Intelligence Flashcards
What is the relationship between intelligence and heritability?
There is evidence that intelligence is has a heritability rate of 50% that varies across lifespan being lowest in childhood (20%) and highest in adulthood (80%).
What is the neural resources theory?
The neural resources theory suggests that performance and neural activity are positively linearly correlated. This means that different subjects have different neural resources ( = possibility of activation of a certain brain region). The higher amount of available resources, the stronger the brain activity the more items you can remember before saturation.
What is the neural efficiency theory?
The neural efficiency theory states that better performance is negatively correlated with less extended brain activation. This is because this theory bases his interpretation of intelligence on neural efficiency. Different subjects have different resources but some can activate them more efficiently. Therefore less resource consumption is required for more efficient individuals
what is the problem with neural efficiency theories?
These theories can be biased by training effects and different strategies that the participants can used to fulfil the task.
What is the WAIS IV scale and how does it measures intelligence?
WAIS IV scale is a full-scale IQ measurement. It measures with subscales both verbal and non-verbal capacities
What is not taken into account by WAIS IV scale?
The fact that different abilities contaminates and are mixed in different tasks is not taken into account. Therefore the labels of the subscales could be misleading.
What did lesion mapping of WAIS indexes show?
Comparisons across lesioned and non lesioned voxels of patients who underwent a stroke.
- There was a significant overlap of regions active across subtests in the verbal comprehension tasks. Similar brain regions were active during different subtests.
- There was no overlap for subtests of processing speed (non-verbal tasks) suggesting that the processes of the different subscales of this index are parts of a non-unitary process.
What is the evidence about peripheral nerve conduction speed and intelligence?
Positive correlation between nerve conduction velocity higher and faster processing of information ( = lower RT) has been showed.
However some replications of the initial study did not confirm this correlation.
What is g-factor according to Spearman?
G-factor is supposed to be a common component of high performance in different tasks that should define what intelligence is. This is used to explain why subjects that show high performance in one kind of task normally show high performance also in different other kinds of tasks.
What is the most common way to behaviourally measure G-factor?
Raven matrices are the most used tool to investigate g-factor.
Is there evidence of different between males and females intelligence?
Although females have 10% less brain volume than males there is no evidence of different levels of intelligence.
Which regions seem to be most predictive of the g-factor?
Duncan et al study (2000) showed that lPFC (lateral pre-frontal cortex) in the highest predictor of good performance in complex tasks. As lPFC is a crucial brain region for working memory it has been suggested that performance in WM tasks is the best predictor of g-factor.
What is the relationship between cortical thickness and g factor (full-scale intelligence)?
The relationship between cortical thickness and general intelligence is based on a different dynamic (pattern) of cortical development in high-performing and average-performing subjects.
high performing subjects:
- thinner PFC at earlier stages (4-8 y)
- rapid increase in cortical thickening
- after peak (at 13 y) rapid thinning
average performing subjects:
- either steady but slow decline in thickness or short initial increase
Is there a correlation between general brain volume and IQ?
Luders et al study (2009) only found a very weak correlation between grey matter (= general brain volume) and IQ.
What is the general ability index and when is it used?
It assess performance based just on verbal and non-verbal abilities cutting out specific WM exercises. It is mostly used in medical contexts.
