Sensation and Perception Flashcards
What side of the body does the right side of the brain sense?
The left
Why do we have a blind spot?
No receptor at the optic disk, which is where the optic nerve connects to the eye
What is sensation?
The stimulation of sensory organs
What is perception?
The selection, organization, and interpretation of sensory input
What is synesthesia?
A condition where perceptual or cognitive activities trigger a sense (music triggers taste)
What is psychophysics?
The study of how physical stimuli are translated into psychological experiences
What is a stimulus?
A detectable input from the environemtn
What is a threshold?
A dividing point between energy levels that do and do not have a detectable effect
How do amplitude and wavelength affect vision?
Amplitude affects brightness and wavelength affects colour
How does light enter the eye?
The cornea
How do the cornea and lens project images onto retina?
Upside down
What is the lens?
A transparent eye structure that is behind the cornea and it focuses the light rays falling on the retina
What is accommodation?
A process which occurs when the curvature of the lens adjusts to alter visual focus
What is the pupil?
Opening in the center of the iris
What is the iris? What does it do?
The computed part of the eye and it contracts and dilates to regulate the amount of light entering the pupils
What is the difference between constricted and dilated pupils?
Constricted let’s in less light but has a clearer image and dilated let’s in more light but has a blurrier image
What are saccades? Why are they useful?
Involuntary eye movements
Essential to good vision, enhance memory, can show hidden desires
What is the retina? What does it do?
The neural tissue lining the inside back surface of the eye
Absorbs light, processes images, sends visual info to brain
Where do the nerves that connect the retina to the brain converge?
The optic disk which is where the optic nerve connects to the eye
What is the difference between rods and cones?
Rods are for night vision and peripheral vision
Cones are for day light vision and colour
Where is the most concentrated spot of rods and cones in retina?
Cones are mostly concentrated in center of eye
Rods are concentrated just outside fovea
What is the fovea?
Tiny spot in center of retina that contains only cones, best visual acuity (sharp and detailed)
What happens when light hits the receptors in retina?
Neural signals are passed along to the optic nerve which sends visual information to the brain
What is the receptive field? What is it made up of?
The area that when stimulated affects the firing of a certain cell
The collection of rods and cones that funnel signal to a specific visual cell in the retina
What is the optic chiasm?
Point where optic nerves from the inside half of each eye cross over and project to opposite half of brain
Where do nerves from left half of the retina send signals to?
Left half of brain
After the optic chiasm the optic nerve splits, what are the two pathways?
Main one goes to thalamus then to occipital lobe
Other goes to area in midbrain called superior colliculus before goin to thalamus then occipital lobe
What is a reversible figure?
An image that is compatible with two interpretations that can shift back and forth
What is a perceptual set? How can you create it?
Readiness to perceive a stimulus in a particular way
By telling someone that an image is one thing
What is feature analysis?
The process of detecting specific elements in visual input and assembling them into a more complex form
What is bottom up processing?
Looking at individual elements and then applying your knowledge to perceive the whole picture
Outer world to senses to brain
What is top down processing?
Looking at whole image before it’s elements
Filling in gaps in images with our brains
What is the phi phenomenon?
Illusion of movement created by presenting visual stimuli in rapid succesion
What is figure and ground principle?
Figure is thing you look at and ground is the background, images can change depending on what you assign to be figure or ground
What is the proximity principle?
Things that are close together belong together
What is the closure principle?
People group elements together to create a sense of closure or completeness
What is the similarity principle?
People group stimuli that are similar together
What is simplicity principle?
Tend to group elements together to form a good or simple image
What is the continuity principle?
Tendency to follow in whatever direction they are being led and connect points in straight or slightly curved lines
What is distal stimuli?
Stimuli that lie in the distance, outside the body
What is proximal stimuli?
The stimulus energies that directly affect sensory receptors
What is a perceptual hypothesis?
An inference about which distal stimuli could be responsible for the proximal stimuli sensed
What does depth perception involve?
Interpretation of visual cues that indicate how near or far away objects are
What are binocular cues?
Clues about distance that are based around the differing views of the two eyes
Examples of binocular cues?
Retinal disparity, objects project images to slightly different locations on the right and left retinas, see two different images
Angle of convergence, sense the eyes converging as they focus on closer objects
What are monocular cues? Work best for?
Clues about distance based on image in a single eye
Distance
Examples of monocular cues?
Relative size, same size object appears different size
Motion parallax, things closer to you move faster than things further away when in motion
Linear perspective, parallel lines go towards one another
Overlap, object that overlaps another is closer
Relative height, things that are higher are seen as further
What is a perceptual constancy? Example?
Tendency to experience a stable perception in the face of continually changing sensory input
Someone walking towards you projects bigger image on retina but you don’t think person is growing
What is a visual illusion?
Discrepancy between the appearance of a visual stimulus and its physical reality
What does amplitude and wavelength affect in hearing?
Hearing:
Amplitude, loudness
Wavelength, pitch
Pitch perception theories?
Place theory, depends on portion of basilar membrane vibrated
Frequency theory, depends on basilar membrane rate of vibration
