Theme 1_lecture 2webversion

7/28/2019 Theme 1_lecture 2webversion

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Outline

1. Bits of the brain revisited2. Three types of patient (again)

3. The emotional brain

4. The intelligent brain


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Last week: I showed you howpatients with brain damage

can reveal amazingly

specific types of disorders.

Often those disorders

follow damage to very

specific brain bits.

Lets review three examples


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Prosopagnosia difficulties in recognising

familiar faces

follows damage to occipito-temporal cortex

(including the fusiform face area)

Recent evidence that this malfunctions in

many individuals with autism.


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Neglect failure to attend to the contralateral

side of space

typically follows damage to the parietal lobe,

especially the parietal lobe on the right


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Clive Wearings dense anterograde amnesia

Wilson, B.A., Baddeley, A.D., & Kapur, N. (1995). Dense amnesia in a

professional musician following herpes simplex virus encephalitis. Journal of

Clinical and Experimental Neuropsychology, 17, 668-681.

normal Clives brain


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Amnesia follows damage to medial temporal

lobes


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The limbic system: plays roles in learning, memory and

emotion.

Closely tied with bits of the frontal lobes, including olfactory

cortex (and therefore with smell!)


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So these examples show how the ability to recognise

faces, remember new things and attend to all sides of

the world depend on particular brain regions

We also mentioned deficits in planning after lesions to the

frontal lobes

Is planning a good example of the sort of things we human

beings are very good at?

Is planning an example of how we are very smart or

intelligent?


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Where does intelligence live?

What is the most likely brain region that contains intelligence?

1. The occipital lobes (we are very visual)

2. The temporal lobes (consciousness and memory?)3. The frontal lobes (planning, staying organised?)

4. Unlikely that intelligence can be localised to one single

brain region


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In the mid 20th century, surgeons starting cutting off the frontal lobes

from the rest of the brain to control behaviour in some difficult

patients with psychiatric problems.

From Watts and Freeman (1944). Intelligence following prefrontal

lobotomy in obsessive tension states. Journal of Neurosurgery, 1, 291-

296.


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The received wisdom at that time was that frontal lobotomydidnt have any effects on how patients performed on

tests of intelligenceindicating it is probably not the

frontal lobes (at least not by themselves)


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Ref.: A. K. Barbey et al., An integrative architecture for general intelligence

and executive function revealed by lesion mapping, Brain: A Journal of

Neurology, 2012

We found that general intelligence depends on a remarkably

circumscribed neural system,

Areas are primarily Left prefrontal cortex, L parietal cortex

and L temporal cortex and the tracts that connect them.

Yellow = Executive

Red = General

intelligence

Orange = commonareas

In brain-damaged

patients


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Intelligence relies not on one brain area, but

involves specific areas working together in a

co-ordinated fashion

In fact the particular regions and connectionswe found indicates that intelligence depends

on the ability of the brain to integrate

information from verbal, visual, spatial andexecutive processes

Barbey 2012


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Right side

CreativeVisual

Artistic

Music

Imagination

Left side

LogicalLanguage

Speech

Science

Writing

Lateralization of brain function??

Much less considered now.

Neuroplasticity suggests much less fixed.


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Whom of these four do you consider the most intelligent?

a. Einstein b. Sherlock Holmes

c. Marie Curie d. Katie Price (a.k.a. Jordan)

What do we mean by intelligence?


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Fluid intelligence---the kind of cognitive skills that dont depend on

overlearned knowledge, e.g. Problem solving in new situations,

flexibility, creativity

Fluid Intelligence is the ability to reason quickly and to think

abstractly.

Interestingly, evidence that it is enhanced by physical activity

in children.


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People tend to differ in crystallised intelligence for

all kinds of reasons, including schooling, diet,

nationality etc.

Some evidence that fluid intelligence might be at

least partially inherited.

Without question as a species we have loads of

fluid intelligence: we have so much of it we

even generate fluid intelligence tests!


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One of our biggest challenges is

being BORN!


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Human beings have big heads

Those big heads contain big

brains


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Big brains must be related to INTELLIGENCE?

Language, perception etc. depend on different

regions of your brain

We seem to have quite large brains, even

compared with our closest relatives,

chimpanzees, gorillas and orangutangs

(In fact, if we keep on evolving)


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Is the human brain really special??

Certainly very different from early mammals


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And it isnt the biggest either

..human brain ~ 1300 g

elephant ~ 5,000 g

sperm whale ~ 8,500 g

The structure of our brain is not all

that different from other mammals

Bottlenosed dolphin

Adult human


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Are our brains that big?


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One bit of the brain, the frontal

cortex, has been associated with

high level executive functions like

planning, task switching, and

behavioral control.


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Do we have more frontal cortex than other species?

Maybe 12% more, if you

compare humans with other

great apes

Semendeferi et al. (2002)

Passingham (2002)

Similar story for prefrontal cortex (the very front part) andprefrontal white matter Holloway (2002); Sherwood et al.

(2005).

White matter important because indicates greater

connectivity.


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Einsteins brain

1. Was it bigger? (The Lancet, 1999)

NO.

2. In fact his cerebral cortex was a bit thin Maybe he had

more neurons in his thin cortex


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Einsteins brain

No...but he had more

glial cells!

Er no, he didnt

have more glial

cellsBut the arms of

the glial cells

were longer

than a sample

of 4 people


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It was, without doubt, one of the finest

minds of all time. Now scientists have

proved that Albert Einstein's brain was

not only unique in its ability to process

concepts: it was also physically

different.

New research comparing the

characteristics of Einstein's brain with

that of four men of similar age has

found remarkable structural differences.

Parts of his brain were found to be

larger than those of the others, and he

also appeared to have had more brain

cells, scientists have found previously.

The brain of the great mathematician

and physicist, who died at the age of 76

in 1955, has long fascinated researchers,

not least because while Einstein's body

was cremated, his brain was saved for

scientific study.

The brain has now been found to possess

a greater number of glial cells for each

neurone, suggesting that Einstein's brain

needed and used more energy.

As a result it may have generated more

processing ability. The job of glial cells is

to provide support and protection for

neurones.

The density of neurones in Einstein's

brain is greater, too, and the cerebral

cortex is thinner than the brains to which

it was compared.

Einstein's brain also has an unusual

pattern of grooves in an area thought to be

involved in mathematical skills. It was 15

per cent wider than the other brains,

suggesting that the combined effect of the

differences may be better connections

between nerve cells involved in mathe-

matical abilities.

The latest research, due to be published

this week, was conducted by scientists in

the United States and Argentina.

"Einstein's astrocytic processes showed

larger sizes and higher numbers of in-

terlaminar terminal masses," say the

researchers.

Exactly what effects these differences

could have is not clear, and the re-

The researchers also suggest that the

structure of Einstein's brain may not have

been unique, and that other people may

have something similar, but never get the

chance to use it.

Perhaps individuals with 'special' brains

and minds are more frequent than sus-

pected. The y just may go unnoticed due to

socio-cul-tural conditions or their early

potential being cancelled following

exposure to unwanted health or child-

rearing hazards during gestation and early

childhood, or lack of an adequate child-

raising environment," say the researchers.

And there's hope us all. The researchers say

that the brain structure shouldn't be seen as

a marker of intelligence in isolation. "In a

species with a heavily socially moulded

brain and mind, such as humans, the full

expression of an individual special aptitude

depends on multiple genetic and

environmental factors."

Inside Einsteins brainOf course it was bigger than yours. But nowwe can show it was a different shape, too

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