Prime-target Pairs Research Articles

Electrophysiological evidence for phonological priming in Spanish Sign Language lexical access

Interactive activation models of lexical access assume that the presentation of a given word activates not only its lexical representation but also those corresponding to words similar in form. Current theories are based on data from oral and written languages, and therefore signed languages represent a special challenge for existing theories of word recognition and lexical access since they allow us to question what the genuine fundamentals of human language are and what might be modality-specific adaptation. The aim of the present study is to determine the electrophysiological correlates and time course of phonological processing of Spanish Sign Language (LSE). Ten deaf native LSE signers and ten deaf non-native but highly proficient LSE signers participated in the experiment. We used the ERP methodology and form-based priming in the context of a delayed lexical decision task, manipulating phonological overlap (i.e. related prime-target pairs shared either handshape or location parameters). Results showed that both parameters under study modulated brain responses to the stimuli in different time windows. Phonological priming of location resulted in a higher amplitude of the N400 component (300–500ms window) for signs but not for non-signs. This effect may be explained in terms of initial competition among candidates. Moreover, the fact that a higher amplitude N400 for related pairs was found for signs but not for non-signs points to an effect at the lexical level. Handshape overlap produced a later effect (600–800ms window). In this window, a more negative-going wave for the related condition than for the unrelated condition was found for non-signs in the native signers group. The findings are discussed in relation to current models of lexical access and word recognition. Finally, differences between native and non-native signers point to a less efficient use of phonological information among the non-native signers.

Neuronal spoken word recognition: The time course of processing variation in the speech signal

Recent neurobiological studies revealed evidence for lexical representations that are not specified for the coronal place of articulation (PLACE; Friedrich, Eulitz, & Lahiri, 2006; Friedrich, Lahiri, & Eulitz, 2008). Here we tested when these types of underspecified representations influence neuronal speech recognition. In a unimodal auditory–auditory word fragment priming experiment target words either had initial coronal PLACE (e.g., tiger) or had initial noncoronal PLACE (e.g., pony). Prime-target pairs were either identical (e.g., ti-tiger, po-pony), differed in initial PLACE (e.g., pi-tiger, to-pony), or were unrelated. Event-related Potentials for identical and related targets started to differ from unrelated targets at 100 ms, indicating early perceptual processing. Different effects for coronal vs. noncoronal variation were observed starting at 200 ms. Results are related to recent neurocognitive research on compensation for assimilation of PLACE (e.g., rainbow realised as *raimbow). A time line of processing PLACE variation at multiple stages is proposed and parallel processing of specified and underspecified representations at the lexical level is discussed.

Semantic Priming of Attention Focus: Evidence for Short- and Long-Term Effects

Research on subliminal priming documents that our brain can understand words, interpret facial expressions and decode symbols even without realizing them consciously. Thus, words presented for merely a few ms can shorten the response times to semantically related target words, if compared to words with opposite meaning (e.g., Klauer & Musch, 2003). While most previous semantic priming studies used semantic prime-target pairs of affective valence, the present study explored for the first time semantic priming effects for prime-target pairs characterizing an attentional focus. In Experiment 1, a subliminally presented prime word was followed by an above-threshold target word such that both words denoted a broad attention focus, both denoted a narrow focus, or one word denoted a broad and the other a narrow focus. Subjects had to judge the focus of the target words, and we found their response times to be shorter when the prime-target pairs were semantically congruent rather than incongruent. In Experiment 2, a block of subliminally presented prime words, all denoting a broad or all a narrow focus of attention, was followed by a block of subliminally presented target words denoting a broad or a narrow focus in a mixed sequence. Subjects had to judge the position of each prime or target, and we found their target response times to be shorter when the target was semantically congruent rather than incongruent with the preceding prime block. We concluded that semantic priming is effective, that it works for primes denoting the attention focus, and that it persists for more than just a fraction of a second.

