Friday, February 1, 2008

7.15 Go Pats!!

What's in an American football game? Why, a display of the ultimate eye-limb coordination, of course. It is a major part of the American culture involving thousands of fans congregating in gigantic stadiums (i.e., bowls) every week (or separately in front of TV sets), cheering for their respective home teams. This season so far, Boston's own, the New England Patriots are a record 18-0, and are playing for a historical 19-0 this coming Sunday (3 Feb, 2008), against the New York Giants for the "World" Championship.

The game is essentially one team trying to march across a 100-yard field, by rushing or passing, to put the football in the end zone for 6 points (add 1 more point if the subsequent field goal is successful, for a total of 7 points). And the other team does its best to block the progress. The rules are quite simple. On each possession, a team has 4 chances to gain 10 yards (to reach another "first down") in order to try and gain the next 10 (i.e., a new "first down, 10 to go"). If the attempts fail, then the opposing team has the possession. Often the best part is to watch a harried quarterback tossing the ball up in the air across the field into the awaiting hands of a running receiver who somehow manages to keep both feet just inside the end zone.

The eye-limb coordination operates in this manner: Following a brief discussion of the game plan in a huddle, the ball is snapped to the quarterback who must then look for an open wide receiver and avoid being sacked at the same time. At this moment, both V1 and MT brain areas are highly activated. As soon as the distance to where the receiver maybe is calculated, the motor cortex goes into high gear directing the tossing arm to wind back and throw up the ball. The ball then sails through the often breezy, frigid autumn/winter air into the wide receiver (or a tightend if the star receiver is unavailable). The receiver while running upfield must also look back to see where the ball is and where the defenders are. MT, V1 and motor areas must all coordinate in order to complete the task at hand. All these are accomplished in a matter of seconds.

As far as the eye in football playing:

The players do lose their contacts during tackles; soft disposable lenses with an adequate supply of solution are therefore recommended. Since the game is often played in sub-freezing temperatures, it'll be interesting to know if the physical properties of the lenses are altered. And if the vision is affected as a result.

It is also known that strenuous physical activities, e.g., Marathon running, can significantly lower the intraocular pressure. No studies have been done to investigate any IOP changes from football (or the even more taxing basketball) playing.

Head-butts are also common despite heavily padded helmets. Whether the impacts aggravate pre-existing retinal breaks or holes thereby causing future retinal detachments is also unknown.

Much remains to be studied, isn't it. Nevertheless, do enjoy Super Bowl XLII wherever you may be.

Go Pats!!
Post-game comment: "Nuts!!"

Sunday, January 27, 2008

7.14 London 2012 and Pokémon

(One of the official London 2012 Olympic Games logos)

After almost a decade of absence, photosensitive epilepsy re-surfaces in England. BBC News reports 1.5 alleged cases of seizure from watching a short animated segment of the Games promotion on TV (5 June, 2007). It involves a "diver diving into a pool which had a multi-colour ripple effect" according to a spokesperson. The segment was promptly removed from broadcasting and the website.

It may not be a bad idea to give it a quick review, for video game designers/players and TV viewers alike.

Photosensitive epilepsy is a subset of epilepsy, involving 3-5% of all cases of epilepsy. Many cases, however, have no history of epilepsy at all. The most common trigger is the flickering light.

It has been established at the beginning of the TV age, that TV monitors with a refresh rate of 50Hz could provoke seizures. It was no longer a problem after the rate improved to 100Hz. During the the Disco era in the 1960s, the flashing strobe lights posed the same issue. Then in the late 1990s, with the immense popularity of TV-based video games, the occurrence of photosensitive seizures became alarmingly frequent. The trigger is still flickering light which is now software/game-specific. The London 2012 episode is, in fact, similar to that of the 700-1,000 children in Japan who suffered seizures after watching a Pokémon explosion cartoon 10 years ago. So it is really up to the video designers to carefully craft their products, e.g., 2 - 50Hz flickering is of course prohibited.
Nintendo Pokémon, i.e., Pocket Monster - ポケットモンスター

Photosensitive epilepsy is not a modern phenomenon. The Roman novelist and orator Apuleius (ca 125-170AD) noted that the spinning potter’s wheel could send onlookers into seizures. Others have reported that sunlight filtered through the leaves of a tree had the the same flickering effect when one passed under the tree. Even the whirling helicopter rotors, at low speed, has been reported to cause seizure. It is the periodicity heightened by contrast and brightness that can initiate aura which leads eventually to seizure.

If you are an avid video gamer (or a watcher for that matter), the following info maybe useful:

1. While playing TV-based video games, the viewing distance should be at least four times the monitor size (conventionally measured diagonally across the screen) - use a tape measure if necessary.
2. Eat and drink on a regular basis when playing.
3. No excessive play time - certainly not to continue when under stress (e.g., lack of sleep, running a fever, etc).
4. Do not play in a dark room, this to avoid high contrasts.
5. If episodes of photosensitivity, seek neurological consult, know how to manage the seizure, and dispose of the triggering games.

It is really a matter of common sense.