Chapter 2 pt.3 Flashcards
In the 1960’s, researchers began focusing on what?
Recording single neurons in the visual receiving area.
Why did researchers decide to study the visual area of the brain?
because stimuli could easily be controlled (controlling light on a screen like dimming and brightness) and because visual stimulation causes activity that’s distributed in many areas of the cortex
As research progressed, researchers began recording from neurons in areas outside the visual area and discovered two things, what were they?
1) Neurons that fire at higher levels respond to complex stimuli (like geometric patterns and faces)
2) Vision isn’t created only in the primary vision area but in many different areas (a specific stimuli causes neural firing in many areas of the cortex not just one)
Hubel and Wiesel started a series of experiments in which they presented visual stimuli to cats, and determined which stimuli caused specific neurons to fire.
What did they find?
They found that each neuron in the visual area of the cortex responded to a specific type of stimulation
What are “Feature Detectors”
Neurons that respond to specific visual stimuli
What is “Experience-dependant Plasticity”
the idea that an organisms neurons develop over time so they respond best to different stimulations
(the more they are exposed to stimuli, their neurons become more complex)
In an experiment, cats were only exposed to vertical stripes on a wall only. What happened when they were exposed to horizontal lines?
They didn’t respond to horizontals at all because their neurons mainly only respond to vertical lines, because they were shaped that way
Charles Gross presented a variety of different stimuli to monkeys. On a projection screen they presented lines, squares, circles, and other stimuli like hands. What was their discovery?
They found a neuron that refused to respond to any of the shapes in the temporal lobe, but it responded to the hand shape. This means that neurons at a higher level in the brain process more complex stimuli instead of basic ones
What is “hierarchical processing”
The progression from lower to higher areas of the brain.
(neurons at a higher level respond to more complex stimuli and vice versa)
What is a “sensory code” and “specificity coding” mean?
Sensory code - refers to how neurons represent various characteristics in an environment
Specificity Coding - the idea that an object can be represented by the firing of a specialized neuron that only responds to that object (this idea is unlikely to be correct)
What is “Population coding” and “Sparse coding”
Population coding is the representation of a particular object by the pattern of firing of a large number of neurons. Sparse coding is the same thing but with a small group of neurons, while majority of neurons remain silent
What is the “localization of function” principle
The idea that specific functions are served by specific areas of the brain
Many cognitive functions are served by the ________ ________.
Cerebral Cortex
What is Cortical Equipotentiality
The idea that the brain operated as a whole (instead of specific areas having specific functions)
