Psyh Exam 2 Flashcards
perception
process by which the brain organizes and interprets sensory information.
Doctrine of specific nerve energies
principle that different sensory modalities exist because signals received by the sense organs stimulate different nerve pathways, leading to different areas of the brain. (anatomical code) certain sensory organs are connected to our brains in certain paths
-we see and hear with our brain, not our eyes and ears
Synesthesia
condition that a sensation in one modality consistently evokes a sensation in another (ex. smelling colours)
-possibly due to increased neural connections between those sensory areas (or inhibition)
anatomical encoding:
doesn’t completely explain why for most ppl our senses are separate, or explain variation of experiences within a particular sense (doesn’t tell us why)
Functional code
used to figure out what our sensory receptros are sensing
-info about which cells are firing, how many and at which rate, also the pattern forms a functional code
Absolute theshold
minimum amount of energy (or quantity) of a stimulus required for it to be reliably detected (at least 50% of the time it’s presented)- works for all senses -for everybody it’s different (especially between different species, as we age etc)
Difference threshold:
smallest difference between two stimuli that a subject can detect
-also known as the “just noticable difference”
difference threshold expressed by?
Weber’s fractions (difference threshold is the same percentage for everybody, for weight it is 2% of the weight you are holding (for 10 pound you only need 0.2 pouds added, 100 pounds you need to add 2 pounds) as the stimulus gets larger you need to add a bigger difference)
Signal detection theory
psychophysical theory that divides the detection of a sensory signal into a sensory process and a decision process
-for you to actually percieve anything you need to do both processes
-sensory is actual stimuli
-decision is the observers bias
- for example being scared that theres a monster under your bed even though you’re not actually sensing something
hit
sensory and decision are both right
false alarm
didn’t sense anything but imagined it
miss wrong
didn’t sense or decide but it was there
correct rejection
didn’t sense and didn’t decide it was there and were right
sensory adaptation
resulting decline in sensory responsiveness when a stimulus is uncahgngin or repetitious (your tongue is awkward in your mouth but you forget about that, wearing clothes and not feeling them on your body)
-not always beneficial (smelling gas in your house, and it going away because you got used to it)
selective attention
-is the process of focusing on selected aspects of the environment while blocking out others
inattentional
is the failure to consciously perceive something you are looking at because you are not attending to it
what is the stimulus for vision?
light
hue
dimension of visual epxerience specified by color names (related to wavelength)
saturation
(colorfulness) dimension of visual experience related to the complexity of light (how wide of narrow the range of wavelengths are)
brightness
dimension of visual experience related to the amount/intensity of the light an object emits/relfects (amplitude (max height) of the light wave)
sclera
white outer layer of eye
cornea
clear layer that covers the front of the eye
pupil
regulates amount of light let into the eye (essentially how light gets into your eye, it dialates or constricts based on the iris but it is the thing that lets in light)
iris
round muscle that adjusts the size of the pupil
lens
clear structure that focuses light onto back of eye
retina (fovea)
neural tissue lining the back of eyeballs interior that contains the receptors for vision
cones
concentrated on fovea to produce high-detail, colour vision at our point of visual focus (anywhere from 5 and 7 million in the eye) cones are how we see colour and really high detail (more focused in the center of the retina
rods
on outer regions of retina provude peripheral vision and are specialized for low light conditions (80+ million) (more focused on the peripheral of the retina) (don’t see colour)
- why it’s harder to see colour in the dark (cones aren’t well adapted to low light but rods are)
bipolar neurons
synapse onto photoreceptors
ganglion cells
transmits signals from bipolar neurons to brain
optic disc
area on retina lacking rods and cones
optic nerve
axon tracts from ganglion cells leading to brain
feature-detector cells
-specific group of cells jusst above the cerebellum, responding specifically to faces
-cells by the hippocampus help to perceive the environment
-region of cells by the occipital cortex respond stronger to body parts
Trichromatic theory
colour vision is determined by 3 different cone types that are sensitive to short, medium and long wavelength light. Also known as Young-Helmholtz Theory
- combined activity of all 3 cone types generates a unique signature associated with each perceivec colour (even colours without corresponding wavelengths)
Color blindness and deficiency
normal cone distribution is trichromatic, those with color deficiency are dichromatic and typically don’t have red cones
Opponent-process theory
we perceive colour in terms of opposite ends of the spectrum (red to green, yellow to blue, white black)
Opponent-process cells
in the retina and the thalamus respond in opposite fashion to short and long wavelengths of light
