Priming Asymmetry Research Articles

Priming by numb3r5 does not involve top-down feedback.

Using the same-different task, Perea, Duñabeitia, Pollatsek, and Carreiras (2009) showed that digits resembling letters ("leet digits"; e.g., 1 = I, 4 = A) primed pseudoword strings (e.g., V35Z3D-VESZED), but letters resembling digits ("leet letters") did not prime digit strings (e.g., 9ES7E2-935732), and suggested that this is due to top-down feedback available for letter, but not digit, strings. Here we show that (a) single letters show as much leet priming as 3-letter words (Experiment 1); (b) leet priming is equally robust for digit strings and pseudowords when the string is 4 items long but not when 6 items long (Experiment 2); and (c) with 6-item strings, orthotactically illegal letter strings (e.g., OIAUEQ) behave just like digit strings (Experiment 3). These results indicate that the asymmetry in leet priming is not due to top-down feedback available selectively for letter strings. We offer an alternative explanation based on the Bayesian reader account of masked priming proposed by Norris and Kinoshita (2008), and the role played by the orthotactic knowledge used to extend the functional capacity of visual working memory involved in performing the same-different task.

Inflectional Regularity: Probing the Nature of Lexical Representation in a Cross-Modal Priming Task

Two cross-modal priming experiments address issues concerning the representation and processing of regular and irregular morphology in English as well as methodological issues concerning the use of the cross-modal technique in lexical processing studies. Cross-modal inflectional priming facilitates regular verbs (e.g., walked priming walk) but not irregular verbs (e.g., gave priming give). We found that similar but morphologically unrelated words (e.g., slam priming slim) inhibit each other when presented cross-modally. Based on this effect for form-based inhibition, we interpret the regular/irregular verb priming asymmetry as a reflection of competition between orthographically similar verb forms (e.g., gave-give) which results in target inhibition. In support of this proposal, we found that orthographically dissimilar irregular verbs (e.g., taught-teach) show strong priming facilitation. We account for this result in terms of a two-level lexicon in which irregular verb alternates have distinct form-level entries, but engage a common entry at an abstract morphological level of representation. In addition to serving as evidence concerning the representation of English verbal inflection, the findings from these experiments also set important limits on the claim that the cross-modal priming paradigm automatically circumvents form-related processing effects that are not morphological in character.

A central-peripheral asymmetry in masked priming.

Masked primes presented prior to a target result in behavioral benefits on incompatible trials (in which the prime and the target are mapped onto opposite responses) when they appear at fixation, but in behavioral benefits on compatible trials (in which the prime and the target are mapped onto the same response) when appearing peripherally. In Experiment 1, the time course of this central-peripheral asymmetry (CPA) was investigated. For central primes, compatible-trial benefits at short stimulus onset asynchronies (SOAs) turned into incompatible-trial benefits at longer SOAs. For peripheral primes, compatible-trial benefits at short SOAs increased in size with longer SOAs. Experiment 2 showed that these effects also occur when primes and targets are physically dissimilar, ruling out an interpretation in terms of the perceptual properties of the stimulus material. In Experiments 3 and 4, the question was investigated as to whether the CPA is related to visual-spatial attention and/or retinal eccentricity per se. The results indicate that the CPA is independent of attentional factors but strongly related to the physiological inhomogeneity of the retina. It is argued that central and peripheral primes trigger an initial motor activation, which is inhibited only if primes are presented at retinal locations of sufficiently high perceptual sensitivity. The results are discussed in terms of an activation threshold model.