Response is not accepted for any key press
respond_no_key()
Many of the functions within the trial_ family are designed
to allow participants to respond using a key press, generally by specifying a
a choices argument that indicates which keys will be accepted as valid
responses (e.g., choices = c("f","j")). There are also cases where
you may wish to disable this, so that no key presses will be counted as valid
responses (e.g., when a trial runs for a fixed duration but no response is
expected). In those cases, specifying choices = respond_no_key() will
produce the desired behaviour.