Unconscious manipulation of free choice by novel primes

•Masked primes have been shown to influence free choices.•This may depend on the availability of acquired stimulus–response links.•Here novel primes that never appeared as targets preceded free-choice targets.•Apparently ‘free’ choices were influenced by unseen novel primes.•Non-conscious semantic representations may thus influence free choice behaviour.

The extent to which non-conscious perception can influence behaviour has been a topic of considerable controversy in psychology for decades. Although a challenging task, convincing empirical demonstrations have emerged suggesting that non-consciously perceived ‘prime’ stimuli can influence motor responses to subsequent targets. Interestingly, recent studies have shown that the influence of masked primes is not restricted to target-elicited responses, but can also bias free-choices between alternative behaviours. The present experiment extends these findings by showing that free-choices could also be biased by novel primes that never appeared as targets and therefore could not trigger acquired stimulus–response (S–R) mappings. This new evidence suggests that free-choice behaviour can be influenced by non-consciously triggered semantic representations. Furthermore, the results reported here support accounts of masked priming that posit an automatic semantic categorisation of non-consciously perceived visual stimuli.