Psych 2115 FINAL

vestibular system

Sensory system that determines whether the body is upside down, standing, etc. Sense of balance

Proprioception

The ability to sense location, movement, and action/position of the limbs.

Sensation

registration of physical stimuli from the environment by the sensory receptors

Stimulus

An element of the world around us that impinges on our sensory systems

Perception

Process of creating conscious perceptual experience from sensory input

Transduction

The process of converting physical stimuli, such as light, into an electrochemical signal

Receptors

Specialized sensory neurnos that convert physical stimuli into neural responses

Neural response

Signal produced by receptor cells that can be sent to the brain

Phenomenology

Our subjective experience of perception

Aftereffect

a sensory experience that occurs after prolonged experience of visual motion in one particular direction. Example: g. Another way to observe this illusion at home is to watch the credits at the end of a movie without taking your eyes off the television screen. After watching the credits for 2 minutes, have a friend or family member hit the pause button. You will see an illusion of the movie credits' moving up the screen, even though you know the video is now stopped.

doctrine of specific nerve energies

the argument that it is the specific neurons activated that determine the particular type of experience (activation of the optic nerve leads to visual experiences, whereas activation of the auditory nerve leads to auditory experiences)

constructivist approach

the idea that perceptions are constructed using information from our senses and cognitive processes. Recognizing the face - voice of a loved one

Unconscious inference

Helmholtz's idea that some of our perceptions are the result of unconscious assumptions that we make about the environment.

Weber's Law

the just noticeable difference between two stimuli is related to the magintude / strength of the stimuli. 10 dots vs 20 dots is noticeable, 150 dots vs 160 dots, not so much.

Psychophysics

Study of the relationships between physical stimuli and perception.

Gestalt Psychology

An approach that suggests that we view the world in terms of general patterns + well organized structures rather than separable individual elemenets.

Direct Perception (Gibsonian approach)

the approach to perception that claims that information in the sensory world is complex and abundant, and therefore the perceptual systems need only directly perceive such complexity

Information processing approach

the view that perceptual and cognitive systems can be viewed as the flow of information from one process to another

Computational Approach

an approach to the study of perception in which the necessary computations the brain would need to carry out to perceive the world are specified

Hubel and Wiesel discoveries

1- the behavior of individual cells 2- unexpected levels of organization in the brain 3- information on how the brain develops

Neuropsychology

The study of the relation of brain damagae to changes in behaviour

Agnosia

the inability to recognize familiar objects due to brain damage

Prosopagnosia

face agnosia, a form of agnosia caused by damage to an area of the temporal lobe that results in deficit in recognizing faces.

Amusia

A form of agnosia that results in a person's loss of appreciation of music.

Functional Magentic Resonance Imaging (fMRI)

a neuroimaging technique that generates an image of the brain on the basis of the blood lebels in different areas of the brain, which correlate w activity levels in those regions.

cognitive penetration

the view that cognitive and emotional factors influence the phenomenology of perception - nonperceptual factors affect what we see, hear, taste, and feel.

cognitive impenetrability

Perception is not affected by cognitive factors; only our reporting of perception is, and that our perception remains the same, regardless of our cognitive + emotional state.

size-arrival effect

bigger approaching objects are seen as being more likely to collide with the viewer than smaller approaching objects

Top-down

Making sense of information by using context and what we already know about the situation; knowledge + context

bottom-up

the analysis of the smaller features to build up to a complete perception - colour + shape.

placebo effect

experimental results caused by expectations alone; any effect on behavior caused by the administration of an inert substance or condition, which the recipient assumes is an active agent.

sensation and perception process

physical stimulus -> sensory cells -> transduction -> perception

stimulus-perception relationship

Person's response = Perception, recognition, action.

stimulus-physiology relationship

Presenting a movement stimulus and measuring neural responding

physiology-perception relationship

relationship between physiological responses and behavioral responses

Receptors in eyes

Rods and cones

receptors in ears

hair cells

receptors in mouth

cells in tastebuds

Method of limits:

stimuli are presented in a graduated scale, and participants must judge the stimuli along a certain property that goes up or down

absolute threshold

the smallest amount of stimulus necessary to allow an observer to detect its presence.

method of constant stimuli

A psychophysical method in which a number of stimuli with different intensities are presented repeatedly in a random order.

method of adjustment

a method of limits in which the subject controls the change in the stimulus to find their own threshold.

difference threshold

The minimum amount of difference that can be detected between two stimuli

point of subjective equality

the settings of two stimuli at which the observer experiences them as identical

Psychophysical scale

a scale on which people rate their psychological experiences as a function of the level of a physical stimulus - eg: the Scoville scale measures our experience of 'hotness' at different concentrations of capsaicin.

