Psyh 150 test 2

Sensation

-A system that translates info from outside the nervous system into neural activity. Sensations are messages from our senses.
-How many senses do we have? smell, taste, hearing, vision, touch, spatial sensation, balance, time, etc.

Perception

-An internal representation of the outside world created by processing sensations
-The process through which sensations are interpreted, using knowledge & understanding of the world to become meaningful experiences
-Perceptual experiences can be varied across different people for the same set of stimuli

Perception is a product of:

-the environment we are in
-our expectations that we have about the situation
-where our attention is
-relative comparisons

Even our \___ can change our perceptions in real time

active knowledge

What is sensation and perception?

-Sensation and perception go hand in hand
-However, perception is not the same to all people

Psychophysics

-The relationship between the physical stimulus characteristics and the psychological experiences that they produce for the individual
-Attempts to define a psychological construct mathematically
-Providing some material and substance to otherwise latent constructs
--If we cannot directly measure a "perception" how can we be sure that it truly functions the way we believe it functions?

Absolute threshold

quantified point by which you can detect a change
-The min. amount of energy that can be detected 50% of the time
-differ from person to person
-can be affected by emotional state, expectations, and attention

signal detection theory

-internal "noise" and response bias
-perceptual bias based on individuals
-models different threshold across individuals
-assumes that the detection of faint sensory stimuli depends not only on a person's physiological sensitivity to the stimulus, but also the decision criterion for detection
-produces the following outcomes
--hit
--miss
--false alarm
--correct rejection
-"Just noticeable difference"

Weber's Constant (Weber's Law)

-JND\=Krs
-K\=delta I/I
-The pysical difference between a standard and comparison stimulus that is just noticeably different depends on the physical magnitude of the standard stimulus
-Larger differences are required to activate the "just noticeable difference" when a person perceives the stimuli as having "more" of the physical quantity being tested

Steven's Power Law

To perceive light as 2x's as bright actually needs to be increased 8-9x's, however if doubled electric shock intensity the feeling would be 10x's more intense

Psychophysics is a framework for measurement of how people:

perceive different quantities of stimuli

Psychophysics allows researchers to:

make comparisons and ultimately inferences on how the brain processes info

Bottom-up processing

Detail oriented. Slow and deliberate processing of details and parts of a stimulus also known as "features" that are processed singularly

Top-down processing

-As people, we are cognitive "misers"
-Use of prior knowledge of features, combined with expectations we can better process info. Very fast, no effort involved. Surprisingly accurate, however mistakes in perception can be made because of this

Parallel processing

The best kind of processing. Leads to a better level of understanding and detailed encoding of a scene or stimulus

Important themes

consistency and redundancy of processing; adaptation

General Model of Sensation

-Energy from external stimulus is sent to brain
--nervous system is hard at work constantly communicating
-The sensory input is modified by different receptors
--Your 7 senses all have unique steps and wiring to brain
-Cells in the body are specialized to receive certain kinds of input
-Transduction occurs at sensory receptors
--Transduction is the communication of the sensation of a physical stimulus to an electrical signal that is interpreted by our brains and communicated as a perceptual experience to the individual

Thalamus

Grand central station in your brain for all senses with the exception of smell. All senses travel through the thalamus before being projected into the cortex for processing

Feature detection in the brain...

has been showed in research to be as specific as one single neuron

Complex integrative processing in the brain for meaningful experiences:

includes sensation, perception, emotions, memories, etc

Some sense:

-transduction
-eyes transduce wavelengths of light into visual experience

Vision!

lens in eye focuses things in sight

rods

used for lowlight situation

cones

process high light situations

At focal point, \___ cones than rods

many more (must recognize when light changes)

Trichromatic theory of vision

-research suggests that there are 3 types of cones, that respond to different wavelengths of light
-blue, green, red (not yellow)
-Assumes that all colors we see are some mixture of these three colors
-If all three are equally activated we see white

Opponent process theory of color vision

-The trichromatic theory explains a lot... but not everything
-Have you ever seen a "reddish green" or "yellowish blue"?
-"Opponent processes" occurring post-sensation
--red-green
--blue-yellow
--black-white
-If one is stimulated, the other is inhibited

