Watching TV Makes You Smarter

By STEVEN JOHNSON

The Sleeper Curve

SCIENTIST A: Has he asked for anything special?
SCIENTIST B: Yes, this morning for breakfast . . . he requested something called ''wheat germ, organic honey and tiger's milk.''
SCIENTIST A: Oh, yes. Those were the charmed substances that some years ago were felt to contain life-preserving properties.
SCIENTIST B: You mean there was no deep fat? No steak or cream pies or . . . hot fudge?
SCIENTIST A: Those were thought to be unhealthy. — From Woody Allen's ''Sleeper''

n Jan. 24, the Fox network showed an episode of its hit drama ''24,'' the real-time thriller known for its cliffhanger tension and often- gruesome violence. Over the preceding weeks, a number
Over the last half-century, programming on TV has increased the demands it places on precisely these mental faculties. This growing complexity involves three primary elements: multiple threading, flashing arrows and social networks.

According to television lore, the age of multiple threads began with the arrival in 1981 of ''Hill Street Blues,'' the Steven Bochco police drama invariably praised for its ''gritty realism.'' Watch an episode of ''Hill Street Blues'' side by side with any major drama from the preceding decades -- ''Starsky and Hutch,'' for instance, or ''Dragnet'' -- and the structural transformation will jump out at you. The earlier shows follow one or two lead characters, adhere to a single dominant plot and reach a decisive conclusion at the end of the episode. Draw an outline of the narrative threads in almost every ''Dragnet'' episode, and it will be a single line: from the initial crime scene, through the investigation, to the eventual cracking of the case. A typical ''Starsky and Hutch'' episode offers only the slightest variation on this linear formula: the introduction of a comic subplot that usually appears only at the tail ends of the episode, creating a structure that looks like this graph. The vertical axis represents the number of individual threads, and the horizontal axis is time.

A ''Hill Street Blues'' episode