The Influence of Masked Stimuli on Response Selection: Evidence from a Semantic Categorization Task

Unconscious visual stimuli can be processed by human observers and influence their behaviour. A striking example is a phenomenon known as “free-choice priming,” where masked “prime” stimuli—of which participants are unaware—modulate which of two response alternatives they are likely to choose. Recent efforts to uncover the mechanisms underlying this intriguing effect have revealed that free-choice priming can emerge even in the absence of automatized stimulus-response (S-R) associations between masked primes and specific motor responses, indicating that free choices can be influenced by a masked prime’s meaning (Ocampo, 2015). It remains unknown, however, whether masked primes bias response selections because they are implicitly classified according to task instructions, or because spreading activation occurs within the prime's semantic network. To adjudicate between these two possibilities, participants in the present experiment categorised targets as either animals or people and selected which of two response alternatives they wanted to make following presentation of a free-choice target. Crucially, while implicit classifications could proceed during processing of both animal and person masked primes, only animal primes could trigger spreading activation within their semantic network. This manipulation modulated free-choice priming; only masked animal primes influenced response selections to free-choice targets. This result indicates that an automatic spreading activation mechanism might underlie a masked prime’s ability to influence free-choice responses.     

Priming the mental time-line: effects of modality and processing mode

The notion of a mental time-line (i.e., past corresponds to left and future corresponds to right) supports the conceptual metaphor view assuming that abstract concepts like “time” are grounded in cognitively more accessible concepts like “space.” In five experiments, we further investigated the relationship between temporal and spatial representations and examined whether or not the spatial correspondents of time are unintentionally activated. We employed a priming paradigm, in which visual or auditory prime words (i.e., temporal adverbs such as yesterday, tomorrow) preceded a colored square. In all experiments, participants discriminated the color of this square by responding with the left or the right hand. Although the temporal reference of the priming adverb was task irrelevant in Experiment 1, visually presented primes facilitated responses to the square in correspondence with the direction of the mental time-line. This priming effect was absent in Experiments 2, 3, and 5, in which the primes were presented auditorily and the temporal reference of the words could be ignored. The effect, however, emerged when attention was oriented to the temporal content of the auditory prime words in Experiment 4. The results suggest that task demands differentially modulate the activation of the mental time-line within the visual and auditory modality and support a flexible association between conceptual codes.     

The effect of presemantic acoustic adaptation on semantic “satiation”

A decrement in the strength of the meaning of a word after rapid repetition of that word has been called “semantic satiation.” This study asked whether this “satiation” might be produced by presemantic acoustic adaptation. Category words were utilized to prime the meaning of target words. The adaptation or “satiation” procedure, 30 rapid repetitions of the primes, was compared with a control condition of 3 repetitions. Participants listened to a series of prime words, each repeated by either the same speaker or many speakers, and then made semantic decisions on target words. When all the repetitions of a prime word are produced by the same speaker, presemantic and semantic repetitions are confounded. When the repetitions are produced by different speakers, presemantic acoustic repetition is abolished. A semantic decrement was detected with single-speaker, but not with multiple-speaker, repetitions of prime words. This study concluded that the semantic “satiation” observed here was a decrement in the activation level of semantic representations induced by presemantic acoustic adaptation.     

RT distribution analysis of category congruence effects with masked primes

Macquarie University, Sydney, New South Wales, Australia In the number magnitude decision task (“Is the number bigger/smaller than 5?”), response to a target (e.g., 3) is faster following a masked prime congruent with the target (e.g., 1) than it is following an incongruent prime (e.g., 9). This category congruence effect has been reported to be “interference-dominant” relative to a neutral prime (e.g., the # sign, the number 5) on the basis of the analysis of mean response time (RT). Using RT distribution analysis as well as mean RTs, we identified two bases for this pattern. One relates to the choice of neutral baseline: The # prime, unlike the digit prime, does not factor in the cost of perceptual transition between the prime and target, and therefore underestimates facilitation and overestimates the interference effect. The second basis of the interference-dominant pattern is a disproportionate slowdown of congruent trials in the slow RT bins. Furthermore, this slowdown is greater for primes that had been used as targets than it is with “novel” primes that have not been responded to as targets. We interpret the results as suggesting that the category congruence effect has two components with different time courses—one based on stimulus-response mapping, and the other on semantic categorization.     

