Introduction to Brain and Behaviour Flashcards
What is behavioural neuroscience?
the scientific study of how brain activity influences behaviour.
Give features of Cognitive Neuroscience
- relates to the study of the neural basis of behaviour
- It bridges the gap between biological sciences and psychology and psychiatry
- Psychologists have been investigating the details of mental processes without knowing what parts of the brain are involved
- Understanding the neural basis of a mental process can help distinguish between different theories relating to how that process is performed
What is mental representation?
the sense in which properties of the outside world (e.g. colours, objects) are copied/ simulated by cognition
What is Neural representation?
the way in which properties of the outside world manifest themselves in the neural signal (e.g. different spiking rates for different stimuli)
Who thought mental experiences arose in the heart and who thought they arose in the brain?
- Heart: Aristotle
- Brain: Plato
What is the MIND-BRAIN problem?
How can a physical (brain/body) give rise to mental experience?
What is Dualism and who came up with it?
mind (eternal) and body (mortal) are separate substances – Renie Descartes
What was Renie Descartes theory about how the mind controls the muscles?
He thought the ‘soul’ (the mind) control the movements of the muscles through its influence on the pineal body
The eyes send visual information to the brain, where it could be examined by the soul. When the soul decided to act, it would tilt the pineal body, which would divert the pressurized fluid (which we now know as CSF) through nerves to the appropriate muscles. And this would make the muscles moves.
What did Luigi Galvani do?
18th century Italian physiologist found electrical stimulation of frog’s nerve caused contraction of attached muscle
Ability of muscle to contract and ability of nerve to send a message to muscle were characteristics of the tissues themselves
Brain did not inflate muscles by directing pressurized fluid/air through the nerve (balloonist theory)
Galvani’s experiment proved Descartes wrong and prompted others to study nature of message transmitted by nerve and the means by which muscles contracted
The results of these efforts gave rise to the physiology of behaviour
What is the Dual-aspect theory?
mind and body are two levels of explanation of the same thing (e.g. photons: wave-particle duality)
What is reductionism?
mind eventually explained solely in terms of physical/ biological theory
What do most psychologists deal with and what is this?
Most psychologists deal with generalization – type of scientific explanation; a general conclusion based on many observations of similar phenomena
What do most physiologists deal with and what is this?
Most physiologists deal with reduction – complex phenomena (behaviour) explained in terms of simpler ones
Who was behavioural neuroscience written by?
Written by psychologists who combined experimental methods of psychology with those of physiology
What is the split brain surgery?
For patients with frequent and violent epileptic seizures, surgically splitting the corpus callosum was the only relief
Corpus callosum is a bundle of nerve fibres which connect the right and left cerebral hemispheres
Information can no longer be shared between the two hemispheres
What is distinctive about the right and left side of the brain?
- The right side of the brain controls limbs on the left half of the body
- The left side of the brain controls limbs on the right half of the body
- There is a region of overlap of two visual fields with both halves of the brain
Why does the stimulus need to be presented for 150ms or less when studying split brain patients?
Once the callosum is completely sectioned, information can not be shared between the two hemispheres
However, eye movements can cause loss of lateralization – therefore the stimulus needed to be presented for 150ms or less (faster than the eye can move from central fixation to the stimulus)
What can you use to ensure the stimuli is presented for less than 150ms?
A brief tachistoscopic presentation
What was Roger Sperry and Michael Gazzangia’s first experiment and conclusion?
Procedure:
The split-brain subject fixates on the dot in the centre of the screen while an image is projected to the left or right visual field. He is asked to identify verbally what he sees
If the spoon is presented to the right visual field, the subject verbally answers ‘spoon’
If the spoon is presented to the left visual field the subject verbally answers ‘I see nothing’
Conclusion:
When the left hemisphere, which can speak, sees the spoon in the right visual field, the subject responds correctly. When the right hemisphere, which cannot speaks sees the spoon in the left visual field, the subject does not respond
What was Roger Sperry and Michael Gazzangia’s second experiment on split brain patients?
When the patient is asked to use his left hand to pick out the object shown on the screen to the left visual field (right hemisphere)
The subject chooses the spoon with his left hand because the right hemisphere sees the spoon and control s the left hand – but the right hemisphere is mute and so can’t speak.
What does Anterior/Rostral mean?
Front
What does Posterior/ Caudal mean?
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