Theory 07/Consciousness & Attention/Conscious access
Access Is a Timing Ratio
Masking is explained by signal strength. It may be explained by whether the loop closed in time.
Whether a stimulus reaches consciousness is set by the ratio of recurrent processing time to the interval before the next stimulus, so identical stimuli can be seen or missed depending on timing rather than on strength.
01The evidence
Backward masking abolishes awareness at stimulus-onset asynchronies too short for recurrent processing, and the critical asynchrony is largely independent of stimulus contrast.
02The tension
Access is modelled as a threshold on activation. That predicts that stronger stimuli should resist masking, which is only weakly true.
03The mechanism
Conscious access requires a recurrent exchange between sensory and higher areas. That exchange takes time, and if the next stimulus arrives first, the loop is interrupted.
That makes the ratio of loop time to inter-stimulus interval the determinant, and predicts a critical asynchrony that is stable across contrast, which is what masking data show.
04What this is not
Those make strength the variable. This makes timing the variable, which explains contrast independence.
05Predictions
- P1The masking threshold should be stable across contrast.
- P2It should scale with recurrent loop time.
- P3Perturbing recurrence should shift the threshold.
06Refutation
Thresholds tracking contrast strongly would favour activation models.
07What it changes
It would reframe disorders of awareness as timing disorders.