Naming digits in a semantic blocking paradigm

It is widely agreed that word numerals are processed similar to other words, and, thus, they can be named without semantic mediation. However, there is no consensus about Arabic digits. Although digits seem to have a preferential link to magnitude representation, there is some evidence indicating a possible asemantic route to access phonological information. In the present study, we used a semantic blocking paradigm to explore this question. In Experiment 1, participants were asked to name digits and pictures or numeral words and name of objects in a semantic blocked context and in a mixed context. For both types of numerical notation we found facilitation in the blocked condition relative to the mixed condition. In Experiment 2, participants named two-digit numbers in a blocked condition (short numerical distance) or in a mixed condition (large numerical distance). Again, facilitation was found for the blocked condition relative to the mixed condition. This pattern of results seems to indicate that Arabic digits, like number words, might be named through an asemantic route.     

Semantic processing in the production of numerals across notations

In the present work, we conducted a series of experiments to explore the processing stages required to name numerals presented in different notations. To this end, we used the semantic blocking paradigm previously used in psycholinguist studies. We found a facilitative effect of the semantic blocked context relative to the mixed context for Arabic digits and number words. However, the blocked context produced an interference effect for physical numerosity and Roman numbers. Our results provided further evidence to models suggesting that Arabic digits may be named through an asemantic route similar to that of number words, whereas a semantic route is mandatory to name physical numerosity and Roman numerals.     

Arabic digit naming speed: task context and redundancy gain

There is evidence for both semantic and asemantic routes for naming Arabic digits, but neuropsychological dissociations suggest that number-fact retrieval (2x3=6) can inhibit the semantic route for digit naming. Here, we tested the hypothesis that such inhibition should slow digit naming, based on the principle that reduced access to multiple routes would counteract redundancy gain (the response time advantage expected from parallel retrieval pathways). Participants named two single digit numbers and then performed simple addition or magnitude comparison (Experiment 1), multiplication or magnitude comparison (Experiment 2), and multiplication or subtraction (Experiment 3) on the same or on a different pair of digits. Addition and multiplication were expected to inhibit the semantic route, whereas comparison and subtraction should enable the semantic route. Digit naming time was approximately 15ms slower when participants subsequently performed addition or multiplication relative to comparison or subtraction, regardless of whether or not the same digit pair was involved. A letter naming control condition in Experiment 3 demonstrated that the effect was specific to digit naming. Number fact retrieval apparently can inhibit Arabic digit naming processes.     

Do we access meaning when we name Arabic digits? Electrophysiological evidence

In this study, we evaluated whether the naming of Arabic digits required access to semantic information. Participants named pictures and Arabic digits blocked by category or intermixed with exemplars of other categories while behavioural and electrophysiological measures were gathered. Pictures were named slower and Arabic digits faster in the blocked context relative to the mixed context. Around 350–450 ms after the presentation of pictures and Arabic digits, brain waves were more positive in anterior regions and more negative in posterior regions when the blocked context was compared with the mixed context. The pattern of electrophysiological results suggests that pictures and Arabic digits are both processed semantically and they are subject to repetition effects during the naming task.     

Two routes for the processing of verbal numbers: evidence from the SNARC effect

The functional locus of the semantic system is an important issue in number processing. In the present article, the necessity of addressing a central semantic magnitude system in the processing of printed verbal number words is evaluated by looking at the presence of a spatial-numerical association of response codes or SNARC effect. This effect consists of an association of number magnitude and response-preference (preferred responses to small numbers with the left hand and to large numbers with the right hand) and reflects semantic access. Two experiments were run. In Experiment 1, participants performed a parity judgment task which requires access to number semantics. A SNARC effect was observed. In Experiment 2 a phoneme monitoring task was used, which can, in principle, be performed through direct asemantic transcoding. No SNARC effect occurred. Apparently, written number words access the semantic system only if this is necessary for correct task completion. Hence, a semantic and an asemantic route can be postulated for the processing of word numerals. These observations contrast with the processing of Arabic numerals for which semantic effects are omnipresent. Implications of this explicit demonstration of a dissimilarity between the processing of digits and of number words are discussed. Received: 25 October 2000 / Accepted: 21 May 2001     

Number processing of Arabic and Hebrew bilinguals: Evidence supporting the distance effect

