On the role of the upper part of words in lexical access: evidence with masked priming

More than 100 years ago, Huey (1908/1968) indicated that the upper part of words was more relevant for perception than the lower part. Here we examined whether mutilated words, in their upper/lower portions (e.g., ), can automatically access their word units in the mental lexicon. To that end, we conducted four masked repetition priming experiments with the lexical decision task. Results showed that mutilated primes produced a sizeable masked repetition priming effect. Furthermore, the magnitude of the masked repetition priming effect was greater when the upper part of the primes was preserved than when the lower portion was preserved-this was the case not only when the mutilated words were presented in lower case but also when the mutilated words were presented in upper case. Taken together, these findings suggest that the front-end of computational models of visual-word recognition should be modified to provide a more realistic account at the level of letter features.     

Beyond binary judgments: Prime validity modulates masked repetition priming in the naming task

Bodner and Masson (2001) reported that masked repetition priming of lexical decisions is often greater when the repetition primes appear on a high, rather than a low, proportion of trials. They suggested that processing episodes are constructed for masked primes and that recruitment of those episodes is affected by the probability that the prime will be useful for processing the target. If context-sensitive recruitment of primes is a general mechanism, a similar effect should also occur in a nonbinary response task. In accord with this hypothesis, using the naming task and a 45-msec prime duration, we show that masked repetition priming effects for uppercase words, case-alternated words, and pseudohomophones were greater when .8 rather than .2 of the trials involved repetition (vs. unrelated) primes. Prime validity effects are consistent with a memory recruitment view of priming but may be difficult to explain using activation-based mechanisms.     

Priming word recognition with orthographic neighbors: effects of relative prime-target frequency

Four lexical decision experiments were performed with an orthographic priming paradigm in which test words were preceded by orthographically related or unrelated prime words. When prime words were presented for 350 ms without a mask, it was observed that primes that are lower frequency orthographic neighbors of the target interfered with target processing relative to an unrelated condition. When primes were higher frequency neighbors of the target, no interference or facilitation was observed. On the other hand, with briefly presented masked primes, interference was observed with higher frequency prime words. Finally, facilitatory effects in masked repetition priming were obtained with both high- and low-frequency prime-target pairs. The results are interpreted in terms of activation and selection processes operating in visual word recognition.     

Boundary conditions for the influence of unfamiliar non-target primes in unconscious evaluative priming: The moderating role of attentional task sets

Evaluative priming by masked emotional stimuli that are not consciously perceived has been taken as evidence that affective stimulus evaluation can also occur unconsciously. However, as masked priming effects were small and frequently observed only for familiar primes that there also presented as visible targets in an evaluative decision task, priming was thought to reflect primarily response activation based on acquired S–R associations and not evaluative semantic stimulus analysis. The present study therefore assessed across three experiments boundary conditions for the emergence of masked evaluative priming effects with unfamiliar primes in an evaluative decision task and investigated the role of the frequency of target repetition on priming with pictorial and verbal stimuli. While familiar primes elicited robust priming effects in all conditions, priming effects by unfamiliar primes were reliably obtained for low repetition (pictures) or unrepeated targets (words), but not for targets repeated at a high frequency. This suggests that unfamiliar masked stimuli only elicit evaluative priming effects when the task set associated with the visible target involves evaluative semantic analysis and is not based on S–R triggered responding as for high repetition targets. The present results therefore converge with the growing body of evidence demonstrating attentional control influences on unconscious processing.     

Evidence from the attentional blink for different sources of word repetition effects

T2 in an attentional blink paradigm served as a high- or low-frequency prime word for a subsequent repeated target. Consistent with research in visual word identification, only reported primes facilitated the identification of a target repeated approximately 8 s after RSVP. Priming was greater for low- than high-frequency words. Analogous with masked priming, a blinked T2 facilitated report of a repeated target occurring 318 ms after T2 in RSVP. The blinked repetition priming effect was additive with target frequency. These results indicate that: (1) the outcomes of processing prime words are a key factor in repetition priming effects, with blinked and reported T2s behaving like masked and unmasked primes, respectively, (2) there may be different sources of repetition effects, (3) there is a consistent cross-paradigm pattern of repetition effects that occurs as a function of prime–target interval and the ability to identify the word on its first and second presentation.     

