1.4 Sensation and Perception Flashcards
sensation
- basic registration of light, sound, pressure, odor, or taste from the environment
- hardware
perception
- the organization, identification, and interpretation of a sensation in order to form a mental representation
- software
transduction
takes place when many sensors in the body convert physical signals from the environment into encoded neural signals sent to the central nervous system
psychophysics
- the subfield of psychology devoted to the study of physical stimuli and their interaction with sensory systems.
- methods that measure the strength of a stimulus and the observer’s strength of a stimulus and the observer’s sensitivity to that stimulus
- participants are asked to make simple, more objective judgements
absolute threshold
the minimum intensity needed to just barely detect a stimulus in 50% of trials
just noticeable difference (JND)
the minimal change in a stimulus that can barely be detected
weber’s law
just JND of a stimulus is a constant proportion despite variations in intensity
weber’s law example
- If 105 g can only be distinguished from that of 100 g, then the JND is 5 g
- If the mass is doubled…
- The difference threshold also
doubles to 10 g
- So 210 g can be distinguished
from 200 g
sensory adaptation
sensitivity to prolonged stimulation tends to decline over time as an organism adapts to current conditions
length in light waves
- distance from top arch to top arch or bottom curve to bottom curve
- hue or what we perceive as color
amplitude in light waves
- the height of the wave from top arch to bottom curve
- determines brightness
purity in light waves
- shows saturation/richness of colors
- dark blue vs light blue
cornea
clear, smooth other tissue allowing light to pass through
retina
- light-sensitive tissue lining the back of the eyeball
- has rods and cones
accommodation (eyesight)
- the process by which the eyes maintain a clear image on the retina
- causes near-sightedness and far-sightedness
rods
- photoreceptors that become active under low light conditions for night vision
cones
photoreceptors that detect color, operate under normal light conditions, and allows us to focus on fine details
gestalt perceptual grouping rules:
simplicity
- the visual system tends to select the simplest or most likely interpretation
- we see an arrow rather than a triangle on top of a rectangle
gestalt perceptual grouping rules:
closure
- we fill in missing elements of a visual scene to complete an image
gestalt perceptual grouping rules:
continuity
we perceptually group together edges of contours with the same orientation
gestalt perceptual grouping rules:
similarity
regions that are similar are perceived are belonging together
gestalt perceptual grouping rules:
proximity
objects that are close together tend to be grouped together
gestalt perceptual grouping rules:
common fate
elements of a visual image that move together are perceived as parts of a single moving object
frequency (wavelength) in sound waves
- measured in Hertz (Hz)
- perceived by humans as pitch
- depends on how often the peak in air pressure passes the ear
amplitude in sound waves
- height of the sounds waves
- perceived by humans as loudness
complexity in sound waves
- simple (one wave) = pure tone
- complex (multiple waves) = mix of frequencies
Thermoreceptors
- nerve fibers that sense cold and warmth
vestibular system
- three fluid-filled semicircular canals and adjacent organs located next to the cochlea in each inner ear
- allows us to maintain our balance
smell
- only sense directly connected to the forebrain
- has pathways into the frontal lobe, amygdala, and other forebrain structures
- suggests that smell has a close relationship with emotional and social behavior
olfactory receptor neurons (ORNs)
- receptor cells that initiate the sense of smell
- odorant molecules bind to sites on these specialized receptors
pheromones
biochemical odorants emitted by other members of its species that can affect an animal’s behavior or physiology
papillae
small bumps on the tongue that contain hundreds of taste buds each