The ear

-sound is vibration
-amplitude refers to intensity of sound stimulus
-frequency refers to rate of vibration of the air creating the sound
-Pitch is how high or low the sound is, determined by both the amplitude and frequency of the incoming sound stimulus

Cochlea

lots of little hairs and liquid

Both ears are needed to locate sound

-The interaural level difference allows us to process differences in the incoming stimulus
-Following this, we can deduce the location of the sound without vision
--However, it should be noted that we can locate it much better when we can see also
--We can process multiple systems of info at the same time, from different senses and aggregate this info into one perception

Smelling is special

-The only sense that does not route through the thalamus for processing of the info
--communication, pheromones no longer used
-Instead, info is sent through the olfactory bulb from the olfactory receptors. There are some 20 million sensory neurons in the nose

Detects chemical communications

-Pheromones form of chemical communication
-we excrete androgen and estrogen-like chemical compounds similar to how many animals do
-In animals, these pheromones can explicitly direct behavior

Tasting

-Tastes are called gustatory sensations and are comprised of both info from the taste buds and olfactory senses
-4 basic tastes, diff from flavors
--sweet salty bitter sour
--Potentially 2 more- "umami" (yummy) and "fatty"

Sensation of touch

-Tactile sensation is the general sense of touching
-Thermoception is the sense of heat and cold
-Nociception is the sensation of physical pain
-You have specialized receptors all over to detect different types of sensation on the skin

Pain

-we could not survive without sensation of "pain"
-entirely psychological
-no specific neurons for pain. all free nerve endings can communicate pain

1st pain

when we experience a sharp quick sensation of pain. This info travels quickly along myelinated neurons

2nd pain

when info arrives seconds or minutes after occurrence

Gate control theory of pain

-Signals of pain travel up through the spinal cord to the brain
-The Substantia gelantinosa is a bundle of neurons in the spine in which they must pass through- this is the "gate"
-According to the gate control theory of pain, only a certain amount of info about pain can pass through this area at one time
-If other signals from other neurons are sent through this area, they can "close the gate" to other communications

Anti-nociceptive signals

anti pain signals

Perceptions have certain structural components to them that aid...

us in dealing with the abundance of info coming in at any given moment

Gestalt psychology

the notion that we perceive the world in terms of "wholes" or "gestalts"

Basic perceptual organizations is done in terms of:

-figure (what we focus on)
-ground (background, foreground)
-proximity or nearness
-similarity
-good continuation (camouflage)
-illusory contours
-closure

Perception is organized by expectations as well

-Stimuli can be recognizable under changing conditions
-size constancy (size and distance scaling)
--objects and people don't change size suddenly
-shape constancy
--objects and people don't suddenly change shape
-Brightness constancy
--the relative brightness of figure and ground

KEY CONCEPT OF SENSATION & PERCEPTION

CONSTANCY

Consciousness

ones awareness of
-the outside world
-our mental processes, thoughts, feelings, perceptions

Consciousness is a \_____ experience

subjective

qualia

properties of subjective experience

Consciousness is

-not necessarily observable
-personal (individual differences)
-product of our attentional awareness that is produced by activity in the brain

Nature of consciousness

-Intentionality- intend to focus on something
--pay attention to \_____
\---has a limited capacity
-Unity- you are focusing on something
--resistant to division
\---like watching tv while studying
-Selectivity- select what you focus on
--dichotic listening (listen to one ear not the other)
\---Cocktail party phenomenon
-Transience-fluid
--change what you attend to
--necker cube

frontal lobe

planning

motor cortex

movement

parietal lobe

spatial awareness

occipital lobe

vision

temporal lobe

hearing

The global workplace model

consciousness is the experience of brain output

Hemineglect

unaware of deficits

visual neglect

lack of brain activity in certain areas- unable to experience some output

minimal consciousness

turning away from bright light

full consciousness

able to report mental state (thinking out loud)

self-consciousness

reflective

variations in consciousness

full, altered, locked in, sleep, minimally vegetative, coma, persistent vegetative

locked in

-TBI- traumatic brain injury
-cant see, hear, feel
-cannot move, communicate

syncope

faint, pass out
-temporary loss of consciousness
-usually due to hypotension

concussion

-TBI
-can have temporary loss of consciousness
-amnesia

black out

-gap in memory of loss of consciousness

higher consciousness or super consciousness

-spiritual achievement
-religion
-awareness of your ego

corpus callosum

-connects the brains hemispheres
-severing the corpus callosum- split brain
-there are a few differences between the functinoing of the left and right hemispheres for the brain

