Lecture 9 - Neuroscience of intelligence

Question 1

What are the 4 ways to measure the brain?

Answer 1

1. MRI
   - looks at brain structure + the different type of brain tissue a person has
   - can indicate how healthy brain tissue is
2. FMRI
   - looks at brain function
   - measures blood flow changes during mental tasks
3. EEG
   - measures electrical activity at rest/ in response to stimuli
4. MEG methods
   - measures magnetic energy from electrical activity of the brain

Question 2

What do more intelligent brains look like - Ritchie et al?

Answer 2

• 672 people
• 15 cognitive tests
• g score calculated
• used MRI scans
• brain measurements and correlation with g:
  -> total brain volume, c = 0.31
  -> brain white matter integrity, c = 0.24
  -> brain cortical thickness, c = 0.24
  -> brain white matter intensities, c = -0.20

Question 3

Higher intelligence scores tend to go with having…

Answer 3

• Larger whole brain volume
• Thicker grey matter on surface of brain
• Healthier white matter connections overall
• Fewer white matter scars causing ‘leakage’
• A larger brain overall
• Possibly greater numbers of nerve cells

Question 4

Goriounova et al?

Answer 4

• Wanted to test if smarter brains are equipped with faster and larger brain cells
• Studied 46 people who needed surgery for brain tumours or epilepsy
• Each took an IQ test before the operation
• Provided biological cellular evidence that individuals with a higher IQ possess larger/more complex dendrites and are able to sustain faster action potentials

Question 5

Neurons and intelligence?

Answer 5

• IQ scores positively correlate with cortical thickness of the temporal lobe
• average total length and no. of dendritic branches in pyramidal cells (associated with advanced cognitive functions) correlates with IQ scores
• higher IQ scores are accompanied by faster action potentials = help process information quickly and efficiently

Question 6

What part of the brain is important for fluid intelligence?

Answer 6

• widely accepted theory that working memory is crucial for fluid intelligence
• Gray et al found that p’s scoring higher on Raven’s Matrices tests (fluid intelligence) were more accurate in a challenging working memory task where the left PFC was heavily engaged

Question 7

Are smarter brains more connected than others - Seidlitz 2018?

Answer 7

• built a map showing how well connected the ‘hubs’ were
• hubs = high number of pyramidal neurons that can simultaneously capture multi dimension info during higher cognitive functions
• found that highly connected hubs identified in left frontal and temporal cortex were predictive of a higher IQ score