Sensation and Perception Sensation - your “window” to the world; taking in information Perception - interpreting what comes in your “window”; interpreting/understanding information taken in VIDEO - Intro to Sensation / Perception

Do you see a seal balancing a ball in front of a trainer? ...or two ballroom dancers? A reversible figure is a drawing that is compatible with two different interpretations that can shift back and forth. This shifting is caused by information given to you about the drawing, called a perceptual set. A perceptual set creates the shift in how you interpret sensory input. The Visual System: Perceptual Processes The Other Senses: Taste, Smell, and Touch Psychophysics: Basic Concepts and Issues The Auditory System: Hearing Essentials of Sight

Bottom-up vs. Top-down Processing Begins with sense receptors and works UP to the brain Associated with Sensation Can be thought of as “first” of the two Information processing guided by “higher level” mental processes Associated with Perception Can be thought of as “second” of the two

Difference Threshold (Just Notable/Noticeable Difference) The smallest amount of change needed to detect a change in a stimulus

Absolute Threshold Do you hear anything? The minimum stimulation needed to detect a stimulus 50% of the time.

Weber’s Law Computes the "Just Noticeable Difference". The change needed is proportional to the original intensity of the stimulus. The more intense the stimulus the more change is needed to notice the difference.

Ernst Weber (1795 – 1878) Anatomist / physiologist introduced the “Just Noticeable Difference” (JND) concept expressed the principle of difference threshold

Gustav Fechner (1801 – 1887) key figure in “Psychophysics” science of quantitative relationships between sensation and their stimuli expressed the JND as a mathematical formula and called it “Weber’s Law”

Subliminal Messages Stimuli below our absolute threshold. Do Subliminal Messages work? Evidence suggests minimal influence Probably a placebo effect

Subliminal Messages Stimuli below our absolute threshold. Do Subliminal Messages work? Evidence suggests minimal influence Probably a placebo effect examples

A Letter from College Dear Mom, $chool is really great. I am making lot$ of friend$ and $tudying very hard. With all my $tuff, I $imply can't think of anything I need, $o if you would like, you can just $end me a card, a$ I would love to hear from you. Love, $u$an P.$. Thank$ for $ending the $weater!

Dear Susan, I kNOw that astroNOmy, ecoNOmics, and oceaNOgraphy are eNOugh to keep even an hoNOr student busy. Do NOt forget that the pursuit of kNOwledge is a NOble task, and you can never study eNOugh. Love, Mom P.S. Thanks for your NOte!!

Signal Detection Theory predicts how and when we detect the presence of a stimulus assumes that “absolute threshold” is dependent on context/situation says that detection depends on experience, expectations, motivation, fatigue

Sensory Adaptation The diminished sensitivity as a consequence of constant stimulation

Sensory Transduction transforming stimulus energy into neural impulses In vision, light waves are transformed into neural impulses and messages from the eye to the thalamus and then to other parts of the brain. In hearing, sound waves are transformed into neural impulses and messages from the ear to the auditory cortex of the temporal lobe. Remember the characters from Sky High? They could change from their physical, bodily form into something else altogether. Click the image above to watch the characters transform.

Vision VIDEO - How Does Vision Work? Our most “dominating” sense Visual capture

How do we see? Upside down

Phase One: Getting the light in the eye

Phase Two: Transduction Cones (explain rods)

Phase Three: In the Brain Goes to the Visual Cortex located in the Occipital Lobe of the Cerebral Cortex Feature Detectors Parallel Processing We have specific cells that see the lines, motion, curves and other features of this turkey. These cells are called feature detectors.

David Hubel (1926-2013) / Torsten Wiesel (1924 - ????) researched visual sensation / perception Nobel Prize (Physiology/Medicine) for their work discovering feature detectors

Parallel Processing The processing of several aspects of an object simultaneously. Motion Form Color Depth

Color Vision Two Major Theories

Why is her top green?

Trichromatic Theory (Young-Helmholtz Theory) Three types of cones: Red Blue Green These three types of cones can make millions of combinations of colors. Does not explain afterimages or color blindness well.

Afterimages

Color-Deficient Vision People who suffer red-green blindness have trouble perceiving the number within the design

Opponent-Process theory The sensory receptors come in pairs. Red/Green Yellow/Blue Black/White If one color is stimulated, the other is inhibited.

Opponent Process- Afterimage Effect

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Perceptual Ideas

Top-Down Processing We perceive by filling the gaps (using past experiences and schema) I _ant ch_co_ate ic_ cr_am. Perceptual Set – a mental predisposition; the experiences, assumptions, and expectations that influence our perception If you see many old men in glasses, you are more apt to process a picture of an old man rather than that of a mouse.

