Lax parents blamed for 'attention deficit' behaviour
Matthew Kirkcaldie
Matthew.Kirkcaldie at newcastle.edu.au
Tue Aug 5 20:42:26 EST 2003
In article <bgpd55$rnh at library2.airnews.net>,
"Jeff Utz" <kidsdoc2000 at hotmail.com> wrote:
> If you go to www.pubmed.gov (PubMed, the database of millions of medical
> articles) and search for ADHD + brain imaging, 221 articles come up. Of
> course, not all of them answer your question.
True - but all of these studies are based on regional blood flow and
receptor binding, qualities which change on a minute-to-minute basis in
normal brains without suggesting that there's a structural abnormality
or a pathological process at work.
Observable processes which result from brain activity still fall under
the category of behaviour in my book. Brain imaging allows better
observation, but it's not more fundamental than activity in the skeletal
musculature or the ANS. For example, if we observe an increase in blood
flow to a particular gyrus, there is no way of knowing whether metabolic
demands have increased because the region has more information to deal
with, or is trying to suppress its inputs, or is subject to increased
feedback from other brain regions. Imagine trying to deduce the
workings of a city by measuring the amount of light coming from its
buildings.
Changes in receptor binding indicate large-scale differences in activity
over a period of time, but there is no way to extract a causal
relationship out of this correlational data. Altered receptor
distribution may produce changed behaviour for these people; equally,
their "abnormal" behaviour may produce alterations in receptor density
once new patterns are established. Neither case provides a basis for
preferring a behavioural treatment over a pharmaceutical treatment, or
vice versa.
If a behavioural treatment is shown to be effective, I say go ahead with
that, rather than trying to alter the activity of transmitter systems
whose coarsest effects on behaviour are poorly understood. Our brains
have evolved to enable us to operate effectively in the environment in
which we find ourselves, and to adapt behaviour accordingly. Why is it
so hard to accept that children with ADHD have grown up in an
environment in which this pattern of behaviour produced positive
feedback initially? The argument about siblings in the same family is
specious: who really believes that parents treat all their children in
exactly the same way? Doesn't parenting experience change parenting
practice? And besides, who knows what the cues shaping behavioural
development REALLY are?
Regards,
Matthew.
More information about the Neur-sci
mailing list