Auditory context effects in picture naming investigated with event-related fMRI

Naming an object entails a number of processing stages, including retrieval of a target lexical concept and encoding of its phonological word form. We investigated these stages using the picture-word interference task in an fMRI experiment. Participants named target pictures in the presence of auditorily presented semantically related, phonologically related, or unrelated distractor words or in isolation. We observed BOLD signal changes in left-hemisphere regions associated with lexical-conceptual and phonological processing, including the midto-posterior lateral temporal cortex. However, these BOLD responses manifested as signal reductions for all distractor conditions relative to naming alone. Compared with unrelated words, phonologically related distractors showed further signal reductions, whereas only the pars orbitalis of the left inferior frontal cortex showed a selective reduction in response in the semantic condition. We interpret these findings as indicating that the word forms of lexical competitors are phonologically encoded and that competition during lexical selection is reduced by phonologically related distractors. Since the extended nature of auditory presentation requires a large portion of a word to be presented before its meaning is accessed, we attribute the BOLD signal reductions observed for semantically related and unrelated words to lateral inhibition mechanisms engaged after target name selection has occurred, as has been proposed in some production models.     

Multichannel fNIRS assessment of overt and covert confrontation naming

Confrontation naming tasks assess cognitive processes involved in the main stage of word production. However, in fMRI, the occurrence of movement artifacts necessitates the use of covert paradigms, which has limited clinical applications. Thus, we explored the feasibility of adopting multichannel functional near-infrared spectroscopy (fNIRS) to assess language function during covert and overt naming tasks. Thirty right-handed, healthy adult volunteers underwent both naming tasks and cortical hemodynamics measurement using fNIRS. The overt naming task recruited the classical left-hemisphere language areas (left inferior frontal, superior and middle temporal, precentral, and postcentral gyri) exemplified by an increase in the oxy-Hb signal. Activations were bilateral in the middle and superior temporal gyri. However, the covert naming task recruited activation only in the left-middle temporal gyrus. The activation patterns reflected a major part of the functional network for overt word production, suggesting the clinical importance of fNIRS in the diagnosis of aphasic patients.     

Word order does not constrain phonological activation in single word production

It has recently been claimed that the canonical word order of a given language constrains phonological activation processes even in single word production (Janssen, Alario, & Caramazza, 2008). This hypothesis predicts for languages with canonical adjective–noun word order that naming an object (i.e., noun production) is facilitated if the task-irrelevant colour of the object (i.e., adjective) is phonologically similar to the object name (e.g., blue–boat as compared to red–boat). By contrast, there should be no corresponding effect in naming the colour of the object (i.e., adjective production). In an experiment with native speakers of German, however, we observed exactly the opposite pattern. Phonological congruency facilitated colour naming but had no effect on object naming. Together with extant data from other languages our results suggest that object colour naming is affected by the phonology of the object name but not vice versa, regardless of the canonical word order in the given language.     

FMRI of two measures of phonological processing in visual word recognition: ecological validity matters

Previous functional magnetic resonance imaging (fMRI) studies have investigated the role of phonological processing by utilizing nonword rhyming decision tasks (e.g., Pugh et al., 1996). Although such tasks clearly engage phonological components of visual word recognition, it is clear that decision tasks are more cognitively involved than the simple overt naming tasks, which more closely map onto normal reading behavior. Our research aim for this study was to examine the advantages of overt naming tasks for fMRI studies of word recognition processes. Process models are presented to highlight the similarities and differences between two cognitive tasks that are used in the word recognition literature, pseudohomophone naming (e.g., pronounce BRANE) and rhyming decision (e.g., do LEAT and JEAT rhyme?). An fMRI study identified several differences in cortical activation associated with the differences observed in the process models. Specifically, the results show that the overt naming task involved the insular cortex and inferior frontal gyrus, whereas the rhyming decision task engaged the temporal-parietal regions. It is argued that future fMRI research examining the neuroanatomical components of basic visual word recognition utilize overt naming tasks.     

Lexical selection is not by competition: a reinterpretation of semantic interference and facilitation effects in the picture-word interference paradigm

The dominant view in the field of lexical access in speech production maintains that selection of a word becomes more difficult as the levels of activation of nontarget words increase--selection by competition. The authors tested this prediction in two sets of experiments. First, the authors show that participants are faster to name pictures of objects (e.g., "bed") in the context of semantically related verb distractors (e.g., sleep) compared with unrelated verb distractors (e.g., shoot). In the second set of experiments, the authors show that target naming latencies (e.g., "horse") are, if anything, faster for within--category semantically close distractor words (e.g., zebra) than for within--category semantically far distractor words (e.g., whale). In the context of previous research, these data ground a new empirical generalization: As distractor words become semantically closer to the target concepts--all else being equal--target naming is facilitated. This fact means that lexical selection does not involve competition, and consequently, that the semantic interference effect does not reflect a lexical level process. This conclusion has important implications for models of lexical access and interpretations of Stroop-like interference effects.     

