Receptors

• Transduction vs. Conduction

Taste Experiment

• Close eyes• Instructor will hand you a piece of gum• Pinch nose closed and hold closed with one hand• Insert gum into mouth and chew with other hand• Try to guess flavor• Rate flavor intensity on scale of 1 to 3

– 1 no flavor– 2 mild flavor– 3 strong flavor

• Repeat procedure but with nose unplugged• Record results

Photoreception and Local Integration

Blind spot test

• Follow instructions on hand-out

• Measure distance of paper to eye (each eye)

• Record distance in cm

Sound

Transduction of Sound

Sound Waves (outer ear)

Mechanical Vibrations (middle ear)

Fluid Waves (inner ear)

Chemical signals

Action Potentials

Amplitude = loudness = Greater bending of hair cells

Wavelength = pitch = Location of crossing along cochlear duct

Mosquito Sounds

Somatic Sensory Receptors

Thermoreceptors

• Map location of hot and cold receptors on back of hand– Indicate location of 25 receptors

• Blue for cold• Red for hot

• Take picture of map with digital camera

Two-point Threshold

Test on

1. Back of hand

2. pointer finger, finger tip

3. One other location of your choosing

Record distance between tips of toothpick when 2 points can be detected

Keeping the Information Straight

• Modality

• Location

• Intensity

• Duration

• Integration

Perception is dependent on communication between different parts of the brain

Temporal Lobe of Cerebrum

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Facial Recognition

Temporal Lobe of Cerebrum