Ch 11: Sensation, Perception, and Cognition (Princeton Review) Flashcards
What is the absolute threshold?
the minimum sensory stimulus intensity required to activate a sensory receptor 50% of the time
p. 311
What is the minimum noticeable difference between any two sensory stimuli, detected 50% of the time?
the just noticeable difference (or the difference threshold)
p. 312
Weber’s law dictates that two stimuli must differ by a ________ __________ in order for their difference to be perceptible.
constant proportion
For humans, 2 objects must differ in weight by 2%, two lights must differ in intensity by 8%, and two tones must differ in frequency by 0.3%.
p. 312
Besides the sensory stimuli itself, what else about our psychological state influences whether or not we will detect something?
alertness
expectation
prior experience
motivation
p. 312
In signal detection theory, explain the four outcomes that are possible with a given sensory stimulus.
A hit means the signal was present and was detected.
A miss means the signal was present but was NOT detected.
A false alarm means the signal was NOT present but was falsely detected.
A correct rejection means the signal was NOT present and the person did not think it was.
p. 312
A strong signal produces more ____ than _____, while a weak signal produces more _____ than _____.
hits than misses
misses than hits
(Khan Academy video)
According to the gestalt principle of _________, when attempting to identify an object, we first identify its outline, which then allows us to figure out what the object is. Only after the whole emerges do we start to identify the parts that make up the whole.
emergence
p. 312
Which gestalt principle describes the tendency of ambiguous images to pop back and forth, alternating different possible interpretations of the image?
the principle of multistability or multistable perception
p. 313
The law of _________ suggests that things that are near each other seem to be grouped together.
The law of _________ suggests that things that are similar tend to appear grouped together.
proximity
similarity
p. 314
Which law suggests that we perceive smooth, continuous lines and forms, rather than a disjoined one?
the law of continuity (or the law of good continuation)
p. 314
The gestalt law of _______ predicts that we will perceive things as a complete and logical entity, because our brains will fill in the gaps in the missing information.
closure
p. 314
What gestalt law predicts that objects moving in the same direction or moving in synchrony are perceived as a unit or group?
the law of common fate
p. 314
The gestalt law of _____________ predicts that things that are joined or linked or grouped are perceived as connected.
connectedness
p. 314
____-__ processing begins with the sensory receptors and works up to the complex integration of information occurring in the brain. We tend to use this approach when we have little or no prior experience with a stimulus.
bottom-up
p. 315
____-__ processing occurs when the brain applies experience and expectations to interpret sensory information.
Top-down
(note that the brain uses both bottom-up and top-down processing simultaneously)
Name and describe the two binocular cues.
These are most important for perceiving depth when objects are close to us in our visual field.
retinal disparity - the brain compares and integrates the images projected onto the two retinas in order to perceive distance
convergence - uses the extent to which the eyes turn inward when looking at an object in order to gauge its distance. The more inward strain, the closer the object.
p. 308
The long list of monocular cues:
relative size
interposition
relative clarity
texture gradient
relative height
relative motion
linear perspective
light and shadow
Monocular cues are depth cues that depend on info available to either eye alone and are important for judging distances of objects that are far away since the retinal disparity is only slight. We must rely on a combination of these cues.
If objects are assumed to be the same size, the one that casts the smaller image on the retina appears more distant.
Which monocular cue does this describe?
relative size
p. 309
If one object blocks the view of another, we perceive it as closer.
Which monocular cue does this describe?
interposition
p. 309
We perceive hazy objects as being more distant than sharp, clear objects.
Which monocular cue does this describe?
relative clarity
p. 309
Change from a coarse, distinct texture to a fine, indistinct texture indicates increasing distance. (Example of red poppies in a field.)
Which monocular cue does this describe?
texture gradient
p. 310
We perceive objects that are higher in the visual field as farther away.
Which monocular cue does this describe?
relative height
p. 310
As we move, stable objects appear to move as well. Objects that are near to us appear to move faster than objects that are farther away.
Which monocular cue does this describe?
relative motion (aka motion parallax)
p. 310
Parallel lines appear to converge as distance increases. The greater the convergence, the greater the perceived distance. (example of railroad tracks)
Which monocular cue does this describe?
linear perspective
p. 310
Closer objects reflect more light than distance objects. The dimmer of two identical objects will seem farther away.
Which monocular cue does this describe?
light and shadow
p. 311
In humans, once a hair cell in the ear dies, it will never regrow. The hair cells that detect higher frequency sounds are the smallest and the most ______ _______. This explains why elderly people have a loss of sensitivity to high-pitched sounds.
easily damaged
p. 311
In order to process vast amounts of visual information very quickly and effectively, our brains employ ________ ___________
parallel processing
(note: also utilized for other stimuli as well)
p. 307
The human brain dedicates approximately __% of the cortex to processing visual information, while only _% is devoted to processing touch information, and a mere _% processes auditory information.
