The most critical part of this project is the recognition system within the Affective Tigger. The sensors are designed to detect very specific behaviors but it is the ability of the Affective Tigger to interpret and appropriately respond to those signals which make the interaction a success.
The recognition system was initially implemented with experimentally determined parameters. For example, when I bounce the Affective Tigger can I trigger the sensor? Then I handed the toy to the first subject. She was not strong enough to trigger the sensor, so I recalibrated the system (both in hardware and software) to be more sensitive. The next child proved strong enough, and the appearance of an appropriate response from the Affective Tigger signified that the parameters were correctly set. This procedure was carried out with all the sensors simultaneously and iteratively, until the Affective Tigger was correctly responding to the intentions of the average child.
The behavior of the Affective Tigger is entirely software based. Each sensor produces an emotional trigger either in the positive or negative direction. When the Affective Tigger is `VERY happy' and he gets turned upside down, he drops down a level to `happy' before becoming `neutral' then `unhappy', `VERY unhappy', and finally shutting down. This progression occurs on the order of a minute, and is stretched out by the child's continued interaction and activation of other sensors.
The interaction between the child and the Affective Tigger is not completely unchecked. When the Affective Tigger is already `very unhappy' and the child continues to `make him unhappy' the Affective Tigger will take a time-out. The Affective Tigger shuts down for a period of 60 seconds to allow the child a moment to compose herself. He remains completely unresponsive during this time. This time-out, as much as the negative emotional cues, is what teaches the child that this kind of behavior is unacceptable. In the twelve trials, the Affective Tigger only timed-out once. The time-out made the child very agitated.
A proposal was made to include external input to the Affective Tigger from a pager or radio control. For example, the Affective Tigger might become unhappy and say ``I'm hungry, let's go eat'' when he receives a page from a parent who just put dinner on the table. This allows someone like a parent or therapist, to break into the interaction if so needed. With autistic children it is sometimes important to break into the interaction like this, in order to stop the repetition and provide a new stimulus [Cohen and Donnellan, 1987].