Brain Function & Localisation

Phrenology  Theory created by Franz Joseph Gall  Associated various human characteristics with areas of the brain e.g. constructiveness and language

Pierre Flourens  Asked by the F.A.S. to carry out experiments on animals in order to see if Gall’s theories were correct.  Used several new methods to see the behaviours the different  Was able to distinguish between areas of the brain that controlled voluntary and involuntary movement

Pierre Paul Broca  Carried out post mortem experiments on the brain of a mentally challenged patient ‘Tan’  Was able to clearly see the area of the brain responsible for speech.

Carl Wernicke  Discovered a similar area in the temporal lobe, which, when lesioned, led to sensory deficit in language.  Allowed him to conclude that there were links between the two hemispheres and their functions.

Gustav Fritsch and Eduard Hitzig  Experimented using electrical stimulation of the cerebral cortex  Observed involuntary muscle movement in various body parts.

Sir David Ferrier  Also used electrical stimulation of the cortex to deduce which areas of the brain were required for precise motor control  Corroborated by surgical evidence

PET Scans  Use positron emissions from a radioactive tracer to show a functional image of the body.

fMRI  Neuro-imaging technique that measures blood flow to different areas of the brain to produce a functional image.  By measuring blood flow the activity levels in different areas of the brain can be studied  In fMRI it is the magnetic signal from hydrogen nuclei in water (H2O) that is detected.