Sensation and Perception Lecture Flashcards
what is sensation
involves the detection of external stimuli like light or pressure
the response to these stimuli and transmission of these responses to the brain = sensation
- direct, respond, transmit
what is perception
involves the processing, organization and interpretation of sensory signals in the brain
this results in an internal representation of the stimuli and your conscious experience of it
what is transduction
processes by which sensory receptors pass impulses to connecting neurons when they recieve stimulation
- pressure from the skin in case of touch
pressure interacts with sensory organs (organs that can sense stimuli like eyes, ears, skin)
the receptors which are specialized cells in these organs detect it
these receptors detect the stimulus into electrical signals / action potentials and send to the brain (PNS to CNS = sensory neurons = afferent)
the brain processes and interprates
what is the absolute threshold
the minimum intensity of a stimulation that must occur before you experience the proper sensation or detect it
- how much of a stimulus do you need to hear the sound
- how much intensity, how loud, what frequency
what is the difference threshold
it is the noticeable difference between 2 stimuli
- the minimu, amount of change required for a person to detect a difference
EX: if you are eating spicy noodles, are you going to notice if we add another packet of chili sauce
what are the 5 basic qualities in every taste experience
sweet
salty
savoury
bitter
umami
the bumps you see on your tongue are the _____
papillia
and the taste buds are found on the inside of them
where are the smell receptors located
called the olfactory bulb
in the forebrain under the frontal lobes
the olfactory epithelium is a thin layer of tissue embedded with smell receptors
these tissue receptors transmit information to the bulb in the brain
what is the orbitofrontal cortex (OFC)
recieves information from smell, taste, and visual systems
flavour of perception
mechanoreceptors explain
respond to mechanical distortion or pressure
- the most sensitive mechanoreceptors are found near the cochlea
where is the primary somatosensory cortex located on the brain and what does it do
dividing the line between the frontal and the parietal lobe
- it is the region in the brain responsible for processing sensory infromation from the body
- the cortex is mapped out in a way that different body regions correspond to specific cortical areas = sensory homunculus - larger areas represent more sensitive body parts like the hands and lips
explain pain receptions and the types of fibres associated with specific types of pain
pain reception is activated by being burned, injured etc - dangerous stimuli
myelinated fibres = for sharp immediate pain - for fast movement
Lightly or non-myelinated fibres = for dull and steady pain
what is the gate control theory of pain
for pain to be experiences
pain receptors must be activated and the neural gate in the spinal cord must allow the signals to the brain
gate open = pain is experiences
gate closed = pain is reduced or prevented
name 3 somatosenses
touch sensation - pressure, pinching through mechanoreceptors in the skin
pain perception - pain reception that sends signals to the open gate of the spinal cord if immediate pain
temperature perception
T/F the optic disk in the park of the eye directly across from the cornea, etc is a blind spot
true
T/F muscles do not change shape to accommodate distant/closer objects
false
they accommodate all the time to change the shape of the lens to adjust it to focus on distant objects
it thickens to focus on closer objects
explain the photoreceptors cells in the retina
rods and cones helps us see = photoreceptor
RODS: night vision they see black and white colour, low detail
- along the edges of the retina
CONES: day vision, detec colour = red, gree, blue, sharp detail
- along the center of the retina
is there more rods than cones
yes
explain the visual transmission from the light to the optic nerve
light, rods and cones, horizontal cells (which make up the optic nerve), ganglion cells (which make up the optic nerve), optic nerve, gets sent to thalamus that deals with vision which directs the signal to the primary visual cortex (occiputal lobe)
what are the three types of cones
S cones = short wavelength = blue
M cones = medium wavelength = green
L cones = long wavelengths = reds
what is the trichromatic theory
red, blue, green
the perception of colour is determined by the ratio of acitivty among these 3 colour receptor cones
what is the opponent-process theory
explains how we perceive colour by using opposing pairs of colours - focusing on the ganglion cells in the retina
- red vs green
- yellow vs blue
- white vs black
when one colour is activated the other is suppressed
when you stare at something red, the red cones get fatigued and when u look away u see a green afterimage
what does motion sensitive neurons mean
the fatigue of certain motion sensitive neurons leads to motion after effects like the waterfall illusions
where does the information of visual transmission process go after it reaches the primary visual cortex (occupital lobe)
it can be sent to 2 different pathways
DORSAL STREAM: where stream
- determining where an object is and its spatial relation to other objects (parietal lobe)
VENTRAL STREAM: what stream
- determining perception and recognition of objects and determining shape and colour (temporal lobe)
what are the 9 gestalt principles of perceptual organization
- figure-group relationship (whatever is not in focus is automatically the background)
- illusory contours (perceive contours like circles even when they are not there)
- proximity (close togther makes them group together)
- similarity (group figures according to how closely they resemble each other)
- continuation (interpret interspecting lines as continuous rather than changing direction)
- closure (complete figures that have gaps)
- retinal disparity (depth perception, using the disparity between both eyes to compute distances)
- monocular depth cues (familiar size, linear perspectives, texture gradients)
- motion cues (objects farther away = move slowly rather than objects that are closer
what is bottom up processing
information is sent from lower level processing areas to HIGHER level processing areas
what is top down processing
info from higher level areas sent to lower areas
- higher influences the lower because expectations and previous knowlegde inform perceptions
what is contralaterial organization
left side of the brain controls the right side
right side of the brain controls the left side
what is the fusiform face area
area of the brain that becomes active when people look at faces
the left hemisphere is usually dominant in ____ and the right hemisphere is usually dominant in ____
LEFT:
language processing
logical and analytical tasks
detail oriented processing
reading and writing
RIGHT:
spatial and visual processing
creative and artistic abilities
emotional processing
