Chapter 4: Sensation and Perception Flashcards
What is the difference between sensation and perception?
Sensation is the physical detection of something by the organs, whereas perception is the brain’s interpretation of these raw sensory inputs.
What is transduction?
The process where the nervous system converts external stimulus into electrical signals within the neurons.
What is a sense receptor and what is their function?
A specialized cell that transduces a specific stimulus.
What is sensory adaptation?
Where activation of our senses is heightened when it is first observed and later declines in strength.
What is psychophysics?
The study of how we perceive sensory stimuli based on their physical characteristics.
What is an absolute threshold?
The lowest level of a stimulus the brain can detect 50% of the time.
What is the “just noticeable difference” (JND)?
The smallest change of intensity of a stimulus that we can detect.
What is Weber’s law?
There is a constant proportional relationship between the JND and the original stimulus intensity.
What is the signal detection theory?
A theory that describes how we detect stimuli under uncertain conditions.
What are phosphenes?
Vivid sensations of light caused by pressure on your eye’s receptor cells.
What is synesthesia?
A condition in which people experience cross-modal sensations.
What is selective attention?
The process of isolating one sense and ignoring or minimizing the others.
What is the cocktail party effect?
Our ability to pick out an important message in a conversation that doesn’t involve us.
What is inattentional blindness?
Failure to detect stimuli that are in plain sight when our attention is elsewhere.
What is change blindness?
Failure to detect obvious changes in one’s environment.
What are the sclera, iris, and pupil?
The sclera is the white of the eye; the iris is the coloured part of the eye; the pupil is the hole where light enters the eye.
When do pupils dilate?
When we’re trying to process complex information.
What is the cornea?
A curved and transparent layer over the iris and pupil.
What is the role of the eye’s lens?
Fine tuning visual images.
What is the process called accommodation?
Where the lenses change shape to focus light on the back of the eyes.
What is myopia?
Nearsightedness; the ability to see things close up.
What is hyperopia?
Farsightedness; the ability to see things far away.
What is presbyopia?
The loss of flexibility of the lens due to aging.
What is the retina?
Thin membrane at the back of the eye.
What is the fovea and it’s responsibility?
Central part of the retina responsible for sharpness of vision.
What are rods and what are they responsible for?
They are receptor cells in the retina that allow us to see in the dark.
What is dark adaptation?
The time in the dark before rods regain maximum light sensitivity.
What are cones and what are they responsible for?
Receptor cells in the retina that allow us to see in colour.
What is the optic nerve?
Nerve that travels from the retina to the brain that conveys visual information.
What is the optic chiasm?
The split where half the optic nerve travels to one part of the brain and the other half travels to a different area.
What is the blind spot?
A part of the visual field we can’t see because it is devoid of sensory receptors.
What is the trichromatic theory?
Proposes that we base our colour vision on three primary colours (red, blue, and green)
What is the opponent process theory?
Theory that we perceive in terms of three pairs of opponent colours: red/green, blue/yellow, or black/white.
What is visual agnosia?
A deficit in perceiving objects where an individual can see an object’s characteristics but cannot recognize or name it.
Who are more sensitive to higher pitch sounds?
Young people.
What is the general range of hearing in humans in Hz?
20 to 20,000 Hz.
What is timbre?
The quality or complexity of a sound.
What are the parts of the outer ear?
The pinna and ear canal.
What is the main function of the outer ear?
To funnel sound into the eardrum.
What are the three ossicles of the middle ear called?
The malleus, the incus, and the stapes.
What is the function of the cochlea?
It converts vibration into neutral activity.
What is the organ of Corti?
A tissue containing hair cells that are necessary for hearing.
What is the basilar membrane and what does it do?
A membrane supporting the organ of Corti and the hair cells in the cochlea.
What parts of the cochlea are most critical for hearing?
The organ of Corti and the basilar membrane.
What do the semicircular canals in the inner ear do?
What is the place theory?
A particular place along the basilar membrane matches a tone with a specific pitch.
What is the frequency theory?
The rate at which the neurons fire action potentials reproduces the pitch.
What is the volley theory?
Sets of neurons fire at their highest rate slightly out of sync with each other.
What is conductive deafness?
Deafness due to the malfunction of the ear.
What is nerve deafness?
Deafness due to the damage of the auditory nerve.
What is olfaction?
Sense of smell.
What is gustation?
Sense of taste.
What are the five basic tastes?
Sweet, salty, sour, bitter, and umami.
Where do odours travel after reaching the receptors in the nasal passage?
The message enters the brain, reaches the olfactory cortex, and parts of the limbic system.
Where do tastes travel after being detected by the taste buds on the tongue?
The message enters the brain, reaches the gustatory cortex, somatosensory cortex, and parts of the limbic system.
What are pheromones?
Odourless chemicals that serve as social signals to our species that alter sexual behaviour.
Define somatosensory.
Our sense of touch, temperature, and pain.
What is proprioception?
Our body position sense (also called kinesthetic sense).
What is the vestibular sense?
Sense of equilibrium or balance.
What are mechanoreceptors?
Specialized nerve endings located on the ends of sensory nerves in the skin.
What is the gate control model?
A proposition that the stimulation we experience competes with and blocks the pain from consciousness.
What is phantom pain?
A condition where amputees sense their missing limb in an uncomfortable way.
What is pain insensitivity?
When an individual is completely unable to detect painful stimuli.
What are the two kinds of proprioceptors?
Stretch receptors in our muscles and force detectors in our muscle tendons.
Where does proprioceptive information enter and travel through the brain?
It enters the spinal cord, then upward through the brain stem and thalamus to reach the somatosensory and motor cortexes.
What is parallel processing?
The ability to attend to many sense modalities at one time.
What are the roles of the three semicircular canals in the inner ear?
They sense equilibrium and help maintain balance.
What is bottom-up processing?
Processing in which a whole is constructed from parts.
What is top-down processing?
Processing influenced by beliefs and expectancy.
What is a perceptual set?
Set formed when expectations influence perceptions.
What is perceptual constancy?
The process where we perceive stimuli consistently across various conditions.
What is size constancy?
Our ability to perceive objects as the same size no matter how far away they are from us.
What is colour constancy?
Our ability to perceive colour consistently across different levels of lighting.
What is the definition of the Gestalt principles?
Rules regarding how we perceieve objects as wholes within their overall context.
What are the six Gestalt principles?
Proximity, similarity, continuity, closure, symmetry, and figure-ground.
What is prospagnosia?
Face blindness.
What is the role of the fusiform gyrus in the temporal lobe?
Facial recognition.
What is the phi phenomenon?
The illusory perception of movement produced by the successive flashing of images.
What is motion blindness?
When an individual cannot seamlessly string still images processed by their brain into the perception of ongoing motion.
What is depth perception?
The ability to see spatial relations in three dimensions.
What are monocular depth cues?
When we can perceive three dimensions using only one eye.
What are binocular depth cues?
When we can perceive three dimensions using both eyes.
What are the six pictorial cues that help us perceive depth?
Relative size, texture gradient, interposition, linear perspective, height in plane, and light and shadow.
What is motion parallax?
The ability to judge the distance of moving objects from their speed.
What is binocular disparity?
How each eye sees things differently.
What is binocular convergence?
Reflexively focusing on something nearby using the eye muscles.
What is subliminal perception?
The processing of sensory information below the limen.
What is the limen?
The level of conscious awareness.
What is subliminal persuasion?
Subthreshold influences over our votes in elections, product choices, and life decisions.
