MouseTrial is based on the technique of discrete trials which is an important
part of the ABA approach to autism treatment. The two terms are
often used interchangeably but strictly speaking ABA is a broader term encompassing any application
of behavioural principles towards a therapeutic goal. Discrete trial is only one of many techniques used
in ABA programs. The abbreviation DTT (discrete trial training) is often used.
so what is it?
This question is best answered by a visit to the Polyxo website
by Jason Wallin. This is a superb resource for anybody interested in ABA and DTT. It gives a very
clear explanation of the technique with detailed examples. For even more detail, see the brilliant online
training materials by the Mariposa School in
North Carolina. But in brief, the idea of discrete trial
is to do lots of short "exercises" with the child in the absence of distractions. In classic ABA the
exercises are usually carried out at a table. In other variants of the technique you might do them round
the house or mix them in with your daily routine.
components of a discrete trial
Many different kinds of exercise are used in discrete trial training. In MouseTrial we concentrate on
receptive object labeling which is simply jargon for a trial where a child shows that
he has understood a verbal command by touching (or clicking) the correct item. In regular discrete trial work
several other kinds of routine are also employed, including matching, sorting, copying actions, carrying out
instructions and verbally identifying objects. But there's a common sequence to all of the trials:-
- CD, the discriminative stimulus.
Academic jargon for the cue or instruction that you want the child to respond to. In MouseTrial this
is the "click on-" audio file that plays when the array of objects is displayed.
- SP, the prompting stimulus.
The hint or prompt that the teacher gives to help the child respond
correctly. This stage is left out if the initial response is rapid and correct. In MouseTrial it's
the flashing yellow background that appears behind the target item.
- R, the response.
This is the resulting behaviour in the child which in MouseTrial we hope is a mouse-click on the
- SR, the reinforcing stimulus.
The reinforcer. A reward or treat for giving the right response. Needless to say in MouseTrial this
function is provided by the animations.
- ITI, the inter trial interval.
Sometimes considered an optional stage, this is simply a pause between trials. Often occurring naturally
as the child scoffs the reinforcer or the teacher fumbles desperately to find the necessary materials
for the next trial.
why does it work?
Until the neuropathology of autism is fully understood nobody can really claim to know why discrete trial
work is effective. But it's not beyond the bounds of possibility that it acts a bit like a "workout for the
brain", stimulating the neurons in some way and helping them reconnect in more favourable configurations.
As such, it may be related to the process of recovery after brain injury or stroke.