Semantic priming is affected by real-time phonological competition: Evidence for continuous cascading systems

Lexical-semantic access is affected by the phonological structure of the lexicon. What is less clear is whether such effects are the result of continuous activation between lexical form and semantic processing or whether they arise from a more modular system in which the timing of accessing lexical form determines the timing of semantic activation. This study examined this issue using the visual world paradigm by investigating the time course of semantic priming as a function of the number of phonological competitors. Critical trials consisted of high or low density auditory targets (e.g., horse) and a visual display containing a target, a semantically related object (e.g., saddle), and two phonologically and semantically unrelated objects (e.g., chimney, bikini). Results showed greater magnitude of priming for semantically related objects of low than of high density words, and no differences for high and low density word targets in the time course of looks to the word semantically related to the target. This pattern of results is consistent with models of cascading activation, which predict that lexical activation has continuous effects on the level of semantic activation, with no delays in the onset of semantic activation for phonologically competing words.     

Examining the interactivity of lexical orthographic and phonological processing.

The number and type of connections involving different levels of orthographic and phonological representations differentiate between several models of spoken and visual word recognition. At the sublexical level of processing, Borowsky, Owen, and Fonos (1999) demonstrated evidence for direct processing connections from grapheme representations to phoneme representations (i.e., a sensitivity effect) over and above any bias effects, but not in the reverse direction. Neural network models of visual word recognition implement an orthography to phonology processing route that involves the same connections for processing sublexical and lexical information, and thus a similar pattern of cross-modal effects for lexical stimuli are expected by models that implement this single type of connection (i.e., orthographic lexical processing should directly affect phonological lexical processing, but not in the reverse direction). Furthermore, several models of spoken word perception predict that there should be no direct connections between orthographic representations and phonological representations, regardless of whether the connections are sublexical or lexical. The present experiments examined these predictions by measuring the influence of a cross-modal word context on word target discrimination. The results provide constraints on the types of connections that can exist between orthographic lexical representations and phonological lexical representations.     

Lexical and sublexical processes in the perception of transposed-letter anagrams

Evidence from priming and lexical decision tasks suggests that nonwords created by transposing adjacent letter pairs (TL nonwords) are very effective in activating lexical representations of their base words, because the process of orthographic matching tolerates minor changes in letter position. However, this account disregards the possible role of sublexical processing in reading. TL nonwords are perceptually ambiguous, with lexical and sublexical processing giving rise to conflicting interpretations. The consequences of this ambiguity were investigated in a lexical decision experiment with primes that were either high or low bigram frequency TL versions of target words. Priming effects were much larger for low BF primes (e.g., pucnh–PUNCH) than for high BF primes (e.g., panit–PAINT). This finding is interpreted as evidence that lexical activation can be inhibited by competing output resulting from sublexical processing of TL letter string. We conclude that phonological processing is an important determinant of responses to TL stimuli, and we consider how this interpretation might be accommodated within the dual-route cascaded (DRC) model of word recognition.     

Conceptual coherence affects phonological activation of context objects during object naming

In 4 picture-word interference experiments, speakers named a target object that was presented with a context object. Using auditory distractors that were phonologically related or unrelated either to the target object or the context object, the authors assessed whether phonological processing was confined to the target object or not. Phonological activation of the context objects was reliably observed if the target and context objects were embedded in a conceptually coherent scene (e.g., if the picture showed a mouse eating some cheese), regardless of whether the target was cued by its thematic role (agent vs. patient) or by color. However, this activation dissipated if the two objects were presented in an arbitrary object array (e.g., if the cheese was presented along with a finger). These findings suggest that conceptual coherence among multiple objects affects the information flow in the conceptual-lexical system during speech planning.     

Basic processes in reading: can functional phonological recoding be blocked?

A widely held view is that phonological processing is always involved in lexical access from print, and is automatic in that it cannot be prevented. This claim was assessed in the context of a priming paradigm. In Experiment 1, repetition priming was observed for both pseudohomophone-word pairs (e.g., brane-brain) and morphologically related word pairs (e.g., marked-mark) in the context of lexical decision. In Experiment 2, subjects searched the prime for the presence of a target letter and then made a lexical decision to a subsequent letter string. Phonological priming from a pseudohomophone was eliminated following letter search of the prime, whereas morphological priming persisted. These results are inconsistent with the claim that a) lexical access from print requires preliminary phonological processing, and b) functional phonological processing cannot be blocked. They are, however, consistent with the conclusion that, for intact skilled readers, lexical access can be accomplished on the basis of orthographic processing alone. These results join a growing body of evidence supporting the claim that there exist numerous points in visual word recognition at which processing can be stopped.     

