Sensation and Perception Exam 1

what is sensation and when does it occur

detecting and encoding

• happens in the beginning

what is perception

the result of the psychological processing

• all the stuff that goes on

how does sensation and perception relate to psychology

it studies behaviors and psychology studies mind behaviors

what 3 disciplines does psychology come from

• philosophy

• physiology

• religion (nature vs nurture debate)

give a rundown of empiricism

• 16/1700s

• wanted to have objective measures

• tabula rasa

define tabula rasa

blank slate

• we are a blank slate where our experiences our written by our senses

• babies are born knowing some things (we aren’t complete blank slates)

when does the process of tabula rasa happen

ALL THE TIME!

what was the first psychology lab/experiment

Wilhelm Wundt (Freud studied with him)

• from Leipzig, Germany

• 1879

• studied vision, perception, objision, and reaction time

why should we care about sensation and perception

• intellectual curiosity

• investigate how we gather information about our world

• determine capabilities and limits

• practical considerations (applications)

does perception = physical stimulus

NO!

• we only capture 1/3 of light

what is the chain reaction within studying sensation and perception

investigating how we gather information about the world leads to determining our capabilities and our limits which leads to practical considerations or applications

what are the 11 senses

• sight

• hearing

• taste

• smell

• touch

  • pain

  • temperature

  • passive touch

  • active touch

• proprioception

• interoception

• vestibular

give an example of passive touch

a tap on the shoulder

give an example of active touch

exploring with skin - mainly your hands

what are the senses of pain, temperature, passive and active touch considered to be

exteroception

what is proprioception

the sense of your body’s position

what is interoception

the knowledge about our bodies own internal state

• ex: having a fever, feeling your heartbeat

what is the vestibular sense

• balance

• posture

• postural stability

what did J.J Gibson do

• created a way of thinking about perception

• he was the founder of ecological psychology

  • his research came from WWII

what is ecological psychology

• when we move throughout the world we create information (circular process)

• optic flow/visual flow

• affordances

give an example of affordances

pen affords writing, we pick it up and we write

• for an ant, a pen affords as a barrier, they have to move around it

J.J Gibsons 5 information grabbing perceptual systems

basic orienting, auditory, haptic (touch), taste-smell, visual

• said that gathering information about the world helps up survive and procreate

• picking up information vs detecting sensation

J.J Gibsons study

did a study on WWII military pilots about them landing their planes, most of them would crash to land because they were relying on visuals mainly and it was dark out when flying

what are the approaches to the study of perception

• psychological

• biological

• theoretical

what are the approaches of the study of perception based in

discipline and mental

what does the psychological approach to perception include

• phenomenal/naturalistic research

• experimental research

what is phenomenal/naturalistic research

it relies on subjective reports of evidence

• limitations: you cant use this for animals or babies because they cant talk

• if you cant describe your experience you are most likely going to relate it to something similar that you have experienced

what is experimental research

objective, the search for cause and effect

• empiricists: Hobbes, Locke

• they use objective measures (example: letter chart at the eye doctors)

• limitations: is it the real world (external validity - being able to go from the lab to the real world) because everything is too controlled (if you make it more real world you lose control)

what does the biological approach to perception include

• lesion technique

• brain scans

what is the lesion technique

lesion part of the brain to see how it will effect whatever perception were interested in

• limits: its permanent, unethical, having to cut through other parts of the brain to get to the area of interest can impact the results

• natural lesion examples: tumor, war

what is the brain scan technique

MRI, PET scans, FMRI, evoked potentials

• location, geography, specificity? where specifically is the electrical signal coming from?

• does activity = perception?

• can we link the mental to the physical world?

• this expensive asf

what is the theoretical approach to perception

thinking in science has guided experiment in science

includes analogy

what is analogy

relating something to something that is already known

• examples: cameras to eyes, computers to brains

• trying to make sense of things using the zeitgeist

define zeitgeist

the spirit of the times - what is fashion/whats known

• examples: nerves are hollow and filled with gas, helium was big at the time

what are levels of analysis and define it

where the study is focusing on the individual/organism

• cellular

• system

• organism

we choose the level

what do neurons do

• receive information

• get excited, release neurotransmitters

what is missing from the neuron in sensation

dendrites

• we still need a start so we use photo receptors or hair cells as an example

• we cant do anything with the senses if there is no receptor (you need to interact with it)

