Active masks and active inhibition: a comment on Lleras and Enns (2004) and on Verleger, Jaskowski, Aydemir, van der Lubbe, and Groen (2004)

Verleger, Jaskowski, Aydemir, van der Lubbe, and Groen and Lleras and Enns have argued that negative compatibility effects (NCEs) obtained with masked primes do not reflect self-inhibition processes in motor control. Instead, NCEs are assumed to reflect activation of the response opposite to the prime, triggered by the presence of prime/targetlike features in the mask. Thus, no NCEs should be elicited when masks do not contain such task-relevant features. In Experiments 1 and 3, the authors demonstrate that NCEs can be obtained when masks contain only irrelevant features. Experiment 2 demonstrates that positive compatibility effects (PCEs) will occur with such masks when masked primes are presented peripherally. These results are inconsistent with the mask-induced activation accounts but are in line with the self-inhibition hypothesis of the NCE. Although perceptual interactions and mask-induced motor activations may contribute to NCEs under certain conditions, they cannot provide a full explanation for these effects.     

负相容效应中启动项-目标项关系对阈下信息加工的影响

采用掩蔽启动范式考察了负相容效应中启动项与目标项关系对阈下信息加工的影响,以及是否存在语义水平的负相容效应.两个实验分别以双箭头和汉字为掩蔽启动项,考察启动项和目标项重复、加工水平相同及加工水平不同三种条件下的启动效应.结果发现,两个实验的重复及加工水平相同条件下都出现负相容效应,且重复条件下启动量最大,加工水平不同条件下则无启动.这表明:(1)启动项与目标项的知觉重复影响启动量,但不是负相容效应的必要条件,只有当启动项和目标项加工水平相同时,才出现负相容效应;(2)存在语义水平上的负相容效应,阈下语义信息可得到加工并表现为对后继同类反应的抑制.     

Negative congruency effects: a test of the inhibition account

Masked priming experiments occasionally revealed surprising effects: Participants responded slower for congruent compared to incongruent primes. This negative congruency effect (NCE) was ascribed to inhibition of prime-induced activation [Eimer, M., & Schlaghecken, F. (2003). Response faciliation and inhibition in subliminal priming. Biological Psychology, 64, 7-26.] that sets in if the prime activation is sufficiently strong. The current study tests this assumption by implementing manipulations designed to vary the amount of prime-induced activation in three experiments. In Experiments 1 and 3, NCEs were observed despite reduced prime-induced activation. Experiment 2 revealed no NCE with at least similar prime strength. Thus, the amount of prime activation did not predict whether or not NCEs occurred. The findings are discussed with regard to the inhibition account and the recently proposed account of mask-induced activation [cf. Lleras, A., & Enns, J. T. (2004). Negative compatibility or object updating? A cautionary tale of mask-dependent priming. Journal of Experimental Psychology: General, 133, 475-493; Verleger, R., Jaskowski, P., Aydemir, A., van der Lubbe, R. H. J., & Groen, M. (2004). Qualitative differences between conscious and nonconscious processing? On inverse priming induced by masked arrows. Journal of Experimental Psychology: General, 133, 494-515].     

The negative compatibility effect with nonmasking flankers: a case for mask-triggered inhibition hypothesis

Visual targets which follow a prime stimulus and a mask can be identified faster when they are incompatible rather than compatible with the prime (negative compatibility effect--NCE). According to the self-inhibition hypothesis, the initial activation of the motor response is elicited by the prime based on its identity. This activation leads to benefits for compatible trials and costs for incompatible trials. This motor activation is followed by an inhibition phase, leading to an NCE if perceptual evidence of the prime is immediately removed by the mask. The object-updating and mask-triggered inhibition hypotheses emphasize the role of the mask content (i.e. whether the mask possesses target-like features). We show that the NCE may appear even if nonmasking neutral flankers are presented instead of a mask. Moreover, although with target-like flankers the NCE is larger, it occurred if flankers and targets are built from dissimilar elements. Therefore, masks/flankers can evoke an inhibition phase independently of whether or not they remove evidence for the prime and whether they are similar to the targets.     

Perceptual interactions between primes,masks, and targets: Further evidence for object updating

The negative compatibility effect (NCE) is the finding that, under certain conditions, responses to targets are faster when preceded by incompatible primes than when preceded by compatible primes and this effect now appears to be caused, at least in part, by facilitation resulting from perceptual interactions between the prime, mask, and target when task-relevant masks are used (Lleras & Enns, 2004, 2005, 2006). The current experiment reports a new methodology that allows us to systematically explore the ways in which these perceptual effects influence reaction times and error rates. The data indicate that mask–target overlap, mask–prime overlap, and having a task-relevant prime all affect performance in experiments examining the NCE. In addition, our data provide additional support that object-based updating contributes to the NCE when perceptual interactions between stimuli are likely.     

