Marriage of cognitive psychology and neuroscience
Goal= discover the brain mechanisms that give rise to human mental functions
Important to assume the fact that the mind is composed of specific parts
Modules: The sections of the brain, each of which is responsible for particular cognitive operations
The brain as the organ of the mind
Gall and Spruzheim: first to attempt to discover which parts of the brain are specialized for which cognitive
Their chart no longer taken seriously, their underlying premises still deserve consideration: specific
functions can be localized in specific parts of the brain
They used a speculative method
they believed that if a function is ↑ developed, then it must be larger
larger function= protrusion in the skull
Phrenology: study of the shape/size/protrusions of the cranium in an attempt to discover the relation of parts of the
brain to various mental activities and abilities.
Localization of function: the attempt to discover correspondences between specific cognitive functions and specific
parts of the brain, based on the assumption that there is a strict one-to-one correspondence between specific functions
and specific parts of the brain.
Histology: Microscopic analysis of tissue structure.
Franz: expert in the technique of ablation
Cortex of an animal destroyed, results were observed
The effects of ablation should depend on what part of the brain was removed
Conclusion: mental processes are not due to the independent activities of individual parts of the brain,
but to the activities of the brain as a whole.
Franz and Lashley: studied the effects of ablation of the frontal lobe in rats
Make small hole in the rat brain
Determine where the lesion occurred by histology
Then make lesions to other parts of the brain
if there were reflex paths transversing the cortex, then surgery would destroy them
no evidence that special connections developed in the brain
++ attempts to formulate an answer to the brain/mind relation
Important to distinguish between consciousness (narrower concept) and mind (broader concept).
Interactionism: Mind and brain are separate substances that interact with/influence each other.
Epiphenomenalism: Mind is a superfluous by-product of bodily functioning.
Parallelism: Mind and brain are two aspects of the same reality and flow in parallel.
Isomorphism: Mental events and neural events share the same structure. Necker cube important example because an external stimulus is constant, but the internal subjective experience
Produced by a prolonged inspection of a figure according to Köhler. His hypothesis was discredited.
Methods in Cognitive neuroscience
indirect route to study brain mechanisms (human brain = inaccessible to invasive approaches)
Lesions are carefully controlled, lesions can be reversible
allows relationship between different parts of the brain to be specified
full understanding of an animal’s brain may not lead to full understanding of the human brain
Homunculus structures are difficult to identify across species
Tell us much about the structure and function of the human brain
Combine knowledge of sensory systems with precise stimulus presentation and response recording
Cannot draw specific link between behaviour and underlying brain mechanisms e.g. eye movement studies
Study of brain injuries
Provide a kind of substitute for experiments that provide evidence for the localization of 1 or + functions
link symptoms displayed to parts of the brain that are damaged
seldom neat & tidy= difficult to yield definitive evidence
Paul Broca: classic study of the consequences of brain damage
speech production severely impaired (know what to say but unable to do so)
Damage to posterior part of the left inferior frontal gyrus
Broca’s aphasia: A deficit in the ability to produce speech as a result of damage to broca’s area
Broca’s area: area of the brain’s left hemisphere that is responsible for how words are spoken
Karl Wernicke: speech production is intact, but comprehension is severely impaired
Damage to posterior part of the left superior temporal gyrus
Wernicke’s aphasia: A deficit in the ability to comprehend speech as a result of damage to Wernicke’s area
Wernicke’s area: area of the brain’s left hemisphere that is responsible for processing the meaning of words
Broca and Wernicke made important contributions to the problem of localization of function
Their discoveries cannot be interpreted in any straightforward way
Broca’s area is not completely responsible for speech production and Wernicke ’s area is not completely