chapter 1 Flashcards
perceptual process
steps leading from a stimulus to a response
7 steps of the perceptual process
- stimulus in the environment
- stimulus hits receptors
- receptor processes
- neural processing
- perception
- recognition (goes both ways with perception)
- action (goes both ways with recognition)
distal stimulus
stimulus in the environment - ex a tree
proximal stimulus
is the result of the distal stimulus hitting receptors - is an internal representation of the distal stimulus
ex our perception of a tree isn’t based on getting it in our eye, its based on the light reflected from the tree entering the eye and reaching visual receptos
principle of transformation
stimuli and responses created by stimuli are transformed, or changed, between the distal stimulus and perception
principle of representation
everything we perceive is based on representations of stimuli formed on receptors and activity of our nervous system, not direct contact with stimuli
steps 1 and 2
distal stimuli becomes proximal through transformation and representation
step 3 receptor processes
sensory receptors transform environmental energy into electrical energy (transduction) and shape perception by the way they respond to different properties of the stimuli
step 4 neural processing
neurons transmit signals from receptors to and within the brain and change (or process) these signals as they are transmitted
frontal lobe and perception
receives signals from all senses - plays a role in perceptions that involve coordination of information received through two or more sense
step 5 perception
conscious awareness
step 6 recognition
placing an object in a category that gives it meaning
step 7 action
motor activities in response to the stimulus
three major components of the perceptual process (simplified)
stimulus, physiology, behaviour
stimulus behaviour relationship
relates stimuli to behavioural responses like perception, recognition, and action
psychophysics
method used to study stimulus behaviour relationship - measures relationships between stimulus and behaviour - ex oblique effect
oblique effect
people have an easier time detecting gratings oriented vertically or horizontally as opposed to obliquely
stimulus physiology relationship
relationship between stimuli and physiological responses, like neurons firing
physiology behaviour relationship
physiological responses and behavioural responses
absolute threshold
smallest stimulus level that can just be detected
method of limits
measures a persons threshold - stimuli are presented in either ascending or descending order, person makes a judgement on whether or not they can identify them
crossover point
change from detection to no detection (yes to no) - threshold comes from the average of all the crossover points taken from all the replications of the procedure
method of constant stimuli
stimuli presented one at a time but in random order of intensity - most accurate
method of adjustment
participant, rather than experimenter, adjusts the stimulus intensity - fastest
difference threshold
smallest difference between two stimuli that enables us to tell the difference between them
what are three ways to measure perceptual abilities
magnitude estimation, recognition testing and reaction time
hard problem
how do the physical dimensions of the world turn into psychological experiences?
what is perception?
the psychological dimension of experience - things like pitch, brightness, loudness, as opposed to sound waves, light, food particles
knowledge
any information the perceiver brings to a situation - prior experience and expectations
materialism/physicalism
there is no mind - everything is physical
stimulus behaviour/perception relationship example oblique effect
measuring grating acuity - stimulus is oriented gratings and behavioural response is detecting it the grating’s orientation (and in turn detecting the lines)
grating acuity
the smallest width of lines participants can detect
stimulus physiology relationship- oblique effect
measuring grating acuity by looking at physiological responses of the brain (using metabolism and blood flow to record neuronal activity) in response to different orientations
physiological behaviour/perception relationship - oblique effect
measuring grating acuity through measuring perception/detection and physiological responses - measured in same participants = more direct assessment of physiology behaviour relationship
classical psychophysical methods
methods for measuring stimulus behaviour relationships using psychophysics
fechner - measures thresholds
- method of limits
- method of constant stimuli
- method of adjustment
magnitude estimation and the power function
measures how stimulus intensity affects our estimations of its magnitude
method for magnitude estimation
a standard stimulus gets assigned a value - participants are presented with varying intensities of the stimulus and rate it in proportion to the standard
recognition test
why is it important to make the distinction between the physical and the perceptual
because there isn’t a one-to-one relationship - our perceptual response to stimuli doesn’t line up exactly with physical intensity - there are also lots of physical things that exist that we can’t perceive
