Response inhibition in the Negative Compatibility Effect in the absence of inhibitory stimulus features

Abstract The Negative Compatibility Effect (NCE) is a reversal in priming effects that can occur when a masked arrow prime is followed by an arrow target at a long stimulus-onset asynchrony (SOA). To test the explanation that the NCE is actually a positive priming effect elicited by mask features associated with the prime-opposed response, we devise masks that always point in the same direction as the prime, eliminating all antiprime features. We find large positive priming effects for arrow primes without masks and for arrow masks without primes. When a neutral mask is introduced, priming effects turn negative at long SOAs. In the critical case where the mask is an arrow in the same direction as the prime, the prime does not add to the positive priming effect from the mask shape, but instead strongly diminishes it and induces response errors even though all stimuli point in the same direction. No such feature-free inhibition is seen when arrows are replaced by color stimuli. We conclude that even though response activation by stimulus features plays a role in the NCE, there is a strong inhibitory component (though perhaps not in all feature domains) that is not based on visual features.