Semantic competition between hierarchically related words during speech planning

There is overwhelming evidence that during speech planning semantically related words become lexically activated and compete for selection with the to-be-produced target word. The vast majority of this evidence stems from studies using the picture-word task, in which a distractor word (e.g., bird) drawn from the same semantic category as the target (e.g., fish) was shown to inhibit the picture-naming response more strongly than did an unrelated distractor word. By contrast, corresponding evidence from distractor words (e.g., carp) bearing a hierarchical relation to the target (e.g., fish) is sparse and inconclusive. In the present study, we investigated effects of subordinate-level distractors during basic-level naming and effects of basic-level distractors during subordinate-level naming. Hierarchically related distractors were found to inhibit the naming response in both situations. This pattern of results did not depend on whether the pictures were preferably named at the basic level or at the subordinate level. The results suggest that hierarchically related name alternatives compete for selection.     

Color-object interference in young children: A Stroop effect in children 3½-6½ years old

The Stroop color–word task cannot be administered to children who are unable to read. However, our color–object Stroop task can. One hundred and sixty-eight children of 3½–6½ years (50% female; 24 children at each 6-month interval) were shown line drawings of familiar objects in a color that was congruent (e.g., an orange carrot), incongruent (e.g., a green carrot), or neutral (for objects having no canonical color [e.g., a red book]), and abstract shapes, each drawn in one of six colors. Half the children were asked to name the color in which each object was drawn, and half were to name each object. Children's predominant tendency was to say what the object was; when instructed to do otherwise they were slower and less accurate. Children were faster and more accurate at naming the color of a stimulus when the form could not be named (abstract shape) than when it could, even if in its canonical color. The heightened interference to color-naming versus object-naming was not due to lack of familiarity with color names or group differences: Children in the color condition were as fast and accurate at naming the colors of abstract shapes as were children in the form condition at naming familiar objects.     

Color makes a difference: two-dimensional object naming in literate and illiterate subjects

Previous work has shown that illiterate subjects are better at naming two-dimensional representations of real objects when presented as colored photos as compared to black and white drawings. This raises the question if color or textural details selectively improve object recognition and naming in illiterate compared to literate subjects. In this study, we investigated whether the surface texture and/or color of objects is used to access stored object knowledge in illiterate subjects. A group of illiterate subjects and a matched literate control group were compared on an immediate object naming task with four conditions: color and black and white (i.e., grey-scaled) photos, as well as color and black and white (i.e., grey-scaled) drawings of common everyday objects. The results show that illiterate subjects perform significantly better when the stimuli are colored and this effect is independent of the photographic detail. In addition, there were significant differences between the literacy groups in the black and white condition for both drawings and photos. These results suggest that color object information contributes to object recognition. This effect was particularly prominent in the illiterate group.     

材料类型和颜色典型性影响颜色-物体Stroop效应

通过两个实验考查材料类型和颜色典型性对颜色-物体Stroop效应的影响。实验1,考查颜色-物体（图片）Stroop效应。结果颜色典型性差异显著,命名图片的颜色和图片的名称都产生显著的颜色-物体Stroop效应。实验2,考查颜色-物体（词语）Stroop效应。结果颜色典型性差异显著,命名词语的颜色产生颜色-物体Stroop效应,命名词语的名称未产生颜色-物体Stroop效应。结论,材料类型和颜色典型性影响颜色-物体Stroop效应。     

Naming and categorizing objects: Task differences modulate the polarity of semantic effects in the picture–word interference paradigm

The picture-word interference paradigm is a prominent tool for studying lexical retrieval during speech production. When participants name the pictures, interference from semantically related distractor words has regularly been shown. By contrast, when participants categorize the pictures, facilitation from semantically related distractors has typically been found. In the extant studies, however, differences in the task instructions (naming vs. categorizing) were confounded with the response level: While responses in naming were typically located at the basic level (e.g., "dog"), responses were located at the superordinate level in categorization (e.g., "animal"). The present study avoided this confound by having participants respond at the basic level in both naming and categorization, using the same pictures, distractors, and verbal responses. Our findings confirm the polarity reversal of the semantic effects--that is, semantic interference in naming, and semantic facilitation in categorization. These findings show that the polarity reversal of the semantic effect is indeed due to the different tasks and is not an artifact of the different response levels used in previous studies. Implications for current models of language production are discussed.     

