Intro to the Brain

Wernickes area

At the junction of the temporal lobe and parietal lobe responsible for speech comprehension

- can produce it clearly
- can't understand speech
- nonsensical and incoherent

Investigations into the effects of brain damage on behaviour

Language controlled by the frontal and temporal lobes

Aphasia is acquired language disorder which = difficulty producing/understanding spoken or written language

Occur after damage to one or both of the following: Borcas area (frontal lobe) or wernicke’s area (temporal lobe)

Brocas Area

= speech production

frontal lobe

Brocas aphasia

can understand speech but not produce it clearly.

slurred, stammered and difficult

Paul Broca identified the area responsible

Visualising the structure of the living human brain

- Histology is the study of the microscopic anatomy of cells and tissues

- Tissue must treated to remove blood and be fixed using a substance such as formalin

- Once brain is fixed it is sliced using a microtome - which can slice 10-80 um thick

- Tissues stained to reveal finer details

Invasive physiological methods - experimental lesions

procedure

destruction of part of the brain (through a variety of methods) and evaluation of the subsequent animal behaviour

rationale

the function of a brain can be inferred from the changes/absence of a behaviour after the brain area has been destroyed

Aspiration lesions

1) Anaesthesia and incision of scalp
2) Removal of section of skull and incision through meningeal layer to expose cortex
3)Suction used to aspirate brain tissue

Sub Cortical Lesions

1) Electrical current passed through a wire with exposed tip
2) Wire positioned in a particular region
3) Current produces heat which kills surrounding cells

Chemical Lesions

1) More selective lesions
2) Neurotoxins may be used to selectively destroy specific cell bodies
3) Administered via micro-injection

Reversible Lesions

1) Coolant pumped through a cryoprobe
2)Neurons near tip cool and stop firing
3) When removed , tissue warms up and normal neuronal activity resumes