1. E2 Perception of Stimuli
To what extent is what we perceive a construct of our minds and limited by the receptors we have?

2. E2.1 Sensory receptors
Mechanoreceptors: respond to mechanical force or pressure
E.g. pressure receptors in arteries respond to change in blood pressure, pressure receptors in our inner ear are sensitive to waves of fluid
Chemoreceptors: respond to chemical substances
E.g. pain receptors respond to chemicals released by damaged tissues
E.g. taste receptors in tongue

3. E2.1 Sensory receptors
Thermoreceptors: respond to change in temperature
E.g. warmth receptor/cold receptor
Photoreceptors: respond to light energy
E.g. rod cells (black/white vision) and cone cells (color vision)

4. E2.2 The human eye

5. E2.4 Rod vs Cone cell Rod Cone
Sensitive to light and function in dim light
Less sensitive to light and function in bright light
One type of rod: absorbs all wavelengths of visible light
Three types of cones: sensitive to red light, blue light and green light respectively
Group of rod cells (up to 200) connected to optic nerve
Single cone cell connected to optic nerve
Widely dispersed through the retina give wider field of vision
Cone cells concentrated near fovea

6. E2.3 The retina
Rod/cone cells synapse with bipolar neurons which synapses with a ganglion cell.
Axons of the ganglion cell make up the optic nerve.

9. Which side of the band is darker?

11. Contralateral processing
Nerve fibers bringing information from the right half of the visual field converge at optic chiasms and pass to the left brain (and vice versa) = contralateral processing
Two eyes are apart, images are slightly different  3D stereoscopic vision