Sensation & Perception

The Lion King

Political Subliminal Message ection/index.php?nav_action=election&nav_su baction=overview&campaign_id=177 ection/index.php?nav_action=election&nav_su baction=overview&campaign_id=177 ection/index.php?nav_action=election&nav_su baction=overview&campaign_id=177 ection/index.php?nav_action=election&nav_su baction=overview&campaign_id=177 What impact does this message have? What impact does this message have? Will it last? Will it last?

Subliminal Messages Hidden messages targeted at our subconscious mind. Hidden messages targeted at our subconscious mind. Examples: Small images inside a larger picture Examples: Small images inside a larger picture An audio message hidden inside a recording An audio message hidden inside a recording Messages in song played backward Messages in song played backward Hidden words or pictures that quickly appear Hidden words or pictures that quickly appear Powerful marketing tools Powerful marketing tools Effect us on a emotional level Effect us on a emotional level Short lived results Short lived results

Sensation & Perception Sensation- stimulation of the sense organs Sensation- stimulation of the sense organs Raw data of experience: smells, sights, sounds, pain, etc. Raw data of experience: smells, sights, sounds, pain, etc. Perception- creating meaning from the raw sensory information Perception- creating meaning from the raw sensory information

Basic Process 1. Sensory organs absorb energy from a physical stimulus in the environment 2. Sensory receptor cells detect stimulus energies and convert them into neural impulses (transduction) 3. The message is sent to the brain by way of neurons 4. Specific areas of the brain organizes the input and transforms them into something meaningful

Psychophysics Threshold- is a dividing point between energy levels that we do or do not detect Threshold- is a dividing point between energy levels that we do or do not detect Absolute Threshold- minimum amount of stimulation that an organism can detect 50% of the time Absolute Threshold- minimum amount of stimulation that an organism can detect 50% of the time Environment can affect detection of a stimulus Environment can affect detection of a stimulus Online demo: Online demo:

JND- just noticeable difference is the smallest difference in the amount of stimulation that a specific sense can detect The absolute threshold is the jnd from nothing (no stimulus) The absolute threshold is the jnd from nothing (no stimulus) JND is greater for stronger stimuli than for weaker ones JND is greater for stronger stimuli than for weaker ones As a stimulus increases in magnitude, the JND becomes larger As a stimulus increases in magnitude, the JND becomes larger

Sensory Adaptation Gradual decline in sensitivity to prolonged stimulation Gradual decline in sensitivity to prolonged stimulation Ex: Garbage Ex: Garbage In reality, the stimulus intensity (the odor) stays the same but with continued exposure your sensitivity to it decreases In reality, the stimulus intensity (the odor) stays the same but with continued exposure your sensitivity to it decreases Ex: Jumping into a swimming pool Ex: Jumping into a swimming pool It allows people to ignore the obvious but you can notice CHANGES in sensory input It allows people to ignore the obvious but you can notice CHANGES in sensory input

The Visual System

Parts of the Eye Cornea (1) transparent covering/protection Cornea (1) transparent covering/protection Pupil and Iris (2) bright light/contracts, dim light/relax Pupil and Iris (2) bright light/contracts, dim light/relax Lens (3) focuses light on the retina Lens (3) focuses light on the retina Retina (4) receptor cells that absorbs light Retina (4) receptor cells that absorbs light Optic disk/Blind Spot (5) Optic disk/Blind Spot (5) Optic Nerve (6) Optic Nerve (6) Fovea (7) Fovea (7) Blind Spot Activity!! Blind Spot Activity!!

The Retina Millions of receptor cells Millions of receptor cells 10 % of light 10 % of light Rods- 100 to 125 million Rods- 100 to 125 million Cones- 5-6 million Cones- 5-6 million Expt- What Color is it?? Expt- What Color is it??

Light and Dark Adaptation

From the Eye to the Brain

Afterimage

Form Perception Perceptual Set - The influence of prior assumptions and expectations on perceptual interpretations Perceptual Set - The influence of prior assumptions and expectations on perceptual interpretations

Perceptual Set What do you see in the center picture: a male saxophonist or a woman’s face? Glancing first at one of the two unambiguous versions of the picture is likely to influence your interpretation. What do you see in the center picture: a male saxophonist or a woman’s face? Glancing first at one of the two unambiguous versions of the picture is likely to influence your interpretation.

Feature Analysis Bottom Up Processing & Top Down Processing Bottom Up Processing & Top Down Processing I cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. It dseno’t mataetr in what oerdr the ltteres in a word are, the olny iproamtnt tihng is taht the frsit and lsat ltter be in the rghit pclae.

Phi Phenomenon The illusion of motion when fixed lights are turned on and off in a sequence The illusion of motion when fixed lights are turned on and off in a sequence Stare at the X in the middle and notice what happens. Is the Green Dot Moving? Stare at the X in the middle and notice what happens. Is the Green Dot Moving?

Size Distance Relationship

Context & Culture What is above the woman’s head? In one study, nearly all the East Africans who were questioned said the woman was balancing a metal box or can on her head and that the family was sitting under a tree. Westerners, for whom corners and boxlike architecture are more common, were more likely to perceive the family as being indoors, with the woman sitting under a window. What is above the woman’s head? In one study, nearly all the East Africans who were questioned said the woman was balancing a metal box or can on her head and that the family was sitting under a tree. Westerners, for whom corners and boxlike architecture are more common, were more likely to perceive the family as being indoors, with the woman sitting under a window.

Sensory Deprivation & Restored Vision Early visual experience can have a profound effect on perception. Early visual experience can have a profound effect on perception. Do the kittens ever fully regain normal sensitivity to horizontal or vertical lines? NO. Do the kittens ever fully regain normal sensitivity to horizontal or vertical lines? NO. From the time their eyes first opened, and until the age of 5 months, these kittens were removed from darkness each day to spend 5 hours alone in a black-and-white striped cylinder with a clear glass floor. A stiff collar prevented the kittens from seeing anything else, even their own bodies. Afterward, these kittens had difficulty perceiving horizontal forms, compared with other kittens exposed only to horizontal forms.