Fig. 3.

Reproducibility, stability, and vector norm for blank control trials. A–F are the same as in Fig. 2, but for target-absent (control) trials. In this case, reports of “seeing” an object reflect endogenously generated perceptual false positives. Data were noisier because there were fewer trials of this type. Because no object was present on the screen, these trials count as instances where perceptual decision making was decoupled and deconfounded from bottom-up sensory information processing. Note that the significant difference in the norm at ∼600–800 ms (E) is in the opposite direction of what might otherwise lead to a lower average dva for seen trials (A), and thus the observed difference in across-trial variability (reproducibility) cannot be tied to a simple difference in signal strength. The difference in the norm is also the opposite of what one might intuitively predict for seen versus unseen trials. Recurrent network models, however, allow for higher energy in a network that fails to settle into a decision state. The timing of the early difference in within-trial variability (stability) is consistent with that of the visual-awareness negativity (88).