Chapter 4 Sensation and Perception

You Tube: Hallucination video

 Sensation – process of receiving information from the environment.  Adaptation – allows us to filter meaningless stimuli out.  Perception – process of organizing sensory info to make it meaningful. Demonstrations – 4x4 Squares; Eye Dropper A)Sensation – dominated by vision. 1) Sight – light is broken down from white (origin-sun) to wavelengths/frequencies.

 Evidence suggests that other senses will compensate partly for sight loss. Explore PCS  Over time, as our lens becomes less flexible, focusing on objects gets tougher….thus eyeglasses.  Afterimages (p97) 2) Hearing – comes in the form of sound waves. Humans lag behind some animals in use of sound. (Dolphin, Dog) Measured intensity (loudness) isMeasured intensity (loudness) is through the Decibal.

Test Your Sense of Pitch You will hear a number of well-known tunes. Some will be played correctly, while others will be played incorrectly (with some wrong notes). Your task is to decide whether the tunes are played correctly or incorrectly. Here's an example to show you the kind of thing to expect. Click the link below that says "Play example tune." A music player will load on a new page and begin playing the tune. When it finishes, use your browser's Back button to return to the quiz. After taking the test you can see if you can hear pitch or not.

3) Touch – “Cutaneous” senses, based on three types of receptors: a) Pressure Report b) Temperature Report c) Injury/Poison Report…ugh Demo. Touch Threshold - toothpicks 4) Smell – olfaction; powerful in humans when involved in emotional events. Ex. Cotton Candy….others? Our most animal-like, though we lag here in this area as well.

 Pheremones – odor chemicals emitted by the body. Designed to “reach” a partner.  Do we have these? 5) Taste – from receptors called “Buds.” Four types: salt, sweet, sour, bitter. “Need” for sugar/salt based on physical demand (pregnancy tastes, etc.) for balance.“Need” for sugar/salt based on physical demand (pregnancy tastes, etc.) for balance. “Detectors” of bitter and sour also natural (poison, spoiled food)“Detectors” of bitter and sour also natural (poison, spoiled food) Connection to vision andConnection to vision and Appearance (p105)

B) Perception – The way we “see” things. 1) Size Constancy – the ability to maintain the size of an object regardless of distance from you. Ex. Moon/Thumb Ex. ants/skyscrapers. Size and maturity of people is a factorSize and maturity of people is a factor Color, Shape, Space, Brightness also.Color, Shape, Space, Brightness also. 2) Depth Perception – ability to see the relation of objects in space. Inherent very early in life…see text “baby cliff.” Ex. All thumbs p.109

Dog Depth Perception FAIL

Adaptability of Senses