Dual Task Cost – How much is too much?

As was initially suggested by the BEST test, perhaps a 10% dual task cost (reduction in performance due to the introduction of a purposeful distractor) would be acceptable. Greater than this (more than 10%), would indicate an impairment, lack of automaticity (procedural memory capacity), or other. For clear example, if someone walks more than 20% slower because they are attempting to review a list of grocery items. However, recent evidence suggests that 40% may be a more acceptable DTC threshold. However, this is most certainly industry and task specific. For example, if I am an NFL wide-receiver, the acceptable threshold with a defender oncoming, crowd cheering, teammate crossing and pass coming to run my route accurately had better be less than 5% margin of error. Therein, you see the limitation in applying an acceptable. That is just the start of the conversation.