30%
8%
3%
p. 307
What allows us to perceive depth and distance?
binocular and monocular cues
What type of receptor are Pacinian corpuscles, where are they found, and what stimulus activates them?
mechanoreceptors found in the skin, activated by pressure
p. 307
What type of receptor are taste cells, where are they found, and what stimulus activates them?
chemoreceptors
found on taste buds on the tongue
food chemicals
p. 307
What type of receptor are rods and cones, where are they found, and what stimulus activates them?
electromagnetic receptors
retina
light
p. 307
What type of receptor are auditory hair cells, where are they found, and what stimulus activates them?
mechanoreceptors
organ of Corti
vibration
p. 307
The Ruffini cylinders and the Merkel receptors fire to _________ ________.
constant pressure
(Khan academy practice passages)
Both the ________ corpuscle and the ________ corpuscle fire when pressure is first applied and again when pressure is released.
Meissner
Pacinian
Adaptation requires a _________ stimulus.
constant
(Khan Academy practice passage)
What is kinesthesia?
the sense of movement
What does the Law of Pragnanz say?
The law of prägnanz is sometimes referred to as the law of good figure or the law of simplicity. This law holds that when you’re presented with a set of ambiguous or complex objects, your brain will make them appear as simple as possible.
What otolithic organs sense changes in position and acceleration?
the utricle and saccule
What structure do humans lack that nocturnal animals have which allows them to see at night?
a tapetum lucidum
Weber’s law states that the K value is calculated by dividing the change in stimulus by the initial stimulus value. This equation written out is:
ΔI/ I = K
The structures of the eye first form an image on the ______, which detects light and converts the stimuli into ______ ___________ to send to the brain.
retina
action potentials
p. 302
Light enters the eye by passing through the cornea, the clear portion of the front of the eye. Light is refracted (bent) as it passes through the cornea which is highly curved and acts like a lens. Why is the cornea able to do this?
Because the refractive index of the cornea is higher than that of air.
p. 302
The cornea is continuous at its borders with the ______, the white of the eye. Beneath this is a layer called the _______.
sclera
choroid
p. 302
Why is the choroid able to absorb excess light within the eye?
Because it contains darkly-pigmented cells.
p. 302
What structure is just inside the cornea and what does it contain?
the anterior chamber contains aqueous humor
p. 302
At the back of the anterior chamber is a ________ called the iris with an opening called the pupil.
membrane
p. 302
Just behind the iris is the ________ _______, also containing aqueous humor. Sitting in the part back of this structure is the _____.
posterior chamber
lens
p. 302
The curvature of the lens (and thus its refractive power) is varied by the ______ muscle.
ciliary
p. 302
Light passes through the vitreous chamber en route from the lens to the retina. This chamber contains a thick, jelly like fluid called ________ _____. The retina is located at the back of the eye.
vitreous humor
(not to be confused with aqueous humor)
p. 302
What are the only examples of electromagnetic receptors in the human body?
These receptors synapse with nerve cells called _______ _____.
rod and cone cells of the retina (aka photoreceptors)
bipolar cells (the name implies they have only 1 axon and 1 dendrite)
p. 297
The bipolar cells in turn synapse with ________ _____, whose axons comprise the optic nerve, which travels from each eye toward the occipital lobe of the. brain where complex analysis of a visual image occurs.
ganglion cells
p. 302
Stimulus intensity is coded by….
….the frequency of action potentials.
p. 298
What structure of the eye is clear and bends light as it passes through?
cornea
If the cornea “acts as a lens”, what is the role of the lens?
to fine-tune the angle of incoming light, so that the beams are perfectly focused upon the retina
p. 302
Which type of cell is concentrated in the fovea?
cones (rods are NOT found in the fovea, but are found in the periphery of the eye)
Although rods are 1,000x more sensitive to light than are cones, rods are NOT sensitive to detail and instead are generally involved in peripheral vision in normal or bright light. Due to their sensitivity to photons, rods do most, if not all, of their photoreception in dark situations
(From Princeton Review, practice Exam 2; Khan Academy video: photoreceptors)
Red cone cells make up 60% of the cone cells, green make up 30%, and blue makes up only __%.
10%
(Khan Academy video: Photoreceptors)
Which type of cell (rods or cones) has a longer “recovery time”?
rods
(e.g. it takes your eyes a longer time to adjust between light and dark environments)
All rods contain only a single pigment type called __________.
rhodopsin
In the dark, when rods and cones are resting, retinal has several trans double bonds and one cis double bond. In this conformation, retinal and its associated opsin keep a sodium channel open. The cell remains __________. Upon absorbing a photon of light, retinal is converted to the all-trans form. This triggers a series of reactions that ultimately closes the sodium channel, and the cell hyperpolarizes.
depolarized
p. 304
What is the term for normal vision?
emmetropia
p. 304
Too much curvature of the cornea or lens causes light to be bent too much, which focuses light in front of the retina. This is called….
