Task 1: Measuring Experiences Flashcards
Includes questions based on both textbooks, the lecture and online resources
Detectors?
eyes, ears, skin receptors and nasal and mouth receptors
Computer?
brain
Sensation
ability to detect a stimulus and turn that detection into a private experience
Perception
act of giving meaning to a detected sensation
Name the 7 steps involved in the perceptual process
- Attended stimulus (i.e. environmental stimulus)
- Light is reflected and transformed
- Receptor processing
- Neural processing
- Perception
- Recognition
- Action
Name the 2 principles involved in step 1 and 2 of the perceptual process
- Principle of transformation
2. Principle of representation
Principle of transformation
= stimuli and responses created by stimuli are transformed between the environmental stimulus and perception
Principle of representation
= everything a person perceives is based not on direct contact with stimuli but on representations of stimuli that are formed on the receptors and on activity in the person’s nervous system
Name the 2 optics of the eye and their locations
- Cornea: front of eye
2. Lens: directly behind it
Sensory receptors
cells specialized to respond to environmental energy, with each sensory system’s receptors specialized to respond to a specific type of energy
Visual receptors respond to …
light
Auditory receptors respond to…
pressure changes in air
Touch receptors respond to …
pressure transmitted through the skin
Smell and taste receptors respond to …
chemicals entering the nose and mouth
Name the 2 receptor processes of step 3
- Transduction
2. Shape perception
Define transducion
when visual receptors of the retina receive light, they transform light energy into electrical energy, as the receptors contain a light-sensitive chemical called visual pigment which reacts to light
Define shape perception in relation to receptor processes
the way visual receptors of the retina they respond to stimuli because the ability to see dim light depends on having a high concentration of pigment in the receptors and because there are different types of pigments (some pigments respond better to light in the blue-green part of the spectrum and others respond better to the yellow-red part of the spectrum)
Define neural processing (step 4)
processing continues the process of transformation that began when the stimulus was transformed into a small image inside the eye, which was then transformed into a small image inside the eye -> electrical signals in the visual receptors
Electrical signals from each sense arrive at the _____ in the ____
primary receiving area, cerebral cortex
Electrical signals from each of the follow arrive at what lobe of the cerebral cortex (primary receiving are)
a. vision
b. hearing
c. skin senses
a. occipital lobe
b. temporal lobe
c. parietal lobe
What does the frontal lobe do after electrical signals reach the primary receiving area?
plays an important role in perceptions that involve coordination of information received through two or more senses
Recognition (step 6)
placing an object in a category, that gives it meaning
Visual form agnosia, give an example
inability to recognize objects e.g. prosopagnosia i.e. face blindess
Knowledge/cognitive influences on perception (step 5-6)
information that the perceiver brings to the situation e.g. memories, expectations etc
Bottom-up processing
(or data-based processing) is based on the stimuli reaching the receptors
Top-down processing
(or knowledge-based processing) refers to processing based on knowledge.
-> As stimuli become more complex, the role of top-down processing increases
Name the 2 approaches to studying perception
- Psychophysical
2. Physiological
Psychophysical approach
measures the relationship between the stimuli and perception
Oblique effect
better detail for verticals and horizontals compared to slanted lines (stimuli)
-> brain response (physiological) was larger when detecting horizontals than slanted (perception)
Physiological approach (2 relationships)
a. stimuli and physiological responses
b. physiological responses and perception
Psychometric function
an inferential model applied in detection and discrimination tasks. It models the relationship between a given feature of a physical stimulus, e.g. velocity, duration, brightness, weight etc., and forced-choice responses of a human test subject.
Absolute Threshold
minimum stimulus intensity that can just be detected e.g. for seeing light, the threshold would be the intensity at which the light can just barely be seen or hearing where the intensity of sound can barely be heard.
