WHEN Rachel Hudson was 2, she recalled details about things she had done weeks and months before, prompted by her mother, a psychologist studying children's memories. But by the time she was 8, the only episode Rachel could recall from her first couple of years was a trip to Disneyland.
The old mystery of just why most people are unable to dredge up memories from the first years of life has a new solution, thanks to research like that of Rachel's mother, Dr. Judith Hudson of Rutgers University.
The ability to fix a childhood memory strongly enough to last into adulthood, psychologists now say, depends on the mastery of skills of attention, thought and language at the level of an average 3- or 4-year-old. People simply do not retain into adulthood memories of specific episodes that took place at 1 or 2, before these crucial abilities emerge, although research like that with Rachel shows that as young children they do, indeed, have such memories.
"Most adults have trouble remembering much, other than fragmentary impressions, before they were 3 1/2," said Dr. Robyn Fivush, a psychologist at Emory University in Atlanta. "Yet we know that children as young as 2 can remember what happened to them even months before."
The new research, based largely on studies of the developing memories of young children, contradicts Freud's notion that "infantile amnesia," the inability of adults to remember the events of early infancy -- is due to the later repression of perverse lusts and hatreds that seethe during the first years of life.
Instead, the findings suggest a more innocent end to life's early amnesia: that toddlers acquire the skills for remembering significant episodes in their lives only as they acquire the language skills necessary for later retrieval. As they have conversations with adults about past events, psychologists say, infants learn the art of shaping events into a story, the form that allows memories to be retrieved many years later.
"We have a whole new way of thinking about earliest memories, based on studies of what young kids actually remember," said Dr. Ulric Neisser, a psychologist at Emory. "At 2 1/2 or 3, kids are not very interested in the past. You don't see a bunch of 3-year-olds sitting around talking about old times."
Dr. Neisser added, "But ask a 2-year-old about what happened on a visit to grandma's months before, and she'll have some memories: 'saw a horsie.' The question is why, as adults, don't we remember those very episodes from life's first few years?"
Part of the answer, psychologists say, lies in distinguishing between three fundamentally different kinds of memory. One is a "generic" memory, in which the most general attributes of a familiar situation are stored, like what grandma always served for lunch, or what color the rooms were in a childhood house.
Such general characteristics do not pertain to any single episode but are distilled from a series of repeated episodes, which Dr. Neisser has called repisodes, episodes that blend into a generic memory. When an event has occurred in a child's life about five or more times, it tends to be stored in memory in this general form.
A second kind of memory, "episodic," is for specific events, like a visit to grandma's when a favorite, rarely seen, cousin was also there. Such memories are for a distinct event at a given time and place. But few of these specific episodes -- such as what was eaten for breakfast that morning -- are significant enough to warrant remembering years later.
But out of such specific episodes people select and weave together the particularly meaningful events that compose "autobiographical memory," the story of one's life. These are the specific memories that last throughout a lifetime, beginning with what people call their earliest memory. As autobiographical memory begins, infantile amnesia ends. The Power of Story
From the time children begin to talk, around age 2, they have both generic and episodic memories, researchers say. But they do not begin to weave together autobiographical memory until around age 3 1/2, according to research reported by Dr. Katherine Nelson, a psychologist at the City University of New York, in the January issue of Psychological Science.
On the basis of research with young children, Dr. Nelson, as have others, concluded that although children as young as 1 or 2 do have episodic memories, these memories almost never last into later childhood, let alone adulthood. Autobiographical memory seems to take root only as children begin to have conversations with their parents or others about what has happened to them.
"Parents implicitly model for their young children how to piece together a story with a beginning, a middle and an end about what has happened," said Dr. Fivush. "Between 3 1/2 and 4 1/2, children reach a critical level of language ability, where words become the medium through which you represent the events of your life to yourself rather than, say, images. And years later, when you tell a story from your earliest years, language is the medium of retrieval."
The process of autobiographical memory seems to be given a great impetus by adults who review events with a young child. In Dr. Fivush's research, young children of parents who mulled over incidents with much embellishment of detail had at 4 years better memories for things that had happened to them than did children of parents who typically simply asked, "Do you remember the time we went to the circus?"
"At around 3 or 4, you find mothers talking a lot about past events to a kid," said Dr. Neisser. "Then a kid starts to value her memories and starts to tell stories about herself. The events you can easily remember as an adult are those you had, back then, put into a narrative, at least in your own mind."
At about the same period, children learn from talking to parents and others that a given event can be seen from multiple perspectives. "Around age 4 children seem to start to understand that people see things differently," said Dr. Fivush. "I might have gone to the circus and been scared by the big animals, while someone else loved it." Photos as Hindrance
This cognitive ability to see an event from several points of view, some psychologists contend, may add to the thoroughness with which it is remembered, as a stronger net of associations is built. The onset of that ability also marks the point at which most people have their earliest lasting memory.
Still another capacity that ripens around age 4 is the ability to perceive the structure ofevents more as an adult would, highlighting the most salient points. Toddlers notice mostly what to adults seem to be trivial details, psychologists say.
Oddly, seeing an event in a photo frequently or discussing it often with others does not determine how well it is remembered, either in the short term or in later autobiographical memory. Dr. Fivush had parents keep track of distinctive events in the lives of children between the ages of 2 and 6 and also had them note how often the children talked over those events or looked at photos of them. There was no apparent effect on the children's memory.
Indeed, talking over an event with a very young child may somehow interfere with its being stored in memory, according to findings by Dr. Neisser, with JoNell Adair, a graduate student, that will be published in The Journal of Experimental Psychology later this year.
In a study of college students, in which their memories were verified by checking with their parents, Dr. Neisser and Ms. Adair found that events from the first four years of life that became enshrined in family stories or for which there were photos were remembered less well than events that had no such memory aids.
But they also found that those students who had been hospitalized or who had had a sibling born between their second and third birthday could usually still remember the event. "For such highly memorable events, people seem to have memories, though a bit fragmentary, as early as age 2, though that may mean closer to 3," said Dr. Neisser.
Other studies of adult's earliest memories have found that most date from around 3 1/2. A few people report no memories of their childhood at all before age 8 or so. Revising the Autobiography