A dual task priming investigation of right hemisphere inhibition for people with left hemisphere lesions

BackgroundDuring normal semantic processing, the left hemisphere (LH) is suggested to restrict right hemisphere (RH) performance via interhemispheric suppression. However, a lesion in the LH or the use of concurrent tasks to overload the LH's attentional resource balance has been reported to result in RH disinhibition with subsequent improvements in RH performance. The current study examines variations in RH semantic processing in the context of unilateral LH lesions and the manipulation of the interhemispheric processing resource balance, in order to explore the relevance of RH disinhibition to hemispheric contributions to semantic processing following a unilateral LH lesion.MethodsRH disinhibition was examined for nine participants with a single LH lesion and 13 matched controls using the dual task paradigm. Hemispheric performance on a divided visual field lexical decision semantic priming task was compared over three verbal memory load conditions, of zero-, two- and six-words. Related stimuli consisted of categorically related, associatively related, and categorically and associatively related prime-target pairs. Response time and accuracy data were recorded and analyzed using linear mixed model analysis, and planned contrasts were performed to compare priming effects in both visual fields, for each of the memory load conditions.ResultsControl participants exhibited significant bilateral visual field priming for all related conditions (p < .05), and a LH advantage over all three memory load conditions. Participants with LH lesions exhibited an improvement in RH priming performance as memory load increased, with priming for the categorically related condition occurring only in the 2- and 6-word memory conditions. RH disinhibition was also reflected for the LH damage (LHD) group by the removal of the LH performance advantage following the introduction of the memory load conditions.ConclusionsThe results from the control group are consistent with suggestions of an age related hemispheric asymmetry reduction and indicate that in healthy aging compensatory bilateral activation may reduce the impact of inhibition. In comparison, the results for the LHD group indicate that following a LH lesion RH semantic processing can be manipulated and enhanced by the introduction of a verbal memory task designed to engage LH resources and allow disinhibition of RH processing.

Evidence for Early Morphological Decomposition: Combining Masked Priming with Magnetoencephalography

Are words stored as morphologically structured representations? If so, when during word recognition are morphological pieces accessed? Recent masked priming studies support models that assume early decomposition of (potentially) morphologically complex words. The electrophysiological evidence, however, is inconsistent. We combined masked morphological priming with magneto-encephalography (MEG), a technique particularly adept at indexing processes involved in lexical access. The latency of an MEG component peaking, on average, 220 msec post-onset of the target in left occipito-temporal brain regions was found to be sensitive to the morphological prime-target relationship under masked priming conditions in a visual lexical decision task. Shorter latencies for related than unrelated conditions were observed both for semantically transparent (cleaner-CLEAN) and opaque (corner-CORN) prime-target pairs, but not for prime-target pairs with only an orthographic relationship (brothel-BROTH). These effects are likely to reflect a prelexical level of processing where form-based representations of stems and affixes are represented and are in contrast to models positing no morphological structure in lexical representations. Moreover, we present data regarding the transitional probability from stem to affix in a post hoc comparison, which suggests that this factor may modulate early morphological decomposition, particularly for opaque words. The timing of a robust MEG component sensitive to the morphological relatedness of prime-target pairs can be used to further understand the neural substrates and the time course of lexical processing.

Perceptual and Conceptual Priming of Environmental Sounds

It is still unknown whether sonic environments influence the processing of individual sounds in a similar way as discourse or sentence context influences the processing of individual words. One obstacle to answering this question has been the failure to dissociate perceptual (i.e., how similar are sonic environment and target sound?) and conceptual (i.e., how related are sonic environment and target?) priming effects. In this study, we dissociate these effects by creating prime-target pairs with a purely perceptual or both a perceptual and conceptual relationship. Perceptual prime-target pairs were derived from perceptual-conceptual pairs (i.e., meaningful environmental sounds) by shuffling the spectral composition of primes and targets so as to preserve their perceptual relationship while making them unrecognizable. Hearing both original and shuffled targets elicited a more positive N1/P2 complex in the ERP when targets were related to a preceding prime as compared with unrelated. Only related original targets reduced the N400 amplitude. Related shuffled targets tended to decrease the amplitude of a late temporo-parietal positivity. Taken together, these effects indicate that sonic environments influence first the perceptual and then the conceptual processing of individual sounds. Moreover, the influence on conceptual processing is comparable to the influence linguistic context has on the processing of individual words.

Does discourse congruence influence spoken language comprehension before lexical association? Evidence from event-related potentials

The goal of this study was to examine how lexical association and discourse congruence affect the time course of processing incoming words in spoken discourse. In an event-related potential (ERP) norming study, we presented prime-target pairs in the absence of a sentence context to obtain a baseline measure of lexical priming. We observed a typical N400 effect when participants heard critical associated and unassociated target words in word pairs. In a subsequent experiment, we presented the same word pairs in spoken discourse contexts. Target words were always consistent with the local sentence context, but were congruent or not with the global discourse (e.g., “Luckily Ben had picked up some salt and pepper/basil,” preceded by a context in which Ben was preparing marinara sauce (congruent) or dealing with an icy walkway (incongruent). Event-related potential effects of global discourse congruence preceded those of local lexical association, suggesting an early influence of the global discourse representation on lexical processing, even in locally congruent contexts. Furthermore, effects of lexical association occurred earlier in the congruent than incongruent condition. These results differ from those that have been obtained in studies of reading, suggesting that the effects may be unique to spoken word recognition.

