it can be organized and accessed from the long-term
store.
The information-processing model is particularly
useful in understanding explicit memory, the type of
memory of greatest interest to parents and teachers.
Explicit memories are potentially conscious and can
be described verbally or pictured in images. A child
uses explicit memory when she describes a class field
trip or edits a report by applying grammatical rules
she has learned. In contrast, some information may
affect task performance without entering the individ-
ual’s conscious awareness. In this case, it is described
as implicit memory. Implicit memory is assessed by
indirect measurements, such as determining how
much quicker individuals can add letters to complete
a word when they have previously been presented
with a target word, or by physiological indicators,
such as changes in galvanic skin response.
Understanding children’s memory requires iden-
tifying the age-related changes that occur in the com-
ponents of the information processing system. The
first significant advance, of course, is the emergence
of memory in development. In the next section, the
point in life at which the memory system can be con-
sidered to be ‘‘up and running’’ will be discussed. The
following sections will examine the changes that occur
during childhood in the memory stores and in the use
of strategies. The importance of these transitions in
children’s everyday lives will be explored in each sec-
tion.
The Developmental Onset of Memory
The memory stores described above are assumed
to be universal and present throughout life. Indeed,
there is evidence that the capacity to store informa-
tion in long-term memory begins even before birth.
In a well-controlled investigation conducted by An-
thony DeCasper and Melanie Spence, the researchers
asked pregnant women to read aloud a Dr. Seuss story
during the last six weeks of their pregnancies, a point
in prenatal development at which fetuses can hear.
Shortly after birth, the newborns’ recognition memo-
ry was tested by comparing their reactions to the fa-
miliar passages versus similar but new story excerpts,
both of which were read by the babies’ mothers. The
assessment built on the knowledge that babies can
learn to modify the time between bursts of sucking
when a change in sucking is followed by the presenta-
tion of a stimulus that serves as a reinforcer. The new-
borns wore headphones and were given a pacifier that
recorded their sucking bursts. They indeed modified
the way they sucked when the change in sucking was
followed by the familiar passage, but they did not do
so with the unfamiliar passage. The fact that the old,
but not the new, passages served as reinforcers dem-
onstrated that the babies could recognize the stimuli
to which they were exposed before birth.
Although even very young infants can recognize
sights, sounds, and smells they have previously en-
countered, the ability to recall an object or an experi-
ence develops later. Recall differs from recognition in
that it requires coming up with a response as well as
determining that it is correct. Some simple recall is
present in the second half of the first year. As every
babysitter knows, very young infants remain calm
when their parents go out; by around seven months
of age, however, separation protest is apparent. By
about nine months of age, babies can imitate an ac-
tion after a twenty-four-hour delay. Note that early re-
call is heavily dependent on cues and is limited to
relatively brief time intervals. Recall continues to de-
velop over the second year of life, corresponding to
the development of the prefrontal cortex and other
brain structures associated with explicit memory. Be-
tween age two and two and a half, toddlers can be ex-
pected to remember to stay away from common
hazards, provide their first and last names when
asked, repeat parts of nursery rhymes, and possess
simple event schemas (also called scripts) for everyday
events.
By age two and a half, as is well documented in
the work of Robyn Fivush and her colleagues, chil-
dren describe specific past experiences such as a trip
to an amusement park. Such early memories, howev-
er, do not generally become a permanent part of au-
tobiographical memory, the subset of episodic
memory that represents individuals’ own life histo-
ries. Most people do not recall anything that hap-
pened before they were three years of age. This
phenomenon is described as infantile amnesia. Al-
though the reasons for infantile amnesia are not com-
pletely understood, several factors appear to be
important in explaining the developmental emer-
gence of autobiographical memory. One of these is
the maturation of the frontal lobes of the brain, which
continues throughout early childhood. A second fac-
tor appears to be the emergence of the self-concept,
which serves as a conceptual framework for the orga-
nization of memories. Another is the role of social in-
teractions in maintaining early memories. Katherine
Nelson has emphasized the importance of the child’s
participation in family discussions about past events
for keeping early memories alive, a process described
as reinstatement. Children are about three years old
before they can actively participate in conversations
about past events. Finally, some early memories may
not be retrieved at later points in development
because they are not effectively cued. Because the typ-
ical everyday environments of older individuals differMEMORY 257