Sensation and Perception Flashcards
What is sensation?
The process of detecting physical energy from the environment and converting it into neural signals.
What is perception?
The process of organizing and interpreting sensory information
What is transduction?
The conversion of physical energy into neural signals
What is the absolute threshold?
The minimum stimulation needed to detect a stimulus 50% of the time
What is sensory adaptation?
Reduced sensitivity due to constant stimulation
What is the difference threshold (just noticeable difference)?
The smallest difference between two stimuli that can be detected
What are rods and cones?
Rods detect dim light and motion; cones detect color and fine detail.
What does signal detection theory explain?
How we detect a stimulus amid background noise, factoring in decision-making and uncertainty
What are the 4 possible outcomes in signal detection?
Hit, miss, false alarm, correct rejection
What is the blind spot?
Area where the optic nerve exits the eye — no receptors
What is the fovea?
The central part of the retina with a high concentration of cones — sharpest vision
What is the optic nerve?
Carries visual info from the retina to the brain
What is the cochlea?
A spiral-shaped organ in the inner ear that contains hair cells for hearing
What is place theory?
Different frequencies stimulate different locations on the basilar membrane
What is frequency theory?
The rate of nerve impulses matches the frequency of the sound wave
What are the chemical senses?
Taste (gustation) and smell (olfaction)
What are the 5 basic tastes?
Sweet, sour, salty, bitter, umami
What is kinesthesis?
The sense of body part position and movement
How does culture influence perception
Experience and cultural background shape what we focus on and how we interpret sensory info
What are critical periods in perception?
Developmental windows where sensory input is necessary for proper perception to develop.
What is selective attention?
Focusing on a specific stimulus while ignoring others.
What are binocular cues?
Depth cues that depend on both eyes — retinal disparity and convergence
What is the vestibular sense?
The sense of balance and body orientation — located in the inner ear
What are perceptual sets?
A mental predisposition to perceive something in a certain way
What is figure-ground perception?
The ability to distinguish an object (figure) from its background (ground)
What is inattentional blindness?
Failing to see visible objects when attention is directed elsewhere
What are monocular cues?
Depth cues available with one eye — e.g., linear perspective, relative size, texture gradient
What are Gestalt principles of perception?
Rules like proximity, similarity, continuity, closure, and figure-ground that organize visual info
What causes perceptual illusions
Mismatch between reality and how our brain interprets stimuli — errors in perception, not sensation
What is motion parallax?
Nearby objects appear to move faster than distant ones when in motion
What is the Trichromatic (Young-Helmholtz) Theory?
Theory that we have three types of cones: red, green, and blue. All colors are perceived by combining these
What evidence supports Trichromatic Theory
Colorblindness patterns (red-green or blue-yellow deficiencies) align with specific cone malfunctions
What is the Opponent-Process Theory
Theory that color perception is controlled by opposing pairs: red–green, blue–yellow, and black–white
What does Opponent-Process Theory explain?
Afterimages and why we don’t see reddish-green or bluish-yellow
How do the two color theories work together?
Trichromatic theory explains color detection at the retina level, while opponent-process theory explains processing in the brain (thalamus & visual cortex)
Cornea
Protects the eye
Pupil
Controls the amount of light that can enter the eye
Lens
Focuses light onto the retina
Myopia
When the eyeball is too long
Dichromats
Individuals with a deficiency in one of the systems of colour vision
