I notice on my blog information this morning an
unusually large number of reads of an old post, http://childmyths.blogspot.com/2011/07/eye-contact-with-babies-what-when-why.html.
I would guess that this interest is because of various announcements of a research
article in Nature by Warren Jones and
Ami Klin, “Attention to eyes is present but in decline in 2-6-month-old infants
later diagnosed with autism” (on line, 6 November 2013). A piece on the front
page of the New York Times discussed
the Nature paper (http://well.blog.nytimes.com/2013/11/06/a-babys-gaze-may-signal-autism-study-finds/).
I hope everyone will understand that this research
does not make it possible for parents to assess their young baby’s typical or atypical
development by seeing whether they “make eye contact”, that is, engage in
mutual gazing for short periods with another person, or visually track another
person’s eyes. This study, valuable as it is, does not give guidelines for
evaluating a baby’s gaze in an everyday social setting. All babies, like all older persons, look at
eyes sometimes, at mouths sometimes, at other parts of the face sometimes—and away
from a person at other times. Whether they do “mutual gazing” with another
person depends to some extent on what the other person looks like or does,
whether the distance and illumination are favorable, whether the baby is tired,
etc. An important point made by Jones and Warren is that differences in eye-tracking
are not present at birth, when babies do not reliably look at eyes, but are
seen after two months, when typical development involves an increase in
attention to eyes so that by 6 months typically-developing babies look at eyes
as much as adults do.
In any case, the babies in the Jones and Klin study did not “make eye contact”; there was none to
be made, because the babies were watching a video of another person, not
engaging face-to-face with a real person who could look back at them. The
question was whether recordings of their eye movements showed that the babies
looked at the videorecorded eyes or at other parts of the face or the screen,
and how long their gaze lingered on a particular area. Typically-developing babies
begin to look at the eyes more and more as they mature from about 2 months to
about 6 months, but it appears that for babies who will later be diagnosed as
autistic, this developmental process is “derailed” during that period.
The Times report
quoted Warren Jones as saying that eye-tracking (following another’s eyes with
one’s gaze) is only one channel that may be related to autism. He proposed that
social communication through touch or
listening is probably similarly related to autism, but these processes are more
difficult to measure than eye movements. (This suggests, by the way, that a
treatment that increased eye contact might not necessarily affect autistic
development, because the atypical gaze may be only one symptom of a central
problem.)
Naturally, the concern with early diagnosis of
autism is associated with the hope that early intervention would get the “derailed”
social development back on track. The New York Times report included the suggestion that intensified or
pleasurable social experiences might be helpful if they were provided during
the possible sensitive period or window of opportunity that may be indicated by
the Jones and Klin study. Does this suggestion imply that parents of autistic
children have done something wrong, or failed to do something right? Does the
strong genetic factor at work in autism determine that these infants need
unusual care given by their parents, different care than is needed by more
typically-developing babies? How do the interactions
between genes and environment guide development?
There are several ways in which genes and
environment can interact. One of these, a passive interaction, means that the
environment directly affects development in different ways depending on a
person’s genetic make-up. For example, if
a genetic problem made a baby not very sensitive to social signals like
gaze, and if those signals needed to be experienced for good development, more
intense or noticeable signals might help development. This is an idea that has
been around for some time. Nikolaas Tinbergen, the Nobel Laureate in Medicine,
suggested that people working with
autistic children should wear masks with big eyes to get the children’s
attention. Some alternative treatments for autism have parents wear large
eyeglasses and hold objects beside their eyes when they offer the objects to
autistic children. There is no evidence that this is effective, though, so if
there is a gene-environment interaction in autism it may not be this kind, and
treatments that use these methods will probably not be helpful no matter how
early they are provided.
Gene-environment interactions may also be evocative.
This means that the genetic material causes the individual to act in ways that
make some experiences more likely to happen. This might mean that when
typically-developing babies pay attention to eyes, they attract adults to
socialize with them, and that socialization facilitates good development. If babies who will later be diagnosed as
autistic do not pay attention in that way, or do other things that attract
adult play and interaction, they might not receive social interactions that are
needed to facilitate development. In that case, treatment might involve helping
parents become more responsive to any cues the babies give, or more able to
find ways of interacting even though the baby doesn’t “give the signal”. This
might or might not need to happen during a particular early period, although
the Jones and Klin study seems to suggest that there are important changes
early on.
Gene-environment interactions can also be active.
This means that the genetic material causes the baby to do things that
naturally provide certain experiences--
like moving in ways that strengthen muscles and increase flexibility, or
preferring some foods over others. Children who find dancing or singing or
talking easy and fun will do those things over and over and get even better at
them as they actively seek these experiences. Toddlers with Williams syndrome
are said to seem to have a “hunger” for eye contact, and although they are initially
slow to talk they later become extremely sociable and communicative. If this were the case in autism, it may
be that typically-developing children are genetically determined to do things
like looking and imitating that encourage good development, and autistic
children lack that determinant. In that case, it would be a matter of a great
deal of work to determine what it was that babies typically did that gave them
the “right experiences”, and to figure out how such experiences could be given
to autistic children. Even then, it would have to be shown empirically that the
treatment was effective.
Finally, it’s possible that there is little or no
gene-environment interaction. The Jones and Klin finding may simply show a
developmental trajectory that is different for typical and autistic children
because of their genetic differences. The increasing differences between 2 and
6 months might, unfortunately, not indicate a sensitive period, but just result
from innate developmental patterns. In that case, early diagnosis might or
might not help interventions work.
There is a lot of other interesting work that Jones, Klin, and
others have published, and I hope to be able to comment on it soon.
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