PSYC-251 Lecture 2: PSYC 251 Lecture 2: Lecture Notes 1:24
Document Summary
Hippocrates said that the brain was the seat of all mental activity and that when the brain isn"t working, you get mental and emotional problems. Galen said the brain was responsible for mental activity. The link between brain and cognition built steam in the renaissance. The brain is part of the nervous system : cns brain and spinal cord, periphernl nervous system everything else, nerves in arms & legs, for example. Electrical action potential travels down the axon, using a sudden influx of sodium ions to transport a charge. The message gets ot the synapse, the gap between cells, where the message is chemical. Nts diffuse from the presynaptic neuron to the postsynaptic neuron & can be excitatory or inhibitory signals causing or stopping an action potential. Whether an action potential occurs depends on the summation of all chemical messages. The action potential either does or does not occur, there is not a middle ground.