1. LOCALIZATION & LATERALIZATION OF BRAIN FUNCTION

2. INTRODUCTION:
The Brain is the only body organ to exhibit both localisation and lateralisation of function.
Localization = Different areas of the brain do different things.
Lateralization = Each brain hemisphere is adapted to certain functions better than the other.

3. 3 EARLY INVESTIGATORS OF BRAIN FUNCTION
1) Franz Josef Gall ( )
 Cranioscopy, or phrenology
 Size + shape cranium =
Size + shape brain
 Mental abilities innate and fixed
 Level of development of ability
reflection of size of cerebral organ

4. 2) Jean-Pierre Flourens (1794-1867)
 First experimental lesions in brain.
 Not precise; severe brain damage
occurred in some cases.
 No specific areas found, but
different lesions caused different
problems.

5. 3) Paul Broca ( )
 First put forward for specific
language centre In the brain.
 Patient with brain damage
understood everything said to him,
but could only say 'tan' in reply
(Broca's aphasia).
 Patient with similar symptoms
found to have brain damage in
same area in post mortem
examination.

6. AN EXAMPLE OF BRAIN LOCALIZATION:
 Different areas of brain associated with same functions.
 Broca's area: Articulation of speech. Patients with Broca's
aphasia can understand speech but cannot articulate it
themselves.
 Wernicke's area: Understanding language. Patients with
Wernicke's aphasia can articulate speech but are unable
to understand it.
 Other brain areas concerned with speech double up with
other functions; e.g. memory, emotions, concentration etc.

7. THE CORTEX The cortex is the part of the brain
Emotion, experience, planning, initiative, language
production , frontal motor area.
> Senses, touch , monitoring of body parts
> Vision.
Hearing, language comprehension and memory
The cortex is the part of the brain
which is most strongly associated
with the mind and general
consciousness.

9. THE LIMBIC SYSTEM
Hypothalamus - basic drives; temperature control,hunger, thirst & sex
 Hippocampus - memory function and learning
 Amygdala - basic emotions (fear & rage), forming emotional memories.

10. THE CEREBELLUM & THE BRAIN STEM
 Cerebellum- movement and balance.
 Medulla - regulation of vital function (breathing, circulation).
 Pons – plays role in sleep and arousal
 Reticular formation - relay network controlling sensory input
and regulating arousal, alertness and sleep.

11. BRAIN LATERALIZATION & THE CEREBRAL
HEMISPHERES
 Each hemisphere responsible for the opposite side of the body.
 Left hemisphere receives information from right field of view and
vice versa
 Work with split brain patients helped to identify differences in
function of the two hemispheres of the brain.
 Hemispheric specialization also linked with handedness, in that
right handed people have a dominant left hemisphere and so on.

13. STUDYING THE BRAIN  EEG (electroencephalogram)
 Brain Scans (MRI, PET, CAT)
 Electrical Stimulation