Sensation and Perception Flashcards
Sensation
is the conversion of signals (auditory, physical, electromagnetic) to electrical signals in the nervous system
Perception
processing of sensory info to make sense of its significance
Sensory Receptors (photoreceptors, hair cells, nociceptors etc)
nerves that respond to sensory stimuli and trigger electrical signals. associated with sensory ganglia (collections of cell bodies outside the CNS) and transmit to projection areas in the brain (for further analysis)
Threshold
absolute minimum that causes change in signal transduction
Absolute Threshold
minimum amount of stimulus needed to be detected by sensory system
Threshold of conscious perception
minimum amount of stimulus needed so that it will be brought into perception (awareness)
Difference Threshold or JND
minimum difference needed in two things before it becomes noticeable
Weber’s Law
jnd for stimulus is proportional to the magnitude of the stimulus
Signal Detection Theory
refers to the effects of nonsensory factors such as experiences, motives and expectations on the perception of stimuli. insight into response bias. experiment has 4 outcomes-hit, miss, false alarm, correct rejection
Eye parts
Cornea- filters incoming light
Iris- has constrictor and dilator pupillae which open and close pupil
Lens- refracts incoming light
rods- BW vision
cones- color vision
sclera and choroid- support eye
Visual Pathway
lens–>retina–>rods and cones–>bipolar cells–>ganglion cells–>horizontal and amacrine cells–>optic nerve –>optic chiasm–>optic tract–>Lateral geniculate nucleus of thalamus –> occipital lobe
- also goes to superior collicular for startle reflex
Parallel Processing
all senses use this. combine info regarding shape(by parvocellular cells- high spatial resolution and low temporal resolution ), color (by cones) and motion(by magnocellular cells) to sense object
- happens without much conscious thought
Parallel Procession
all senses use this. combine info regarding shape(by parvocellular cells- high spatial resolution and low temporal resolution ), color (by cones) and motion(by magnocellular cells) to sense object
Auditory pathway
cochlea–>vestibularcochlear nerve –> medial geniculate nuclei in thymus–> auditory cortex in temporal lobe
- also goes to inferior collicular for startle reflex
Membranous Labyrinth Components
cochlea- sound detection
semicircular canals- rotational acceleration, balance
saccule and utricle- linear acceleration, motion and orientation
Olfactory Pathway
olfactory nerves–> olfactory bulb –> olfactory tract –> limbic system
Somatosensation
pressure
pain
temperature
vibration
two point threshold
minimum distance necessary between two points of stimulation before its felt as two distinct stimuli
physiological zero
normal temp of skin to which objects are compared to determine if they are cold or hot
gate theory of pain
pain sensation is reduced when other somatosensory signals are present
Bottom up processing
data driven. Taking sensory information and assembling and integrating it. slower but less prone to mistakes
Top down processing
conceptually driven. recognizing an object based on memory and expectation with little attention to detail. faster but more mistakes
Gestalt Principles
ways brain can figure out what an incomplete picture is
Gestalt Laws
Proximity- things close to ne another are perceived as a unit
similarity- similar objects are grouped together
good continuation- elements following same pathway are grouped together
closure- when space is enclosed by group of lines it is perceived as closed line
pragnanz- perceptual organization will always be simple, regular and symmetric
subjective contours- edges or shapes that are not actually present can be implied by surrounding objects
