1. The Brain, Scanning and Sperry

2. Spec check: 4.2.2 Biopsychology
Localisation of function in the brain and hemispheric lateralisation: motor, somatosensory, visual, auditory and language centres; Broca’s and Wernicke’s areas, split brain research. Plasticity and functional recovery of the brain after trauma.

3. Lesson Objectives Recall the key terms already known
Identify the 5 areas of the brain
Describe all 4 brain scanning techniques used within biopsychology
Develop at least 2 strengths of each technique
Develop at least 2 weakness of each technique
Distinguish between the 2 hemispheres and the tasks they complete
Complete an APRC for Sperry’s research
Consider a GRAVE for Sperry’s research

4. SCANNING
PET
Radioactive material (tracer) is injected (s the brain uses glucose as energy), the areas of the brain which are most active absorb it.
Computer produces coloured images of the level of activity occurring throughout the brain.

5. EEG
Based on the assumption that info is processed as electrical activity – action potentials / nerve impulses transmitted along neurons
Electrodes attached to the scalp
A record of the brain wave patterns produced by millions of neurons, producing characteristic patterns

6. ERP’s Similar to EEG but key difference is…
Isolating specific responses of neurons to specific stimuli or tasks
Stimulus presented, picture, … researcher looks for activity related to that stimulus

7. fMRI
Measures brain activity in specific areas by detecting associated changes in blood flow
Based on the idea that when we perform a task, the neurons that are most active will use the most energy
3D map of the brain is produced highlighting different areas that are involved in different neural activities

8. Post Mortem examinations
Correlating behaviours before death with brain structures after death
Study physical brain of an individual who displayed a certain behaviour which could suggest brain damage
Broca is a good example – Tan displayed speech problems – PM highlighted problems with his frontal lobe the specific area known now as Broca’s area

9. How good is a split brain?
SPLIT BRAIN RESEARCH
How good is a split brain?

10. Brains come in two halves…
You can see the brain has two hemispheres, the left and right. They appear, from the outside, to be identical.

11. These halves are normally held together…
By the corpus callosum - communication between the hemisphere is predominately via these pathways.
By the corpus callosum - communication between the hemisphere is predominately via these pathways. Pathways are severed in some patients with severe epilepsy. NOTE: the OPTIC CHIASM is not severed, and the MOTOR CONNECTIONS from the contra-lateral side of the body are also left intact with this procedure. Thus, the left hand is still controlled by the right hemisphere and the right hand by the left hemisphere.
Key term

12. Sometimes this bridge is cut through…
Pathways are severed in some patients with severe epilepsy
Why?
See
Specifically, in split brain patients, it is the corpus callosum which is severed.
For more info :

13. NOTE: the OPTIC CHIASM is not severed, and the MOTOR CONNECTIONS from the contra-lateral side of the body are also left intact with this procedure. Therefore, the left hand is still controlled by the right hemisphere and the right hand by the left hemisphere.

14. So what did he actually do?!
Sperry won the Nobel Prize in Medicine & Physiology in 1981 "for his discoveries concerning the functional specialization of the cerebral hemispheres" as a result of this work.
So what did he actually do?!
Sperry won the Nobel Prize in Medicine & Physiology in 1981 "for his discoveries concerning the functional specialization of the cerebral hemispheres" as a result of this work.

15. severed in a split brain operation).
It is more complex with vision because the fields overlap and information is exchanged over the optic chiasm (not
severed in a split brain operation).
Following a split brain operation, the view of the left visual field is represented only in the right hemisphere and the view of the right visual field is represented only in the left hemisphere.
It is more complex with vision because the fields overlap and information is exchanged over the optic chiasm (not
severed in a split brain operation). Following a split brain operation, the view of the left visual field is represented
only in the right hemisphere and the view of the right visual field is represented only in the left hemisphere.

16. REMEMBER: left hemisphere, responsible for speech
The participant is asked to look at the fixation point in the middle of the screen.
The dollar sign, presented to the left visual field, is passed only to the right hemisphere.
The question mark, presented to the right visual field is passed only to the left hemisphere.
The patient will therefore respond to ‘point with your left hand to what you saw’ by pointing to the ‘dollar sign’ ….
…..but when asked ‘say what you saw’, they will respond by saying ‘a question mark’.
This is because the left hand, controlled by the right hemisphere, is only aware of the dollar sign.
The left hemisphere, responsible for speech, is only aware of the question mark.
REMEMBER: left hemisphere, responsible for speech
The participant is asked to look at the fixation point in the middle of the screen. The dollar sign, presented to the left visual
field, is passed only to the right hemisphere. The question mark, presented to the right visual field is passed only to the left
hemisphere. The patient will therefore respond to ‘point with your left hand to what you saw’ by pointing to the ‘dollar sign’
but when asked ‘say what you saw’, they will respond by saying ‘a question mark’. This is because the left hand, controlled
by the right hemisphere, is only aware of the dollar sign. The left hemisphere, responsible for speech, is only aware of
the question mark.
Have a look at

17. Two different objects are flashed up on either side of the fixation point.
When the participant is asked to find the thing they have seen with his left hand (which he cannot see because it is behind the screen) he feels for and locates the pear.
The image of the pear, presented to the left visual field, has only entered the right hemisphere and this is guiding the left hand.
When, in contrast, the participant is asked to verbally report what he has seen, he says ‘five’.
This is because a number five was presented to the right visual field and is available to the speech areas in the left hemisphere.
Two different objects are flashed up on either side of the fixation point. When the participant is asked to find the thing he
has seen with his left hand (which he cannot see because it is behind the screen) he feels for and locates the pear. The image
of the pear, presented to the left visual field, has only entered the right hemisphere and this is guiding the left hand.
When, in contrast, the participant is asked to verbally report what he has seen, he says ‘five’. This is because a number
five was presented to the right visual field and is thus available to the speech areas in the left hemisphere.
See also websites:

