Chapter 5 - Sensation and Perception Flashcards
Sensation
Detection of stimuli (physical),
goes to brain
Perception
Interpretation of sensory input, conscious experience
Bottom-up Processing
Basically, start with the individual elements that make up an object, put them together, and interpret as whole
(Building up)
Top-down Processing
Interpret sensory information with existing knowledge, expectations, experience
Transduction
Process whereby the sensory info is converted to neural signals for the brain to interpret
(Translating stimuli to neural signals)
Stimulus
Any DETECTABLE input from the environment
Sensory thresholds:
Absolute Threshold
The minimum amount of stimulation
that can be detected
- 50% of the time
Sensory Adaptation
A decline in sensitivity due to constant stimulation
The Auditory System
Sensory system for Hearing and Sound
Stimulus for Sound
Sound waves
Sound Waves
Vibrations of molecules that travel through a medium, such as air
What can sounds be described in?
Amplitude and Frequency
What is amplitude measured in?
Decibels (dB)
Amplitude graphs are called
Power spectras
Frequency
Pitch of the sound
What is frequency measured in?
Cycles per second or Hertz (Hz)
What does pitch depend on?
Frequency
Range of hertz
20 Hz to 20,000 Hz (spectogram)
Gustatory System
Sensory system for Taste
Gustatory Receptors
Clusters of taste cells found in
the taste buds
Gustatory Receptors
Clusters of taste cells found in
the taste buds
5 different types of taste
Sweet, salty, sour, bitter, umami
Catfish and Taste
•100,000 taste buds (up to 700,000!)
•Located in mouth, lips…all over body
Catfish
•Used for finding prey, mates, navigating
The Olfactory System
Sense of smell, jogs memory
What are the stimuli for the olfactory system?
Chemical substances
What are the receptors in the olfactory system?
Olfactory cilia (hair) to olfactory bulb to other parts of the brain
Unique patterns of what = unique _____
Unique patterns of Stimulation = unique Perception
The Olfactory System animal
Snakes
•No taste or smell receptors
•Jacobson’s organ (Vomeronasal)
The Tactile System
Sense of touch
Tactile stimulation
Anything that comes in contact with skin
Types of tactile stimulation
Temperature, pressure, pain
What matters more in the tactile system?
Higher order processes (e.g. being tickled)
Where do tactile stimulation signals go to in the brain?
Signals to Thalamus, then parietal lobe
A tactile system animal
Vibrating Spiders
• Most have poor eyesight
• Use web vibrations for
• Status of web
• Health • Yummy food
• Courtship
• Territory defense
The Visual System
Sensory system for Light
Sense of sight
What is the stimulus for the visual system?
Light
What is light measured in?
Nanometers (one billionth of a metre)
The Order in which light enters through the eye
- Light enters through the CORNEA ->
- Behind the pupil is the elastic LENS >
- RETINA - multilayered tissue at rear>
- OPTIC NERVE to brain (occipital lobe)
What are the two Visual Receptors?
Rods and Cones
Rods
Receptor with key role in NIGHT and peripheral vision
Cones
Receptor with key role in daylight vision and COLOUR
Gestalt Psychology
Humans have basic tendencies to actively organize what they see
• For human perception, the WHOLE is GREATER than the sum of its parts
• Ambiguous figure-ground relationships
Gestalt Laws of Organization
• Law of similarity (parts of configuration are similar, grouped together)
• Law of proximity (things are close to one another)
• Law of closure (people tend to close the edge)
• Law of continuity (people link continuous lines together)
What are the perceptual constancies?
Shape Constancy, Size constancy, Brightness constancy
Shape Constancy
Perception of certain shapes from different views
Friend’s face has a different shape when you look at their profile than face on - has the friend’s face changed?
Size Constancy
Perception of size from different views
Walk to your car - image on your retina gets larger, do you perceive your car to be growing?
Brightness Constancy
Perception of colour and surroundings due to brightness
Colour of your jacket may be different in full sunlight than in shade
