Lecture 16 Flashcards
What is Difference Threshold?
The smallest difference between two stimuli that can be detected 50% of the time
What is Weber’s Law?
The idea that the difference threshold is directly proportional to the magnitude of the stimulus with which the comparison is being made
How do sensory neurons respond to constant levels of stimulation?
By decreasing the activities of those neurons
What does Sensory Adaption refer to?
Diminishing sensitivity to an unchanging stimulus
What part of the electromagnetic energy spectrum can humans see?
400nm to 700nm
What is the Cornea?
Transparent protective structure at front of eye
What is the Pupil?
Adjustable opening behind cornea that controls amount of light entering the eye
What is the Lens?
Elastic structure that change form to help focus
How does the lens focus more on distant objects?
Becomes thinner
How does the lens focus more on closer objects?
Thicker
What is the retina?
A multi-layers structure at the back of the eye contains light-sensitive photoreceptors which transduce light energy into electrical impulses
What is Myopia?
Nearsightedness, light focussed in front of the retina
What is Hyperopia?
Farsightedness, light focussed behind the retina
What are Rods?
One of two types of light sensitive cells found in the retina
What are the characteristics of Rods?
Contribute to black/white vision Function best in low light 500 more times sensitive than cones Found throughout the eye but not in the fovea. Concentrated mostly in peripheral vision