Perceptual invariance or orientation specificity in American Sign Language? Evidence from repetition priming for signs and gestures

Repetition priming has been successfully employed to examine stages of processing in a wide variety of cognitive domains including language, object recognition, and memory. This study uses a novel repetition priming paradigm in the context of a categorisation task to explore early stages in the processing of American Sign Language signs and self-grooming gestures. Specifically, we investigated the degree to which deaf signers’ and hearing nonsigners’ perception of these linguistic or nonlinguistic actions might be differentially robust to changes in perceptual viewpoint. We conjectured that to the extent that signers were accessing language-specific representations in their performance of the task, they might show more similar priming effects under different viewing conditions than hearing subjects. In essence, this would provide evidence for a visually based “lack of invariance” phenomenon. However, if the early stages of visual-action processing are similar for deaf and hearing subjects, then no such difference should be found. In both groups, we observed robust effects of viewpoint, indicating that repetition priming for identical prime–target pairs was greater than in cases of categorisation in which the prime and target varied in viewpoint. However, we found little evidence of group-related differences that could be interpreted as effects of perceptual invariance. These outcomes indicate that initial stages of sign and gesture recognition required for the categorisation of action types do not differ as a function of experience with a signed language. Instead, our data are consistent with and extend previously described visual-perceptual studies that have reported evidence for orientation-specific representations of human actions.

Unconscious semantic activation depends on feature-specific attention allocation

We examined whether semantic activation by subliminally presented stimuli is dependent upon the extent to which participants assign attention to specific semantic stimulus features and stimulus dimensions. Participants pronounced visible target words that were preceded by briefly presented, masked prime words. Both affective and non-affective semantic congruence of the prime-target pairs were manipulated under conditions that either promoted selective attention for affective stimulus information or selective attention for non-affective semantic stimulus information. In line with our predictions, results showed that affective congruence had a clear impact on word pronunciation latencies only if participants were encouraged to assign attention to the affective stimulus dimension. In contrast, non-affective semantic relatedness of the prime-target pairs produced no priming at all. Our findings are consistent with the hypothesis that unconscious activation of (affective) semantic information is modulated by feature-specific attention allocation.

Beyond Demand: Investigating Spontaneous Evaluation of Chord Progressions with the Affective Priming Paradigm

We assume that evaluative processes in response to musical stimuli can occur spontaneously without explicit demand, and that these responses are important for the emergence of emotions evoked by music. Two versions of the affective priming paradigm served to study spontaneous evaluation of music. In Experiment 1, a lexical decision task (LDT) and in Experiments 2 and 3, an evaluative decision task (EDT) was employed. A total of 20 original four-part, five-chord piano sequences with no specified harmonic resolution were used as primes. During the LDT, congruency in valence of prime-target pairs did not affect response times to the targets. However, for the EDT, significant effects of priming were obtained, indicating that spontaneous evaluations of primes must have occurred. No moderating influences of music expertise or any other person variable on spontaneous evaluation were observed. The diverging results of LDT and EDT point to the possibility that spontaneous evaluative processes are sensitive to context manipulations. Results are discussed with reference to harmonic and semantic priming studies.

Motor expertise modulates the unconscious processing of human body postures

Little is known about the cognitive background of unconscious visuomotor control of complex sports movements. Therefore, we investigated the extent to which novices and skilled high-jump athletes are able to identify visually presented body postures of the high jump unconsciously. We also asked whether or not the manner of processing differs (qualitatively or quantitatively) between these groups as a function of their motor expertise. A priming experiment with not consciously perceivable stimuli was designed to determine whether subliminal priming of movement phases (same vs. different movement phases) or temporal order (i.e. natural vs. reversed movement order) affects target processing. Participants had to decide which phase of the high jump (approach vs. flight phase) a target photograph was taken from. We found a main effect of temporal order for skilled athletes, that is, faster reaction times for prime-target pairs that reflected the natural movement order as opposed to the reversed movement order. This result indicates that temporal-order information pertaining to the domain of expertise plays a critical role in athletes’ perceptual capacities. For novices, data analyses revealed an interaction between temporal order and movement phases. That is, only the reversed movement order of flight-approach pictures increased processing time. Taken together, the results suggest that the structure of cognitive movement representation modulates unconscious processing of movement pictures and points to a functional role of motor representations in visual perception.

