Serial Conscious Processing

• Slower than parallel processing• Allows us to solve new problems which

require focus

• Volunteers?

Selective Attention

• Relate back to bias– Class experience: awareness of your nose, fingers,

hands, feet, smells, sounds, sights – or are you just taking notes?

• Selective Attention: focusing conscious awareness on PARTICULAR stimulus

Selective Inattention

http://www.youtube.com/watch?v=vJG698U2Mvo

Selective Inattention• Inattentional Blindness: failing to see visible

objects when our attention is directed elsewhere

• Change Blindness: failing to notice changes in the environment

http://www.youtube.com/watch?v=VkrrVozZR2c

Other types of blindness

• Choice-blindness: people seldom notice deception and will in fact readily explain a wrong preference– Johansson experiment (2005)

• Choice-blindness blindness: people tend believe they have the ability to perceive deception when it occurs

Pop-out phenomenon

• When stimuli are so powerful and strikingly distinct, we don’t choose to attend to the stimuli, they draw our eye and demand our attention

Review Brain Games: Pay Attention• Inattentional blindness

– Failing to see visible objects when our attention is directed elsewhere

• Change blindness– Failing to notice changes in the environment

• Choice blindness– People seldom notice deception, and will readily explain a

wrong choice• Choice-blindness blindness

– When asked if they would notice deception in an experiment in which they were deceived, most insist they would

• In other words – it’s a blindness of their blindness

Unit 4: Sensation and Perception• Sensations: take stimuli in• Perception: what we do with it

• Psychophysics: study of relationship between physical characteristics of stimuli and our psychological experience of them

Thresholds• Absolute threshold – try a riddle?– Gustav Fechner

• Signal detection theory– Totally depends on you and your experience– Think of airport security baggage screeners

• Subliminal– Literally “below threshold”– Is it legit? Yes – how does absolute threshold explain it?– Can advertisers use it to persuade us? No – explain using the word fleeting– What is the end result? Much of our information occurs automatically, out of sight, off

the radar screen of our conscious mind– Priming?

• Difference threshold– Also called just noticeable difference (JND)– Detectable difference increases with size of stimulus– Weber’s law (proportion – not amount)

• Sensory adaptation– Why does your fart only smell for a little bit?– Darting eyes

Vision

• The eye receives light waves and converts energy into neural impulses by a process called Transduction.

http://www.exploratorium.edu/learning_studio/cow_eye/video_big_all.htmlhttp://www.exploratorium.edu/learning_studio/cow_eye/video_big_all.html

The Process• Light energy hits the rod or cone which

creates a photochemical reaction • Photochemical reaction creates an

electrical impulse sent to bipolar cells, which funnel the electricity to ganglion cells

• Ganglion cells, whose combined axons create the Optic Nerve,

• which leads to the brain. The spot where the Optic nerve leaves the eye is a blind spot.

Where feature detectors detect.

Visual Processing

• Feature detectors: – Separate neurons/neural networks in the

brain– sensitive to specific stimuli, angles, lines,

edges, shapes or movements– allowing brain to differentiate individual

objects or movements to concentrate on.

• Wavelength = hue• Amplitude = brightness

Problems

• If the lens or cornea is distorted in relation to the eye then it affects the acuity or sharpness of the image seen.

• One is said to be either nearsighted or farsighted when this occurs.