Lexical and sublexical processes in the perception of transposed-letter anagrams

Evidence from priming and lexical decision tasks suggests that nonwords created by transposing adjacent letter pairs (TL nonwords) are very effective in activating lexical representations of their base words, because the process of orthographic matching tolerates minor changes in letter position. However, this account disregards the possible role of sublexical processing in reading. TL nonwords are perceptually ambiguous, with lexical and sublexical processing giving rise to conflicting interpretations. The consequences of this ambiguity were investigated in a lexical decision experiment with primes that were either high or low bigram frequency TL versions of target words. Priming effects were much larger for low BF primes (e.g., pucnh-PUNCH) than for high BF primes (e.g., panit-PAINT). This finding is interpreted as evidence that lexical activation can be inhibited by competing output resulting from sublexical processing of TL letter string. We conclude that phonological processing is an important determinant of responses to TL stimuli, and we consider how this interpretation might be accommodated within the dual-route cascaded (DRC) model of word recognition.     

Semantic relatedness among objects promotes the activation of multiple phonological codes during object naming

In a picture–word interference experiment the authors demonstrate that a semantic–categorical relation between a to-be-named target picture and a context picture promotes the phonological activation of the to-be-ignored context picture. No such phonological activation is observed if the objects are semantically unrelated. This finding gives further insight into the mechanisms that modulate the activation flow in the conceptual-lexical system during speech planning. In contrast to recent picture–picture interference studies, the results provide direct evidence that the phonological activation of a context object is dependent on its semantic processing.     

Phonological and conceptual activation in speech comprehension

We propose that speech comprehension involves the activation of token representations of the phonological forms of current lexical hypotheses, separately from the ongoing construction of a conceptual interpretation of the current utterance. In a series of cross-modal priming experiments, facilitation of lexical decision responses to visual target words (e.g., time) was found for targets that were semantic associates of auditory prime words (e.g., date) when the primes were isolated words, but not when the same primes appeared in sentence contexts. Identity priming (e.g., faster lexical decisions to visual date after spoken date than after an unrelated prime) appeared, however, both with isolated primes and with primes in prosodically neutral sentences. Associative priming in sentence contexts only emerged when sentence prosody involved contrastive accents, or when sentences were terminated immediately after the prime. Associative priming is therefore not an automatic consequence of speech processing. In no experiment was there associative priming from embedded words (e.g., sedate-time), but there was inhibitory identity priming (e.g., sedate-date) from embedded primes in sentence contexts. Speech comprehension therefore appears to involve separate distinct activation both of token phonological word representations and of conceptual word representations. Furthermore, both of these types of representation are distinct from the long-term memory representations of word form and meaning.     

The effects of phonological similarity on the semantic categorisation of pictorial and lexical stimuli: evidence from continuous behavioural measures

Behavioural and neuroimaging studies provide evidence of automatic activation of phonology (e.g., covert speech) during the recognition of lexical stimuli. Implicit processing of phonological information was investigated in a kinematic study of semantic categorisation of pictures (session A) or words (session B). Participants clicked one of two items (target and distractor) based on their semantic congruency (artefact or natural) with a cued-word. Phonological similarity between cued-word and distractor was varied. The presence of the phonological distractor produced trajectories with greater curvature towards the competing semantic category than did the presence of a distractor not phonologically related. This suggests that the semantic categorisation of pictorial and lexical stimuli is influenced by the automatic activation of phonological information. Trajectories’ curvature reveals competition between partially activated phonological and semantic representations suggesting that phonological codes involved in linguistic processing influence the dynamic competition underlying the semantic categorisation of lexical and pictorial.     

Automatic activation of phonological information in reading: Evidence from the semantic relatedness decision task

A semantic relatedness decision task was used to investigate whether phonological recoding occurs automatically and whether it mediates lexical access in visual word recognition and reading. In this task, subjects read a pair of words and decided whether they were related or unrelated in meaning. In Experiment 1, unrelated word-homophone pairs (e.g., LION-BARE) and their visual controls (e.g., LION-BEAN) as well as related word pairs (e.g., FISH-NET) were presented. Homophone pairs were more likely to be judged as related or more slowly rejected as unrelated than their control pairs, suggesting phonological access of word meanings. In Experiment 2, word-pseudohomophone pairs (e.g., TABLE-CHARE) and their visual controls (e.g., TABLE-CHARK) as well as related and unrelated word pairs were presented. Pseudohomophone pairs were more likely to be judged as related or more slowly rejected as unrelated than their control pairs, again suggesting automatic phonological recoding in reading.     