what do action potentials do

get the ball rolling

where to find action potential

the synapse

define synapse

the space between neurons where energy is transferred or not

define neurotransmitter

chemical energy that is released

what is a pre synaptic neuron

a neuron that releases the neurotransmitters

what is the post synaptic neuron

the neuron that accepts neurotransmitters

what is excitation

the depolarization of the neuron

• it becomes more positive

• the process of transduction continues and the surrounding neurons fire

what is inhibition

the hyper polarization of a neuron

• becomes more negative

• the process of transduction ends

what is the process of reaching action potential

• resting potential of a cell (negative)

• depolarizes (+)

• hits action potential (the sodium potassium pump removes all positivity)

• hyper polarizes (-)

• refractory period

• resting state

define transduction

the changing of physical energy into neural energy

who is the founder of psychophysics

Gustav Theodor Fechner

define psychophysics

the link between mental with the physical

• how do we get from mental to physical stimulation

define absolute threshold

the minimum amount of change of stimulation that we need for detection

• definitive, final, concrete, never changes WRONG

• it has variability

what is the method of constant stimulus

you pick your intensity levels at random

• removes the predictability of stimulus

• have to have a lot of trials

where is the absolute threshold

its difficult to find on an s curve

• use the graphical technique of going over 50% and drop down on the graph

• there is variability

• on the graph in class it was 5.4

examples of absolute threshold

• vision - candle flame at 30 miles

• sound - watch ticking at 20 ft

• touch - fly wings at 3 in

  • passive touch example

what does it mean when we say there is variability

there is variability between individuals (intervariability) and there is variability within the self (intravariability)

what is the difference threshold

how much more or less stimulation is needed to notice a change occurred

• AKA just noticeable difference

properties of JND or difference threshold

• it is NOT constant

• it changed depending on what the initial condition is

• you have variability

what are the methods for measuring perception

• absolute threshold

• difference threshold

• scaling

• signal detection

• time course of perception

• sensory neuroscience

• computational methods

what is scaling

it characterizes the perceptual response across a range of physical values

• magnitude estimation: assigns a number to a stimulus indicating its sensitivity, either freely or in comparison to a standard

• cross modal matching: adjusts a stimulus of one type to match the level of another

what is signal detection

it measures the ability to make decisions about whether a stimulus falls into a category

• use the accuracy of assignment to signal vs noise to derive measures of discrimination and the decision criterion

what is time course of perception

measures when perception occurs in relation to a stimulus event

• masking: controlling stimulus duration by proceeding or following with a competing event

• simple reaction time: measure the time from stimulus onset to response

what is sensory neuroscience

describes perception in terms of activity of sensory receptors, neurons, and brain regions

• recording from a neuron: inserting an electrode to detect neural firing

• neurotransmitting: non-invasively measuring brain activity by electrical, magnetic, or other signals

what are computational models

describe perception in the form of computer algorithms or mathematical equations

• statistical optimization, bayesian, or neural net: use experience to direct processing of currently sensed information

what is the method of limits

psychophysical method where particular dimension of a stimulus, or difference between 2 stimuli is varied incrementally until the participant responds differently

what is the method of adjustment

method of limits where participant controls the change in the stimulus

what is webers law

a principle describing the relationship between stimulus and resulting sensation that says the JND is a constant fraction of the comparison stimulus

• K=(change in I)/I

• K webers constant

• change in I is the detectable difference

• I is the comparison intensity

• the change in I isn’t constant but dividing by I is

what is webers fraction

the constant of proportionality in webers law

what is fechners law

the principle describing the relationship between stimulus and resulting sensation that says the magnitude of subjective sensation increases proportionally to the logarithm of the stimulus intensity

what is magnitude estimation

psychophysical method where the participant assigns values according to perceived magnitudes of the stimuli

what is stevens power law

the principle describing the relationship between stimulus and resilting sensation that says the magnitude of subjective sensation is proportional to the stimulus magnitude raised to an exponent

• S=aI^b

• S is sensation

• a is constant

• I^bis stimulus intensity raised to a power

what is a criterion

in reference to signal detection theory, an internal threshold that is set by the observer

