Chapter 3 - Sensation And Perception Flashcards
Perception
How our brain organizes the sensations and makes sense of it
Absolute threshold
Minimum amount of stimulation that a human can detect
Difference threshold
What it takes for humans to detect a change in an amount of stimulation, just noticeable difference - Weber’s Law
Sensory adaptation
Habituation - if you have a continual stimuli you will become unaware of it until it is brought back to your attention
Visual purple
Chemical that allows our eyes to be more sensitive to low light situations
Signal detection
Stimuli present - detection - successful hit
Not detected - false negative hit
Stimuli not present - detection - false positive
Not detected - successful miss
Sensation
External information, just the experience
The eye
Cornea - outer protective layer of the eye
Iris - colored part of the eye, it is a muscle that contracts and dialates to control the amount of light that enters the eye
Pupil
Lens - what focuses the image on the back of the eye, it focuses the image up side down, the muscles around the eye help us focus on things closer to us
Retina - the black part of the eye where nerve cells receive light
Rods - receptor cells on the retina that look like rods, they are responsible for black and white, low light, peripheral, not good visual sharpness
Cones - receptor cells, imagines are clear, color, make up the fovea
Optic disc - blind spot, brain fills in the gap
Color vision
Trichromatic theory - three cones, each is receptive to certain wave, red blue and green, these are combined to make colors
Opponent-process theory - three cones, but they are responsive to opponent colors, when cone is hit by light it is responsive to one color and vice versa, red/green, blue/yellow, black/white
Hearing
Pitch - wave lengths, distance between peaks, higher the pitch the shorter the distance between the waves
Volume - amplitude, height of waves, lower the wave the shorter the volume
Ear and Hearing
Pinna is the outer part of the ear, it catches waves that hit it and funnels them into the auditory canal. Waves travel through the canal and hit the ear drum, the ear drum vibrates once the waves hit it. The ossicles the. Vibrate because of the ear drum, they change the vibrations into a different type of frequency that we can hear and they go through the cochlea. The cochlea is filled with fluid and cilia, the waves travel through the fluid and is converted into energy by the cilia. They have to be converted because neurons use elecetricity not waves. They send the message to the auditory nerve to the thalamus
Hearing loss
Damage to the ear drum through loud noises
Infections can also effect the ear drum
Nerve damage can also cause hearing loss
Damage to the cilia is not preventable and causes hearing loss through aging
Other senses
Nose - chemicals go through the nose to our nasal passage, there are cilia receptors that collect th chemicals and send the information to the olfactory nerve and to the olfactory bulb, only sense that doesn’t go to the thalamus
Taste - our ability to sense a taste, we taste through taste buds (cells) they send electrial impulses to the brain, we can only taste chemicals that are water soluble
Touch - different sensory nerve endings that are responsible for different feelings of touch. Sensing some type of change in temperature and or pressure. Sensory neurons send info about touch through the spinal cord to the thalamus to the parietal
Kiesthetic sense
Deals with sense of movement, where are different body parts are in relation to each other at all times
Vestibular sense
Deals with where we are in regards to space around us and balance
Roles of attention
We only perceive what we give our attention to
What can affect our attention
Competing stimuli, noise, motivation, habituation, repetition, etc
Perceptual Sets
The idea that we often times see what we expect to see. Influence our perception of what we are perceiving because it can change things based on experience, expectations, etc
Bottom up
When we perceive things we are trying to recognize the meaning in patterns, piecing it together so we can perceive it. Simply recognizing there is something there
Top down processing
Perceiving things with meaning through the pattern presented - putting meaning to the image. Bottom up and top down happen at the same time
Gestalt principles
Figure-ground - we either perceive things as a figure or a background. Background is typically stable, and the figure is not so if the background moves we perceive the figure as moving
proximity - we group things based upon proximity
Closure - we tend to see things as wholes, even when they aren’t. Ex: 13 and b
Perceptual Constancies
Shape - we perceive things maintain their shape, even if they visually and psychically don’t
Size - same with size
Depth perception
Binocular cues - two eyes, distance and depth, triangulation
Monocular cues - one eye, distance based on obstruction, clarity, etc.
Culture also plays a role in perception