Selective Attention The focusing of conscious awareness on a particular stimulus. Selective Attention causes change (or inattentional) blindness. cocktail party effect selective attention to one voice among many 5th Period

Second Period

Gestalt Psychology Gestalt – an organized whole; from German for “form” or “whole” Gestalt psychologists emphasized the tendency to integrate pieces of information into a meaningful whole. Gestalt Psychology says that we innately look at things in groups, not as isolated elements. “The whole is greater than the sum of it’s parts.”

Proximity Closure Similarity Continuity The Gestalt principles of form perception include proximity, closure, similarity, simplicity, and continuity. The Visual System: Perceptual Processes The Other Senses: Taste, Smell, and Touch Psychophysics: Basic Concepts and Issues The Auditory System: Hearing Essentials of Sight

Grouping & Gestalt Psychology Proximity - group objects that are close together as being part of same group Similarity - objects similar in appearance are perceived as being part of same group Continuity - objects that form a continuous form are perceived as same group Connectedness – objects that are uniform and linked are perceived as single units Closure - we fill gaps to create a whole or complete image Closure

Figure Ground Relationship Visually, our first perceptual decision is “What is the figure?” in the image and “What is the ground?” (background). The figure ground relationship can also be applied as a principle of auditory perception.

Depth Perception experiment Eleanor Gibson - Visual Cliff Experiment If you are old enough to crawl, you are old enough to see depth perception. We see depth/distance by using two cues that researchers have put in two categories: Monocular Cues Binocular Cues

Binocular Cues We need both of our eyes to use these cues. Retinal Disparity - as an object comes closer to us, the differences in the images for our eyes becomes greater. “finger sausage” 3-D movies Convergence - as an object comes closer, our eyes have to come together to keep focused on the object

Monocular Cues You really only need one eye to use these. Linear Perspective Interposition Relative Size Texture Gradient Light / Shadowing

Perceptual Constancy Shape Constancy Size Constancy Color Constancy Objects change in our eyes constantly as we or they move….but we are able to maintain content perception Shape Constancy Size Constancy Color Constancy Brightness Constancy However, color and brightness also depend on context!

Perceptual Adaptation inverted vision program 7: start @ 15:39 The ability to adjust to an artificially altered visual field

Hearing Our auditory sense

The Ear

Transduction in the ear Sound waves hit the eardrum then anvil then hammer then stirrup then oval window. Everything is just vibrating. Then the cochlea vibrates. The cochlea is lined with mucus called basilar membrane. In basilar membrane there are hair cells. When hair cells vibrate they turn vibrations into neural impulses. Sent then to thalamus up auditory nerve. It is all about the vibrations!!!

Hearing – Perceiving Pitch Place Theory Frequency Theory Different pitches stimulate different parts of the basilar membrane within the cochlea Best explains high pitch sensation The rate of nerve impulses matches the frequency of tone Sound waves of 100 waves per second = 100 pulses per second travel up the auditory nerve Best explains low pitch sensation

Nerve (Sensorineural) Deafness Conduction Deafness Nerve (Sensorineural) Deafness Something goes wrong with the mechanical/vibration process in hearing. Hearing aids to help. The hair cells in the cochlea get damaged. Loud noises can cause this type of deafness. NO WAY to replace the hairs. Cochlear implant is possible.

Touch Sensory receptors are located in our skin “Gate-Control Theory” of Pain spinal cord blocks or allows pains signals to pass to brain Phantom limb

Taste We have bumps on our tongue called papillae. Taste buds are located on the papillae (they are actually all over the mouth). Sweet, salty, sour, bitter, and umami . Sensory Interaction – principle that one sense influences others (i.e. – taste & smell)

Olfactory System Why are smells often involved with emotions?

Kinesthetic Sense tells us where our body parts are uses receptors located in our muscles, joints, and tendons You would use kinesthesis to touch the button to make copies of your buttocks.

Vestibular Sense tells us where our body is oriented in space. our sense of balance. located in our semicircular canals and vestibular sacs of the inner ear.

Motion Perception Stroboscopic Effect Phi Phenomenon a rapid series of slightly varying images perceived as moving images (flip book, “old” movies) Phi Phenomenon illusion of movement created when two or more -----lights next to each other blink on and off

Parapsychology the study of paranormal phenomena, including ESP and psychokinesis ESP – extrasensory perception; perception outside of sensory perception Telepathy Telekinesis Clairvoyance Precognition

Human Factors Psychology branch of Psychology explores… how human and “machines” interact how “machines” and physical environments can be adapted to human behaviors

FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF MANY YEARS.

FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF MANY YEARS.

Vision – Seeing – Visual Audition – Hearing – Auditory Olfaction – Smelling – Olfactory Gustation – Tasting – Gustatory