FIGURE 1.

Encoding scheme for answering a binary question. The red periods require mental drawing (MD) imagery, whereas the green periods required spatial navigation (SN) imagery. If participants chose to answer “yes”, they started performing the MD task when they heard a “yes”, halted their imagery when they heard the cue “stop”, and ignored the auditory cues related to the “no” response. The hypothesized HbO response for a “yes” answer is shown by the upper white waveform. If participants chose to answer “no”, they started performing the SN task when they heard a “no”, halted their imagery when they heard the cue “stop”, and ignored the auditory cues related to the “yes” response. The hypothesized HbO response for a “no” answer is shown by the lower white waveform.