Repetition proportion biases masked priming of lexical decisions

Although subjects have little or no awareness of masked primes, Bodner and Masson (2001) found that priming of lexical decisions is often enhanced when masked repetition primes occur on a high proportion of trials. We used baseline prime conditions to specify the locus of this repetition proportion (RP) effect. In Experiments 1A and 1B, a .8-RP group showed more priming than did a .2-RP group, and this RP effect was due to both (1) increased facilitation from repetition primes and (2) increased interference from unrelated primes. In Experiment 2, we used the baseline condition to show that subjects are sensitive to RP rather than to the proportion of unrelated primes. Direct comparisons of a given prime condition (repetition, unrelated) across RP conditions were more stable than were comparisons relative to the baseline condition. The increased costs and benefits of repetition priming when RP is higher implicate a context-sensitive mechanism that constrains accounts of masked priming.     

Negative priming from masked words: retrospective prime clarification of center-surround inhibition?

Masked repetition and semantic priming effects were examined in 2 experiments. In Experiment 1, a masked-prime lexical decision task followed a phase of detection, semantic, or repetition judgments about masked words. In Experiment 2 participants made speeded pronunciations to target words after they tried to identify masked primes, and the proportion of semantically and identically related prime-target pairs was varied. Center-surround theory CT. H. Carr & D. Dagenbach, 1990; D. Dagenbach, T. H. Carr, & A. Wilhelmsen, 1989) predicts positive repetition priming but negative semantic priming when people attempt, but fail, to extract the meanings of masked words. A retrospective prime-clarification account, in contrast, predicts that semantic and repetition priming effects will vary (being positive or negative) as a function of expectations about the prime-target relation. The data support a retrospective prime-clarification account, which, unlike center-surround theory, correctly predicted negative repetition priming effects.     

Masked priming of words and nonwords in a naming task: Further evidence for a nonlexical basis for priming

Masked priming effects in word identification tasks such as lexical decision and word naming have been attributed to a lexical mechanism whereby the masked prime opens a lexical entry corresponding to the target word. Two experiments are reported in which masked repetition priming effects of similar magnitude were obtained with word and nonword targets in a naming task. Masked orthographic priming was more stable for word than for nonword targets, although morphological primes produced no advantage beyond that achieved by matched orthographic primes. These results, taken together with the recent finding that repetition priming of nonwords can be obtained in the lexical decision task, support the view that masked priming of words and nonwords has a nonlexical component. We suggest that masked primes can enhance target identification by contributing to the construction of an orthographic or a phonological representation of the target, regardless of the target's lexical status.     

汉语听觉阈下启动效应：来自听觉掩蔽启动范式的证据

使用汉语双字词为实验材料,采用听觉掩蔽启动范式,通过3个实验考察汉语听觉阈下启动效应。结果发现,真词的听觉阈下重复启动效应显著,并且听觉阈下重复启动效应不受启动、目标发音者性别一致性的影响。但真词的阈下语音、语素和语义启动效应及假词的阈下重复和首字启动效应都不显著。这些结果说明,听觉通道阈下呈现的汉语双字词的词汇水平信息可以得到无意识加工。汉语双字词的听觉阈下启动效应可能是基于启动词整词表征的无意识激活。     

Being forward not backward: lexical limits to masked priming

This study investigated whether masked priming is mediated by existing memory representations by determining whether nonwords targets would show repetition priming. To avoid the potential confound that nonword repetition priming would be obscured by a familiarity response bias, the standard lexical decision and naming tasks were modified to make targets unfamiliar. Participants were required to read a target string from right to left (i.e., "ECAF" should be read as "FACE") and then make a response. To examine if priming was based on lexical representations, repetition primes consisted of words when read forwards or backwards (e.g., "face", "ecaf") and nonwords (e.g., "pame", "emap"). Forward and backward primes were used to test if task instruction affected prime encoding. The lexical decision and naming tasks showed the same pattern of results: priming only occurred for forward primes with word targets (e.g., "face-ECAF"). Additional experiments to test if response priming affected the LDT indicated that the lexical status of the prime per se did not affect target responses. These results showed that the encoding of masked primes was unaffected by the novel task instruction and support the view that masked priming is due to the automatic triggering of pre-established computational processes based on stored information.     

