单选题
Virtually nobody has memories from very early
childhood-but it's not because we don't retain information as young children.
Rather, it may be because at that age, our brains don't yet function in a way
that bundles information into the complex neural patterns that we know as
memories. It's clear that young children do remember facts in
the moment-such as who their parents are, or that one must say "please" before
morn will give you candy. This is called "semantic memory."
Until sometime between the ages two and four, however, children lack "episodic
memory" - memory regarding the details of a specific event. Such memories are
stored in several parts of the brain's surface, or "cortex." For example, memory
of sound is processed in the auditory cortexes, on the sides of the brain, while
visual memory is managed by the visual cortex, at the back. A region of the
brain called the hippocampus (海马体) ties all the scattered pieces
together. "If you think of your cortex as a flower bed, there
are flowers all across the top of your head," said Patricia Bauer of Emory
University in Atlanta. "The hippocampus, tucked very neatly in the middle of
your brain, is responsible for pulling those all together and tying them in a
bouquet (花束) ." The memory is the bouquet-the neural pattern of linkages between
the parts of the brain where a memory is stored. So why do kids
usually fail to record specific episodes until the two-to-four age range? It may
be because that's when the hippocampus starts tying fragments of information
together, said psychologist Nora Newcombe of Temple University in Philadelphia.
And there may be a reason for this, Newcombe said. Episodic memory may be
unnecessarily complex at a time when a child is just learning how the world
works. "I think the primary goal of the first two years is to acquire semantic
knowledge and from that point of view, episodic memory might actually be a
distraction," Newcombe said.
单选题
It can be learned that children under the age of two