Cognitive neuroscience- the study of the physiological basis of cognition.
At the beginning the structure of the brain was viewed as a nerve net (signals could
be transmitted throughout the net in all directions) because the staining techniques
could not resolve small details at the time and so that’s what it appeared as.
Golgi showed the structure of the neuron and then Cajal changed the revolution and
showed that the cells were individual units called neurons and figure out that
individual cells transmit signals in the nervous system.
Parts of a neuron
Cell body- keeps the cell alive
Dendrites-recieves signals from other nueorns
Axon- transmits signals to other neurons
Synapse- small gap between the axon one neuron and the dendrite anther
Neurons are connected to each other to form neural circuits
Neurons that pick up information from the environment are receptors and have a
cell body and axon and special receptors that pick up information from the
Adrian- recorde the action potentials and showed that action potential travles all the
way without changing its size.
A neurotransmitter is released from one end of the axon to the dendrite through the
Adrian discovered that the intensity of a stimulus can be represented by the rate of
nerve firing. example, increasing the pressure to the skin causes neurons in the
touch system to fire more rapidly, so more neurons fire rapidly in the visual system
and therefore an increased perception of brightness.
Localization of Function
The cerebral cortex – layer of tissue that covers the brain
First areas to receive signals from each of the senses
1) temporal lobe- receiving area for sound but on the underside is for task and
2) occipital lobe- receiving area for vision
3) parietal lobe- the area for the skin sense
4) frontal lobe receives signals from all of the senses and plays an important
role in perception and a small area for smell and taste Prosopagnosia- inability to recognize faces as a result of damage to the areas in the
PET- measures blood flow to look at brain activity
Subtraction technique- You take the control of an action and then manipulation
condition and subtract the activation to get a measure of the activation.
FMRI- measurement of blood flow, indicates brain activity by looking at how strong
the hemoglobin responds to the magnetic field.
Fusiform face area – area that responds to faces in the temperal lobe in the fusiform
Parahippocampal place area – activated by pictures representing indoor and
Extrastriate body area- activated by pictures of bodies and parts of bodies
Module- an area specialized for a specific function. The FFA, PPA,EBA are modules
for perceiving faces, bodies, and places.
Localization of language
Broca found an area in the frontal lobe specialized for producing language called it
Broca’s area and loosing speech was Broca’s aphasia.
Damage to the temporal lobe is called Wernicke’s area and can not produce
meaningful speech, the condition is called Wernicke’s aphasia.
New research however shows that patients with Broca’s aphasia have problems
with form as in if the sentence can be interpreted in two d