TEXTBOOK – Chapter 2
Phrenology = Gall. Flourens said no, there is no localization of function and that injury to any part affects all
higher functions equally.
Aphasia: loss of speech ability. May be able to understand language, normal motor functions.
Broca’s area: responsible for production of speech. Broca had a patient with aphasia, discovered lesion in that
area after death, etc.
Wernicke’s area: understanding speech. Ability to speak is unaffected by this area.
Wernicke tried to blend two opposing views. Proposed that simple sensory/motor functions are localized but
the interaction of these modules produces more complex aspects of perception, action and behaviour.
- E.g. language. Broca’s area responsible for articulation of speech sounds, Wernicke’s area responsible
Phineas Gage. Frontal lobe damaged. Personality/judgment affected. Originally used to argue against
functional specialization, but actually provides evidence for it.
Histology: study of structure/organization of organs at microscopic level.
Penfield had definitive studies on functional specialization. I smell burnt toast, relief of seizures, etc.
Functional anatomy: a field dedicated to understanding how the brain is organized to carry out various
REASONS WHY PPL CLUNG TO HOMOGENEITY FOR SO LONG
Parallelism: a large number of mental functions are simultaneously processed along 2 or more pathways (in
diff regions of the brain too)
- Somatosensory: touch perception.
Brain lateralization: the brain allocates many functions across 2 cerebral hemispheres.
- One hemisphere dominates in stuff like language comprehension and speech production.
- However lots of the time mental functions are distributed among the 2 hemispheres, so even when
one is damaged the other one may still be active and functional.
- Left hemisphere actually larger in most ppl. Specialized for handedness too.
Nervous system = all sensory processes.
- CNS: brain and spinal cord.
- PNS: neurons, etc. Everything else.
Cerebrum – divided into 2 regions or lobes.
- Occipital lobe: very back of head. Vision - Temporal lobe: along the sides. Hearing.
- Parietal lobe: top middle portion. Touch.
- Frontal lobe: judgment/personality, etc. Front (forehead)
In the cerebrum there are certain parts that are white and certain parts that are grey.
- White matter: much of the bulk within interior, fibres that interconnect the brain areas.
- Grey matter: Mostly on the surface of brain (surface is called cerebral cortex). The actual collection of
cells responsible for processing sensory, motor and cognitive functions. Some grey matter in interior as
well (amygdala etc, not important)
Cerebral cortex is where all the diff functions of the lobes take place.
Sulcus: lines in the wrinkles in the brain. “Narrow fissures”
Gyrus: the accompanying elevated regions of the wrinkles.
Cytoarchitectonics: Differences in the architecture of the brain (some parts thicker, etc)
Müller was like: law of specific nerve energies. Diff nerve fibres are dedicated to diff sensory modalities. Make
specific connections so that diff centres in the brain are stimulated.
Lalalala brain parts etc. Not important, hopefully.
Parallel systems: at lower levels of nervous system, parallel pathways (from same modality) function
independently and don’t mix. But once they get to the cortex, those signals must be integrated so that
coherent perception is produced, one that encompasses all aspects of the sensory stimulus.
Hierarchy: Recepter and associated fibres, thalamus, then cortex.
Contralateral representation: left controls right, vice versa.
Neurons all have pretty much the same properties, but they are able to produce a diverse set of experiences.
Reticular theory: what Golgi believed. Neurons and fiber networks are separate entities, instead of just
extensions of the neuron. Disproved after.
The neuron doctrine: Cajal. What we believe now, connected neurons in a network etc etc.
Soma/cell body: nucleus, producing energy, components necessary to keep cell functional (the heart of the
neuron!). On opposite sides of it are the dendrites and axon.
Dendrites: receive inpu