sensation perception and visioncoursework.mansfield.edu/psy1101loher/1101 - 9 - vision... · 2020....
TRANSCRIPT
Sensation and Perception
Be able to recognize:
1. Difference between “sensation” and “perception.”
2. Absolute thresholds (with examples) and just noticeable
differences.
3. Parts and functions for major components of the visual
processing system.
4. Explanation for near- and far-sightedness.
5. Dark and light adaptation. (text)
6. Hubel and Wiesel's study of processing in the visual cortex.
(text & video)
7. SKIP theories of color vision.
Objectives
Sensation and Perception: The Distinction
• Sensation:
Immediate response in the brain caused by
stimulation of a sensory organ (eye, ear, etc.).
• Perception:
Selection, organization, and interpretation of
sensory input
( adapted from Thomson Higher Education, 2007, 2001)
Sensation
Sensation begins with a detectable stimulus
– Fechner: Concept of “threshold”
– “Absolute threshold” = Detected 50% of the time.
( adapted from Thomson Higher Education, 2001)
Some Human Thresholds
(adapted from Wadsworth/Thomson Learning, 2001)
Visual Sensation
The Eye
( adapted from Thomson Higher Education, 2007)
Cornea Transparent “window” at front of eye
Iris Colored circular muscle that expands and
contracts, controlling amount of light that enters
the eye - Responsible for eye color
Pupil Opening at center of eye through which light
passes
Lens Transparent – focuses light on retina
Blind Spot Area of the retina lacking visual receptors
The Eye
(Cengage, 2019)
The Retina: An Extension of the CNS
• Retina: absorbs light, processes images,
and sends information to the brain
• Receptor cells:
– Cones: Visual receptors for colors and
bright light (daylight)
– Rods: Visual receptors for dim light; only
produce black and white
• Adaptation: becoming more or less sensitive to
light as needed
( adapted from Thomson Higher Education, 2007)
Rods, Cones, & Ganglion Cells
(adapted from Wadsworth/Thomson Learning, 2001)
Nearsightedness
Farsightedness
Dark
Adaption
Visual
Pathways
Hubel & Wiesel: Feature Detectors
Discovering Psychology - Zimbardo
Post-
Occipital
Processing
Reading?