Subthreshold semantic priming: Not a context effect

Bernstein, Bissonnette, Vyas, and Barclay (1989) showed that masked primes can be recognized more often when followed by a related target than when followed by an unrelated target. They suggested that this effect may allow subjects in subthreshold semantic priming experiments to recognize the masked primes on the related semantic priming trials, even when the subjects cannot recognize masked primes presented alone. The present experiment found that when masked primes are presented at recognition rates comparable to those used in published studies of subthreshold masked priming, the forced choice recognition of masked primes followed by related targets was similar to that of masked primes presented alone (25% vs. 22%). In addition, the recognition of masked primes on the forced choice trials was highly predictive of masked prime recognition on the semantic priming trials.     

Subliminal access to abstract face representations does not rely on attention

The present study used masked repetition priming to examine whether face representations can be accessed without attention. Two experiments using a face recognition task (fame judgement) presented masked repetition and control primes in spatially unattended locations prior to target onset. Experiment 1 (n=20) used the same images as primes and as targets and Experiment 2 (n=17) used different images of the same individual as primes and targets. Repetition priming was observed across both experiments regardless of whether spatial attention was cued to the location of the prime. Priming occurred for both famous and non-famous targets in Experiment 1 but was only reliable for famous targets in Experiment 2, suggesting that priming in Experiment 1 indexed access to view-specific representations whereas priming in Experiment 2 indexed access to view-invariant, abstract representations. Overall, the results indicate that subliminal access to abstract face representations does not rely on attention.     

Transposed-Letter Priming Across Inflectional Morpheme Boundaries

This study reports findings from two experiments testing whether a transposed-letter (TL) priming effect can be obtained when the transposition occurs across morphological boundaries. Previous studies have primarily tested derivationally complex words or compound words, but have not examined a more rule-based and productive morphological structure, i.e., inflectionally complex words, using masked priming. Experiment 1 tested TL priming with nonword primes and inflected targets (FOCUSING). Nonword primes were formed by transposing letters either within the root morpheme (fcousing) or across two morphemes (focuisng). Experiment 2 used the same nonword primes, but had the root words as targets (FOCUS). Both experiments showed similar TL priming effects for within-morpheme and across-boundary positions, indicating that morphological decomposition takes place only after letter positions in a word have been assigned. This finding provides additional evidence to previous research testing derived and compound words showing TL priming regardless of the position of transposition.     

Associative priming effects with visible, transposed-letter nonwords: JUGDE facilitates COURT

Associative priming effects can be obtained with masked nonword primes or with masked pseudohomophone primes (e.g., judpe?CCOURT, tode?CFROG), but not with visible primes. The usual explanation is that when the prime is visible, these stimuli no longer activate the semantic representations of their base words. Given the important role of transposed-letter stimuli (e.g., jugde) in visual word recognition, here we examined whether or not an associative priming effect could be obtained with visible transposed-letter nonword primes (e.g., jugde?CCOURT) in a series of lexical decision experiments. Results showed a sizable associative priming effect with visible transposed-letter nonword primes (i.e., jugde?CCOURT faster than neevr?CCOURT) in Experiments 1?C3 that was close to that with word primes. In contrast, we failed to find a parallel effect with replacement-letter nonword primes (Experiment 2). These findings pose some constraints to models of visual word recognition.     

Subliminal words activate semantic categories (not automated motor responses)

Semantic priming by visually masked, unidentifiable (“subliminal”) words occurs robustly when the words appearing as masked primes have been classified earlier in practice as visible targets. It has been argued (Damian, 2001) that practice enables robust subliminal priming by automatizing learned associations between words and the specific motor responses used to classify them. Two experiments demonstrate that, instead, the associations formed in practice that underlie subliminal priming are between words and semantic categories. Visible words classified aspleasant or unpleasant in practice with one set of response key assignments functioned later as subliminal primes with appropriate valence, even when associations of keys with valences were reversed before the test. This result shows that subliminal priming involves unconscious categorization of the prime, rather than just the automatic activation of a practiced stimulus-response mapping.     