Morphological priming during reading: Evidence from eye movements

We report an eye movement experiment that investigated whether prior exposure to morphologically related and unrelated primes influenced processing of a target word that appeared later in the same sentence. Prime-target pairs had a semantically transparent (e.g., marshy-marsh) or only an apparent morphological relationship (e.g., secretary-secret), or were morphologically unrelated but overlapped in orthography (e.g., extract-extra). Reading times for target words revealed facilitation effects in measures of both early and late processing only for targets that followed semantically transparent morphological primes, providing evidence of semantically mediated priming between words read normally in a sentence. In addition, an increase in target word skipping and in regressions from a posttarget region when targets followed primes rather than control words, regardless of the morphological relationship between the words, suggests that prime-target orthographic overlap influences parafoveal processing of target words. We discuss our findings in relation to morphological priming during isolated word recognition and the process of lexical identification during reading.

Lack of semantic priming effects in famous person recognition in Mild Cognitive Impairment

IntroductionGrowing evidence indicates that individuals with Mild Cognitive Impairment (MCI) manifest semantic deficits that are often more severe for items that are characterized by a unique semantic and lexical association, such as famous people and famous buildings, than common concepts, such as objects. However, it is still controversial whether the semantic deficits observed in MCI are determined by a degradation of semantic information or by a deficit in intentional access to semantic knowledge. Here we used a semantic priming task in order to assess the integrity of the semantic system without requiring explicit access to this system. This paradigm may provide new insights in clarifying the nature of the semantic deficits in MCI. MethodsWe assessed the semantic and repetition priming effect in 13 individuals with MCI and 13 age-matched controls who engaged in a familiarity judgment task of famous names. In the semantic priming condition, the prime was the name of a member of the same occupation category as the target (Tom Cruise–Brad Pitt), while in the repetition priming condition the prime was the same name as the target (Charlie Chaplin–Charlie Chaplin). ResultsThe results showed a defective priming effect in MCI in the semantic but not in the repetition priming condition. Specifically, when compared to controls, MCI patients did not show a facilitation effect in responding to the same occupation prime-target pairs, but they showed an equivalent facilitation effect when the target was the same name as the prime. ConclusionThe present results provide support to the hypothesis that the semantic impairments observed in MCI cannot be uniquely ascribed to a deficit in intentional access to semantic information. Instead, these findings point to the semantic nature of these deficits and, in particular, to a degraded representation of semantic information concerning famous people.

Semantic priming for coordinate distant concepts in Alzheimer's disease patients

Semantic priming paradigms have been used to investigate semantic knowledge in patients with Alzheimer's disease (AD). While priming effects produced by prime–target pairs with associative relatedness reflect processes at both lexical and semantic levels, priming effects produced by words that are semantically related but not associated should reflect only semantic activation processes. This study was aimed at further investigating automatic semantic priming effects in AD patients when semantically related concepts with little to no lexical association are used. Twenty patients with mild to moderate AD and 20 matched controls (NCs) performed a lexical decision task on 30 concept pairs (15 in the living and 15 in the non-living domain) in an automatic semantic priming paradigm. In order to investigate the relationship between priming alteration and semantic damage, we chose concepts from a database. This allowed us to quantify semantic indexes relative to the structural representation at the feature level.No priming was found in NCs or mild AD patients, probably because feature similarity was insufficient in the concept pairs used. Similar to the hyperpriming observed in previous studies, the appearance of priming in the moderate AD group suggests early semantic damage in which attribute knowledge is partially affected. Furthermore, the finding that priming was predicted by the level of sharing (in the semantic system) of features common to the two concepts in the pairs indicates that the level of redundancy of attribute information is the main factor responsible for resiliency to neurological damage in AD.

