Sensation and Perception Flashcards
Sensation
The detection of physical energy by sense organ, which then sends info to the brain
Perception
The brain’s interpretation of raw sensory input
Transduction
Process of converting external energy or substance into electrical activity within neurons
Absolute Threshold
Lowest level of a stimulus need for the nervous system to detect a change 50% of the time
Weber’s Law
Constant proportional relationship between the smallest change we can detect and the original stimulus intensity
This means that the larger the original stimulus, the larger the just noticeable difference needs to be for it to be detected.
Vestibular Sense
Inner ear senses balance, spatial orientation
How one’s body is oriented with respect to gravity
Proprioception/Kinaesthetic Sense
Body position and movement of body parts relative to one another
Sensory Capacities at Birth - Hearing
Babies can hear before birth
Preference for complex sounds
Sensory Capacities at Birth - Vision
Limited Focus / Poor Acuity
Difficulty Discriminating Colour - Less intense
Rapid development, by 11 months acuity adult level (2 months focus)
Early Vision
Prefer Faces Overall
Contrast Sensitivity
Depth Sensitivity
Sensory Capacities at Birth - Pain
CNS Immaturity
May feel pain more intensely
Risk of pain medication
Pain relief from - Breast milk, Sugar Solution , Comfort from holding
Vision as we age
Visual Acuity worsens
Increase in use of corrective lenses
Acuity
sharpness or keenness of thought, vision or hearing
Macular Degeneration
Causes loss in the centre of the field of vision
Presbyopia
Harder to focus on nearby objects
Impaired Eyesight can happen due to ….
Reduction in light reaching retina
-Increased sensitivity to glare
-Harder to perceive colour
-Harder to see in dim light
Presbycusis
Age related hearing loss
Why does hearing decline?
Degeneration of neural pathways
- Reduced Blood Supply
- Cell Death
Sensation
The detection of physical energy by sense organ, which then sends info to the brain
Perception
The brain’s interpretation of raw sensory input
Ambiguous Figures
Perception not fixed/absolute - single image can have multiple interpretations
Perceptual Organisation
The way information is received by our senses and interpreted to make it meaningful.
What are the 4 aspects of perceptual organisation?
Form Perception
Depth or Distance Perception
Motion Perception
Perceptual Constancy
Form Perception
Organises sensory information into meaningful shapes and patterns
Perceptual Set
Expectations influence perception
Only see certain aspects, ignore details
Gestalt View
The whole is more than the sum of the parts
We tend to organise visual elements into groups or unified wholes
6 Gestalt Principles
Law of proximity
Law of similarity
Law of continuity
Law of closure
Law of symmetry
Form and Ground
Depth or Distance Perception
The organisation of perception in three dimensions
Monocular Cues
Binocular Cues
Motion Perception
Monocular cues
Uses visual input from one eye
Binocular Cues
Uses visual input integrated from the two eyes
Binocular Disparity
Each eye gets a different picture of the world
The greater the difference between pictures the closer the object
Binocular Convergence
Eyes points inwards when looking toward close objects
Eyes move outwards when looking at distant objects
Perceptual Constancy
Ability to maintain an unchanging perception of an object despite variations in retinal image
Three main types of Perceptual Constancy
Size Constancy
Shape Constancy
Colour Constancy
Shape Constancy
Perceive true shape of object despite variations in shape in the retinal image
Colour Constancy
the perceived color of objects remains relatively constant under varying illumination conditions.
Size Constancy
Ability to perceive the true size of an object despite variations in the size of the retinal image
Inattentional Blindness
Failure to perceive a prominent object because attention is on another task
Change Blindness
Failure to perceive changes in a scene when there is a momentary interruption to views of that scene