The Use of Lexical Prosody for Lexical Access of the Japanese Language

It has been suggested that English listeners do not use lexical prosody for lexical access in word recognition. The present study was designed to examine whether this argument could be generalized to the Japanese language. Two experiments using a cross-modal priming task were conducted. The participants made a lexical decision regarding a visual target following an auditory prime that was either the prosodically congruent or incongruent homophone of the target. In experiment 1, the primes were presented as complete words, and in experiment 2, they were presented as word fragments. In both experiments, the priming effects were observed only in the congruent condition. These results suggest that the prime activated only the representations of prosodically congruent words. We therefore concluded that Japanese listeners use lexical prosody for lexical access of their language and that the role of lexical prosody is determined language-specifically.     

Interlinguistic conflict: Word–word Stroop with first and second language colour words

The congruency (or Stroop) effect is a standard observation of slower and less accurate colour identification to incongruent trials (e.g. “red” in green) relative to congruent trials (e.g. “red” in red). This effect has been observed in a word–word variant of the task, when both the distracter (e.g. “red”) and target (e.g. “green”) are colour words. The Stroop task has also been used to study the congruency effect between two languages in bilinguals. The typical finding is that the congruency effect for L1 words is larger than that for L2 words. For the first time, the present report aims to extend this finding to a word–word variant of the bilingual Stroop task. In two experiments, French monolinguals performed a bilingual word–word Stroop task in which target word language, language match, and congruency between the distracter and target were manipulated. The critical manipulation across two experiments concerned the target language. In Experiment 1, target language was manipulated between groups, with either French (L1) or English (L2) target colour words. In Experiment 2, target words from both languages were intermixed. In both experiments, the congruency effect was larger when the distracter and target were from the same language (language match) than when they were from different languages (language mismatch). Our findings suggested that this congruency effect mostly depends on the language match between the distracter and target, rather than on a target language. It also did not seem to matter whether the language-mismatching distracter was or was not a potential response alternative. Semantic activation of languages in bilinguals and its implications on target identification are discussed.

     

Code-switching effects in bilingual word recognition: a masked priming study with event-related potentials

Two experiments tested language switching effects with bilingual participants in a priming paradigm with masked primes (duration of 50 ms in Experiment 1 and 100 ms in Experiment 2). Participants had to monitor target words for animal names, and ERPs were recorded to critical (non-animal) words in L1 and L2 primed by unrelated words from the same or the other language. Both experiments revealed language priming (switching) effects that depended on target language. For target words in L1, most of the language switch effect appeared in the N400 ERP component, with L2 primes generating a more negative going wave than L1 primes. For L2 target words, on the other hand, the effects of a language switch appeared mainly in an earlier ERP component (N250) peaking at approximately 250 ms post-target onset, and showing greater negativity following an L1 prime than an L2 prime. This is the first evidence for fast-acting language-switching effects occurring in the absence of overt task switching.     

Why do non-color words interfere with color naming?

In the non-color-word Stroop task, university students' response latencies were longer for low-frequency than for higher frequency target words. Visual identity primes facilitated color naming in groups reading the prime silently or processing it semantically (Experiment 1) but did not when participants generated a rhyme of the prime (Experiment 3). With auditory identity primes, generating an associate or a rhyme of the prime produced interference (Experiments 2 and 3). Color-naming latencies were longer for nonwords than for words (Experiment 4). There was a small long-term repetition benefit in color naming for low-frequency words that had been presented in the lexical decision task (Experiment 5). Facilitation of word recognition speeds color naming except when phonological activation of the base word increases response competition.     

The Impact of Stimuli Color in Lexical Decision and Semantic Word Categorization Tasks

In two experiments, we examined the impact of color on cognitive performance by asking participants to categorize stimuli presented in three different colors: red, green, and gray (baseline). Participants were either asked to categorize the meaning of words as related to the concepts of “go” or “stop” (Experiment 1) or to indicate if a neutral verbal stimulus was a word or not (lexical decision task, Experiment 2). Overall, we observed performance facilitation in response to go stimuli presented in green (vs. red or gray) and performance inhibition in response to go stimuli presented in red. The opposite pattern was observed for stop‐related stimuli. Importantly, results also indicated that color might also be used to categorize neutral stimuli. Overall, these findings provide support to the green‐go and red‐stop color associations and test the potential functional autonomy acquired by these colors and the boundary conditions to their effects on stimuli categorization.     

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.     