Eye movements to pictures reveal transient semantic activation during spoken word recognition

Two experiments explore the activation of semantic information during spoken word recognition. Experiment 1 shows that as the name of an object unfolds (e.g., lock), eye movements are drawn to pictorial representations of both the named object and semantically related objects (e.g., key). Experiment 2 shows that objects semantically related to an uttered word's onset competitors become active enough to draw visual attention (e.g., if the uttered word is logs, participants fixate on key because of partial activation of lock), despite that the onset competitor itself is not present in the visual display. Together, these experiments provide detailed information about the activation of semantic information associated with a spoken word and its phonological competitors and demonstrate that transient semantic activation is sufficient to impact visual attention.     

Inhibition with orthographically similar low-frequency word targets preceded by high-frequency primes

The role of inhibition (increased latency) for lexical decisions on targets preceded by orthographically related high- and low-frequency primes was examined. There was more inhibition for targets preceded by orthographically related high-frequency primes, compared to the same targets preceded by orthographically unrelated primes. These results were interpreted as verification of a version of Colombo's (1986) inhibition hypothesis, modified to fit the current paradigm. According to the modified version of Colombo's hypothesis, the lexical memorial representation of a similarly spelled high-frequency prime competes with the target for recognition when the target is presented. In the current experiment, the lack of phonological inconsistency effects (e.g., TOUCH-COUCH vs. SPOKE-COUCH) was not interpreted to mean that phonological processing did not occur. The lack of phonological inconsistency effects was seen as the result of phonological processes being averaged across targets that were still influenced lexically by the memorial representations of similarly spelled high- and low-frequency primes.     

Activation of distractor names in the picture-picture interference paradigm

In four experiments, participants named target pictures that were accompanied by distractor pictures with phonologically related or unrelated names. Across experiments, the type of phonological relationship between the targets and the related distractors was varied: They were homophones (e.g., bat [animal/baseball]), or they shared word-initial segments (e.g., dog-doll) or word-final segments (e.g., ball-wall). The participants either named the objects after an extensive familiarization and practice phase or without any familiarization or practice. In all of the experiments, the mean target-naming latency was shorter in the related than in the unrelated condition, demonstrating that the phonological form of the name of the distractor picture became activated. These results are best explained within a cascaded model of lexical access--that is, under the assumption that the recognition of an object leads to the activation of its name.     

Strategic reliance on phonological mediation in lexical access

The present study investigated strategic variation in reliance on phonological mediation in visual word recognition. In Experiment 1, semantically related or unrelated word primes preceded word, pseudohomophone (e.g.,trane), or nonpseudohomophone (e.g.,trank) targets in a lexical decision task. Semantic priming effects were found for words, and response latencies to pseudohomophones were longer in related than in unrelated prime conditions. In Experiment 2, related or unrelated word primes preceded word or pseudohomophone targets. A relatedness effect was found for words, although it was significant at a 600-msec prime-target stimulus onset asynchrony (SOA) and not at a 200-msec SOA. There was no relatedness effect for pseudohomophones. Experiment 3 was a replication of Experiment 2, except that pseudohomophones were replaced by nonpseudohomophonic orthographic controls. Facilitation effects for related target words were greater in Experiment 3 than in Experiment 2. The results reflect apparent variations in the expectation that a related prime reliably indicates that a target is a word. Although reliance on phonological mediation might be strategically contingent, there could be a brief time period in which phonologically mediated lexical access occurs automatically. Whether phonological information is maintained or suppressed subsequently depends on its overall usefulness for the task.     

Head up, foot down: object words orient attention to the objects' typical location

Many objects typically occur in particular locations, and object words encode these spatial associations. We tested whether such object words (e.g., head, foot) orient attention toward the location where the denoted object typically occurs (i.e., up, down). Because object words elicit perceptual simulations of the denoted objects (i.e., the representations acquired during actual perception are reactivated), we predicted that an object word would interfere with identification of an unrelated visual target subsequently presented in the object's typical location. Consistent with this prediction, three experiments demonstrated that words denoting objects that typically occur high in the visual field hindered identification of targets appearing at the top of the display, whereas words denoting low objects hindered target identification at the bottom of the display. Thus, object words oriented attention to and activated perceptual simulations in the objects' typical locations. These results shed new light on how language affects perception.     

