Skin SensesTouch , Pain, Temperature

WARM UP:

1. Paper cut2. Twist Ankle3. Bite tongue4. Hand in bucket of ice water5. Hit funny bone6. Being tickled (a lot)7. Falling on ice8. Holding in a full bladder for a long

time9. Burn tongue on pizza10. Leg cramp11. Accidentally poked in eye

12. Hit head on wall 13. Fall down stairs14. Bad headache15. Immunization16. Hand sanitizer in a cut17. Stub toe18. Leg fall asleep19. Burn hand on hot pan20. Poke self under fingernail

On a piece of paper rate the following on a scale of 1-10 (1 is you barely notice pain, 10 is worst pain imaginable)

Touch, Pain, Temperature

• Tactile System• Skin consists of three layers (epidermis,

dermis, hypodermis)• It is the dermis where nerves are located• Receptors are specialized for touch, pain and

temperature (vary greatly)• Sensations can interact with each other• Also psychological factors (pain, tickling, etc)

Pain• Perceptual experience with negative qualities (Wall, 2000)

• Adaptive and necessary even though negative• If we didn’t have pain we would be in serious danger

(very rare condition)• Hard to study because so many variables• Free Nerve Endings– name for pain receptors• Pain is different from body part to body part and from

person to person• Perception of pain is physical AND psychological• Influenced by socialization, attitude, experiences and

culture

ouch!Yikes!

Ashyln Blocker

• New York Times Article

• You Tube Video (4 minutes)

Life without pain

• Video clip (a little graphic…)

PainUnderstanding Pain

• Biological Influences–Noiceptors–Gate-control theory–Endorphins–Phantom limb sensations–Tinnitus

Nociceptive pain -Caused when special nerve endings—called nociceptors—are irritated. -ex. Feel it when you burn yourself, twist your ankle, or stub your toe. -dull or sharp aching pain-it can be mild to severe. -can be a temporary condition, or can also be a chronic condition.

(like Cancer pain and arthritis pain )-responds well to pain medications, anti-inflammatory agents, or other drugs -does not respond well to neurostimulation.

Neuropathic pain (nerve pain)-caused by a malfunction of the nervous system due to an injury or an illness. -can be a sharp, intense, shocking, or shooting pain. -does not usually respond as well to standard pain therapies, such as over-the-counter pain medications (ex. ibuprofen) and prescription pain medications. -can often be managed by neurostimulation.

Neurostimulation – a device implanted under skin that delivers mild electrical signals to the epidural space near your spine through one or more thin wires, called leads. The electrical signals cause a tingling sensation in the area of your chronic pain. Neurostimulation provides pain relief by blocking the pain messages before they reach the brain.

Gate Control Theory (Melzak and Wall, 1962)• Said that activating pain receptors does not directly cause

pain• the spinal cord contains a neurological "gate" that either

blocks pain signals or allows them to continue on to the brain

• Therefore pain medication may work by causing the brain to release inhibitory inter- neurons that can block the pain signal at the spinal chord

• Also if touch and pain signals from the same part of the body are transmitted to the brain, we don’t feel the pain as strongly (ex. You bump your leg and rub it)

• More “bottom up”

Neuromatrix Theory of Pain (Melzack, 1999)

• Has updated/ replaced Gate Control Theory• Says brain possesses Body-self Neuromatrix

(BSN) which integrates inputs to produce an output pattern that we experience as pain

• BSN is influenced by genetics and sensory input, emotional input, stress regulation and “self modulation” (inborn bodily awareness)

• Could be used to explain phantom limb pain• Not just bottom up, top down

The pain circuit

PainUnderstanding Pain

• Psychological Influences–Rubber-hand illusion–Memories of pain

Touch

• Rubber hand illusion (shows top down perception)

Therefore touch is not just bottom up.

PainUnderstanding Pain

• Social-Cultural Influences

Biopsychosocial approach to pain

PainControlling Pain

• Physical methods• Psychological methods

Body Position and Movement Kinesthesis

the system for sensing the position and movement of individual body parts

Without this sense you feel “disembodied” Stand right heel in front of left toe and shut eyes

Vestibular Sense the sense of body movement and position including the sense of balance Semicircular canals Twirl around and come to an abrupt halt

Paranormal Phenomena (psi)

Extra Sensory Perception– Telepathy

• Reading another’s thoughts– Clairvoyance

• Perceiving events beyond sensory experiences– Precognition

• Perceiving future events

Psychokinesis– Mind over matter (moving objects)

Tests of Paranormal

• Statistics show that most “predictions” can better be accounted for by chance alone

• Many experiments have “tested” parapsychology• Even if it existed, it would rarely be “reproduced”

and therefore cannot be scientifically proven• Some studies have shown the paranormal

occuring at a likelihood slightly greater than chance…

Thinking question?

• Do you believe in ESP and the paranormal?