In the current study, a direct assessment of the effect of language lexical‐syntactic structure and magnitude semantic access on numerical processing was made by contrasting the performance of Arabic/Hebrew bilinguals in a digital (Hindi‐digits/Arabic‐digits) and verbal numerical comparison task (Arabic, an inverted language: Units‐Decades, Hebrew, a non‐inverted language: Decades‐Units). Our data revealed in the digital presentation format (Experiment 1) a regular distance effect in Arabic language‐Hindi digits and Hebrew language‐Arabic digits, characterized by an inverse relation between reaction times and numerical distance with no difference in the mean reaction times of participants in Arabic‐L1 and Hebrew‐L2. This indicates that both lexical digits of two‐digit numbers in L1 and L2 are similarly processed and semantically accessed. However in the verbal presentation format (Experiment 2) a similar pattern of distance effect was found, but the mean reaction times in Arabic were lower than in Hebrew in each numerical distance. This indicates that the processing of two‐digit number words in L1 and L2 is semantically accessed and determined by the syntactic structure of each language.     

Roman digit naming: evidence for a semantic route

Earlier research with monolinguals and bilinguals showed that numbers may be named through both a semantic and a phonological route, depending on the number's language and format (Arabic or verbal), task demands, and naming language. The present study investigated the importance of the semantic route for the processing of a third representation of magnitude, namely Roman digits. Using an interference paradigm, we showed that the processing of Roman target digits is influenced by Arabic digit distractors, both in a naming task and a parity judgment task. Roman digits were processed faster if the target and distractor were of the same magnitude. If this was not the case, processing speed slowed down as the numerical distance between target and distractor increased. This strongly suggests that semantic access is mandatory when naming Roman digits. Implications are discussed for the number processing domain and for models of translation in bilinguals.     

Are Arabic numerals processed as pictures in a Stroop interference task?

In a picture-word interference task, picture naming is interfered by an incongruent word, but word naming is hardly hindered by the presence of an incongruent picture. In this study, we investigated whether Arabic digits are processed more like pictures or like words. We report two experiments in which Arabic digits and verbal numerals were confronted in a Stroop task. Arabic digit naming is interfered by the presence of an incongruent verbal numeral, while naming the verbal numeral is not influenced by the presence of an incongruent Arabic digit. In a second experiment, we excluded the hypothesis that the results are due to ignoring the Arabic digits: interferences from an incongruent distracter were similar for both notations in a semantic classification task. It seems that an asemantic conversion for Arabic digits is too slow to influence naming times, and that Arabic digit naming, like picture naming, is semantically mediated.     

Mental comparison of size and magnitude: size congruity effects

Paivio (1975) found that the latency to choose the larger of two named objects does not depend on congruity between the object sizes and the sizes of the object names. Because size congruity does affect latencies for pictorially presented objects, Paivio interpreted this result as support for the dual coding hypothesis. However, Experiment 1 demonstrated that Paivio's results were an artifact of his experimental design. Size congruity does affect latencies to choose the larger of two named objects when object pairs are not repeated. When the same object pairs are used repeatedly, as in Paivio's experiment, the effect disappears. In this case the response is probably remembered, so that the objects need not be compared. To determine the processing stages affected by size congruity, both the distance between stimulus sizes and the size congruity were manipulated in Experiment 2. Three groups of subjects chose either the greater Arabic digit, the greater named digit, or the larger named object. Size congruity interacted with distance only for Arabic digits. For both Arabic digits and named digits, the interference caused by size incongruity was greater than the facilitation caused by size congruity, whereas for object names, the facilitation was greater than the interference. A model of the interaction between physical size comparisons and conceptual size comparisons is proposed to account for these results.     

Semantic alignment and number comparison

Are the quantity representations activated by Arabic digits influenced by semantic context? We developed a novel paradigm to examine semantic alignment effects (e.g., Bassok et al. in J Exp Psychol Learn Mem Cogn 34:343–352, 2008) in number comparison. A horizontal word pair (either less more or few many) appeared for 480 ms to prime either relative magnitude (less more) or quantity (few many). Then a horizontal pair of single digits that were either successors (near) or differed by at least four (far) appeared above the word pair. Participants indicated verbally whether or not the word and digit pairs were congruent with respect to left-to-right ascending or descending relative magnitude. The RT advantage for far number pairs compared to near pairs (the distance effect) was greater with magnitude primes (81 ms) than quantity primes (17 ms), demonstrating a semantic alignment effect. This effect disappeared in Experiment 2 in which participants received identical stimuli but named the larger of the two digits and were free to ignore the primes. Nonetheless, mean RT in Experiment 2 was faster with prime and target pairs both ascending or both descending, but only with quantity primes. This prime-dependent order-congruity effect suggests that semantic alignment with respect to numerical order affected number comparison in Experiment 2. The results thereby demonstrate that number comparison exhibits task-dependent semantic alignment effects and recruits distinct numerical representations as a function of semantic context (e.g., Cohen Kadosh and Walsh in Behav Brain Sci 32:313–373, 2009).     

