Contrast multiple responses against a standard

[Lee Hogarth]

Dear all,

In my task, I collect multiple responses from two keys, A and B.
Participants have to select the correct key in each trial to be
rewarded. If they choose the incorrect key or swap keys they are not
rewarded.

Consequently, I need to compare every response made in each trials,
against the correct standard for that trial, either "A" or "B".

If any one of these responses deviates from the standard, no reward
follows. If all the responses equal the standard, then reward follows.

Does anyone have a chunk of e-basic that compares mutiple responses
against a standard.

Many thanks for you help.

Lee Hogarth.