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absolute sensory threshold
the minimum amount of a stimulus you need to perceive a sensation
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sensation
detection of an reaction by sensory stimuli through sensory organs and transmission of response to the brain
sensory stimuli -> sensory organs -> brain
-biological impact
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perception
-processing and interpretation of sensory stimuli
-psychological impact that is driven by our present/past experience
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difference threshold
the minimum amount of stimuli needed to perceive a difference
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Weber's law
Webster believes that to perceive a difference, the stimuli must have different constant proportion and not have a constant amount
- example:
- using extra $200 for laptop (unlikely to spend)
- vs.
- using extra $200 for house (likely to spend)
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signal detection theory
detection of a stimulus depends partly on a person's:
- experiences
- expectations
- alertness
- motivation
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blindsight
the ability to respond visual stimuli without having any conscious visual experience
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fovea
-it is densely packed with cones
-has the highest visual
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interaural time difference
to perceive a difference in arrival time of sound between the two ears
allow us to localize sound
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feature detection
the way neurons in the visual pathway respond to specific features of a stimulus
angle, shape, direction of movement
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subtractive color mixing
physical mixing of color to remove reflected wavelengths
combination of pigments
ex. mixing paints
you see color black
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additive color mixing
mixing of different wavelengths of light to increase reflected wavelengths
combining light to get white
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color constancy
we perceive familiar objects as having consistent color
even if changes in illumination alter the wavelengths being reflected
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bottom-up processing
sensory information starts from low level to high level of processing area
low level = entry level sensation
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top-down processing
information from higher order processing areas influences sensory information at low level areas
-we use our expectations and past experiences to interpret sensation
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TASTE
What is the stimulus energy needed?
gustation (the action of tasting)
sweet, salty, sour, bitter, umami
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TASTE
What sensory organs are involved?
sensory organs to taste include, tongue, mouth and throat
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TASTE
What sensory receptor types are involved?
the cilia is a small hairlike receptor that sticks out to receive info
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TASTE
What is the pathway to the brain?
taste receptors in taste bud transmit signal along a cranial nerve through the thalamus, to other areas of the brain resulting perception
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SMELL
What is the stimulus energy needed?
- Olfaction-the sense of smell
- the only sense that doesn't go to thalamus first
volatile chemicals act as stimulus energy
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SMELL
What is the pathway to the brain?
pathway to the brain glides along the olfactory nerve to areas of the cortex and amygdala
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SMELL
What sensory organs are involved?
the nose and nasal passage
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SMELL
What sensory receptor types are involved?
olfactory receptors, in the olfactory epithelium, transmit the signal to the olfactory bulb which transmits it along the olfactory nerve to areas of the cortex and amygdala
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TOUCH
What is the stimulus energy needed?
touch is stimulated through temperature and pressure
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TOUCH
What sensory organs are involved?
skin is a sensory organ for touch
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TOUCH
What sensory receptor types are involved? How is the sound transduced, as in converting energy from one form to another?
receptors are found everywhere, mainly at base of hair follicles
- 2 type of fibers transduce pain signals
- fast fibers create sharp and immediate pain
short fibers create dull, chronic pain that makes the person remember not to make same mistake
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TOUCH
What is the pathway to the brain?
temperature and pressure receptors in your skin transmit signal from brain stem to thalamus
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SOUND
What is the stimulus energy needed?
stimulus like noise with different wavelength (noise), frequency (pitch) and amplitude (intensity)
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SOUND
What sensory receptor types are involved? How is the sound transduced, as in converting energy from one form to another?
- sound wave enters pinna
- moves down ear canal
- vibrates ear drum
- cause ossicles to vibrate
- vibrate oval window creating waves in cochlear fluid
- waves in fluid cause basilar membrane to move
- this bends hair cells
- moving hair cells transmit neural signal to auditory nerve
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SOUND
What is the pathway to the brain?
the pathway to the brain starts from the auditory nerve
going to thalamus
specifically to the medial geniculate nucleus
and the thalamus will transfer the wave to the auditory cortex
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What are the 2 types of photoreceptors in the retina?
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What are the functions of the 2 types of photoreceptors?
- Rods
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found in periphery - -respond to low light
- -night vision
- Cones-found in center
- -respond to high light
- -color vision
- -vision acuity
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How does light move through cell layers in the retina?
1. bleaching - light enters the eye and break down photopigments
2. causes membrane changes in photoreceptor
3. activates interneurons
4. interneurons work to exaggerate signals from photoreceptors
5. pass signals to ganglion cells
6. ganglion cells- first neurons in visual pathway with axons
7. collect info from a group of bipolar cells/interneurons
8.send signal to optic nerve
9.optic nerve sends signal from retina to brain
10. half of he nerves cross over at the optic chiasm
11. from optic chiasm signal goes to thalamus
12. info then sent to visual cortex
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What are the functions of our "other senses"?
kinesthetic sense
vestibular sense
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kinesthetic sense
- position of your body and limbs in space
- and in relation to one another
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vestibular sense
sense of balance
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How do we use monocular cues to judge depth?
Monocular cues judge depth through the use of separate eyes
top down processing
linear perspective
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monocular cues -linear persepective
parallel lines, width length decreases when distance increase
ex. train tracks
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monocular cues - relative size/ height
we perceive objects that are higher in our view as being farther away
objects that are farther away seem smaller on the retina than close objects of the same size
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