Sensation & Perception II: Audition+

Brian J. Piper, Ph.D.

Objectives

• Audition (hearing)• Olfaction (smell)• Gustatory (taste)• Touch/Pain & pain

control!

Audition

Sound waves are compressing and expanding air molecules.

Wavelength: determines pitch, measured in Hz (20 – 20kHz)Amplitude: determines loudness, measured in dB

Loudness

-----------------------------------------120 dB

Pitch

• 50 kHz: +– Drugs– Sex– Play– “Tickling”

• 22 kHz: -– Cold– Fear

Testing consisted of placing the subjects in a 45 by3520 cm opaque plastic test box with corn-cob bedding.Subjects then received 2 min exposure to astandard tickle test-sessions consisting of four successivecycles of 15 s of no stimulation followed by 15 s oftickle stimulation [13]. This procedure was conductedonce per day for two consecutive days. For all animals(in this and all subsequent experiments) the tickling wasdone with the right hand and consisted of rapid initialfinger movements across the back with a focus on theneck, followed by rapidly turning the animals over ontheir backs, with vigorous tickling of their ventral surface,followed by release after a few seconds of stimulation.This was repeated throughout each tickling session. Even though the tickling was brisk and assertive,care was taken not to frighten the animals.

Paaksep & Burgdorf (2000) Behav Brain Research, 115, 25-38.

Hearing

• Sound -> Ear -> Auditory Nerve -> Temporal Cortex

The Ear

Dr. Fred H

ossler/ Visuals U

nlimited

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.

Inner Ear: Innermost part of the ear, containing the cochlea, semicircular canals, and vestibular sacs.

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

Localization of Sounds

Because we have two ears, sounds that reach one ear faster than the other ear

cause us to localize the sound.

Localization of Sound

1. Intensity differences2. 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.

Critical & Sensitive Periods

• Time during development when stimulation is especially important

• Visual example• Language example

Neuroplasticity (10% Myth)

Merabet & Pascual-Leone (2010) Nature Neurosci, 11, 44-52.

Touch

The sense of touch is a mix of four distinct skin senses—pressure, warmth, cold, and

pain.

Skin Senses

Only pressure has identifiable receptors. All other skin sensations are variations of

pressure, warmth, cold and pain.

Burning hot

Pressure Vibration

Cold, warmth and pain

Hereditary Sensory Autonomic Neuropathy

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.

Ashley Blocker (right) feels neither painnor extreme hot or cold.

AP Photo/ Stephen M

orton

Hereditary Sensory Autonomic Neuropathy

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.

5 min:http://www.youtube.com/watch?v=1vLsZ_dXFAg

“I feel your pain”

• fMRI is used in females to examine activation during pain (electric shock) versus non-pain

• Self versus significant other

Singer et al. (2004). Science, 303, 1157-1162.

Empathy for Pain

Pain > No Pain

SelfOther

Singer et al. (2004). Science, 303, 1157-1162.

Sympathetic Pregnancy

• Male experiences:– Weight gain– Nausea– Hormone abnormalities– Labor pains

Therapeutic Touch

• Worth -> Neuroscience & Methodology -> Scientific Attitude

Rosa et al. (1998). JAMA, 279, 1005-1010.

Therapeutic Touch

• Worth -> Neuroscience & Methodology -> Scientific Attitude

Rosa et al. (1998). JAMA, 279, 1005-1010.

Therapeutic Touch

• Worth -> Neuroscience & Methodology -> Scientific Attitude

Rosa et al. (1998). JAMA, 279, 1005-1010.

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.

Pain Control & Acupuncture

Pain can be controlled by a number of therapies including drugs, surgery, exercise, hypnosis, and even thought distraction.

Pain Control & Acupuncture

• Chronic back pain patients completed a double-blind study with 6 licensed acupuncturists (4-19 years experience):– Individualized– Standardized– Sham– Usual Care

Interpretation?

Evaluating Information• Backward- Pubmed

• Forward: Google Scholar

Biopsychosocial Influences

Taste

Traditionally, taste sensations consisted of sweet, salty, sour, and bitter tastes.

Recently, receptors for a fifth taste have been discovered called “Umami”.

Sweet Sour Salty Bitter Umami(Fresh

Chicken)

Receptors

• Sweet: sucrose• Sour: pH• Saltiness: NaCl• Bitter: organic (Carbon)• Umami: Monosodium Glutamate• Fat: ?

SmellLike 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.

Tracking in Humans

Porter et al. (2006) Nature Neuroscience, 10, 27-29.Quick Time Video (2 min): ID 80474881 PW 03171962http://www.nature.com.ezp-prod1.hul.harvard.edu/neuro/journal/v10/n1/extref/nn1819-S2.mov

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 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.

6th Sense: 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.

Integration of Auditory & Visual

• McGurk Effect• http://www.youtube.com/watch?v=G-lN8v

Wm3m0

Brain & Senses

• Phantom Limb Pain: may occur following loss of appendage

• Tinnitus: an auditory sensation that may occur following hearing loss

• Phantom Sights: visual hallucinations that may occur following visual loss

Psychological Factors in Perception

• Kids: carrots + milk• Adults: wine & music (Joshua Bell)• Last 30 sec:

http://www.youtube.com/watch?v=hnOPu0_YWhw

Pain Perception

• Harvard undergraduates rated the painfulness of electric shocks.

• A confederate was employed to manipulate intentionality.

Gray & Wegner (2008) Psychological Science, 19, 1260-1262.

Summary

• Structures of Sensation• Perception > Sensation

• John Milton: The mind is its own place, and in itself can make a heaven of hell, a hell of heaven.