18. An object flashed to one visual field only, pts responds differently depending on the side. If the object is shown to the right visual field it enters the left hemisphere and is reported verbally (eg ‘I see a ball’). The participant cannot however find the object with their left hand because the right hemisphere is unaware of what has been presented.
If the object is shown to the left visual field it enters the right hemisphere and the participant can find the object with their left hand (eg the pencil).
The participant will claim, verbally, to have seen nothing because the left hemisphere is unaware of what has been presented.
When a participant has an object flashed to one visual field only, they respond differently depending on the side. If the object
is shown to the right visual field it enters the left hemisphere and is reported verbally (eg ‘I see a ball’). The participant cannot
however find the object with their left hand because the right hemisphere is unaware of what has been presented. If the object
is shown to the left visual field it enters the right hemisphere and the participant can find the object with their left hand
(eg the pencil). The participant will claim, verbally, to have seen nothing because the left hemisphere is unaware of
what has been presented.
Another illustration can be seen at:

19. Since the images reaching the left and right hemispheres from the two visual fields are independent in split brain patients, like Nicola, they can perform two tasks at once without interference.
They are, in fact, somewhat quicker than normal participants at such responses!
Since the images reaching the left and right hemispheres from the two visual fields are independent in split brain patients
they can perform two tasks at once without interference. They are, in fact, somewhat quicker than normal participants
at such responses!
See

20. So what’s going on?
So what’s going on?
Normally, communication is possible between the left and right hemispheres so both sides of the brain have access to
information about both visual fields and have access to speech. This is because information is transferred across
the corpus callosum.
See also
Normally, communication is possible between the left and right hemispheres so both sides of the brain have access to information about both visual fields and have access to speech. This is because information is transferred across the corpus callosum

21. So, what does all this tell us?
A little about what it’s like to be human – we talk about having a stream of consciousness, but that seems to be composed of two trains of thought that have to be united: the function of the corpus callosum, which integrates our understanding, especially of emotional, spatial, creative and other aspects of our interpretation of the world and combines it with our ability to sequence, to speak and to apply logic.
It allows us to express our grasp of a complex physical and social world.
A little about what it’s like to be human – we talk about having a stream of consciousness, but that seems to be composed
of two trains of thought that have to be united: the function of the corpus callosum, which integrates our understanding,
especially of emotional, spatial, creative and other aspects of our interpretation of the world and combines it with our
ability to sequence, to speak and to apply logic. It allows us to express our grasp of a complex physical and social world.

22. How do the hemispheres differ?
Left hemisphere
Right hemisphere
Speech
Production of speech, comprehension of the literal meaning of speech
Emotional inflections, understanding jokes & humour, sarcasm, emotional content of speech
Auditory System
Sounds related to speech
Non-language environmental sounds (e.g., rain) and music
Emotions
Expressions of happiness
Expressions of anger, fear, disgust; interpreting the emotional expressions of other people
Vision
Details
Spatial processing (eg arranging pieces of a puzzle or drawing a picture)
How information is used
Details, parts, pieces
Overall configuration
What information is used
High spatial frequency: many and frequent visual changes 
Low spatial frequencies: few visual changes 
How do the hemispheres differ?
How do the left and right hemispheres differ?

23. A man who had been trying to quit smoking tried to light up a cigarette and once he got it lit his left hand would grab the cigarette and put it out!

24. A man and his wife were having a discussion that his right brain must not have agreed with.
In order to show its dismay with the topic of conversation, the left arm tried to hit the wife!
The man had to physically wrestle the left arm in order to stop it.

25. After her commisurotomy a woman was oversleeping for work, but her right brain heard her alarm and woke up.
It realized that the left brain was not aware of the alarm and that she, therefore, wasn’t aware of it either.
The left hand (right brain) was so frustrated with the situation and slapped her across the face to wake her up!

26. Where to now?
If you’ve found this interesting, you might enjoy this ‘game’ on the Nobel Prize website!
YouTube for more videos!
In the seminars this week we will explore Nicolas condition in more depth
Also, we need to be able to evaluate this research

27. 4.2.2 Biopsychology
• The divisions of the nervous system: central and peripheral (somatic and autonomic).
• The structure and function of sensory, relay and motor neurons. The process of synaptic transmission, including reference to neurotransmitters, excitation and inhibition.
• The function of the endocrine system: glands and hormones.
• The fight or flight response including the role of adrenaline.
• Localisation of function in the brain and hemispheric lateralisation: motor, somatosensory, visual, auditory and language centres; Broca’s and Wernicke’s areas, split brain research. Plasticity and functional recovery of the brain after trauma.
• Ways of studying the brain: scanning techniques, including functional magnetic resonance imaging (fMRI); electroencephalogram (EEGs) and event-related potentials (ERPs); post-mortem examinations.
• Biological rhythms: circadian, infradian and ultradian and the difference between these rhythms. The effect of endogenous pacemakers and exogenous zeitgebers on the sleep/wake cycle.

28. So, ensure you have notes
I would have an APRC and GRAVE of Sperry
Use your text books to add to todays info
Start reading about plasticity of the brain
Add to your glossary's
Always exam questions to practice as well 