MCAT Behavioral Sciences

Franz Gall (1758-1828)

Doctrine of Phrenology: f a particular trait was well-developed, then the part of the brain responsible for that trait would expand → push on part of skull → bulge on head

Pierre Flourens (1794-1867)

Studied functions of major sections of brain via ablation/extirpation → studied behavioral consequences → specific part of brain have specific functions and removal of one part weakens whole brain

William James (1842-1910)

Functionalism: studied how mental processes help individuals adapt to their environments

John Dewey (1859-1952)

Functionalism: criticized concept of reflex arc, breaking thep rocess of reacting to a stimulus into discrete parts. Should focus on study of organism as a whole if functioned to adapt to environment.

Paul Broca (1824-1880)

Examined behavioral deficits of people with brain damage → specific functional impairments could be linked with specific brain lesions. Found Broca’s area via lesions (left side of persons brain) → unable to speak.

Hermann von Helmholtz (1821-1894)

First to measure speed of nerve impulse → measure link between psychology and physiology (psychology from realm of philosophy → realm of quantifiable natural science)

Sir Charles Sherrington (1857-1952)

Inferred existence of synpases. Thought it was electrical process but now know mainly chemical process.

3 Types of Neurons

Sensory / Afferent neurons → transmit sensory info from receptors to spinal cord and brain

Motor / Efferent neurons → transmit motor information from brain and spinal cord to muscles and glands

Interneurons → found between other neurons → most numerous of three types of neuron

Reflex arcs

Interneurons linked to this reflexive behavior

Sensory neurons → interneurons → back into the muscle directly

Nervous system two primary components

Central nervous system: brain + spinal cord

Peripheral nervous system: nerve tissue and fibers outside

• 31 spinal nerves

• 12 cranial nerves