AP psychology chapter 5 Flashcards
Transduction
The process of translating incoming stimuli into neural signals. Sensory organs receive messages, which get transformed into neural impulses, travel to the thalamus, then to different parts of the brain.
Sensory adaptation
Awareness/perception of a sensation decreases due to constant contact/stimulation.
Sensory habituation
Awareness/perception of a sensation decreases due to a lack of focus.
Cocktail-party phenomenon
When an individual’s attention involuntarily switches to something/someone else.
Sensation
Activation of our senses (eyes, ears, etc.).
Perception
How we interpret/understand sensations.
Vision
The dominant sense in human beings, which humans use more than any other sense.
Cornea
Protective covering, helps focus light.
Pupil
Like the shutter of a camera (opening into eyes). The iris is the muscle that dilates it.
Lens
Focuses light through the pupil via accommodation, curved and flexible.
Accommodation
The ability for the lens to change shape and allow for a change in focus from far to near.
Retina
Images are inverted and projected here like the projection screen for a film. Multiple layers of cells are activated by different wavelengths of light.
Cones and rods
Cones are cells activated by color, rods are black and white, rods:cones = 20:1, Cones are concentrated towards the center of the retina. Peripheral vision relies on rods and is mostly black and white, though it may appear colored.
Fovea
An indentation at the center of the retina, has the highest concentration of cones.
Bipolar cells
The next layer of cells, fires if the cones/rods fire.
Ganglion cells
Activates if enough bipolar cells fire.
Optic nerve
Sends impulses to a region in the thalamus called the LGN, made up of the axons of ganglion cells. Consists of 2 parts, impulses from the left side of each retina go to the left hemisphere and vice versa.
Optic chiasm
Where the optic nerves cross.
Blind spot
The spot where the optic nerve leaves the retina, has no cones or rods.
Lateral geniculate nucleus (LGN)
A region in the thalamus, the optic nerve sends impulses there, and it sends messages to the occipital lobe.
David Hubel and Torsten Wiesel
Discovered feature detectors.
Feature detectors
Cells in the visual cortex that respond selectively to various parts of a visual image, such as line orientation, color, and movement.
Trichromatic theory
3 types of cones in retina: red, blue, and green. Doesn’t explain color blindness and afterimages.
Afterimages
If a color is stared at for a while and after a black or white screen, an afterimage of the object in the opposite color will be seen temporarily.
Opponent-process theory
States that sensory receptors in the retina come in pairs: red/green, yellow/blue, black/white. When one is stimulated, the other is inhibited from firing. Explains colorblindness and afterimages.
Dichromatic colorblindness
If an individual is missing a pair of sensory receptors, it will be hard for them to see those colors, e.g red/green or blue/yellow colorblindness.
Opponent process theory of afterimages
Sensors for a particular color will fatigue when a color is stared at for too long, so when the blank wall is looked at, the opponent part of the pair fires, which creates an opposite color afterimage.
Outer ear
Pinna, auditory canal.
Middle ear
Tympanic membrane, 3 bones (the ossicles): hammer (malleus) connected to anvil (incus) connected to stirrup (stapes), oval window (membrane similar to eardrum).
Inner ear
Cochlea, organ of Corti, auditory nerve.
Cochlea
Filled with fluid, moves when oval window vibrates. The floor of the cochlea is the basilar membrane, lined with hair cells connected to the organ of Corti.
Organ of Corti
Neurons activated by the movement of Cochlea hair cells, impulses transmitted to brain via auditory nerve.
Pitch theories
Explains how we hear different pitches or tones. 2 theories: place theory and frequency theory.
Place theory
Pitch if sensed because different hair cells respond to different frequencies based on location in cochlea, only works for high frequencies.
Frequency theory
Pitch is sensed because cells fire at different rates (frequencies).
Conduction deafness
Occurs when something goes wrong in the conducting system before the cochlea (e.g deteriorating stirrup).
Nerve (sensorineural) deafness
Occurs when the cochlea hair cells are damaged, usually by loud noise.
Touch
Change in temp = energy. There are many different nerve endings for temperature, pressure, pain, etc., is concentrated.