A processing advantage associated with analytic perceptual tendencies: European Americans outperform Asians on multiple object tracking

Analytic visual processing and holistic visual processing have been conceptualized in terms of attention to focal objects vs. the background. We expand the study of perceptual biases associated with these attentional patterns using the multiple object tracking task, which measures people's ability to track multiple moving target objects amidst otherwise identical distractors. We test two competing hypotheses: (1) Asians' more frequent eye saccades will enable them to quickly cycle through the multiple target objects before the objects move too far away, giving them another perceptual advantage; and (2) European Americans' tendency to focus attention on the focal objects while inhibiting attention to less important objects might facilitate tracking of multiple moving objects. We find that European Americans significantly outperform Asians on multiple object tracking. The research expands the conceptualization of analytic processing and holistic processing to include selective attention as a key component, a facet that has not been previously identified.     

A test of the embodied simulation theory of object perception: potentiation of responses to artifacts and animals

Theories of embodied object representation predict a tight association between sensorimotor processes and visual processing of manipulable objects. Previous research has shown that object handles can ‘potentiate’ a manual response (i.e., button press) to a congruent location. This potentiation effect is taken as evidence that objects automatically evoke sensorimotor simulations in response to the visual presentation of manipulable objects. In the present series of experiments, we investigated a critical prediction of the theory of embodied object representations that potentiation effects should be observed with manipulable artifacts but not non-manipulable animals. In four experiments we show that (a) potentiation effects are observed with animals and artifacts; (b) potentiation effects depend on the absolute size of the objects and (c) task context influences the presence/absence of potentiation effects. We conclude that potentiation effects do not provide evidence for embodied object representations, but are suggestive of a more general stimulus–response compatibility effect that may depend on the distribution of attention to different object features.     

Attending to illusory differences in object size

Focused visual attention can be shifted between objects and locations (attentional orienting) or expanded and contracted in spatial extent (attentional focusing). Although orienting and focusing both modulate visual processing, they have been shown to be distinct, independent modes of attentional control. Objects play a central role in visual attention, and it is known that high-level object representations guide attentional orienting. It not known, however, whether attentional focusing is driven by low-level object representations (which code object size in terms of retinotopic extent) or by high-level representations (which code perceived size). We manipulated the perceived size of physically identical objects by using line drawings or photographs that induced the Ponzo illusion, in a task requiring the detection of a target within these objects. The distribution of attention was determined by the perceived size and not by the retinotopic size of an attended object, indicating that attentional focusing is guided by high-level object representations.     

Ease of processing constrains the activation flow in the conceptual-lexical system during speech planning

In 3 picture-word interference experiments, speakers named a target object in the presence of an unrelated not-to-be-named context object. Distractor words, which were phonologically related or unrelated to the context object's name, were used to determine whether the context object had become phonologically activated. All objects had high frequency names, and the ease of processing of these objects was manipulated by a visual degradation technique. In Experiment 1, both objects were nondegraded; in Experiment 2, both objects were degraded; and in Experiment 3, either the target object or the context object was degraded. Distractor words, which were phonologically related to the context objects, interfered with the naming response when both objects were nondegraded, indicating that the context objects had become phonologically coactivated. The effect vanished when both objects were degraded, when only the context object was degraded, and when only the target object was degraded. These data demonstrate that the amount of available processing resources constrains the forward cascading of activation in the conceptual-lexical system. Context objects are likely to become phonologically coactivated if they are easily retrieved and if prioritized target processing leaves sufficient resources.     

Is a Pink Cow Still a Cow? Individual Differences in Toddlers' Vocabulary Knowledge and Lexical Representations

When a toddler knows a word, what does she actually know? Many categories have multiple relevant properties; for example, shape and color are relevant to membership in the category banana . How do toddlers prioritize these properties when recognizing familiar words, and are there systematic differences among children? In this study, toddlers viewed pairs of objects associated with prototypical colors. On some trials, objects were typically colored (e.g., Holstein cow and pink pig); on other trials, colors were switched (e.g., pink cow and Holstein‐patterned pig). On each trial, toddlers were directed to find a target object. Overall, recognition was disrupted when colors were switched, as measured by eye movements. Moreover, individual differences in vocabularies predicted recognition differences: Toddlers who say fewer shape‐based words were more disrupted by color switches. “Knowing” a word may not mean the same thing for all toddlers; different toddlers prioritize different facets of familiar objects in their lexical representations.