Quick and Fun Mind and Body Tricks

July 23, 2007 10:09 AM

I'm looking for quick little health tricks/demonstrations I can do with little or no props.

It can do with the senses, mind or body. Thank you.

posted by JaySunSee to health (15 comments total)

Gently hit the knee with a rubber mallet.
posted by Blazecock Pileon at 10:25 AM on July 23, 2007

Optical illusions come to mind, but you'd need them on cards. Would that be too prop-heavy? There are also some neat things on this page.

I may have ruined the remainder of my day's productivity with that page, truth be told.
posted by jquinby at 10:32 AM on July 23, 2007 [1 favorite]

I've got your nose.
posted by peacecorn at 10:38 AM on July 23, 2007

Not sure if this qualifies...
That thing where you stand facing a wall as close as possible and you push against the wall with the leading edges of your arms (i.e., the backs of your hands, not the palms) for about 30-60 seconds. Then, you step away and raise your arms and they feel like they're floating.
posted by cocoagirl at 10:50 AM on July 23, 2007

Veins appear blue underneath the skin because the fat content in skin is just enough to block the reddish part of the light spectrum. The same thing happens when you underwater--red is the first color to fade away.

(It has nothing to do with oxygen-poor blood turning blue, like I was taught in grade school. Blood is never blue, only varying shades of red)

And, oh yeah, my favorite. The "find your visual blind spot" test. Everybody has one, and it's sometimes smack dab in the center of your field of vision.
posted by Brian James at 11:19 AM on July 23, 2007

Have someone close their eyes while you rub a pencil between their crossed fingers. They will distinctly feel two pencils, instead of one, because the 'outside' of each finger is being stimulated, and the brain--even knowing that the fingers are crossed--can't adjust.
posted by weapons-grade pandemonium at 11:34 AM on July 23, 2007

1. Stick small, pointy things (not sharp, eg toothpicks) in a circle through some kind of card so they're stable. Use about six.

2. Blindfold subject/have them close their eyes.

3. Touch card to palm. Ask how many points subject feels. They will probably answer accurately.

4. Touch card to non-sensitive part of body, like mid-back or shoulder. Subject will be less accurately able to count number of contact points due to lower concentration of nerve endings in those areas. Could lead into discussion of the sensory/motor homunculi if subjects would appreciate it.
posted by rhoticity at 11:53 AM on July 23, 2007

Any simple health indicators come to mind? I vaguely remember one in Esquire magazine (circa 2005) where you pinch the loose skin on the top of your hand for a pre-determined amount of time and then see how long it takes for the discoloration to go away (the longer it took, the unhealthier your skin was).

Stuff like that?
posted by JaySunSee at 12:16 PM on July 23, 2007

You can check skin turgor (ie hydration status) by pinching skin on the top of the hand and seeing how long it takes to return to normal (flat).

You can check capillary refill ability by pressing gently on someone's nail and seeing how quickly the color returns.

With a flashlight, if you shine it in one eye and watch the other one, the iris that is not getting light shined in it will contract (checks for consensual (?) reflex).

Balance can be checked by having the individual close their eyes and stand with feet flat on the floor, at shoulder width.

Using a q-tip and a toothpick, you can check for proper nerve function by having the individual close their eyes and having them indicate whether whatever touched them (on their arms and legs) was soft or pointy.

These are just a few random nursing things I've learned over the course of my education. I might think of more later.
posted by nursegracer at 12:55 PM on July 23, 2007 [1 favorite]

Not health-oriented, but fun playing with proprioception:

Have your subject lie face-down on the ground with eyes closed, forehead touching the ground, arms out in front.

Stand in front of them, pick up their arms by the wrists and hold them straight out and up (about a 30-degree angle, maybe?) while their forehead is still on the ground. Hold like that for 15-30 seconds, talking to them to distract while their bodies adjust to the sensation.

Then slowly, slowly lower their arms, keeping them at full extension. The victim subject should feel like their arms are passing through the ground itself into some sort of nebulous space below.
posted by dkg at 3:14 PM on July 23, 2007

Have someone close their eyes and attempt to walk forward five steps, back five steps, in a straight line, ten times. For this to work, the room has to be completely quiet. Sometimes, a person will slowly rotate in one direction or another. If they do, there's a possibility that they have some vestibular (balance system) dysfunction in the ear that is on the side they deviate toward.
posted by jennyjenny at 3:24 PM on July 23, 2007

Here's a couple more:

• Demonstrate stereo vision and some failure modes of fine-grained proprioception:
  
  Subject should close one eye and, keeping elbows bent, wave hands briefly in loose circles in front of body. Keeping the same eye closed and elbows bent, try to touch the tips of your index fingers together. It's difficult (for me, anyway) to get the depth right.
  
  Repeat experiment with both eyes open: success demonstrates the utility of stereo vision.
  
  Repeat experiment with one eye open but with arms hanging initially at sides (no "randomizing" waving in circles) -- it's much easier because your proprioceptive system is using dead reckoning from a known reference position of both arms.
  
  
• Demonstrate how the shape of the outer ear affects our ability to localize sound vertically (needs a set of keys for a prop):
  
  Subject should stand comfortably with eyes closed. Experimenter stands in front of subject and jingles keys directly in front of the subject. Initially, the experimenter should narrate what they are doing, and jingle them first at a little above the subject's knee level ("low"), at the subject's chest level ("middle"), and then once more, but higher than the head ("high").
  
  Next, jingle randomly between the three locations, and at each jingle, the subject should state whether they think it's low, middle, or high. For most people, they will get these right every time.
  
  Finally, ask the subject to fold the tops of their ears down and hold them gently that way. Do another round of random jingling, while subject attempts to state the location of the keys. It's rare that someone can do significantly better than random guessing.
  

posted by dkg at 3:39 PM on July 23, 2007

Ok, now we're cooking with gasoline :)
posted by JaySunSee at 4:14 PM on July 23, 2007

I like this one - make a fist and clench hard. Count to 30 seconds.

Now, slowly open your hand. Your fingers will sort of creak open in stops and starts. Very cool effect.
posted by tomble at 4:45 AM on July 24, 2007

Thanks everybody!
posted by JaySunSee at 4:15 PM on July 24, 2007