Unit 4 (Sensation and Perception) Flashcards
Sensation
The action of detecting external stimuli and converting those stimuli into neural responses
Perception
Cognitive process that involves the selection, organization, and interpretation of stimuli
Our five senses
Vision, Hearing (audition), Taste (gustation), Smell (olfaction), Skin senses (position senses)
Sensory receptors
Convert sources of sensory stimuli, such as light and sound, into neural impulses
Sensory transduction
Conversion of environmental energy into a neural response
Absolute sensory threshold
Smallest amount of a stimulus that can be reliably detected (is something there)
Difference sensory threshold
Smallest difference between the stimulus that can be reliably detected (is something else there)
Selective attention (change blindness)
Only seeing certain things and not noticing when something else changes
Weber’s Law
The amount you must change a stimulus to detect a difference is given by a constant fraction of the original stimulus
Signal detection theory
Predicts when we will detect weak signals
Sensory adaptation
Process by which sensory receptors adapt to constant stimuli by becoming less sensitive to them
Habituation
Adapt over time to a stimulus. This is something which the body learns to ignore
Vision stimuli
Light (wave of electromagnetic energy)
Pupil
Hole in iris
Cornea
Outer layer at front of eye
Iris
Pigmented muscles
Ciliary muscle
Change shape of the lens
Lens
Bends light to focus it on the retina
Retina
Neural tissue that transduces light energy into neutral impulse
Optic nerve
Collection of neurons that transmit signals from retina to the brain
Fovea
Region of retina with highest acuity
Optic Disk (blind spot)
Point where optic nerve leaves eye
Photoreceptor cells
Sensory receptor cells for light
Rods
For dim light vision
Cones
For bright light and color vision (high acuity)
Trichromatic Theory (colorblindness)
The eye contains 3 distinct receptors for color: Red, Blue, and Green. By the combination of all three, all colors can be produced
Dichromatism
Patients lack one type of cone
Opponent Process theory (afterimages)
The eye contains 3 pairs of visual mechanisms that respond to different wavelengths of light. Each is capable of responding to either of the two hues, but not both at the same time
Hearing stimuli
Wave of changes in air pressure
Wavelength
Pitch
Amplitude
Loudness
Wave purity
Timbre
Cochlea
Structure of inner ear that contains hair cells, the sensory receptor sells for sound
Outer Ear
Pinna, Auditor canal, Eardrum
Middle Ear
Ossicles (small bones)
Ossicles
Hammer (malleus), Anvil (incus), Stirrup (stapes)
Inner Ear
Cochlea, Semicircular canals, Vestibular sacs
Chemical Senses
Monitor the chemical environment (taste and smell)
Qualities of taste
Sweetness, Saltiness, Sourness, Bitterness, Umami (meat)
Taste buds
Sensory receptor cells for taste that are located on the tounge
Smell stimuli
Chemicals in the air
Hair Stimuli
Sensory receptor cells for smell that are located high in the nasal cavity (can regenerate, making them unique natural cells)
Skin Senses
Touch, Pressure, Warmth, Cold, Pain
Skin
Contains sensory receptor cells that code for touch, pressure, warmth, cold, and pain (somatosensory cortex)
Kinesthetic Sense
Tells us about movement of body parts and their position in relation to each other. Receptors in joints, ligaments, and muscles.
Vestibular Sense
Tells us about balance and the position of the body in space. Receptors in semicircular canals and vestibular sacs of the inner ear.
Paying Attention
What determines which stimuli attract your attention and what gets ignored?
Salient detail
A detail that captures attention
Peripheral detail
A detail that does not draw our attention, makes up the perceptual background
Stimulus Factors
Those that make some stimuli more compelling than others (Contrast, Intensity, Size, Motion, Repetition)
Personal Factors
Characteristics of a perceiver that influence which stimuli get attached to (What we perceive is influenced by out past experience, expectations, and motivation)
Mental set
When we are predisposed to perceive something
Bottom-Up Processing
When what we perceive is determined by the pieces of information we recieve
Top-Down Processing
When what we perceive is determined by what the perceiver already knows
Law of Proximity
Group of stimuli based on proximity
Law of Similarity
Grouping
Ocular Cues
Built into visual system
Binocular Cues
Two eyes (retinal disparity, convergence)
Retinal Disparity
Each eye has a different picture and the brain is able to put those two images together to make one
Convergence
When something gets closer, the eyes point inward to focus on that thing
Monocular Cues
Only one eye (accommodation, physical cues)
Accommodation
Muscles in the eyes send signals about shape of the lens to the brain
Physical Cues
Linear perspective, Interposition, Relative size, Texture gradient, Patterns of shading, Motion parallax
Linear Perspective
Parallel lines seem to converge in the distance
Interposition
Things blocking something have to be closer than what it is blocking
Relative Size
Things closer to us seem bigger than things farther away
Texture gradient
You can see the texture of things that are closer, better
Patterns of Shading
Help with introposition
Motion Parallax
When you are moving, things closer to you get blurred, while things farther away stay somewhat stationary
Perceptual Constancies
Allows you to perceive aspects of your world as constant, despite the fact that the image displayed on the retina may change (Size constancy, Shape constancy, Brightness constancy, Color constancy)