Incidental learning of S-R contingencies in the masked prime task

Subliminal motor priming effects in the masked prime paradigm can only be obtained when primes are part of the task set. In 2 experiments, the authors investigated whether the relevant task set feature needs to be explicitly instructed or could be extracted automatically in an incidental learning paradigm. Primes and targets were symmetrical arrows, with target color, not shape, the response-relevant feature. Shape and color covaried for targets (e.g., <> always blue, >< always green), whereas primes were always black. Over time, a negative compatibility effect (NCE; response benefits when prime and target had different shapes) developed, indicating that primes affected the motor system. When target shape and color varied independently (control condition), no NCE occurred, in line with the assumption that the NCE reflects task set-dependent motor processes, not perceptual interactions.     

Masked inhibitory priming in english: evidence for lexical inhibition

Predictions derived from the interactive activation (IA) model were tested in 3 experiments using the masked priming technique in the lexical decision task. Experiment 1 showed a strong effect of prime lexicality: Classifications of target words were facilitated by orthographically related nonword primes (relative to unrelated nonword primes) but were inhibited by orthographically related word primes (relative to unrelated word primes). Experiment 2 confirmed IA's prediction that inhibitory priming effects are greater when the prime and target share a neighbor. Experiment 3 showed a minimal effect of target word neighborhood size (N) on inhibitory priming but a trend toward greater inhibition when nonword foils were high-N than when they were low-N. Simulations of 3 different versions of the IA model showed that the best fit to the data is produced when lexical inhibition is selective and when masking leads to reset of letter activities.     

Semantic priming effects from single words in a lexical decision task

The present research examines the semantic priming effects of a centrally presented single prime word to which participants were instructed to either "attend and remember" or "ignore". The prime word was followed by a central probe target on which the participants made a lexical decision task. The main variables manipulated across experiments were prime duration (50 or 100 ms), the presence or absence of a mask following the prime, and the presence (or absence) and type of distractor stimulus (random set of consonants or pseudowords) on the probe display. There was a consistent interaction between the instructions and the semantic priming effects. Relative to the "attend and remember" instruction, an "ignore" instruction produced reduced positive priming from single primes presented for 100 ms, irrespective of the presence or absence of a prime mask, and regardless of whether the probe target was presented with or without distractors. Additionally, reliable negative priming was found from ignored primes presented for briefer durations (50 ms) and immediately followed by a mask. Methodological and theoretical implications of the present findings for the extant negative priming literature are discussed.     

负相容效应理论与研究

负相容效应指在掩蔽的箭头启动项后呈现箭头目标项时,对与启动项方向不一致的目标项反应更快。综述了负相容效应的主要理论及研究,包括自我抑制理论和知觉交互作用理论等。讨论了目前负相容效应研究面临的困难与挑战,包括实验控制条件的限制、掩蔽项与启动项特征的相似性以及应用认知神经研究方法进行研究的困难,并从理论更新与整合、神经基础、生态学意义视角等几方面对未来的研究做出展望。     

Masked form priming is moderated by the size of the letter-order-free orthographic neighbourhood

University students made lexical decisions to targets preceded by masked primes. In Experiment 1, transposed-letter primes were used also in the sandwich priming paradigm, in which the target is briefly pre-presented prior to the prime. The priming effects in the masked paradigm, but not in the sandwich paradigm, were moderated by the density of the letter-order-free neighbourhood of the target. In Experiment 2, letter-order-free neighbour prime words produced a priming cost in masked priming. These results are consistent with the idea that sandwich priming attenuates letter-order-free neighbour competition in target identification. Unexpectedly, no priming cost was produced by conventional (letter-position-preserving) word neighbour primes. Order-free neighbours may produce facilitation of target processing less, and more variably, than conventional neighbours.     

