Seeing

Today we discussed sensation and perception.  First, we talked about how there are special receptors for specific types of energy (e.g., light, pressure) and how different animals have the abilities to detect some stimuli that humans cannot detect.  Then we moved to the eye and I described its structure.  To illustrate the different distribution and function of rods and cones (photoreceptors), we attached different letters, numbers and colors to a stick and moved them from the peripheral visual field to the central part of the visual field.  It was easy for the monks to demonstrate that motion can be detected in the periphery and that an object must be in the central part of the visual field to see color and detail.  The monks also experimented with the blind spots in their eyes by moving different shapes and lines in front of themselves so the image fell on to their optic disks (no photoreceptors).  I ended the day by showing several visual illusions; the monks were very interested in these illusions and what they said about perception.