Semantic interference and associative facilitation from words presented in rapid serial visual presentation

Semantic interference in picture naming is readily obtained when categorically related distractor words are displayed with picture targets; however, this is not typically the case when both primes and targets are words. Researchers have argued that to obtain semantic interference for word primes and targets, the prime must be shown for a sufficient duration, prime processing must be made difficult, and participants must attend to the primes. In this article, we used a novel procedure for prime presentation to investigate semantic interference in word naming. Primes were presented as the last word of a rapid serial visual presentation stream, with the target following 600-1,200 msec later. Semantic interference was observed for categorically related targets, whereas facilitation was found for associatively related targets.     

Feature-based attention to unconscious shapes and colors

Two experiments employed feature-based attention to modulate the impact of completely masked primes on subsequent pointing responses. Participants processed a color cue to select a pair of possible pointing targets out of multiple targets on the basis of their color, and then pointed to the one of those two targets with a prespecified shape. All target pairs were preceded by prime pairs triggering either the correct or the opposite response. The time interval between cue and primes was varied to modulate the time course of feature-based attentional selection. In a second experiment, the roles of color and shape were switched. Pointing trajectories showed large priming effects that were amplified by feature-based attention, indicating that attention modulated the earliest phases of motor output. Priming effects as well as their attentional modulation occurred even though participants remained unable to identify the primes, indicating distinct processes underlying visual awareness, attention, and response control.     

情境效应或自动化加工：大学生对老年人的内隐态度

使用词汇判断任务和新近发展起来的情感错误归因程序(AMP)研究范式, 探讨大学生对老年人的内隐态度是否具有情境效应。实验一的结果表明, 大学生被试并不认为老年人比年轻人具有更高的专业能力。实验二和实验三采用被试间设计, 在典型的AMP中分别添加了情境因素, 结果都表明被试在职业、家庭、美德等情境中对老年人没有给出更积极的内隐评价; 被试对中性数字启动的做出的内隐评价比对老年人启动的内隐评价的更积极。     

Effects of phonological similarity on priming in auditory lexical decision

Two auditory lexical decision experiments were conducted to determine whether facilitation can be obtained when a prime and a target share word-initial phonological information. Subjects responded “word” or “nonword” to monosyllabic words and nonwords controlled for frequency. Each target was preceded by the presentation of either a word or nonword prime that was identical to the target or shared three, two, or one phonemes from the beginning. The results showed that lexical decision times decreased when the prime and target were identical for both word and nonword targets. However, no facilitation was observed when the prime and target shared three, two, or one initial phonemes, These results were found when the interstimulus interval between the prime and target was 500 msec or 50 msec. In a second experiment, no differences were found between primes and targets that shared three, one, or zero phonemes, although facilitation was observed for identical prime-target pairs. The results are compared to recent findings obtained using a perceptual identification paradigm. Taken together, the findings suggest several important differences in the way lexical decision and perceptual identification tasks tap into the information-processing system during auditory word recognition.     

Visual attention amplifies response priming of pointing movements to color targets

We studied the influence of spatial visual attention on the time course of primed pointing movements. We measured pointing responses to color targets preceded by color stimuli priming either the same response as the target or the opposite response. The effects of visual attention at the prime and target locations were studied by varying both the cue-prime and prime-target intervals when presenting either exogenous attentional cues or, in a separate experiment, endogenous cues whose processing was a precondition for performing the task. Pointing trajectories revealed large priming effects in which pointing responses were first controlled by prime signals and then captured in midflight by target signals. Priming effects were strongly amplified when the relevant prime locations were visually attended at optimal cue-prime SOAs, with attention modulating the entire time course of the primed pointing movements. We propose that visual attention amplifies the earliest waves of visuomotor feedforward information, elicited in turn by primes and by targets.     

Affective priming with subliminally presented pictures.

Affective priming studies have demonstrated that subliminally presented prime words can exert an influence on responses towards positive or negative target stimuli. In the present series of experiments, it was investigated whether these findings can be extended to pictorial stimuli. Ideographically selected positive, neutral, and negative picture primes that were sandwich-masked immediately preceded positive or negative target pictures (Experiment 1) or words (Experiments 2 & 3). Evaluative categorization responses to these target stimuli were significantly influenced by the valence of the prime. First, it was demonstrated that high anxious participants were selectively slowed when the subliminally presented prime was negative (Experiments 1 & 2). Second, the affective congruence between primes and targets also exerted an influence on the responses, but in a direction that is opposite to what is typically observed in affective priming research. These reverse priming effects are situated within a series of recent similar findings, and implications for theories of affective priming are discussed.     

