sensation and perception discussion

Class announcement

• DB#2 due next Wed, 1/26, 11:59pm

• Quiz/Exam #1 next Friday, 1/28 - on the content from DBs 1 and 2 (neurons, SDT, psychophysics, touch, etc)

– Review questions on canvas and check out the DBs

Touch in our lives

• Helps to identify objects

• Gives info about object attributes that cannot be gleaned from looking at the object alone

• Facilitates normal development

• Social interactions

• Pain perception

• Gives knowledge about body and limb position

• Let’s us know how hot/cold it is

Somatosensation

• Touch is actually considered to be several independent senses: – Pressure – Temperature – Vibration – Pain

• Kinesthesis – Movement/stretch of the skin, tendons, joints

• Proprioception – Kinesthesis, vestibular sense

• There are many kinds of receptors that specialize in each of these senses. – On our skin and inside our bodies

Kinesthesis receptors

- “Proprioception” - Latin: “proprius”→ means

“one’s own”

- Kinesthesis receptors register our limb position and movement - Muscle spindles– measure

length and rate of muscle stretch

- Golgi tendon organs– gauge force via tension in the tendon

Ian Waterman – The man who could not feel

Pride and a Daily Marathon by Jonathan Cole

Imagine losing your “sixth” sense…

"…I looked where my legs were before I started. I looked where my arms were. I looked where my body was and then I started to sit-up very gradually. And I was so euphoric at having sat-up for the first time that I almost fell out the bed because I lost the concentration..."

“I felt disembodied.”

https://www.youtube.com/watch?v=pMEROPOK6v8

Normal development Experiments with monkeys

• If all monkeys care about is food, they should respond equally to the wire and cloth “mother monkeys”

• Turns out, they don’t. (Harlow & Harlow, 1969)

Normal development Evidence from humans

• Mothers can recognize their infants by touch alone – Texture and temperature are important cues

• Premature infants grow more rapidly if stroked or touched – Also more alert and are better able to tolerate noise

• Infants who are not touched, do not develop normally

Kangaroo Care

https://www.snopes.com/fact-check/kate-ogg/ https://www.youtube.com/watch?v=FJ39-KJr_vA http://www.nydailynews.com/news/world/mom-cuddles-bring-premature-baby-declared-dead-life-article-1.2148177

Advances in Neonatal Care • Vol. 8, No. 3S • 2008 • pp. S3–S23

-There are scientific benefits of kangaroo care (not just “mother’s love”) -For example:

-“physiologic (heart rate, respiratory rate, apnea, periodic breathing, oxygen saturation level and desaturation events, temperature, weight gain, infection, and hypoglycemia) -“behavioral (crying, sleep, pain, and breastfeeding behaviors) -“psychosocial (parental feelings, attachment, and interactions)”