Neurologist's Party Tricks: Demonstrate How the Brain Can Reset Body Image


Ramachandran's Phantoms in the Brain is a must-read for anyone who has or has known anyone who has experienced phantom sensations in a missing limb, or hallucinations due to a "scotoma" - a blank spot in one's field of vision. For science buffs, it's simply fascinating.

Once you learn that your body image and sensory perceptions are formed in a sort of back-and-forth dialogue between sensory input and cognitive output, your ideas about the human mind do change. I'm going to jot down a few notes on what I will call "neurologist's party tricks" for future reference, and quite possibly use these notes to try out on a few friends.

1. How Long is My Nose?

This illusion requires three participants who can concentrate and match a rhythm. Person A must sit on a chair, blindfolded. Person B must sit on a chair just in front of Person A, facing the same direction. Person C must guide Person A's hand to Person B's nose, moving Person A's hand in a rhythmic manner on Person B's nose. At the same time, the very talented Person C must use the same rhythm to stroke and tap the same sequence on Person A's nose.

If all goes according to plan, an illusion will be created in which Person A perceives his/her nose as being extended to the location of Person B's nose - an impossibly long nose! This results from the brain rationalizing the sensation from Person A's hand as touching Person A's own nose, when it is not. About half of the people who assume the role of Person A will find that their brain makes the assumption that sensing the same rhythm on one's hand and one's nose cannot be a coincidence; therefore, it must be both one's own nose and hand.

2. Is That My Rubber Hand?

The next illusion requires the purchase of a dummy rubber hand and the construction of a two-foot by two-foot cardboard barrier, a table, and two participants. Person A sits at a table, hiding his/her right hand behind the cardboard barrier. Person B now strokes the same locations on the dummy hand and the hidden hand while Person A looks at the dummy hand.

If all goes well, Person A's mind will experience the weird feeling that sensations are coming from the dummy hand. The brain rationalizes that sight and touch are connected, and adjusts body image to fit the illusion.


The work of Ramachandran and other neurologists has helped many people who have suffered pain from phantom limbs following accident or amputation. For the rest of us, it offers a fascinating insight into the workings of the human mind.

Comments

Post a Comment

Popular posts from this blog

How to Cancel a Gym Membership in Alberta

Image
Although I signed up for a fitness club membership with the best of intentions, it just wasn't working out. Sure, kickboxing for 30 minutes (https://www.30minutehit.com/locations/gym/calgary-sw-kickboxing-boxing-fitness.html) was a great workout, but it was a little too hard on my joints and the balls of my feet. That, and too-frequent corrections from my trainer were undermining my confidence and making my form worse! No, that's not me in the picture. But enough about me. If you want to cancel a gym membership in Alberta, here are a few pointers. Alberta law says that you can cancel a direct sales contract within 10 days of receiving a copy. Therefore, if you weren't given a copy of your membership contract, it follows that you can then cancel at any time. The Fair Trading Act of Alberta, section 27, says, "A consumer may, without any reason, cancel a direct sales contract at any time from the date the sales contract is entered into until, subject to the reg
Read more

Henna Hair Coloring Tips: Lush vs. Light Mountain

Image
Being born with mousy (blondish? brownish?) hair and an ounce of vanity will lead to a lifetime of hair coloring... Unfortunately, lots of exposure to the sorts of chemicals found in typical hair dyes will lead to allergic reactions in people sensitive to such things. I started using Lush (http://www.lush.ca/) henna because I still wanted to color my hair, but didn't want the hives or scabs that resulted when I used L'Oreal or Garnier. At the time, my hair had been highlighted a little too zealously so I ended up with bright orangey-red hair. Kinda pretty yet kinda too much for me. As my hair grew out, the color softened. Henna coats the hair shaft like lacquer, so red henna over mousy gives you reddish-brown. If I had skin tones that truly suited auburn, that would've been fine. I tried Lush Caca Brun to tone down the red, but then my hair became too dark and I looked tired. With repeated henna-colorings, the only way to remove ALL the henna is to grow it out.
Read more

Review of Calgary Summer Camps: Royal City Soccer, JunioTech, Quickdraw, STEM Learning Lab

Image
Summer camp can be an amazing experience for kids, while the cost to parents can be significant. The following are some brief notes on our family's experiences with each... Royal City Soccer www.royalsoccer.com/alberta This was our boys' favorite summer camp. Each day begins with soccer-related activities, individual and group instruction, and some healthy competition. The afternoons end with swimming in an outdoor pool, weather permitting, or indoor games if there is rain. Memorable moments included a game where kids took on the instructors, awards for being a good sport, take-home soccer balls, free necklaces, free candy, and photos sent home with a final email. The instructors were excellent with children, and the other kids in the camp had great attitudes. Lots of varied activity kept kids busy and happy. Bonuses: early dropoff times, late pickup times, professional handling of paperwork. JunioTech Robotics www.juniotech.com We chose this camp for robotics a
Read more