• if the internal response is above criterion, the observer gives one response and if its below it gives another response

what is sensitvity

the ability to perceive via the sense organs

• extreme responsiveness to radiation, especially light of a specific wavelength

• the ability to respond to transmitted signals

• in relation to signal detection theory, a measure that defines the ease with which an observer can tell the difference between the presence and abscense of a stimulus or the difference between stimulus 1 and 2

what is a receiver operating characteristic curve

in relation to signal detection theory, the graphical plot of the hit rate as a function of the false alarm rate

• if they are the same, points fall diagonal - indicates observer can tell difference between presence and absence of signal

what is the doctrine of specific nerve energies

states the nature of a sensation depends on which sensory filters are stimulated rather than how they are stimulated

• founded by Johannes Muller

define cranial nerves and how many pairs are there

nerves that originate in the brainstem and reach sense organs and muscles through openings in the skull

• 12 pairs of them

what are the 3 pairs of cranial nerves for sensory information

• olfactory (I)

  • first pair, axons of neurons bundle together after passing through cribriform plate to form the nerve

  • conducts impulses from the olfactory

• optic (II)

  • second pair, arise from the retina and carry visual information to the thalamus and other parts of the brain

• vestibulocochlear (vIII)

  • eighth pair, connect the inner ear with the brain transmitting impulses concerned with hearing and spatial orientation

  • composed of the cochlear nerve branch and vestibular nerve branch

what are the 3 pairs of cranial nerves that move the eyes

• oculomotor (III)

  • 3rd pair, innervate all the extrinsic muscles of the eye except the lateral rectus and superior oblique muscles

  • innervate the elevator muscle of the upper eyelid (ciliary muscle) and sphincter muscle at the pupil

• trochlear (IV)

  • 4th pair, innervate the superior oblique muscles of the eyeballs

• abducens (VI)

  • 6th pair, innervate the lateral rectus muscle of the eye

facial nerve (VII)

• 7th pair

• innervates the tongue, soft palate, facial muscles, salivary glands, tear glands

glossopharyngeal nerve (IX)

• 9th pair

• innervate the tongue, tonsils, pharynx, and pharyngeal muscles

vagus nerve (X)

• 10th pair

• innervate the heart, lungs, gastrointestinal tract, bronchi, trachea, and larynx

what are the exclusive motor nerves

• spinal accessory (XI)

• hypolossal (XII)

what nerves are for both sensory and motor

• trigeminal (V)

• facial (VII)

• glossopharyngeal (IX)

• vagus (X)

  • particularly important for introception

define poly sensory

blending multiple sensory systems

define sensory integration/multisensory integration and why its helpful

combining different sensory signals

• senses typically work together to learn about the world and guide behavior

• typically, combing several signals yields more accurate and precise information that can be obtained from sensory signals

define neuroimaging

set of methods that generates images of the structure and function of the brain

• allows us to examine the brain in living, behaving humans

define EEG

electroncephalography

• uses electrodes on the scalp to measure electrical activity from population of many neurons in the brain

define ERP

event related potential

• measures electrical activity from a subpopulation of neurons in response to particular stimulus

define MEG

magnetoencephalography

• similar to EEG

• measures changes in magnetic activity across neurons

define MRI

magnetic resonance imaging

• uses responses of atoms to strong magnetic fields to form images of stimulus like the brain

• can be used to measure brain activity

define FMRI

functional MRI

• makes it possible to measure localized patterns of activity in the brain

what is blood oxygen local dependent signal

ratio of oxygenated to deoxygenated hemoglobin that permits the localization of brain neurons most involved in tasks

what is position emission tomography

imaging technique that enables us to define locations in the brain where neurons are especially active

• measures the metabolism of the brain cells using radioactive isotopes

define wave

oscillation that travels through a medium by transferring energy from one particle or point to another without causing any permanent displacement of the medium

define photons

quantum of visible light or other form of electromagnetic radiation demonstrating both particle and wave properties

define hue

perceptual attribute of colors that allows them to be classified as similar to red blue or green

define scatter

disperse something in an irregular way

define reflected

redirect something that strikes a surface unusually back toward its origin

define transmit

to convey something from one thing to another

define refract

alter the course of a wave of energy that passes into something from another medium and measure the degree of refraction in the lens of an eye

what allows us to recognize objects

the eyes forming images of the outside world

define image

picture or likeness