Primes and flankers: Source confusions and discounting

Visual identification of briefly presented target words is affected by the presence of nondiagnostic prime words that immediately precede the target, flanker words simultaneously presented adjacent to the target, and visual masks that immediately follow the target in the same location. Priming is duration dependent: In a forced choice target identification task, brief primes produce a strong preference to choose the primed alternative, whereas long primes have the opposite effect. The ROUSE model (Huber, Shiffrin, Lyle, & Ruys, Psychological Review 108:149?C182, 2001) predicts this interaction by positing that prime features are confused with target features and that evidence regarding the prime features is discounted less for short primes and more for long primes, when both are compared with the optimal level. In the present study, we augmented the typical short-term priming experiment by adding flankers that appeared simultaneously with the target and remained for a short or long duration. In the experiment, we replicated previous priming effects and produced novel effects of flanker duration. ROUSE accounted for both the priming and flanker findings with the previously posited processes, but with different quantitative parameters for flankers: Relative to optimal levels of discounting, all flanker features were underdiscounted, but longer flankers were discounted more than short flankers.     

On the locus of priming and inverse priming effects

Visual stimuli that are made invisible by a following mask can affect overt motor responses and nonmotor processing. Previous studies have compared the effects of primes that were perceptually similar to the subsequent stimulus with those of primes that were perceptually similar to an alternative stimulus. The present study examined the effect of congruent primes that are perceptually dissimilar to the target (or the cue) but are nonetheless associated with the same response (or the same task) as the later stimulus. Positive and inverse priming effects (negative compatibility effects) were studied in a target priming paradigm (Experiments 1 and 2) and in a cue priming paradigm (Experiments 3 and 4). The results showed stronger priming effects with similar primes than with dissimilar congruent primes. However, the effects of perceptually dissimilar congruent primes differed from those of dissimilar incongruent primes. These findings suggest that a substantial part of both positive target and cue priming effects is produced at levels of processing that are not affected by perceptual similarity. The version of inverse priming effects examined in this study, however, seems to arise from perceptual processing that is affected by the similarity between a prime and the stimulus that follows the mask.     

Effects of prime-target spatial separation and attentional deployment on masked repetition priming

In two masked repetition priming experiments with letter stimuli, the positions of prime and target stimuli were varied horizontally from fixation. Priming effects did not interact with position when prime and target location covaried (Experiment 1A) but diminished with increasing prime eccentricity when targets were always centrally located (Experiment 1B). Two accounts of this pattern of priming effects were proposed that postulate two different mechanisms over and above effects of visual acuity. The integration account postulates degree of separation of prime and target stimuli as the critical factor, and the attentional account postulates spatial attention as the critical factor. The results of Experiment 2, in which prime and target positions were manipulated orthogonally, were in favor of the attentional account. Repetition priming did not vary as a function of whether or not primes and targets appeared at the same location, but target processing was facilitated independently of priming when targets appeared at the same location as primes, especially in the right visual field.     

Semantic priming,prime reportability,and retroactive priming are interdependent

In two experiments, semantic analysis of prime words was measured in terms of facilitation in naming a semantically related target word. Targets were degraded but gradually clarified until the subject named them. Subjects reported the prime after naming the target. Experiment 1 used semantic associates as primes at a 50-msec prime-target stimulus onset asynchrony (SOA). Experiment 2 used both semantic-associate and identity primes at a 1,000-msec prime-target SOA. Reported primes showed facilitation in both experiments, whereas unreported primes did not. It appears that primes that undergo enough analysis to facilitate target processing are also available for conscious report. However, retroactive priming in both experiments showed that target processing also had an impact on prime reportability. The interdependence of priming and prime reportability disallows a straightforward interpretation of the origin of the facilitation.     

Effects of prime—target spatial separation and attentional deployment on masked repetition priming

In two masked repetition priming experiments with letter stimuli, the positions of prime and target stimuli were varied horizontally from fixation. Priming effects did not interact with position when prime and target location covaried (Experiment 1A) but diminished with increasing prime eccentricity when targets were always centrally located (Experiment 1B). Two accounts of this pattern of priming effects were proposed that postulate two different mechanisms over and above effects of visual acuity. The integration account postulates degree of separation of prime and target stimuli as the critical factor, and the attentional account postulates spatial attention as the critical factor. The results of Experiment 2, in which prime and target positions were manipulated orthogonally, were in favor of the attentional account. Repetition priming did not vary as a function of whether or not primes and targets appeared at the same location, but target processing was facilitated independently of priming when targets appeared at the same location as primes, especially in the right visual field.     