Asymmetries in the processing of Arabic digits and number words

Numbers can be represented as Arabic digits ("6") or as number words ("six"). The present study investigated potential processing differences between the two notational formats. In view of the previous finding (e.g., Potter & Faulconer, 1975) that objects are named slower, but semantically categorized faster, than corresponding words, it was investigated whether a similar interaction between stimulus format and task could be obtained with numbers. Experiment 1 established that number words were named faster than corresponding digits, but only if the two notation formats were presented in separate experimental blocks. Experiment 2 contrasted naming with a numerical magnitude judgment task and demonstrated an interaction between notation and task, with slower naming but faster magnitude judgment latencies for digits than for number words. These findings suggest that processing of the two notation formats is asymmetric, with digits gaining rapid access to numerical magnitude representations, but slower access to lexical codes, and the reverse for number words.     

About the locus of the distractor frequency effect: Evidence from the production of clitic pronouns

In this study, we report results from two experiments in which pictures were shown with superimposed distractors that varied along two dimensions: frequency (high vs. low) and semantic relation with respect to the picture (related vs. unrelated). In one condition of Experiment 1, participants named pictures with a noun utterance; in the other condition of Experiment 1 and in Experiment 2 participants named pictures with a pronominal utterance. Low frequency distractor words produced greater interference with respect to high frequency words in noun production, but not in pronoun production. Critically, a semantic interference effect, greater interference in the semantically related than unrelated condition, was reported in both experiments, suggesting that distractor words were equally processed in both noun and pronoun conditions. These results are discussed in the context of current models of picture–word interference.     

The role of syntactic context in word recognition

This study examines the role of syntactic information in word recognition. Subjects made a word-nonword decision regarding a target string that was preceded by a syntactically appropriate word, a semantically related word, or an unrelated word. In Experiment 1, with syntactic and semantic trials assigned to separate blocks, syntactically and semantically appropriate context significantly reduced lexical decision for subsequent target words, compared with unrelated contexts. In Experiment 2, the syntactically and semantically primed trials were either blocked separately or mixed within the same block. Significant syntactic and semantic effects were both observed in the blocked condition, but only the semantic effect was obtained in the mixed condition     

Effects of semantic context in the naming of pictures and words

Two experiments investigated whether lexical retrieval for speaking can be characterized as a competitive process by assessing the effects of semantic context on picture and word naming in German. In Experiment 1 we demonstrated that pictures are named slower in the context of same-category items than in the context of items from various semantic categories, replicating findings by Kroll and Stewart (Journal of Memory and Language, 33 (1994) 149). In Experiment 2 we used words instead of pictures. Participants either named the words in the context of same- or different-category items, or produced the words together with their corresponding determiner. While in the former condition words were named faster in the context of same-category items than of different-category items, the opposite pattern was obtained for the latter condition. These findings confirm the claim that the interfering effect of semantic context reflects competition in the retrieval of lexical entries in speaking.     

Word Production and the Picture-Word Interference Paradigm: The Role of Learning

Psycholinguistic experiments conducted with the picture-word interference paradigm are typically preceded by a phase during which participants learn the words they will have to produce in the experiment. In Experiment 1, the pictures (e.g., a frog) were to be named and were presented with a categorically related (e.g., cat) or unrelated distracter (e.g., pen). In the related condition responses were slower relative to the unrelated condition for the participants who had gone through the learning phase. In contrast, participants who had not been previously familiarized with the materials showed facilitation. In Experiment 2 one group of participants, as usual, learned to produce the targets upon presentation of the corresponding pictures (e.g., a frog). The other group learned to produce the same targets upon presentation of unrelated pictures (e.g., a clock). They showed very similar semantic effects. The implications of the findings in the study of word production are discussed.     