Gate control theory
Some pain messages have higher priority than others, can’t feel low-priority pains.
Taste (gustation)
Chemicals absorbed by taste buds, located on papillae. The more dense the amount of taste buds, the more intense the taste.
Papillae
Little bumps on the top of the tongue that contain the taste buds.
Smell (olfaction)
Molecules of substances are drawn up the nose, absorbed by receptor cells at the top of each nostril, linked to olfactory receptor cells, connected to olfactory bulb, sends info to the brain.
Olfactory bulb
Smell impulses go directly to the amygdala (emotional impulses), then hippocampus.
Vestibular sense
Tells the body how it is oriented in space. 3 semi-circle canals filled with fluid trigger hair cells when the head moves and activate neurons.
Kinesthetic sense
Tracks orientation of specific body parts via receptors in muscles and joints.
Absolute threshold
The minimal amount of stimulus able to be detected half the time, e.g smallest amount of light we can see.
Subliminal messages
Any stimuli below the absolute threshold, considered unpercievable.
Difference threshold (just-noticeable difference)
How much a stimulus needs to change for us to notice the change, computed by Weber’s law.
Ernest Weber and Gustav Fechner
Created Weber’s law.
Weber’s law
States that the change needed is directly proportional to the original intensity of the stimulus. The more intense it is the higher the difference threshold.
Signal detection theory
Tries to predict what we will notice amongst competing stimuli, related to response criteria.
Response criteria (receiver-operating characteristics)
Factors like the intensity of the stimuli and the psychological/physical state of the person, e.g someone is more likely to smell apple pie if they are hungry and like apples.
A false positive
The perception of a stimulus that isn’t there.
A false negative
Not perceiving a stimulus that is there.
Top-down processing
Filling in gaps in what is perceived with background knowledge, creates schemata.
Schemata
Mental representations of how someone views the world or expects it to be. Can create perceptual set.
Perceptual set
A predisposition to percieving something a certain way, e.g seeing shapes in clouds.
Bottom-up processing (feature analysis)
Opposite of top-down processing, uses only the visible feature of an object to build a complete perception.
Figure-ground relationship
Determines what is the image and what is the background, several optical illusions play with this rule.
Gestalt rules
States that we innately perceive objects in groups. Several factors on how we group: Proximity, similarity, continuity, closure.
Proximity
Close together = grouped together.
Similarity
Looks similar = grouped together.
Continuity
Objects in a line/curve (patterns) = grouped together.
Closure
Objects that make something recognizable, like a face = grouped together.
Constancy
The ability to maintain constant perception of objects despite changes in factors like angle, shape, variations, etc.
Size constancy
We learn to account for distance in our estimations of size.
Shape constancy
Different angles create different shapes, but we know the shape is still constant.
Brightness constancy
We perceive objects as a constant color even if the light reflecting off of it changes.
Percieved motion
Our ability to gauge movement.
Stroboscopic effect
When still images are presented fast enough they appear to be moving even though they aren’t (flipbooks).
Phi phenomenon
When a series of lightbulbs are turned on fast enough they appear to be one moving light.
Autokinetic effect
When a still light is projected at a dark room and is stared at, it will appear to move.
Depth cues
Differentiates what is near and far
Eleanor Gibson
Conducted the visual cliff experiment, determined when infants perceive depth (3 months).
Cues to perceive depth
Monocular cues and binocular cues.
Monocular cues
Cues that don’t depend on having 2 eyes (used by artists), such as linear perspective, relative size cue, interposition cue, texture gradient, and shadowing.
Binocular cues
Cues that depend on having 2 eyes and results from anatomy, such as binocular disparity (retinol disparity) and convergence.
Linear perspective
One point perspective.
Relative size cue
Objects farther away are smaller, closer bigger.
Interposition cue
Objects that block the view of other objects must be closer.
Binocular disparity
The difference in image location of an object seen by the left and right eyes is due to eye separation.
Convergence
The closer an object is, the closer our eyes must move together to focus on it.
Extrasensory Perception (ESP)
People with ESP claim to perceive sensations outside the senses.