How do thresholds differ?
e.g. damaged hearing - lower threshold
Name 3 methods of determining the threshold
- method of limits
- method of adjustment
- method of constant stimulus
Method of limits
experimenter presents stimuli in either ascending order (intensity is increased) or descending order, indicates results of an experiment that measures a person’s threshold for hearing a tone
- > changes from hearing (Y) to not hearing (N) aka crossover point
- > error of preservation
- > mean of crossover point = threshold
Method of adjustments
stimulus intensity is either increased or decreased until the stimulus can just be detected by the participant not by the experimenter (more accurate) e.g. turning a knob
Advantage of method of adjustments
less time-consuming
Method of constant stimuli
experimenter presents five to nine stimuli with different intensities in random order
- > experimenter chooses light intensities so that the lowest intensity is never detected and the highest one is always detected
- > threshold is defined as the intensity that results in detection on 50 percent of the trials
- > no error of preservation
Advantage of method of constant stimuli
most accurate as it involes many observtions and stimuli presented in a random order which minimizzes order effect
Adaptive testing
first present entire range of loudness, then only present sounds around the threshold
Difference threshold/just noticeable difference
the difference required for detecting a change in weight
Webers law
principle describing the relationship between stimulus and resulting sensation that says the just noticeable difference (JND) is a constant fraction of the comparison stimulus
Webers law formula
S = DL/K S= sensation of stimulus DL = just noticeable difference L = the constant
Fechner’s Law
a principle describing the relationship between stimulus and resulting sensation that says the magnitude of subject sensation increases proportionally to the logarithm of the stimulus intensity
-> response compression
Describe the graph of webers law
perfect positive correlation
Describe the graph of fechners law
increase rapidly, increase slows down, levels off
Fechener’s law formula
S = the psychological sensation
Log R = the logarithm of the physical stimulus level
K = the constant
Psychophysics
the science of defining quantitative relationships between physical and psychological (subjective) events
Magnitude estimation
experimenter presents ‘standard’ stimulus to the subject and assigns it a value, then presents lights of different intensities, and subject is asked to assign a number to each of these lights that is proportional to the brightness of the original light
-> number for “brightness” is the perceived magnitude
Response compression
increase in perceived magnitude is smaller than the increase in stimulus intensity (light)
Response expansion
intensity increased, perceptual magnitude increases more than intensity (electric shocks)
Cross-modality matching
ability to match the intensities of sensations that come from different sensory modalities; allows insight into sensory differences e.g. listener might adjust the brightness of a light until it matches the loudness of a tone
Steven’s power law
relationship between the intensity of a stimulus and our perception of its magnitude
Steven’s power law formula
P = KS to the power of n
P = perceived magnitude
K = constant
S = stimulus intensity raised to a power n
n tells us something about the way perceived magnitude changes as intensity increases
-> greater than 1 (response expansion)
-> less than 1 (response compression)
What does Steven’s law take into account?
rating data are qualitatively different e.g. electric shock vs length
Phenomenological method
person is asked to describe what he or she is perceiving or to indicate when a particular perception occurs
Visual search
observer’s task is to find one stimulus among many, as quickly as possible e.g. everyday example: looking for a friends face in a crowd
Reaction time
the time between presentation of the stimulus and the observer’s response to the stimulus
Response criterion
o E.g. Julie’s response criterion is low (she says “yes” if there is the slightest chance a light is present), whereas Regina’s response criterion is high (she says “yes” only when she is sure that she sees the light).
If the internal response is below criterion, the observer responds ____
no I hear nothing
Name 3 ways of classifying sense other than the five
- each sensor = different sense therefor 5 senses have subcategories e.g. taste (sweet, sour etc)
- 3: Mechanical (touch, hearing), chemical (taste, smell), light
- Perceptual experience e.g. echo location
Proprioception
the awareness we have of where each of our body parts is located in space - possible due to spindles
Name 2 other potential senses
- sensation of how you body’s position was changes in relation to gravity - fluid-filled vestibular system
- sense providing us info about our body’s inner state e.g. hunger, need to empty bladder etc
Electrophysiology
relationship between the stimulus and brain process (present a stimulus and measure brain activity e.g. have a subject click a button when they see a pear- neural firing)
Neuropsychology
the relationship between brain process and stimulus (study the effects of brain damage on behaviour e.g. seeing a glove but not being able to identify it)
Cognitive neuroscience
relationship between stimulus, brain processes and perception finish (present a stimulus and measure both brain activity and perceptual responses)
Name 3 methods from body and behavior task 4 that can meeasure perception
- EEG
- fMRI
- TMS