splitting the brain splits the

conscious mind

left hemisphere

more analytical
-tries to make sense of the world (ie imposing narrative structure, seeking patterns)
detail oriented

right hemisphere

more spatially aware
experiences the world
more abstract

Conscious

focus of your attention
other things of which you are aware

unconscious

automatic behaviors
sensation and perception not under awareness

Unconscious processing influences behavior in interesting ways

-priming effects
-the "freudian slip"
-subliminal perception (is not persuasion)

Theory that sleep is

ADAPTIVE
-maximizing safety
-maximizing efficiency at obtaining food
-minimizing risk

Restoration

-repair our systems
-immune system recharges
-energy stores enhanced
-growth hormones released

Sleep deprivation leads to

-mood problems
-slowed reaction times
-decrements in attention & memory
-increases in the frequency of "microsleeps" (daydreaming)

Why to we sleep?

biologically programmed

Circadian rhythms

-regulates body temperature
-regulates hormone levels
-regulates when we are asleep and when we are awake

\______ contains a "circadian clock" which releases \_____ on a \______ system

hypothalamus; melatonin; interval

(WHY SLEEP?) Learning

-Sleep strengthens neural connections in the brain
--infants sleep a lot
--REM sleep during exam week is important

(WHY SLEEP?) Difficult task solved after sleeping

"just sleep on it"

The brain \_______ info while sleeping, facilitating the formation of \________

rehearses; stronger memories

Sleep has large connections to

-Motor activities such as sequences or adaptations
-visual discriminations
-declarative learning (memorization)
-complex procedural learning

Altered states of consciousness

-varying levels
-brain remains active
-does not completely shut off ever

Sleep Stage 1

-brain waves slow
-overall activity decreases by 50%- bizarre dreamlike stages
-quivers, jerks (in sleep scanner)

Sleep Stage 2

-brain waves even slower
-sleep spindles and K-complexes emerge
-makes up roughly 65% of our total sleep time

k-complex

transition from light sleep to deep sleep

Sleep Stages 3&4

-delta waves emerge
-release of serotonin from brainstem
-these stages are suppressed by alcohol consumption

Sleep Stage 5

-REM sleep (rapid eye movement) (dreaming!)
-High frequency, low amplitude brain waves. A state similar to wakefulness
-Active eyes
-Inactive body

Children have \_______ REM sleep than adults do

MORE

Insomnia

Difficulty falling or staying asleep
typically overestimated in frequency
Causes:
-significant life stress
-illness
-emotional or physical discomfort
-environmental factors

Sleep apnea

stop breathing during sleep
airways are blocked
Causes:
-muscles in the back of the throat relax, allowing obstruction

Somnambulism

(sleep walking) early in the night
common with children
Causes:
-genetics
-sleep deprivation causing changes in sleep levels
-taking sleep medications

Narcolepsy

sudden sleep attacks
Causes:
-genetics
-chemical deficits in the brain that cause sleep
-unable to achieve REM sleep

Sleep Paralysis

waking up unable to move
occurs while you are falling asleep or waking up
Causes:
-lack of sleep
-chaotic sleep schedule
-sleeping on your back
-substance abuse and/or medications

Night terrors

panic and intense emotional arousal at night
more common in non-REM sleep and children
Causes:
-stressful life events
-fevers
-sleep deprivation
-medications

Dreams

-occur during REM and non-REM sleep
--REM: bizarre, emotion-filled, visual/auditory hallucinations, often illogical dreaming
--non-REM: dull, mundane content & activities

Freud's view on dreams

dreams have hidden content that represent unconscious conflicts that the individual has
-manifest content: the superficial meaning
-latent content: the true meaning
-some represent suppressed thoughts

Activation

synthesis hypothesis
-sense comes out of random neural stimulation
-synthesis of activity in visual/motor cortex w/ stored memories
-backed by fMRI evidence

Evolved threat

rehearsal strategies
-dreams stimulate threatening events
--allow people to rehearse coping strategies
-dreams are the result of evolution
--providing solutions to adaptive problems