Ascending series

a series in which a stimulus gets increasingly larger along a physical dimension (intensity of light might increase, amplitude of sound might increase)

Descending series

a series in which a stimulus gets increasingly smaller along a physical dimension

crossover point

the point at which a person changes from detecting to not detecting a stimulus or vice versa

two-point touch threshold

the minimum distance at which two stimuli are just perceptible as separate (the aristotle's illusion)

Difference between method of limits and contant stimuli?

In the method of limits, the stimuli are changed to focus on a paeticular observer's threshold.

In the method of constant stimuli, all stimuli are always presented, and all are selected beforehand; given in random order rather thsn zeroing in on the threshold.

magnitude estimation

a psychophysical method in which the participant assigns values according to perceived magnitudes of the stimuli

response compression

the result when doubling the physical intensity of a stimulus less than doubles the subjective magnitude of the stimulus. 1 teaspoon per gallon elicits the same response as 2 teaspoons per gallon, or only a bit higher, but not by double.

Response expansion

the result when doubling the physical intensity of a stimulus more than doubles the subjective magnitude of the stimulus. electrical shock of 10 = 5 on the pain scale. electrical shock of 20 = perhaps 15 on the pain scale; so objective pain increases, perception increases by much more.

Steven's Power Law

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

a Catch trial

a trial in which the stimulus is not presented to ensure they are telling the truth when there is not stimulus. If there is no stimulus and they say that there is a stimulus, they are not being truthful.

force choice method

a psychophysical method in which a participant is required to report when or where a stimulus occurs instead of whether it was perceived

signal detection theory

a theory predicting how and when we detect the presence of a faint stimulus (signal) amid background stimulation (noise). Assumes there is no single absolute threshold and that detection depends partly on a person's experience, expectations, motivation, and alertness.

False alarm

One of the outcomes of the signal detection theory - when the observer mistakes a harmless signal for a dangerous signal - when a party is cancelled because they thought there was going to be rain but there wasn't any rain

Miss

One of the outcomes of the signal detection theory - when a harmful signal is percieved as harmless

party = happened rain = happened

Hit

One of the outcomes of the signal detection theory - when a harmful singal is correctly percieved as hamrful;

party = didn't happen rain = happened

Correct rejection

One of the outcomes of the signal detection theory - When a harmless signal is percieved as harmless

party = happened rain = didn't happen

Criterion

the bias that can affect the rate of hits and false alams

sensitivity (signal detection theory)

the ease or difficulty with which an observer can distinguish signal from noise

d' (d-prime)

a mathematical measure of sensitivity

receiver operating characteristic (ROC) curve

in signal detection theory, a plot of false alarms versus hits for any given sensitivity, indicating all possible outcomes for a given sensitivity

Electroencephalography (EEG)

using electrodes to measure the electrical output of the brain by recording electric current at the scalp

Magnetoencephalography (MEG)

using a magnetic sensor to detect the small magnetic fields produced by electrical activity in the brain

sensorineural hearing loss

permanent hearing loss caused by damage to the cochlea or auditory nerve or the primary auditory cortex

Conductive hearing loss

the inability of sound to be transmitted to the cochlea

audiometer

a device that can present tones of different frequencies, from low in pitch to high in pitch, at different volumes from soft to loud

audiogram

a graph that illustrates the thresholds for the frequencies as measured by the audiometer - (graphic) record of hearing

Physical stimulus in vision

light

electromagnetic energy

Amplitude (intensity)

Height of a waveform

Wavelength

the distance between peaks on a wave

Amplitude of light translates to:

perception of brightness

Wavelength (and its inverse frequency) translates to:

colour

Frequency

1/wavelength

double slit experiment

a demonstration that light and matter can display characteristics of both classically defined waves and particles

Visible light spectrum ranges from

about 700 nm (red light) to 400 nm (violet light)

eyesight vertically

140 degrees of elevation - 60 degrees from straight in front eyesight up and 80 degrees from straight in front eyesight to down

eyesight horizontally

190 degrees from side to side

photon

a single particle of light

pupil

center of eye

iris

Colored part of the eye

sclera

white of the eye

conjunctiva

tissue that lines the inner surface of the eyelid and outer surface of the eyeball

cornea

the transparent layer covering the iris

extraocular muscles

control eye movement

optic nerve

extends from the back of the eyeball which transmits visual activity to the brain

Inferior and superior rectus muscles

move eye up and down

Lateral and medial rectus muscles

Horizontal eye movements (left and right)

superior and inferior oblique muscles

small rotations of the eyeball like those necessary to focus on objects at different viewing distances

Process of light travelling through eye:

through pupil --> optic lens --> vitreous chamber --> lands on the retina

What does light flow through in the eye?

the iris is the only portion in the eye through which light can flow

Function of the pupil

regulates the amount of light entering the eye

What happens when the circulal muscles of the iris contracts?

pupil is constricted/undilated; light entry is restricted

dilated pupils

allows for more light to enter the eye, optimizing vision in low light conditions

Lens

focusing incoming light - so that the representation of images in the external environment falls only on the retina where it can be processed.

When object is far

falls on the retina - focus on the retina.