Chapter 4: Sensation And Perception Flashcards
Sensation (window to the world)
The stimulation of a sense organ
Brain receives input from your sensory organs
Perception (interpreting what comes through your sense window)
The brain makes out the input from the sensory organs
Transduction
Sensors in your body that convert physical signals from the environment into encoded neural signals which are sent to the CNS
Five senses
Taste, touch, sight, smell, hearing
Psychophysics
Relationship between physical stimuli and sensory response
Gustav Fechner
Structuralist: bits and pieces of consciousness
Absolute threshold
Minimal intensity needed to just barely detect a stimulus 50% of the time
We are most sensitive to a range of _____ corresponding to _______
Tones……… human conversation
Too high of a frequency
We can’t hear it
Too low of a frequency
We can’t hear but can feel
Absolute threshold
How sensitive we are to faint stimuli
Signal detection
Sensory signals face a lot of competition for our attention
Signal detection theory
Response to a stimuli depends on the sensitivity
Detecting signals in the environment
- absolute threshold
- just noticeable change
- noise in environment
- what choosing to pay attention to
Multitasking
Attention to auditory signals means processing of visual signals greatly decreases
Multitasking effects:
The ability to stay focus
Hurts the performance and productivity
Sensory adaptation
Sensitivity to prolonged stimulation declines over time as you adapt
Vision
- Sensing light
- Wavelengths
Accommodation
Focussing- changing lense
Parts of the eye
Cornea, Retina, pupil, iris
Photo receptor cells
In the retina, contain light sensitive pigaments
Two types of photoreceptors
Rods and cones
Rods
Black and white
Oppreates in low light
Not as detailed
Cones
Detect colour
Operate in normal life
Fine details
Fovea
No rods, has the clearest vision
The path of light entering the eye
1) light rays come in and hits the rods and cones
2) Activate bi-polar Cell’s
3) Activate retinal ganglion cells
4) bundles RTC forms optic nerve
5) Goes to thalamus
Blind spot
No rods or cones
Perceiving light
3 types of cones
Blue red green
Perceiving shape
Specialized Neurons
Visual streams
Distinct pathways from occipital cortex to visual areas on other parts of the brain
Ventral stream
The what stream! Temporal lobe
Dorsal stream
Where stream (parietal lobe)
Visual form agnosia
Inability to recognize objects by sight
Visual illusions
Specialized neurons and feature detectors
Parallel processing
Brain processes and makes sense of several aspects of stimulus simultaneously
Binding process
Information from dorsal (where) stream and ventral (what) stream
Perceptual constancy
If a chair tunes blue, we still recognize the chair
Perceiving motion
Need to encode information about space and time
Perceiving change
Change blindness (not noticing the waiter changing)
Audition (hearing)
Hearing is sensing changes in air pressure that unfold in rapid succession over time
3 dimensions of sound waves
1) frequency: correspond to our perception of pitch
2) Amplitude: corresponds to our perception of loudness
3) complexity: corresponds to our perception of timbre
Nature sounds
Relief stress, lowered blood pressure, anxiety, agitation
Parts of the ear
Pinna Ear canal Eardrum Middle ear Inner ear Eustachain Tube
Cochlea
Fluid filled, site of transduction
Procedure or hearing
1) Tiny ear bones amplify sound
2) Chohlea sorts sounds by frequency
3) nerve passes signal from choclea
Sounds above _____ dcibals can cause hearing loss
85
Touch
Haptic Perception
How we feel in the world
Transduction of skin sensations into neaural signals
Pain, pressure, texture, pattern, vibration
Pain
Neccecary for our survival
Neural signals travel to 2 distinct areas in your brain
Gate control theory of pain
Stop pain by rubbing area
Activated neurons
Body positioning
Proprioception: where you are in space
Smell (olfactory)
Only sense that has a direct route to the forebrain
By passes the thalamus
Taste
Necessary for our survival. Poisons are bitter
Papillae
Within one is taste buds
5 primary tastes
Sweet, sour, bitter, salty, unami
Expectations relate to taste
If a candy is yellow, assume it is lemon
New studies find that…..
Sight, hearing, smell, and touch all intertwine
Changing the shape or texture of food can change its taste
Crossmodel interactions
5 senses are not distinct pathways into consciousness
Why do crossmodel interactions occur
Possible neaural connection between auditory nerve and olfactory bulb
Synesthsia
Extra ability
Hear colour, see sound, taste touch
Greek word for: to perceive together