The logic in language: How all quantifiers are alike,but each quantifier is different

Quantifier words like each, every, all and three are among the most abstract words in language. Unlike nouns, verbs and adjectives, the meanings of quantifiers are not related to a referent out in the world. Rather, quantifiers specify what relationships hold between the sets of entities, events and properties denoted by other words. When two quantifiers are in the same clause, they create a systematic ambiguity. “Every kid climbed a tree” could mean that there was only one tree, climbed by all, or many different trees, one per climbing kid. In the present study, participants chose a picture to indicate their preferred reading of different ambiguous sentences – those containing every, as well as the other three quantifiers. In Experiment 1, we found large systematic differences in preference, depending on the quantifier word. In Experiment 2, we then manipulated the choice of a particular reading of one sentence, and tested how this affected participants’ reading preference on a subsequent target sentence. We found a priming effect for all quantifiers, but only when the prime and target sentences contained the same quantifier. For example, all-a sentences prime other all-a sentences, while each-a primes each-a, but sentences with each do not prime sentences with all or vice versa. In Experiment 3, we ask whether the lack of priming across quantifiers could be due to the two sentences sharing one fewer word. We find that changing the verb between the prime and target sentence does not reduce the priming effect. In Experiment 4, we discover one case where there is priming across quantifiers – when one number (e.g. three) is in the prime, and a different one (e.g. four) is in the target. We discuss how these findings relate to linguistic theories of quantifier meaning and what they tell us about the division of labor between conceptual content and combinatorial semantics, as well as the mental representations of quantification and of the abstract logical structure of language.     

Masked priming effect reflects evidence accumulated by the prime

In the same–different match task, masked priming is observed with the same responses but not different responses. Norris and Kinoshita's (2008) Bayesian reader account of masked priming explains this pattern based on the same principle as that explaining the absence of priming for nonwords in the lexical decision task. The pattern of priming follows from the way the model makes optimal decisions in the two tasks; priming does not depend on first activating the prime and then the target. An alternative explanation is in terms of a bias towards responding “same” that exactly counters the facilitatory effect of lexical access. The present study tested these two views by varying both the degree to which the prime predicts the response and the visibility of the prime. Unmasked primes produced effects expected from the view that priming is influenced by the degree to which the prime predicts the response. In contrast, with masked primes, the size of priming for the same response was completely unaffected by predictability. These results rule out response bias as an explanation of the absence of masked priming for different responses and, in turn, indicate that masked priming is not a consequence of automatic lexical access of the prime.     

True and false memory for colour names versus actual colours: Support for the visual distinctiveness heuristic in memory for colour information

In a colour variation of the Deese–Roediger–McDermott (DRM) false memory paradigm, participants studied lists of words critically related to a nonstudied colour name (e.g., “blood, cherry, scarlet, rouge … ”); they later showed false memory for the critical colour name (e.g., “red”). Two additional experiments suggest that participants generate colour imagery in response to such colour-related DRM lists. First, participants claim to experience colour imagery more often following colour-related than standard non-colour-related DRM lists; they also rate their colour imagery as more vivid following colour-related lists. Second, participants exhibit facilitative priming for critical colours in a dot selection task that follows words in the colour-related DRM list, suggesting that colour-related DRM lists prime participants for the actual critical colours themselves. Despite these findings, false memory for critical colour names does not extend to the actual colours themselves (font colours). Rather than leading to source confusion about which colours were self-generated and which were studied, presenting the study lists in varied font colours actually worked to reduce false memory overall. Results are interpreted within the framework of the visual distinctiveness hypothesis.     

The dependence of semantic relatedness effects upon prime processing

The semantic relationship between a prime and a target word has been shown to affect the speed at which the target word is processed. This series of experiments investigated how the semantic priming effect is influenced by the nature of the task performed on the prime word. Subjects were asked to perform either a naming or a letter-search task on the prime word and either a lexical-decision or color-naming task on the target word. When the primes were named, response times for the target words were facilitated in the lexical-decision task and inhibited in the color-naming task. However, these effects were eliminated or reduced to an insignificant level when the primes were searched for letters. We suggest that in order to produce the usual priming effect, the primes have to be processed for meaning rather than probed for constituents.