….myopia (nearsightedness).
p. 304
What type of lens corrects myopia?
a concave (diverging) lens
Too little curvature of the cornea or lens causes light to be bent too little, which focuses light behind the retina. This is called….
hyperopia (farsightedness)
Too little curvature of the cornea or lens causes light to be bent too little, which focuses light behind the retina. This is called….
hyperopia (farsightedness)
What type of lens corrects hyperopia?
a convex (converging) lens would be prescribed
Before light stimulates a rod cell, what conformation is present in rhodopsin?
11-cis-retinal; after light activation it is changed to an all-trans retinal.
Name the structures involved in going from SOUND to HEARING.
sound wave transmitted through air → auricle → external auditory canal → tympanic membrane → malleus → incus → stapes → oval window → perilymph → endolymph → basilar membrane → auditory hair cells → tectorial membrane → neurotransmitters stimulate bipolar auditory neurons → brain → perception
p. 301
Which brain waves are associated with deep sleep?
What is their relative amplitude and frequency?
delta waves are associated with deep sleep.
Remember D for Delta and Deep. These are HIGH amplitude LOW frequency waves (0.5 - 3 Hz), which is why deep sleep is also called slow wave sleep.
p. 325
What type of brain waves are associated with alert wakefulness?
Beta waves
(remember, you beta be awake!) These high frequency (12.5-30 Hz) and have even lower amplitudes than alpha waves
p. 324
What type of brain waves are associated with relaxed wakefulness or drowsiness?
alpha waves
These are low amplitude, and high frequency (8-12 Hz)
p. 324
What type of brain waves are associated with stage 1 (non-REM) sleep?
theta waves; these are of intermediate frequency (3-7 Hz)
p. 324
Polysomnography is a multimodal technique to measure physiological processes during sleep. It includes….
….EEG (electroencephalogram), EMG (electromyogram), EOG (electrooculogram), and other physiological indicators of sleep
p. 324
Stage 2 sleep is denoted by a change to two distinct patterns on the EEG. The person will still have theta waves, these are intermixed with two patterns: _______ and _____ ________. The former is a single wave, of a half second duration and is large and slow. The latter is a burst of waves.
K-complexes and sleep spindles
p. 325
Which stage of sleep is the “final” stage of sleep, but not the deepest level of sleep?
REM sleep
This is also called “paradoxical sleep” bc although the person physiologically appears to be awake, their muscle movement does not corroborate, as the individual is nearly paralyzed except for sudden bursts or twitches. This is also when dreams generally occur.
p. 325
The average sleep cycle is about 90 minutes to go through stages 1, 2, 3, 4, and then REM. Periods of REM sleep are ________ early in the night and get longer as the night progresses. Deep sleep periods (stages 3 and 4) are _______ early in the night and less frequent as the night progresses.
shortest
longest
p. 326
Core body temperature fluctuates between about 96.8 and 100.4 F over 24 hours. This is regulated by the hypothalamus. When does the average adult experience their lowest core body temperature?
About two hours before waking time in the morning
p. 327
Freud believed that the plot lines of dreams, or _______ content, were symbolic versions of underlying _____ content, unconscious drives and wishes that are difficult to express.
manifest
latent
p. 327
What does the activation-synthesis theory suggest?
That dreams are merely byproducts of brain activation during REM sleep.
p. 327
What types of parasomnias (abnormal sleeping behaviors) are associated with stage 3 (slow wave sleep)?
Somnambulism (sleepwalking)
Night terrors
Somniloquy (sleeptalking)
p. 328
During what sleep stage does bruxism usually occur?
Can occur during consciousness or any stage of sleep.
(from MCAT Self-Prep end-of-lesson quiz)
Which tastes are detected by G-protein-coupled receptors?
Remember SWUB:
sweet, umami, and bitter
In Broadbent’s Filter Model of Selective Attention, inputs from the environment first enter a sensory buffer. The selective filter is applied and, this is based on the ________ _________ of the sensory input.
physical properties
p. 316
What phenomenon occurs when information of personal importance from previously unattended channels catches your attention?
the cocktail party effect
(Note: this observation cannot be well accounting for by the filter model of attention.)
p. 317
What model tries to account for the cocktail party effect by stating that rather than a filter, the mind has an attenuator which “turns down” the volume of the unattended sensory input?
Anne Treisman’s Attenuation Model
p. 317
The idea of _________ _______ says that the more something is primed, the more it will be picked up despite distractions.
selective priming
p. 317
In the spotlight model (pertaining to visual attention), it is important to note that the beam of light describes the movement of attention, not the eyes. Shifts in attention actually _______ the corresponding eye movements.
precede
p. 317
One problem with visual processing is called the _______ _______ – the problem of how all these different aspects are assembled together and related to a single object, rather than something else in the visual field.
binding problem
p. 318
What factors determine performance of multi-tasking?
task similarity, task difficulty, and task practice
(task similarity example of writing a paper while talking on a radio program; they interfere bc of the task similarity)
p. 318
What ages roughly correspond to the preoperational stage?
Ages 2 to 7
The preoperational stage corresponds to a lack of _______ reasoning, and _____________, meaning they do not understand that other people have different perspectives.
logical
egocentrism
p. 320