On the masking and disclosure of unconscious elaborate processing. A reply to Van Opstal, Reynvoet, and Verguts (2005)

We have recently argued that unconscious numerical stimuli might activate responses by a match with prespecified action trigger codes (action trigger account) rather than by semantic prime processing (elaborate processing account). [Van Opstal, F., Reynvoet, B., and Verguts, T. (2005). How to trigger elaborate processing? A comment on Kunde, Kiesel, and Hoffmann (2003). Cognition] replicate one piece of evidence for our inference—an inefficiency of primes not presented in target format (verbal or Arabic). But this was found only with letter masks and not with hash masks. The authors conclude that letter masks block unconscious prime processing, and that elaborate processing can account for unconscious priming effects if all its (sometimes subtle) side conditions are considered. We agree that the type of mask in general is an important factor in priming studies but we note that (i) the authors' mask-blocking hypothesis is not well supported by the data, (ii) clear evidence for semantic prime processing in their study is lacking and, (iii) differences in mask efficiency (rather than mask type) might account for the conflicting results. To corroborate this inference we replicate van Opstal et al.'s results with letter masks but reduced mask efficiency. Altogether their data do not challenge the action-trigger account nor do they strongly support the elaborate processing view.     

Identity primes produce facilitation in a colour naming task

Five experiments examined associative or identity priming effects in a colour-naming task with colour-neutral words. In Experiment 1, subjects instructed to read the prime silently showed no associative priming effect but a colour-naming facilitation with identity priming. In Experiment 2, the typical associative priming interference in colour naming was demonstrated in subjects recalling the prime word, but not in subjects reading the prime silently, whereas associative primes facilitated word naming regardless of the prime response requirement. The remaining studies investigated the colour-naming facilitation observed with identity primes. Experiment 3 showed no effects on the facilitation of colour naming from varying the letter case of a silently read prime. Experiment 4 showed facilitation when subjects recalled the prime, and a target frequency effect, with faster colour-naming latencies for high- and medium- than low-frequency targets. In Experiment 5, there was no facilitation for naming the colour of target words paired with non-word primes differing in their initial letter from the target. Taken together, the results suggest that the facilitation of colour naming following identical primes reflects faster target word recognition, whereas the associative priming interference reflects an attentional effect.     

Age-related deficits in low-level inhibitory motor control

Inhibitory control functions in old age were investigated with the "masked prime" paradigm in which participants executed speeded manual choice responses to simple visual targets. These were preceded--either immediately or at some earlier time--by a backward-masked prime. Young adults produced positive compatibility effects (PCEs)--faster and more accurate responses for matching than for nonmatching prime-target pairs--when prime and target immediately followed each other, and the reverse effect (negative compatibility effect, NCE) for targets that followed the prime after a short interval. Older adults produced similar PCEs to young adults, indicating intact low-level motor activation, but failed to produce normal NCEs even with longer delays (Experiment 1), increased opportunity for prime processing (Experiment 2), and prolonged learning (Experiment 3). However, a fine-grained analysis of each individual's time course of masked priming effects revealed NCEs in the majority of older adults, of the same magnitude as those of young adults. These were significantly delayed (even more than expected on the basis of general slowing), indicating a disproportionate impairment of low-level inhibitory motor control in old age.     

A study of masked form priming in picture and word naming

We report a series of picture- and word-naming experiments in which the masked priming paradigm with prime exposures brief enough to prevent prime identification were used. Experiment 1 demonstrates that the prior presentation of the same word prime facilitates both picture and word naming independently of target frequency. In Experiments 2 and 3, primes that were pseudohomophones of picture targets produced facilitatory effects compared with orthographic controls, but these orthographically similar nonword primes did not facilitate picture naming compared with unrelated controls. On the other hand, word targets were primarily facilitated by orthographic prime&#x2014; target overlap. This marked dissociation in the priming effects obtained with picture and word targets is discussed in relation to different explanations of masked form priming effects in visual word recognition and current models of picture and word naming.     

Inverse cue priming is not limited to masks with relevant features

Apart from positive priming effects, masked prime stimuli can impair responses to a subsequent target stimulus which shares response-critical features in contrast to a target assigned to the opposite response. This counterintuitive phenomenon is called inverse priming (or negative compatibility effect). Here we examine the generality of this phenomenon beyond priming of motor responses. We used a non-motor cue-priming paradigm to study the underlying mechanism of inverse priming for relevant features masks which include task-relevant stimulus features and for irrelevant masks which omit task-relevant features. We found inverse cue-priming effects with both types of masks. With task-irrelevant masks inverse cue-priming was emphasized in those participants being unable to perceive the prime. The existence of inverse non-motor priming under conditions where simple perceptual interactions between the stimuli are ruled out as the source of inverse priming is at odds with the view that inverse priming reflects motor inhibition. Alternatives are discussed.