Feature overlap slows lexical selection: Evidence from the picture–word interference paradigm

How does the presence of a categorically related word influence picture naming latencies? In order to test competitive and noncompetitive accounts of lexical selection in spoken word production, we employed the picture–word interference (PWI) paradigm to investigate how conceptual feature overlap influences naming latencies when distractors are category coordinates of the target picture. Mahon et al. (2007. Lexical selection is not by competition: A reinterpretation of semantic interference and facilitation effects in the picture-word interference paradigm. Journal of Experimental Psychology. Learning, Memory, and Cognition, 33(3), 503–535. doi:10.1037/0278-7393.33.3.503) reported that semantically close distractors (e.g., zebra) facilitated target picture naming latencies (e.g., HORSE) compared to far distractors (e.g., whale). We failed to replicate a facilitation effect for within-category close versus far target–distractor pairings using near-identical materials based on feature production norms, instead obtaining reliably larger interference effects (Experiments 1 and 2). The interference effect did not show a monotonic increase across multiple levels of within-category semantic distance, although there was evidence of a linear trend when unrelated distractors were included in analyses (Experiment 2). Our results show that semantic interference in PWI is greater for semantically close than for far category coordinate relations, reflecting the extent of conceptual feature overlap between target and distractor. These findings are consistent with the assumptions of prominent competitive lexical selection models of speech production.     

Interaction of task readiness and automatic retrieval in task switching: Negative priming and competitor priming

When subjects switch between tasks, performance is slower after a task switch than after a task repetition, even when preparation time is long. We report two experiments that support the idea that a large part of these residual task shift costs can be due to stimulus-cued retrieval of previous task episodes. We demonstrate that there are two different factors at work: (1) facilitation of response to the current distractor stimulus, appropriate to the previously relevant, competing task (competitor priming), and (2) impaired processing of previously suppressed responses (negative priming). Negative priming was contingent on the size of the stimulus set, suggesting that distractor suppression comes into effect only if the distractors are highly activated. Importantly, both types of interference interacted with task readiness: Whereas in the nondominant task (picture naming), switch and nonswitch trials were equally affected, the dominant task (word reading) showed priming effects on switch trials only. Thus, the retrieval of previous processing episodes has a selective impact on situations in which task competition is high.     

On the temporal dynamics of language-mediated vision and vision-mediated language

Recent converging evidence suggests that language and vision interact immediately in non-trivial ways, although the exact nature of this interaction is still unclear. Not only does linguistic information influence visual perception in real-time, but visual information also influences language comprehension in real-time. For example, in visual search tasks, incremental spoken delivery of the target features (e.g., “Is there a red vertical?”) can increase the efficiency of conjunction search because only one feature is heard at a time. Moreover, in spoken word recognition tasks, the visual presence of an object whose name is similar to the word being spoken (e.g., a candle present when instructed to “pick up the candy”) can alter the process of comprehension. Dense sampling methods, such as eye-tracking and reach-tracking, richly illustrate the nature of this interaction, providing a semi-continuous measure of the temporal dynamics of individual behavioral responses. We review a variety of studies that demonstrate how these methods are particularly promising in further elucidating the dynamic competition that takes place between underlying linguistic and visual representations in multimodal contexts, and we conclude with a discussion of the consequences that these findings have for theories of embodied cognition.     

Two functional magnetic resonance imaging f(MRI) tasks that may replace the gold standard, Wada testing, for language lateralization while giving additional localization information

Two tasks were used to lateralize and localize language functions noninvasively, using functional magnetic resonance (fMRI BOLD sequences). fMRI images produced during comprehension of the gist of a tale derived from an ordered series of inferential questions were used to lateralize and locate the center of and margins within language dominant hemisphere near posterior temporal-parietal-occipital (TPO) cortical area(s), e.g., Wernicke's. A silent noun-generating task was used to lateralize and localize naming functions within and along superior temporal gyrus (STG) and/or the basal temporal language area (BTLA) in fusiform gyrus. Used within a series of tasks, their purpose was to investigate the reliability and validity of replacing the invasive gold standard for language lateralization, Wada test, with a noninvasive test, BOLD fMRI.     