Masked repetition and phonological priming in picture naming

We report a series of picture naming experiments in which target pictures were primed by briefly presented masked words. Experiment 1 demonstrates that the prior presentation of the same word prime (e.g.,rose-rose) facilitates picture naming independently of the target’s name frequency. In Experiment 2, primes that were homophones of picture targets (e.g.,rows-rose) also produced facilitatory effects compared with unrelated controls, but priming was significantly larger for targets with low-frequency names relative to targets with high-frequency names. In Experiment 3, primes that were higher frequency homophones of picture targets produced facilitatory effects compared with identical primes. These results are discussed in relation to different accounts of the effects of masked priming in current models of picture naming.     

Are individual differences in masked repetition and semantic priming reliable?

Despite the robustness of semantic priming (e.g., cat–DOG), the test-retest and internal reliabilities of semantic priming effects within individuals are surprisingly low. In contrast, repetition priming (e.g., dog–DOG) appears to be far more reliable across a range of conditions. While Stolz and colleagues attribute the low reliability in semantic priming to uncoordinated automatic processes in semantic memory, their use of unmasked priming paradigms makes it difficult to fully rule out the influence of strategic processes. In the present study, we explored the reliability of semantic and repetition priming when primes were heavily masked and cannot be consciously processed. We found that masked repetition, but not semantic, priming effects showed some degree of reliability. Interestingly, skilled lexical processors (as reflected by vocabulary knowledge and spelling ability) also produced larger masked repetition priming effects.     

Associative and repetition priming with the repeated masked prime technique: No priming found

Wentura and Frings (2005) reported evidence of subliminal categorical priming on a lexical decision task, using a new method of visual masking in which the prime string consisted of the prime word flanked by random consonants and random letter masks alternated with the prime string on successive refresh cycles. We investigated associative and repetition priming on lexical decision, using the same method of visual masking. Three experiments failed to show any evidence of associative priming, (1) when the prime string was fixed at 10 characters (three to six flanking letters) and (2) when the number of flanking letters were reduced or absent. In all cases, prime detection was at chance level. Strong associative priming was observed with visible unmasked primes, but the addition of flanking letters restricted priming even though prime detection was still high. With repetition priming, no priming effects were found with the repeated masked technique, and prime detection was poor but just above chance levels. We conclude that with repeated masked primes, there is effective visual masking but that associative priming and repetition priming do not occur with experiment-unique prime-target pairs. Explanations for this apparent discrepancy across priming paradigms are discussed. The priming stimuli and prime-target pairs used in this study may be downloaded as supplemental materials from mc.psychonomicjournals. org/content/supplemental.     

Semantic word priming in the absence of eye fixations: Relative contributions of overt and covert attention

In the present study, we investigated the role of covert and overt attention in word identification. In repetition and semantic priming paradigms, prime words were followed by a probe for lexical decision. To make the primes available only to covert attention, we presented them for 150 msec, parafoveally (2.2° away from fixation), and under gaze-contingent foveal masking. To make the primes available to overt attention, we presented them for 150 msec, at fixation, with no masking. Results showed both repetition and semantic priming in the absence of eye fixations on the primes: There was facilitation for identical and semantically related probe words, relative to an unrelated prime-probe condition. This revealed that both word form and meaning can be processed by covert attention alone. The pattern of relative contributions of covert (∼~25%) and overt (∼~75%) attention was similar for repetition and semantic priming.     

Word frequency effect on repetition priming as a function of prime duration and delay between the prime and the target

Two experiments studied the necessary conditions for the occurrence of repetition priming and word frequency effect on priming in a lexical decision task. To examine the role of prime processing duration, the prime was presented either for 50 ms or for 700 ms, and an interfering task was introduced between the prime and the target in order to restrict the time during which the prime was effectively processed and to limit it to exactly 50 ms or 700 ms. The interstimulus interval (ISI) between the prime and the target was 1500 ms or 3000 ms in Expt 1, and 600 ms in Expt 2. With primes presented for 50 ms, repetition priming effects were not dependent on target frequency, decreased with an increase of the ISI, and were no longer significant with an ISI of 3000 ms. With primes presented for 700 ms, repetition priming was systematically larger for low‐frequency words than for high‐frequency words, and remained reliable even with an ISI of 3000 ms. Thus, a minimum of prime duration was required both for maintaining repetition priming effects over more than some hundreds of milliseconds and for the occurrence of frequency effect on repetition priming. Theoretical interpretations of these results are discussed.