PSYCH 2H03 Lecture Notes - Lecture 2: Two-Streams Hypothesis, Depth Perception, Ganglion Cell
11 Jan 2017
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Learning Lec 2 Visual Perception
Written assignments:
- 2 written assignments (5% and 10%)
- Based on experience as participant in cognition-based experiment (e.g. 9 and 52)
- 2% of grade for participation in SONA experiment (1-hour minimum)
- Maximum 2 pages
- Keep the study debrief form
- APA formatting and referencing (including running head, page numbers, etc.)
Chapter 3: Visual Perception
Perceiving the World
- We see the world in terms of meaningful objects
• Visual input needs to be organized
• The visual stimulus that our brain receives does not consist of objects
• Therefore, a lot of processing needs to be done and assumptions need to be made
by our perceptual system
Perception does not equal Sensation
- Stimulus projects on retina, giving a two-dimensional representation of different colours
and intensities of light
• Structure of eye designed to project sharp image onto retina – it is a sophisticated
organ
• We must interpret what we see (perception)
- Out perception goes beyond the information that is given
• Cube: see two images from one picture, different orientations of a cube
Components of visual perception
- Form perception: what is it?
• Identification of objects
• Occipital-temporal pathway (ventral stream) – under
• Damage to system: visual agnosia (inability to recognize objects, cannot interpret
what an object is)
- Depth perceptions: where is it?
• Location of objects and guiding actions and response
• Occipital-parietal pathway (dorsal stream) – over
• Damage to system: problems with reaching for objects and depth perception
- Motion perception: what is it doing?
The Visual System
- Light enters the eye through the cornea
- Cornea and lens refract light rays, producing a sharp image on the retina at the back of
the eye
- Iris opens and closes to control amount of light that enters the eye
- Retina has three layers:
1. Photoreceptors: rods (light and dark, monochrome, does not require much light) and
cones (colour, requires light)
2. Bipolar cells: transmit signals from photoreceptors to ganglion cells
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Based on experience as participant in cognition-based experiment (e. g. 9 and 52) 2% of grade for participation in sona experiment (1-hour minimum) Apa formatting and referencing (including running head, page numbers, etc. ) Out perception goes beyond the information that is given: cube: see two images from one picture, different orientations of a cube. Identification of objects: occipital-temporal pathway (ventral stream) under, damage to system: visual agnosia (inability to recognize objects, cannot interpret what an object is) Depth perceptions: where is it: location of objects and guiding actions and response, occipital-parietal pathway (dorsal stream) over, damage to system: problems with reaching for objects and depth perception. Light enters the eye through the cornea. Cornea and lens refract light rays, producing a sharp image on the retina at the back of the eye. Iris opens and closes to control amount of light that enters the eye. Brain: thalamus or lateral geniculate nucleus to primary visual cortex in occipital lobe.
