Mathematical Brain Teaser
Let's say some primitive organisms divide themselves every
minute in two equals which also divide the next minute and so
on. The saucer in which we started observing this process was
full at 12.00. When was it full to the half?
Logic Brain Teaser
Why is it better to have round manhole covers than square
Lateral Brain Teaser
A table tennis ball fell into a tight deep pipe.
The pipe was only a bit wider than the ball, so you can not
use your hand. How would you take it out, with no damage?
Word Play Puzzles
The letters represent words that are somehow connected in a
You must identify the next letter in the sequence.
Example: M T W T ?
Solution: Wednesday (W), Thursday (T),
Question: J F M A M J J ?
Different words are used to describe well known proverbs
Example: "Rap upon timber"
Solution: "Knock on wood."
Question: Positive aesthetic appeal possesses solely
Each equation contains the initials of words that will make
the statement true. The statements are well-known facts from
the everyday world.
Identify the missing words that will make each statement true.
Example: 1001 = A. N.
Solution: 1001 Arabian Nights
Question: 8 = S. on a S. S.
The following words are used in different orientations to
represent common phrases.
FLIGHTFLIGHT is interpreted as 'Connecting Flights'
Question: BA NK
What word looks the same upside down and backwards?
Forward I am heavy, but backward I am not.
What am I?
Tests and games (Links to other sites)
Memory Self Tests by
Memory Loss Online
Two simple tests of memory: a test of verbal memory and a test
of visual memory. See how your scores compare against other
Cordingley, MD, PhD,
is a clinical neurologist,
teacher and researcher
who works in Athens, Ohio.
"Gosh, coach, it was just a 'ding.' I can
still play, can't I?"
If you're having difficulty understanding what a brain concussion
is, and how your son or daughter's head-injury affects their further
participation in sports, then you're in good company. The nature and
effects of concussions are still poorly understood by many athletes,
parents, coaches, news reporters and, to a certain extent, even the
medical community. But because the brain is a treasured organ -- one
that athletes should want to keep in good working order for the rest
of their lives -- a good understanding of concussions is crucial.
Neurologists and neurosurgeons cringe when they hear
sports-reporters make comments like, "Johnny had a CAT scan and it
showed that he didn't have a concussion." The truth is that CAT
scans don't show concussions. They do show other serious
consequences of head injuries, like bleeding within the brain, or
hemorrhages that compress the brain. But concussions -- while no
less real -- are invisible to brain-imaging tests like CAT scans and
So what is a concussion? If a blow to the head caused
unconsciousness, a concussion occurred. Most people know this. But a
concussion can occur even when there is no loss of consciousness.
Other symptoms after a head-injury indicating a concussion include:
- impaired attention, e.g. vacant
stare, slowness to respond, easy distractibility
- slurred speech, or speech that doesn't make
- clumsiness or unsteadiness
- disorientation, e.g. walking in the wrong
direction, forgetting the day of the week
- excessive emotional reaction, e.g. easy
tears, overly upset
- memory impairment, e.g. asking same
question repeatedly, can't memorize new facts
Other symptoms can develop hours or even weeks
after the injury, including headache, dizziness, poor concentration,
irritability, impaired memory, fatigue, disrupted sleep, anxiety,
depression, and a lack of good judgment or insight.
You'll notice that all these symptoms share a
common feature -- an alteration in brain function. The normal brain
processes, which depend on proper signaling among the brain's 20
billion brain cells, are out of whack.
There can also be physical damage to the
brain's cells. Because brain-cells are so tiny, brain scans don't
detect them. Injuries causing more severe concussions can tear apart
the cells' axons (the long filaments that carry coded messages over
long distances within the brain). As you can imagine, these rips in
the very fabric of the brain can cause lasting impairments in brain
function or require long periods of time for recovery.
One certainty about sports-related concussions
is that they are very frequent. The Centers for Disease Control
estimates there are at least 300,000 of them in the U.S. per year
and they comprise about 20% of all head injuries. Research also
indicates that the brains of high school athletes are more
vulnerable to concussion than those of older athletes, and require
longer periods of time to fully recover.
Individuals who have had one concussion are at
greater risk for another. For example, in one study of high school
and college football players, concussions occurred about six times
more frequently in student-athletes who had experienced prior
concussions than in those who had not. Moreover, repeated
concussions can have more severe outcomes than first concussions.
A rare but particularly scary phenomenon has
been called the "second impact syndrome" in which a second
concussion occurring within days or weeks of an earlier concussion
can produce catastrophic consequences -- including death -- way out
of proportion to the apparent severity of the re-injury.
Because of the potentially serious
consequences, athletes, coaching staffs and parents need to have a
heightened awareness of head-injuries and their need for proper
evaluation, including by medical personnel. Various guidelines have
been created for decisions about when it is safe to resume
participation in contact sports. These guidelines, while based more
on expert opinion than on medical evidence, are still the best
benchmarks we have until more studies are done.
All guidelines agree that an athlete needs to
become symptom-free in all areas -- thinking, memory, emotions,
coordination, balance, etc. -- before resuming play. After a first
concussion, the athlete should have been normal for at least a week,
and after a second concussion, for probably two weeks.
When should an athlete hang up his or her
cleats and retire from the sport? How many concussions are too many?
No one has a definite answer to either question. As Clint Eastwood's
"Dirty Harry" might ask, "Are you feeling lucky?" Three concussions
in the same season -- or even in an entire sports career -- should
certainly raise concern about long-term damage to the brain.
Of course, student-athletes often pressure
their parents to allow them to return to play sooner than might be
wise. In these circumstances it is useful to recall that many
professional athletes in football, hockey, boxing and other sports
have retired from their lucrative careers rather than suffer
additional concussions. If these high- profile individuals were
willing to give up their big paydays in order to protect their
brains, then perhaps your son or daughter will be able to follow
their examples when less money is at stake. However, if you are the
parent and are being pressured to allow an early return to play, you
just might have to stand tall, do the right thing, and say no.
(C) 2005 by Gary Cordingley
Gary Cordingley, MD, PhD, is a clinical
neurologist, teacher and researcher who works in Athens, Ohio. For
more health-related articles see his websites at: