Sensation & Perception

Sensation: The set of processes by which our sense organs receive information from the environment.  Transduction: The process by which physical energy is converted into sensory neural impulses.  Perception: The set of processes by which people select, organize and interpret sensations.

Transduction

Transduction

Opponent Process Theory

During transferal from ganglion cells to visual cortex, output organized in terms of contrasting colors:• Red-Green

some cells stimulated by green and inhibited by redothers stimulated by red and inhibited by green

• Blue-Yellow• Black-White

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Pictorial cues (can be detected in drawing or photo)     Overlap

Pictorial cues (can be detected in drawing or photo)     Overlap     Height in field of view

Pictorial cues (can be detected in drawing or photo)     Overlap     Height in field of view

• Below horizon, nearer objects are lower in the plane• Above horizon, nearer objects are higher in the plane

Pictorial cues (can be detected in drawing or photo)     Overlap     Height in field of view     Linear perspective 

Pictorial cues (can be detected in drawing or photo)     Overlap     Height in field of view     Linear perspective     Atmospheric perspective 

Retinal Size

Pictorial cues (can be detected in drawing or photo)     Overlap     Height in field of view     Linear perspective     Atmospheric perspective     Familiar size 

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Pictorial cues (can be detected in drawing or photo)     Overlap     Height in field of view     Linear perspective     Atmospheric perspective     Familiar size     Shadows & brightness

 

Ocular motor cues (signals from eye muscles)     Convergence

Ocular motor cues (signals from eye muscles)     Convergence     Accommodation

Binocular disparity

If your SSN ends in an EVEN number, CLOSE your eyes

If your SSN ends in an ODD number, keep your eyes OPEN

If your SSN ends in an ODD number, CLOSE your eyes

If your SSN ends in an EVEN number, keep your eyes OPEN

Top-down and bottom-up processing

Visual Illusions

Ponzo Illusion

Muller-Lyer Illusion

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are needed to see this picture.

Here is a visual-perception challenge for you. See how quickly you can find the dogs in the picture on the next slide. For some reason, men seem to do better at this than women.

Hint: The dogs appear to be white with black spots.

The following are average times for men and women:

Women - 12.46 minutesMen - .23 seconds

Typical Comments by People Taking the Test1. "I couldn't see a dog and I stared at the picture for a good 10 minutes." - Jennifer2. "I think it is one of those pictures where you have to stare at a certain spot and then everything comes into focus, but it never happened to me.  I'll give it another try later." - Mary3. "I almost didn't find the dogs at all!" - Jessica4. "There is a dog in this picture? Where?" - Tara5. "This must be a joke; there are no dogs in this picture." - Amanda