Bottom-up Processing Analysis of the stimulus begins with the sense receptors and works up to the level of the brain and mind. Letter “A” is really a black blotch broken down into features by the brain that we perceive as an “A.”

THE CHT Top-Down Processing Information processing guided by higher-level mental processes as we construct perceptions, drawing on our experience and expectations. THE CHT

Form Perception & Feature Analysis Bottom-Up Processing Based upon properties of the stimulus (e.g., patterns of light & dark areas Top-Down Processing Based upon higher-order information (e.g., prior knowledge & context) What is this picture?

Figure 4.26 Bottom-up versus top-down processing

Vision

Physical Characteristics of Light Wavelength (hue/color) Intensity (brightness)

Wavelength (Hue) Hue (color) is the dimension of color determined by the wavelength of the light. Wavelength is the distance from the peak of one wave to the peak of the next.

Properties of...LIGHT Longer Wavelength Lower Frequency Shorter Higher

Properties of...LIGHT Smaller Amplitude Dull Colors Higher Bright

Intensity (Brightness) Intensity: Amount of energy in a wave determined by the amplitude. It is related to perceived brightness.

Visual Information Processing Optic nerves connect to the thalamus in the middle of the brain, and the thalamus connects to the visual cortex. Preview Question 6: How does the brain process visual information?

Sensation & Perception 4/15/2017 Vision Hubel & Wiesel’s Experiment Some cells in the visual cortex respond only to certain types of visual information, for example, a diagonal line moving up and down. These cells are called feature detectors. Figure 3.8 from: Kassin, S. (2001). Psychology, third edition. Upper Saddle River, NJ: Prentice Hall. Source: Hubel, D. H.., & Wiesel, T.N. (196Davis 2). Receptive fields, binocular interaction and functional architecture in the cat’s visual cortex. Journal of Physiology, 160,106-154. Psychology, 4/e by Saul Kassin ©2004 Prentice Hall ©2001 Prentice Hall

Shape Detection Specific combinations of temporal lobe activity occur as people look at shoes, faces, chairs and houses. Ishai, Ungerleider, Martin and Haxby/ NIMH

Trichromatic Theory of Color Vision Human eye has 3 types of cone receptors sensitive to different wavelengths of light. Helmholtz 1852 Short Medium Long People see colors because the eye does its own “color mixing” by varying ratio of cone neural activity

Opponent Process Theory Ewald Hering - Eye contains 3 mechanisms that produce antagonistic responses to three pairs of colors R G B Y W Why? Afterimages & Color Deficiency

Color Blindness Genetic disorder in which people are blind to green or red colors. This supports the Trichromatic theory. Guys more often color blind Ishihara Test

Opponent Colors Gaze at the middle of the flag for about 30 Seconds. When it disappears, stare at the dot and report whether or not you see Britain's flag.

Hearing

Hearing The Stimulus Input: Sound Waves Sound waves are compressing and expanding air molecules. Preview Question 8: What are the characteristics of air pressure waves that we hear as sound?

Sound Characteristics Frequency (pitch) Intensity (loudness)

The Ear Dr. Fred Hossler/ Visuals Unlimited Preview Question 9: How does the ear transform sound energy into neural messages?

The Ear Outer Ear: Collects and sends sounds to the eardrum. Middle Ear: Chamber between eardrum and cochlea containing three tiny bones (hammer, anvil, stirrup) that concentrate the vibrations of the eardrum on the cochlea’s oval window. Inner Ear: Innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.

Cochlea Cochlea: Coiled, bony, fluid-filled tube in the inner ear that transforms sound vibrations to auditory signals.

Auditory Pathway

Intensity (Loudness) Intensity (Loudness): Amount of energy in a wave, determined by the amplitude, relates to the perceived loudness.

Loudness of Sound Richard Kaylin/ Stone/ Getty Images 120dB 70dB

Frequency (Pitch) Frequency (pitch): The dimension of frequency determined by the wavelength of sound. Wavelength: The distance from the peak of one wave to the peak of the next. Preview Question 10: What theories help us understand pitch perception?

