The minimal amount of stimulation needed to detect a stimulus and cause the neuron to fire 50% of the time.
signal detection theory
This theory takes into consideration that there are four possible outcomes on each trial in a detection experiment: hit, miss, false alarm, and correct rejection.
difference threshold (also just noticeable difference- JND)
The minimum amount of distance between two stimuli that can be detected as distinct.
He noticed that at low weights (like 1oz) it was easy to notice a 0.5oz increase or decrease in weight; but at higher weights (like 32oz) participants were not able to judge 0.5oz differences.
This law states that the greater magnitude of the stimulus, the larger the differences must be noted.
a form of preconscious processing that occurs when we are presented with stimuli so rapidly that we are not consciously aware of them.
The term describing the process which the form of the input is converted into the electrochemical form of communication used by the nervous system. Takes place at the level of the receptor cells.
the switch of sensory input from one side of the body to the opposite side of the brain.
single cell recording
a technique by which the firing rate and pattern of a single receptor cell can be measured in response to varying sensory input.
the image of the object on the retina- it is later inverted and the brain interprets the image correctly.
the transparent structure behind the pupil that changes shape to help focus images on the retina
located in the center of the retina (or fovea) and are sensitive to bright light and color vision.
specialized cells which connect rods and cones to the ganglion cells of the optic nerve.
feature detector neurons
"see" different parts of the pattern such as a line set at a specific angle to background.
Young-Helmoltz or trichromatic theory
According to this theory, the cones in the retina of the eyes are activated by light waves associated with blue, red, and green. We see all colors by mixing these three colors.
opponent process theory
The theory contends that cells within the thalamus respond to opponent pairs of receptor sets- namely black/white, red/green, and blue/yellow. If one color of the set is activated, the other is essentially turned off.
if you stare at a red dot on a page and turn away to a blank piece of white paper, you will see a green dot on the blank piece of paper- this is known as the ________.
the form of sound waves that enters the ear by passing the outer ear and into the ear canal.
The three small bones found in the middle ear (the malleus, the incus, and the stapes) that help to amplify the vibrations from sound waves. The malleus is atached to the tympanic membrane and the stapes is attached to the oval window of the cochlea.
the snail-shaped tube (in the inner ear coiled around the modiolus) where sound vibrations are converted into nerve impulses by the Organ of Corti.
Sacs in the inner ear that are responsible for sensing gravitation and forward, backward, and vertical movement.
theory that asserts that sound waves generate activity at different places along the basilar membrane.
theory that states that we sense pitch because the rate of neural impulses is equal to the frequency of a particular sound.
cutaneous and tactile receptors
receptor cells located in the skin that provide information about pain, pressure, and temperature.
found in joints and ligaments, transmits information about the location and position of the limbs and body parts.
the process by which we become accustomed to a stimulus and notice it less and less over time.
occurs when a change in the stimulus, even a small change, causes us to notice the stimulus again.
the processing through cognition of a select portion of the massive amount of information incoming from the senses and contained in memory.
cocktail part phenomenon
our ability to carry on and follow a single conversation in a room full of conversations.
these theories propose that stimuli must pass through some sort of screen or filter to enter into attention.
attentional resource theories
these theories posit that we have only a fixed amount of attention and that this resource is divided up as is required in a given situation.
achieving recognition of an object by breaking it down into its component parts. it relies heavily on sensory receptors.
refers to the fact that images that are farther from us project a smaller image on the retina than do those that are closer to us.
the patterns of distribution of objects, appear to grow more dense as distance increases.
a monocular cue based on the perception that parallel lines seem to draw closer together as the lines recede into the distance.
the point at which the two lines become indistinguishable from a single line, and then disappear.
a perceptual cue based on the observation that atmospheric moisture and dust tend to obscure objects in the distance more than they do nearby objects.
a perceptual clue that explains why less distinct, fuzzy images appear to be more distant.
the difference in the apparent movement of objects at different distances, when the observer is in motion.
a depth cue that results from the fact that your eyes must turn inward slightly to focus on near objects- the closer the object, the more the eye turns inwards
results from the fact that the closer an object is, the less similar the information arriving at each eye will be.
Eleanor Gibson and RIchard Walk
researchers who developed the visual cliff to test depth perception.
a glass tabletop that appeared to be clear on one side and had a checkerboard design visible on the other side.
this view holds that most perceptual stimuli can be broken down into figure-ground relationships.
the tendency to perceive preferentially fluid or continuous forms, rather than jagged or irregular ones.
feature detector approach
posits that organisms respond to specific aspects of a particular stimulus.
we know that a stimulus remains the same size, shape, brightness, weight, and/or volume even though it does not appear to.
we perceive motion through two processes: one records the changing position of the object as it moves across the retina; the other tracks how we movie our head to follow the stimuli.
an example includes blinking lights on a roadside arrow- they give the appearance of movement.