Chapter 4: Sensations and Perceptions Flashcards
Sensation
the activation of receptors in the various sense organs
Sense organs:
- Eyes
- Ears
- Nose
- Skin
- Taste buds
Sensory Receptors
specialized forms of neurons which send messages to the CNS when stimulated
Absolute Threshold
the smallest amount of energy needed for a person to consciously detect a stimulus 50% of the time it is present
Subliminal Stimuli
stimuli that are below the levels of conscious awareness
- Just strong enough to activate sensory receptors but not strong enough for people to be aware of them
Sensory Adaptation
the tendency of sensory receptor cells to become less responsive to a stimulus that is unchanging
Theories of Color: Trichromatic Theory:
there are 3 main colors; Red, Green and Blue which all combine to create different colors we see
Theories of Color: Opponent Process Theory:
proposes four primary colors with cones arranged in pairs: red and green, blue and yellow and black and white
Retina
the inner membrane of eye that receives information about light using rods and cones
Rods
visual sensory receptors found at the back of the retina, responsible for black and white visions, night vision and peripheral vision
Cones
visual sensory receptors found at the back of the retina, responsible for color vision and sharpness of vision and daylight vision.
Types of Color Blindness
- Monochrome colorblindness: either has no cones or has cones that are not working at all
- Red green colorblindness: either the red or the green cones are not working
5 Basic Tastes
- Sweet
- Salty
- Sour
- Bitter
Brothy
Taste Buds:
taste receptors cells in the mouth responsible for sense of taste
Gustation
the sense of taste
Olfaction(olfactory sense)
sense of smell
olfactory Bulbs
area of the brain located above the sinus cavity and below the frontal lobes which receive information from the olfactory receptor cells
Somesthetic Senses
the body’s senses consisting of the skin sense, kinesthetic sense and the vestibular sense
- e.g. Skin: the sensations of touch, pressure, temperature and pain
Vestibular Sense
also known as the movement, gravity or balance sense which helps us move smoothy
Gate Control Theory
states that all pain signals must pass through a “gate” located in the spinal cord
Perception
the method by which sensations experienced at any given moment are interpreted and organized into some meaningful fashion
Size Constancy
the tendency to interpret an object as always being the same actual size regardless of its distance
Shape Constancy
the tendency to interpret the shape of an object as being constant even when its shape changes on the retina
Gestalts Princples
- Figure Ground
- reversable figures
- similarity
- proximity
- closure
- continuity
- contiguity
Gestalts Principles:
Figure Ground
the tendency to perceive objects, or figures, as existing on a background
Reversable figures
visual illusions in which the figure and ground can be reversed
- 3d square which can be seen two ways
Gestalts Principles:
Similarity
the tendency to perceive things that look similar to each other as being part of the same group
Gestalts Principles:
Proximity
The tendency to perceive objects that are close to each other as part of the same grouping
Gestalts Principles:
Closure
the tendency to complete figures that are incomplete
Gestalts Principles:
Continuity
the tendency to perceive things as simply as possible with a continuous pattern rather than with a complex broken up pattern.
Gestalts Principles:
Contiguity
the tendency to perceive two things that happen close together in time as being related
Depth Perception
he ability to see the world in 3D by telling how far away objects are based on what we see
Clues are either Binocular (3d) or Monocular(2d)
Binocular Clues: Convergence:
when our eyes rotate to focus on an object, the greater the convergence for closer objects and the less the convergence for further objects
Monocular clues: Linear Perspective:
the tendency for parallel lines to converge on each other
Monocular Clues: Relative size
when two objects are similar size but placed at different distances, the closer is viewed as larger
Monocular Clues: Texture Gradient
as distance increases, texture becomes denser and details less distinct
Monocular Clues: Interposition(overlap)
objects that obscure or overlap other objects are perceived as closer
Monocular Clues: Aerial Perspective:
Distant objects appear hazy and blurred due to interfering atmospherically dust compared to closer objects
Monocular Clues: light and shadow
brighter objects are seen as closer than darker and shadowy subjects
Monocular Clues: relative height:
objects that are higher in our field of vision appear to be further away
Factors influencing Perception: Top Down Processing
the use of preexisting knowledge to organize individual features into a unified whole
Factors Influencing Perception: Bottom up Processing
the analysis of the smaller features to build up to a complete perception
- More likely to use for things we have not seen before
