical Activity and ADHD
Acute exercise in children with ADHD immediate improvements in selective attention and increased brain activity during cognitive tests
- significant improvement on standardized tests post-exercise
HIT and attention
- 20 on 10 off tabata, 4 intervals per exercise, 1 minute rest
RESULTS - Faster processing speed following HIIE trial
- Fewer errors following HIIE trial
- Greater speed and accuracy on measures of selective attention following HIIE
Resistance Training and functional plasticity of the aging brain
- 1 year resistance training: 1 or 2 x week
- Both groups say improvement in cognitive function, selective attention and conflict resolution
- group 2 increase brain activity during flanker task, increased brain resources
Does order of combined training matter for cognitive improvement
- 2 single conditions: PE (30 min Mod), COG (30 min computer training program)
- 2 Combination conditions: PE+COG, COG+PE
- Exercise + cognitive training improved cognition regardless of order
- Exercise alone sowed the lowest improvement