Perceiving Pitch Place Theory - pitch determined by Georg von Békésy 1899-1972 (T.W. Theory) Place Theory - pitch determined by point of maximal vibration on basilar membrane. Helps explain how we hear HIGH pitch sounds Traveling Wave Theory 1957 Frequency Theory - pitch determined by the rate at which the hair cells fire… Helps explain how we hear LOW pitch sounds Volley Principle-neural cells alternate firing like soldiers so that some shoot while others reload

Localization of Sounds Because we have two ears, sounds that reach one ear faster than the other ear cause us to localize the sound. Preview Question 11: How do we locate sounds?

Localization of Sound 1. Intensity differences 2. Time differences Time differences as small as 1/100,000 of a second can cause us to localize sound. The head acts as a “shadow” or partial sound barrier. Preview Question 12: What are the common causes of hearing loss, and why does controversy surround cochlear implants?

Psychology, 4/e by Saul Kassin ©2004 Prentice Hall Hearing Hearing Disabilities Conduction Hearing Loss Caused by damage to the eardrum or bones in the middle ear. Sensorineural Hearing Loss Caused by damage to the structures of the inner ear. Psychology, 4/e by Saul Kassin ©2004 Prentice Hall

Touch The sense of touch is a mix of four distinct skin senses—pressure, warmth, cold, and pain. Preview Question 13: How do we sense touch and sense our body’s position and movement? How do we experience pain? Bruce Ayers/ Stone/ Getty Images

Ashley Blocker (right) feels neither pain Pain tells the body that something has gone wrong. Usually pain results from damage to the skin and other tissues. A rare disease exists in which the afflicted person feels no pain. AP Photo/ Stephen Morton Ashley Blocker (right) feels neither pain nor extreme hot or cold.

Biopsychosocial Influences

Gate-Control Theory Melzack and Wall (1965, 1983) proposed that our spinal cord contains neurological “gates” that either block pain or allow it to be sensed. Gary Comer/ PhototakeUSA.com

Taste Traditionally, taste sensations consisted of sweet, salty, sour, and bitter tastes. Recently, receptors for a fifth taste have been discovered called “Umami”. Preview Question 14: How do we experience taste? Sweet Sour Salty Bitter Umami

Sensory Interaction When one sense affects another sense, sensory interaction takes place. So, the taste of strawberry interacts with its smell and its texture on the tongue to produce flavor.

Smell Like taste, smell is a chemical sense. Odorants enter the nasal cavity to stimulate 5 million receptors to sense smell. Unlike taste, there are many different forms of smell. Preview Question 15: How do we experience smell?

Smell and Memories The brain region for smell (in red) is closely connected with the brain regions involved with memory (limbic system). That is why strong memories are made through the sense of smell.

Body Position and Movement The sense of our body parts’ position and movement is called kinesthesis. The vestibular sense monitors the head (and body’s) position. http://www.heyokamagazine.com Bob Daemmrich/ The Image Works Whirling Dervishes Wire Walk

Summary of the Senses

Selective Attention We focus on a very limited aspect of what we experience and ignore the rest Other forms of S.A. are change blindness and inattentional blindness

Facial Recognition After blind adults regained sight, they were able to recognize distinct features, but were unable to recognize faces. Normal observers also show difficulty in facial recognition when the lower half of the pictures are changed. Courtesy of Richard LeGrand

Sensation & Perception 4/15/2017 ESP Extrasensory Perception (ESP) The ability to perceive something without ordinary sensory information. This has not been scientifically demonstrated. Parapsychologists distinguish between three types of ESP: Telepathy – Mind-to-mind communication Clairvoyance – Perception of remote events Precognition – Ability to see future events Psychology, 4/e by Saul Kassin ©2004 Prentice Hall ©2001 Prentice Hall