Negative compatibility effects in the masked-prime paradigm are usually obtained when primes are masked effectively. With ineffective masks—and primes above the perceptual threshold—positive compatibility effects occur. We investigated whether this pattern reflects a causal relationship between conscious awareness and low-level motor control, or whether it reflects the fact that both are affected in the same way by changes in physical stimulus attributes. In a 5-session perceptual learning task, participants learned to consciously identify masked primes. However, they showed unaltered NCEs that (...) were not different from those produced by participants in a control group without equivalent perceptual learning. A control experiment demonstrated that no NCEs occur when prime identification is made possible by ineffective masking. The results suggest that perceptual awareness and low-level motor control are affected by the same factors, but are fundamentally independent of each other. (shrink)

Subliminal primes are assumed to produce weaker and short-lived effects on subsequent behavior compared to clearly visible primes. However, this difference in priming effect may be due to differences in signal strength, rather than level of awareness. In the present study we manipulated prime discriminability by using metacontrast masks and pseudomasks, while keeping the prime strength equal. This manipulation resulted in large differences in discriminability of the primes. However, both immediate response priming and long-term response priming was equal for the (...) poorly discriminable and well discriminable primes, and equal for groups that differed markedly in terms of how well they could discriminate the primes. Our findings imply that discriminability of information is independent of both the immediate and long-term effects that information can have on behavior. (shrink)

People have intuitively assumed that many acts of volition are not influenced by unconscious information. However, the available evidence suggests that under suitable conditions, unconscious information can influence behavior and the underlying neural mechanisms. One possibility is that stimuli that are consciously perceived tend to yield strong signals in the brain, and this makes us think that consciousness has the function of sending such strong signals. However, if we could create conditions where the stimuli could produce strong signals but not (...) the conscious experience of perception, perhaps we would find that such stimuli are just as effective in influencing volitional behavior. (shrink)