The to-do list. Some people tuck one in a shirt pocket or purse. Others keep one on a personal digital assistant or home computer.

Paper or digital, a to-do list, or task list as it’s sometimes called, is of course a list of things that need to be done. Today. This week. This month. Maybe this year. Maybe it is a list of personal things. Maybe it is a list of things to do at work. Often it is both.

Whatever, we compile them as a way to avoid forgetting things. Dentist at 9:30. Make appointment for car service. Sales meeting at 10. Meet with Joe in Accounting 2 p.m. Pick up Jennifer after soccer practice.

Some people keep them faithfully and swear by them. Many others keep their list upstairs, in the noggin — or try to.

If January is the month to get organized, then here, in an ever more hectic world, is a To-Do List for 2005:

• Make your list every day.
• Check it periodically.
• Swell with satisfaction as you do things and check them off.

“In modern society where we all are doing a lot more multitasking than we used to, it becomes a lot more necessary,” said Randolph M. Lee, director of the counseling center at Trinity College in Hartford, Conn., and associate professor of psychology. “It organizes our lives, and we can all use that.”

Faith Manierre of Glastonbury, Conn., who owns and operates Busy Bees Professional Organizing, says the lists are invaluable in removing a layer of stress.

Making a to-do list “frees up our mind,” she says. “If we don’t put it down someplace, our mind will spin through all the things we have to do.” All day, as in that nagging feeling that you forgot something. You probably did.

Lists as management tools

America seems to be list crazy — college basketball Top 25, Letterman’s Top Ten, Top 40 tunes — so why not your own list?

Does keeping a list say something about a personality, that perhaps one is a little obsessive-compulsive?

Although obsessive-compulsive disorder can manifest itself in making lists, Lee said, for most people, keeping a to-do list indicates nothing more than this: “You are organized.”

“That is the boring, basic level,” he said.

Etan Markus, an associate professor of behavioral neuroscience at the University of Connecticut, works with rats and investigates parts of the brain related to memory.

Relevant to to-do lists are the frontal cortex, which deals with planning, and the hippocampus, which remembers events or episodes that occurred during the day.

People developing Alzheimer’s disease, which involves damage to the hippocampus, often start making lists to compensate, Markus said.

For people with attention deficit disorder, or ADD, such lists can be therapeutic. For them, having a list not only helps get things done, but it also has the positive effect of demonstrating “they can manage their life better,” Lee said.

The list provides structure, Manierre said, and once someone with ADD has the structure, “It is like a road map.”

Measure of satisfaction

There are two ways of remembering things. “One is called ‘cued’ recall,” Markus said. “Versus ‘noncued’. We are all much better at cued recall.”

A to-do list is cued recall. “A list is lots of cues to help us remember things, taking something abstract and making it part of cued recall,” Markus said.

Psychologists have conducted studies showing that if a person makes a list that is removed, the person tends to remember things at the beginning and end of the list, and forget those in the middle.

An exception is anything on the list with an emotional wallop; for example, a reminder to buy something a spouse very much wants. That item likely will be remembered even if buried in the middle of the list.

Not only does a to-do list help people remember things that need to be done, the subsequent crossing off of things on a list, or clicking them off on a PDA, brings with it a cozy measure of satisfaction.

“I think it gives us a sense of accomplishment even when we haven’t accomplished nearly as much as we thought,” Lee said. “I know people who literally make to-do lists that include even some things they did yesterday so they can start off crossing things off, because then it looks like you’ve finished half your list. People think to themselves, ‘My life is this busy, but, look, I’ve done a lot of these things.”‘