The time course of implicit processing of facial features: An event-related potential study

In this study, we used ERPs to investigate the time course of implicit face processing. More specifically, we utilized a masked priming paradigm to investigate implicit processing of the eyes and mouth in upright and inverted faces, using a prime duration of 33ms. Two types of prime–target pairs were used: (1) congruent (e.g., open eyes only in both prime and target); (2) incongruent (e.g., open eyes only in prime and open mouth only in target). The identity of the faces changed between prime and target. Participants pressed one button to indicate whether the target face's mouth was open, and another if the eyes were open. The behavioral results indicated a congruent priming effect for upright but not for inverted faces. The ERP results indicated a face orientation effect across all ERP components studied (P1, N1, P2, N170, N2, P3) starting at about 80ms, and a congruency/priming effect on late components (N2, P3), starting at about 200ms. The functional significance of these ERP effects is discussed in relation to unconscious perception and configural face processing.

An adaptive-learning approach to affect regulation: Strategic influences on evaluative priming

An adaptive cognition approach to evaluative priming is not compatible with the view that the entire process is automatically determined by prime stimulus valence alone. In addition to the evaluative congruity of individual prime–target pairs, an adaptive regulation function should be sensitive to the base rates of positive and negative stimuli as well as to the perceived contingency between prime and target valence. The present study was particularly concerned with pseudocontingent inferences that offer a proxy for the assessment of contingencies from degraded or incomplete stimulus input. As expected, response latencies were shorter for the more prevalent target valence and for evaluatively congruent trials. However, crucially, the congruity effect was eliminated and overridden by pseudocontingencies inferred from the stimulus environment. These strategic inferences were further enhanced when the task called for the evaluation of both prime stimuli and target stimuli.

ERP signatures of cross-modal semantic fragment priming: Early context effects in speech perception

Research in speech perception and language comprehension has shown that the processing and recognition of a word (the target) is facilitated if a related word (the prime) precedes it. This effect is observable even if the prime only consists of a word-initial fragment (e.g. bor- facilitates the recognition of border). The fragment priming paradigm has gained an important role in ERP studies on lexical access, since it reliably shows a distinct deflection at around 350 ms after word-onset, taken as index for lexical activation. While previous studies concentrated on form-related prime–target pairs, we are interested in ERP fragment priming components elicited by meaning-related pairs. For that purpose, we designed a cross-modal priming experiment, in which primes were either the initial syllables of their following targets (e.g. bor[ der]– border; phonological condition) or the initial syllables of a semantic relative to these targets (e.g. mar[ gin]– border; semantic condition). We found a reliable P350 effect in the phonological condition, but not in the semantic condition, and a N400 priming effect for the phonological condition. The phonological and the semantic condition differed from the control condition in an early negativity around 180 ms post onset. Our results are discussed with respect to ERP components that index form-based and meaning-based processing, possibly reflecting separate representations.

Decomposition of prefixed words in Russian.

I examined the nature of morphological decomposition in a series of masked-priming experiments with Russian prefixed nouns. In Experiments 1A and 1B, I tested 3 types of prime-target pairs in which the prime was a morphologically simple word, and a facilitation was found when the prime and the target were truly morphologically related (e.g., narost [outgrowth] and rost [growth] are morphologically related via the prefix na- [on]) or apparently morphologically related (e.g., priton [den] and ton [tone] seem to be morphologically related via the prefix pri- [toward], but this relation is false) but not when the relation was purely orthographic (e.g., kumir [idol] and mir [peace]; ku- is not an existing prefix of Russian). These results suggest that all orthographic forms that can be exhaustively parsed into a prefix and a stem are decomposed into (apparent) constituent morphemes during their retrieval from the lexicon. This early segmentation process is driven by morpho-orthographic but not by morphosemantic considerations and applies even for derived forms that are more frequent than their stem.

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.

Emotionally positive stimuli facilitate lexical decisions—An ERP study

The influence of briefly presented positive and negative emotional pictures on lexical decisions on positive, negative and neutral words or pseudowords was investigated. Behavioural reactions were the fastest following all positive stimuli and most accurate for positive words. Stimulus-locked ERPs revealed enhanced early posterior and late parietal attention effects following positive pictures. A small neural affective priming effect was reflected by P3 modulation, indicating more attention allocation to affectively incongruent prime-target pairs. N400 was insensitive to emotion. Response-locked ERPs revealed an early fronto-central negativity from 480ms before reactions to positive words. It was generated in both fronto-central and extra-striate visual areas, demonstrating a contribution of perceptual and, notably, motor preparation processes. Thus, no behavioural and little neural evidence for congruency-driven affective priming with emotional pictures was found, but positive stimuli generally facilitated lexical decisions, not only enhancing perception, but also acting rapidly on response preparation and by-passing full semantic analysis.