Do people access meaning when they name banknotes?

Do people access the monetary value of banknotes when they say them aloud? In this study, we evaluated this question by asking people to name sequences of euro banknotes blocked by category or mixed with exemplars of other categories. The participants did not show an interference effect in the blocked context. The absence of semantic interference effect was also observed when participants named euro banknotes that did not have imprinted monetary value. These results suggest a direct connection between perceiving banknotes and accessing their names.     

Cognitive processing of currency: Euros and dollars

In the current study, we evaluated whether the processing of currency was determined by familiarity of people with banknotes. In Experiment 1, participants who used the Euro currency named sequences of Euro banknotes and Dollar banknotes blocked by category or mixed with exemplars of other categories. The participants showed an interference effect in the blocked context with Dollar banknotes but not with Euro banknotes. In Experiment 2, the interference effect was observed with Euro banknotes when participants were not familiar with the Euro currency. These results suggest that the semantic processing of banknotes depends on the participants' familiarity with currency.     

语义相似性与类别大小对图-词干扰范式下语义效应的影响

采用基本水平命名和类别水平命名任务, 通过2个实验, 考察了图-词之间的语义相似性与类别大小对图-词干扰范式下语义效应的影响。实验1发现, 图片命名时间在语义相似性高的干扰词条件下显著快于在语义相似性低的干扰词条件下, 但这种效应只出现在基本水平命名任务中, 未出现在类别水平命名任务中。图-词之间的语义相似性高低对低熟悉图片命名影响大, 对高熟悉图片命名影响小。实验2显示, 语义关联的干扰词对图片的基本水平命名产生了语义干扰效应, 对图片的类别水平命名产生了语义促进效应。类别大小强化了语义效应：类别大, 图片的基本水平命名的语义干扰效应更大, 图片的类别水平命名的语义促进效应更强。整个研究表明, 图-词之间的语义关联的强度影响语义效应的方向, 图-词之间的语义关联的广度影响语义效应的强弱。需要结合多种理论来解释图-词之间的语义相似性和类别大小对图-词干扰范式下语义效应的影响。     

On the categorical nature of the semantic interference effect in the picture-word interference paradigm

Two picture-word interference experiments are reported in which the boundaries of the semantic interference effect are explored. In both experiments, participants named pictures (e.g., a picture of a car) that appeared with superimposed word distractors. Distractor words from the same semantic category as the word for the picture (e.g., CAR) produced semantic interference, whereas semantically related distractors from a different category (e.g.,Bumper) led to semantic facilitation. In Experiment 2, the semantic facilitation from semantically related distractors was replicated. These results indicate that a semantic relationship between picture and distractor does not necessarily lead to interference and in fact can lead to facilitation. In all but one case tested until now, a semantic relationship between picture and distractor has led to semantic facilitation. The implications of these results for the assumption that the semantic interference effect arises as a consequence of lexical competition are discussed.     

SNARC for numerosities is modulated by comparative instruction (and resembles some non-numerical effects)

The spatial–numerical association of response codes (SNARC) effect is observed for both numerical (Arabic digits) and non-numerical stimuli (size, duration, height). However, in a context of comparative judgment, Arabic numbers are mapped onto space differently from sizes and heights: SNARC for Arabic digits is formed consistently in a certain cultural reading direction, whereas SNARC for sizes and heights is additionally modulated by comparative instruction (it reverses when participants choose larger magnitudes). In the present study, we test whether the spatial characteristic of magnitude processing revealed in a context of comparison is determined by a presence or lack of numerical content of the processed information, or it depends on specific directional experience (e.g., left-to-right ordering) associated with the processed magnitude format. We examine the SNARC effect with the pairwise comparison design, by using non-symbolic numerical stimuli (objects’ collections), for which the left-to-right spatial structure is not as exceedingly overlearned as for Arabic numbers. We asked participants from two reading cultures (left-to-right vs. mixed reading culture) to compare numerosities of two sets, choosing either a larger or smaller one. SNARC emerged in both groups. Additionally, it was modulated by comparative instruction: It appeared in a left-to-right direction when participants selected a smaller set, but it tended to reverse when participants selected a larger set. We conclude that spatial processing of numerosities is dissociated from spatial processing of Arabic numbers, at least in a context of comparative judgment. This dissociation could reflect differences in spatial ordering experience specific to a certain numerical input.