-are inhibited by a particular color produce a burst of firing when the color is removed, just as they would if the opposing color were present
-similarly, cells that fire in response to a color stop firing when the color is removed, just as they would if the opposing color were present
Negative afterimages
the facts above explain why we are susceptible to it when we stare at a particular hue
gestalt psychologists
among the first to study how ppl organize the world visually into meaningful units and patterns
gestalt principles
desrcibe strategies used by the visual system to group sensory building blocks into perceptual units
Figure and ground
figures in our envrionment tend to stand out against a background, issues arise when we have a tough time distinguishing between what is the figure and what is the background
proximity
group them together if they are close
similarity
if things are alike in someway (color, shape, size) they are perceived to belong together
continuity
perceptual rule that lines and other objects tend to be continous, rather than abruptly changing direction
principle of closure
ppl tend to fill in the blanks to percieve a complete object
consciousness
the awareness of oneself and the envrionment
biological rhythms
are periodic, more or less regular fluctuation in a biological system, often having psychological implications (rhythms are based both on external and ENDOGENOUS cues- either inside or things going on outside of the body)
Circadian rhythms
biological rhythms with a ~24 hour periodicity
-ex. sleep cycle, body temp
entrainment
synchronization between biological rhythms and external cues (zeitgebers)
-ex. noisey cat that likes to be fed at a certain time and wakes you up (your biological rythmn is being trained by an outside thing)
-alarm clock is also an example
light entrainment
-slowly changing levels of background illumination detected by specialized ganglion cells of the retina
-light signals communicated to the brain via optic nerve to the optic chiasm
-suprachiasmatic nucleus (SCN) above the optic ciasm recieves light information
-SCN tells the pineal gland to stimulate the releasae of melatonin
-melatonin helps you sleep
ex when it’s getting dark out you start to get sleepy
internal desynchronization
when our normal routine changes
-sleep and wake patterns adjust quickly but temperature and hormones may take a few days
-affects energy level, mental skills, motor cooridination
ex. jet lag, shift work
-it’s easier to stay up at night compared to going to bed early, going to the east of the world (towards europe) it’s harder to adjust
it is real that some ppl are early risers or night owls
seasonal affective disorder (SAD)
experiencing depression during particular seasons (usually winter)
symptomns include sadness, lethargy, drowsiness, cravings (light therapy helps)
waves when awake
beta waves
waves during Stage 1 NREM
begins as alpha and moves to theta
Stage 1 NREM
-light sleep (on the edge of consciousness) very easy to wake up, highly sensitive to noises
waves during stage 2 NREM
Theta waves (sleep spindles to k-complexes)-different types of spikes in our brain waves (no one’s really sure of their purpose, we think they help maintain our sleep?)
-short bursts of rapid waves
waves during stage 3/4 NREM
delta (very slow waves with high peaks) deepest sleep stage
REM (rapid eye movement)
when we start dreaming (typically), brain waves are very active again, most of our skeletal muscles are limp, vivid dreams are reported most often during REM
-even though your brain is active it’s very restfu
1->2->3->2->1->REM->1->2->3->2->1->REM (repeats)
the more cycles we go through the shorter our 3 stage is and the longer the REM
1->2->3->2->1->REM->1->2->3->2->1->REM (repeats)
the more cycles we go through the shorter our 3 stage is and the longer the REM
2 reasons why we sleep
Restore and Repair Hypothesis: the idea that the body needs to restore energy levels and repair any wear and tear experienced during the day’s activities
Preserve and Protect Hypothesis: suggests that two or more adaptive functions of sleep are preserving energy and protecting the organism from harm
signs of sleep deprivation
-more readily falls asleep
-irritability/emotional deficits
-attention/vigilance deficits
-maintenance of energy is hard
-reading/studying next to impossible
-after 2-3 days microsleeps begin to occur
types of insomnia
onset
maintenance
terminal
-primary and secondary
onset insomnia
difficulty falling asleep
maintenance insomnia
difficulty returning to sleep
terminal insomnia
waking up too early
primary insomnia
due to internal source (worrying) its the issue itself
secondary insomnia
results of other disorders, symptom of other things
Restless legs syndrome:
: persistent discomfort in legs and urge to continously shift them into different positions
REM behviour disorder
only occurs during REM sleep, act out dreams due to failure to inhibit motor signals
Somnambulism (sleepwalking)
disorder that involves wandering and performing other activities while asleep
Sleep apnea
temporary inability to breathe during sleep as airway becomes obstructed
-obesity
-damage to medulla
Narcolepsy
extreme daytime sleepiness and even sleep attacks
-few seconds to minutes
-immediately into REM sleep
sleep paralysis
between REM and awake, your muscles can’t move but your brain is awake
which stage of sleep facilitates learning
REM
