Sensation and perception Flashcards
A topic can be understood by studying it at a number of different levels of a system.
levels of analysis
Physiological levels of analysis.
levels ranging from chemical reactions to single neurons, to structures in the brain, to groups of structures in the brain.
proposed that signals could be transmitted throughout the net in all directions.
Nerve net theory
Cell that is specialized to receive and transmit information in the nervous system.
neurons
A network of continuously interconnected nerve fibers (as contrasted with neural networks, in which fibers are connected by synapses).
Nerve net
The idea that individual cells called neurons transmit signals in the nervous system, and that these cells are not continuous with other cells as proposed by nerve net theory.
neuron doctrine
Part of a cell that contains mechanisms that keep the cell alive. In some neurons, the cell body and the dendrites associated with it receive information from other neurons.
cell body
Structures that branch out from the cell body to receive electrical signals from other neurons.
Dendrites
Part of the neuron that transmits signals from the cell body to the synapse at the end of the axon.
Axons
Space between the end of an axon and the cell body or dendrite of the next axon.
Synapse
Group of interconnected neurons that are responsible for neural processing.
neural circuits
Specialized neural structures that respond to environmental stimuli such as light, mechanical stimulation, or chemical stimuli.
Receptors
What did Edgar Adrian win the Nobel prize for in 1932?
recorded electrical signals from single sensory neurons-Adrian recorded electrical signals from single neurons using microelectrodes—small shafts of hollow glass filled with a conductive salt solution that can pick up electrical signals at the electrode tip and conduct these signals back to a recording device. Modern physiologists use metal microelectrodes.
Difference in charge between the inside and outside of a nerve fiber when the fiber is at rest (no other electrical signals are present).
Resting potentail
An electrical response that is propagated down the length of an axon (nerve fiber). Also called an Action potential.
nerve impulse
Propagated electrical potential responsible for transmitting neural information and for communication between neurons. Action potentials typically travel down a neuron’s axon.
action potential
adrian studied the relation between nerve firing and sensory experience by
measuring how the firing of a neuron from a receptor in the skin changed as he applied more pressure to the skin. What he found was that the shape and height of the action potential remained the same as he increased the pressure, but the rate of nerve firing—that is, the number of action potentials that traveled down the axon per second—increased
Point at which we can detect a stimuli more than 50% of the time.
Absolute threshold
Absolute threshold is absolute?
False
Measurement of the minimum difference needed between stimuli variables to be perceptivle. “just perceptible difference” (less than 50%
Difference threshold.
Determines perceptible diffeneces in sensation
Weber’s law
Visual information is processed______in the brain
Cross-hemispherically
What are the two types of receptors in the eye?
Rods and cones
Two visual pathways
Parvocellular and Magnocelluar
what are the limits of our sensation?
Types of energy we can sense and elements of energy we can sense.
Information which falls blow the absolute threshold is considered what?
Subliminal
What two methods can be used to measure absolute threshold?
Contant stimuli method and Method of limits.
Weber’s law determines what?
Perceptible differences in sensation
Our sensory system is an ___through which we become cognizant of relevant internal and external events
active system
We only really allow into awareness what is____
Useful for us.
sensation is the starting point of our sensory experience
false
We do not perceive a great deal of the sensorium T or F
True
Both hemispheres of the brain receive some information from each eye
True
Optic nerve results in a blind spot and our brain ___this section of our vision
autocompletes
-N ~ 120 million
-Better able to represent periphery of vision
-Better in low light
-Tuned to movement
Rods
-N ~ 6 million
-Foveal
-Better in daylight
-Tuned to color
Cones
Visual acuity =
Clarity of vision
-Greatest in the fovea
-Due to relatively few cones per bipolar cell
-Anything outside fovea is dim, gritty and low ——resolution
Visual acuity
What we see in ___on the conditions in which we see it
dependant
Cones
High light levels
Colour
Form
Parvocellular
Rods
Low light conditions
Movement
Magnocellular
Retinotopic maps in early visual areas
Striate occipital cortex
-Basic elements of perception
-Form, colour, relative movement, etc.
Peristriate occipital cortex
Recognition
Inferior temporal cotex
Location of object in space
Parietal cortex
What is colour?
how we percieve differences in light frequencies.
___adapt quickly to low light conditions?
cones
___adapt slower to low light conditions
Rods
-We have three types of cone cells in the eye
-The eye detects three primary colours
-Perceived colour is based on the ratio of primary colours in cone cells
Trichromatic theory
What cant trichromatic theory explain?
Colour opposites.
Colour vision is based on three opponent processes:
Red/green
Blue/yellow
Black/white
Exciting one colour in a pair blocks the other colour
Can explain afterimages
Opponent process theory
____perception occurs in the cortex
Colour
The fact that you can recognize your glasses as such from different angles specifically illustrates ___.
viewpoint invariance
Check My Work
Given that Betty is fluent in Spanish, she can tell when one word ends and the next one begins. This illustrates ___.
speech segmentation
Which of the following terms best describes human perception?
a. conscious
b. simple
c. procedural
d. automatic
procedural
Which of the following statements is accurate?
a. Perceptual rules must be taught to children.
b. Perception is the basis for all human cognition.
c. Sensations are the sole ingredients for perception.
d. Memory formation is unrelated to perception.
b. Perception is the basis for all human cognition.
Fundamentally, the principle of good figure emphasizes ___ in perception.
simplicity
Instead of concluding that there are 15 shapes in total pictured (which is accurate), you are more likely to initially conclude that there are three rows of different shapes due to ___.
the principle of similarity
Testing principles of Bayesian inference necessarily must involve ___.
mathematical procedure
Which of the following best reflects the Gestalt principle of similarity?
a. overlap
b. movement
c. grouping
d. simplicity
c. grouping
When tasked with identifying items in a particular scene, compared to humans a computer ________.
has less memory
Ahmad needs to create a model of the inverse projection problem for a class presentation. What should he indicate as the starting point of the problem?
an ambiguous retinal image
Identifying an object in a scene presents great difficulty for a machine because ________.
the task requires reasoning
Thomas Bayes stated that human perception of objects is based on the combination of which two concepts?
priors and likelihood
