Please Do eat the candy or drink the tea!

Please Doeat the candy or drink the tea! NOT Wait for the instructions.

Biological Psychology:Mechanisms James Kalat N. C. State University

1. Taste Receptors:sweet, sour, salty, bitter, umami • Tea made from leaves of gymnema sylvestre block sweet tastes. (Also block intestinal absorption of carbohydrates.)

2. Neurons and the Action Potential • No loss of intensity as action potential travels • Can be relatively slow. • Demonstration of action potential speed

Velocity of Action Potential =Mean distance from ankle to shoulder/mean difference in response latency =About 1.5 meters/ ______ =

Correct reference: • Rozin, P., & Jonides, J. (1977). Teaching of Psychology, 4, 91-94.

Vision How far can an ant see?

3. Color Vision Young-Helmholtz theory (=trichromatic theory)

Color Vision Opponent-process theory

Rods and cones: • Cones in fovea (center); rods more common toward periphery • Cones for color; rods for b/w • Therefore: Colorblind in periphery. Demonstration

Opponent process theory of color vision:We perceive by three pairs of opposites: • Red versus green • Yellow versus blue • White versus black • Evidence: Negative afterimages

Retinex theory of color vision • We perceive color and brightness by contrasting each image with the rest of the scene. • Combine retina and cortex. • Produces color constancy: Same color despite changes in lighting.

Please Do eat the candy or drink the tea!