Sensation and Perception Flashcards
What is synesthesia?
A crossing over of senses (could be harmful or beneficial)
Give an example of something people with color-grapheme synesthesia would do?
Associating numbers with colors.
Describe the beginning of sensation
Sense organs translate the representation of stimuli.
What is transduction?
Converting a stimulus into nerve impulses.
What is a feature detector?
A certain neuron the responds to a specific stimuli (eg. only responding to straight lines)
Give a brief definition of perception.
Giving meaning to and organizing stimuli, often by recalling a memory. (eg. recognizing someone’s face)
What heavily influences the interpretation of a stimuli (perception)?
Context
What is a way we measure perception and explain this method
Using psychophysics which involves the relationship between a physical stimuli versus how we perceive it.
Define absolute threshold
The amount of a signal that must be provided for an observer to sense it.
Define difference threshold
Lowest amount of change for an observer to sense it.
Describe what a decision criteria is?
How certain we must be before we recognize that a stimulus is present (eg. deciding when we are in danger)
What does signal detection theory address?
What factors affect sensory judgments (eg. being tired/awake)
Define Weber’s Law
Difference threshold is directly proportional to the stimulus with which the comparison is being made. (eg. adding 1 gram to 50 grams could be noticeable but adding 1 gram to 500 grams isn’t)
Define sensory adaptation/habituation?
Diminishing sensitivity in an unchanged environment
What is the cornea?
Transparent protective layer at the front of the eye.
What is the pupil?
Adjustable portion behind the cornea the affects how much light enters (controlled by the iris)
What is the lens?
Elastic structure that changes form to focus
Describe the retina
A multi layered structure at the back of the eye that contains light sensitive photoreceptors which turn light energy into electrical impulses
How can myopia occur in people (nearsightedness)?
Light is focused in front of the retina
How can hyperopia occur (farsightedness)?
Light is focuses behind the retina
Describe rods
A photoreceptor that contributes to vision in the dark and black and white. Found everywhere except for the fovea.
Describe cones
A photoreceptor used for seeing color in light and only found in the fovea.
Describe transduction from the eyes
Bipolar cells receive signals from the rods and cones and then synapse with the ganglion cells and then the signal is sent to the optic nerve.
What is the purpose of horizontal and amarcrine cells?
They modulate the movement of signals across their pathway
How does the blind spot occur?
The axons that form the optic nerve have no photoreceptors so that gap where the signal leaves the eye is a blind spot.
How does dark adaptation occur?
Photopigments, which normally get depleted in light (dependent on amount of light) are not used as much allowing for the rate of regeneration to surpass the rate of depletion
Why is keeping rods dark adapted by red light important?
So first responders eyes can be prepared for any emergency
What is trichromatic theory?
There are three colors that eyes recognize (blue, red, green), each color recognized by one type of cone. Cannot explain afterimages.
What is opponent-process theory?
Each type of cone responds to two different colors.
Explain dual process theory?
Three types of cones that process blue, green, and red and the overlap of these wavelengths allow for other colors to be created.
What are trichromats?
People who see normally
What are dichromats?
People who have one deficient cone type
What are monochromats?
Only notice black and white
What do screens reduce the creation of and why is it important?
Melatonin which is related to sleep
Explain feature detectors.
Neurons that fire action potentials only from certain stimuli. (eg. seeing a straight line fires action potentials from one neuron vs seeing a horizontal line fires another from a different neuron)
What is the stimulus for hearing?
Pressure waves
What does frequency relate to?
Pitch (cycles per second)
What does amplitude relate to?
Loudness
Describe the path of sound through the ear
Sound enters through the outer ear and into the tympanic membrane/ear drum which vibrates entering the middle ear which causes the hammer, anvil and stirrup to all amplify the sound. The sound then enters the cochlea of the inner ear where fluid in the cochlea causes fluid to move which moves the hairs on the basilar membrane which is attached to the organ of corti. The bending of these hairs fires action potentials which eventually reach the primary auditory complex.
Explain frequency theory
The number of nerve impulses matches the frequency of the sound being emitted. Does not account for refractory period of neurons. Correctly explains low frequency
What is place theory?
Cochlear hair cells bend closer to the oval window in high frequency than in low frequency. Correctly explains high frequency.
How does binaural hearing help with localizing sound?
Depending which ear the signal is first received from, you can tell which direction the sound is from. Depending on which ear gets a stronger signal, you can tell where the signal is from. Does not account for vertical movement.
What is the difference between conduction and nerve deafness?
Conduction deafness means there isn’t a strong enough signal being emitted to the cochlea while nerve deafness means the hair cells don’t respond to stimuli.
What is gustation (taste) produced by?
The chemical stimulation of taste buds
What does olfaction (smell) go hand in hand with?
Gustation (taste)
Explain the pathway for smell
Upper nasal cavity->Olfactory bulb->Limbic system
Describe pheromones.
Chemical signals based around scents
What detects pain and temperature?
Free nerve ending receptors
What detects pressure?
Nerve endings on the end of hair cells
Describe gate control theory.
Pain results in the opening and closing of gates that allows or inhibits neurons to fire action potentials to the brain depending on the pain.
Name a psychological and physiological way of reducing pain
Psychological- yelling/swearing to reduce pain
Physiological- release of endorphins.
What is kinesthesis?
Body recognizing where muscles and joints are.
Describe the contents of the vestibular system and how it affects balance
Three semicircular canals have receptors for head movements while vestibular sacs respond to body movement
Describe inattentional blindness
We fail to see things in front of us
Describe change blindness
We fail to recognize change
How do gestalt laws of perceptual organization predict how we perceive stimuli?
Similarity, proximity, closure, continuity
Describe figure vs ground
Figure is what we should focus on while ground is the background
What is a perceptual constant?
A tendency for us to recognize objects perceived in slightly different contexts as being the same.
Describe size constancy
Our perceptual understanding allows us to estimate someone’s size based off of their distance
Describe monocular cues
Visually based pieces of info that can be interpreted with one eye that tell us about size and distance.
Describe binocular cues
Visually based info that can be interpreted with both eyes. Binocular disparity is known as slight differences in what each eye sees.
Describe convergence
Our eyes coming together when something comes close to them
Give an example of apparent motion.
Cartoon characters moving even though they are actually just pictures played in quick succesion.