Components of Stroop-like interference in word reading

Previous research has shown that the naming of the picture of, for example, a guitar is substantially delayed when it is accompanied by the name of an object from the same semantic category (e.g., piano) as compared to a nonword control (e.g., xxxxx). La Heij (1988a) has shown that a large part of this Stroop-like interference effect can be attributed to two semantic characteristics of the distractor word: its semantic similarity to the target picture and its semantic relevance in the task at hand. Furthermore, it was argued that the locus of these two interference effects is the process of target-name retrieval. If this is true, semantic interference effects should diminish or disappear when, instead of a picture-naming task, a word-reading task is used. In the present study this prediction is tested. The effects of four distractor characteristics are examined: semantic relatedness, semantic relevance, response set membership and wordness. In contrast to the original picture-naming task only the effect of wordness reached significance. The results of experiments 2 and 3 show that the absence of significant semantic context effects in experiment 1 is not simply due to the fact that a distractor word has less time to affect a word-reading response. The results are taken to support a name-retrieval account of semantic interference in color and picture naming.     

Distractor strength and selective attention in picture-naming performance

Whereas it has long been assumed that competition plays a role in lexical selection in word production (e.g., Levelt, Roelofs, & Meyer, 1999), recently Finkbeiner and Caramazza (2006) argued against the competition assumption on the basis of their observation that visible distractors yield semantic interference in picture naming, whereas masked distractors yield semantic facilitation. We examined an alternative account of these findings that preserves the competition assumption. According to this account, the interference and facilitation effects of distractor words reflect whether or not distractors are strong enough to exceed a threshold for entering the competition process. We report two experiments in which distractor strength was manipulated by means of coactivation and visibility. Naming performance was assessed in terms of mean response time (RT) and RT distributions. In Experiment 1, with low coactivation, semantic facilitation was obtained from clearly visible distractors, whereas poorly visible distractors yielded no semantic effect. In Experiment 2, with high coactivation, semantic interference was obtained from both clearly and poorly visible distractors. These findings support the competition threshold account of the polarity of semantic effects in naming.     

A word-order constraint on phonological activation

Word-order rules impose major constraints on linguistic behavior. For example, adjectives appear before nouns in English, and after nouns in French. This means that constraints on word order must be language-specific properties upheld on-line by the language system. Despite the importance of these rules, little is known about how they operate. We report an influence of word order on the activation of phonological representations. Participants were presented with colored objects and asked to name either the colors or the objects; the phonological similarity between the object and color names was manipulated. French speakers showed a phonological congruency effect in color naming, but not in object naming. English participants yielded the opposite pattern: a phonological effect in object naming, but not in color naming. Differences in the typical order of nouns and adjectives in French and English provide a plausible account for this cross-linguistic contrast. More generally, these results provide direct evidence for the operation of word-order constraints during language production.     

Is a bear white in the woods? Parallel representation of implied object color during language comprehension

Color is undeniably important to object representations, but so too is the ability of context to alter the color of an object. The present study examined how implied perceptual information about typical and atypical colors is represented during language comprehension. Participants read sentences that implied a (typical or atypical) color for a target object and then performed a modified Stroop task in which they named the ink color of the target word (typical, atypical, or unrelated). Results showed that color naming was facilitated both when ink color was typical for that object (e.g., bear in brown ink) and when it matched the color implied by the previous sentence (e.g., bear in white ink following Joe was excited to see a bear at the North Pole). These findings suggest that unusual contexts cause people to represent in parallel both typical and scenario-specific perceptual information, and these types of information are discussed in relation to the specialization of perceptual simulations.     

Name–picture verification as a control measure for object naming: A task analysis and norms for a large set of pictures

The name–picture verification task is widely used in spoken production studies to control for nonlexical differences between picture sets. In this task a word is presented first and followed, after a pause, by a picture. Participants must then make a speeded decision on whether both word and picture refer to the same object. Using regression analyses, we systematically explored the characteristics of this task by assessing the independent contribution of a series of factors that have been found relevant for picture naming in previous studies. We found that, for “match” responses, both visual and conceptual factors played a role, but lexical variables were not significant contributors. No clear pattern emerged from the analysis of “no-match” responses. We interpret these results as validating the use of “match” latencies as control variables in studies or spoken production using picture naming. Norms for match and no-match responses for 396 line drawings taken from Cycowicz, Friedman, Rothstein, and Snodgrass (1997) can be downloaded at: http://language.psy.bris.ac.uk/name-picture_verification.html