Efficiency as a
function of occurrence probabilities *p*.
for a model *X *formed by
post-multiplying *S* (a matrix
containing *n* columns, modeling *n* possible event-related responses every
SOA) by *B. B* is a random binary vector that
determines whether the *n*th response
is included in *X* or not, where_{}. Right panels: A
comparison of some common designs. A graphical representation of the occurrence
probabilities *p* expressed as a
function of time (seconds) is shown on the left and the corresponding
efficiency is shown on the right. These
results assume a minimum SOA of one second, a time-series of 64 seconds and a
single trial-type. The expected number
of events was 32 in all cases (apart from the first). Left panels: Efficiency in a stationary
stochastic design with two event types both presented with probability *p* every SOA. The upper graph is for a contrast testing for
the response evoked by one trial type and the lower graph is for a contrast
testing for differential responses.