Transfer of orthogonal stimulus–response mappings to an orthogonal Simon task

When up–down stimulus locations are mapped to left–right keypresses, an overall advantage for the up–right/down–left mapping is often obtained that varies as a function of response eccentricity. This orthogonal stimulus–response compatibility (SRC) effect also occurs when stimulus location is irrelevant, a phenomenon called the orthogonal Simon effect, and has been attributed to correspondence of stimulus and response code polarities. The Simon effect for horizontal stimulus–response (S–R) arrangements has been shown to be affected by short-term S–R associations established through the mapping used for a prior SRC task in which stimulus location was relevant. We examined whether such associations also transfer between orthogonal SRC and Simon tasks and whether correspondence of code polarities continues to contribute to performance in the Simon task. In Experiment 1, the orthogonal Simon effect was larger after practising with an up–right/down–left mapping of visual stimuli to responses than with the alternative mapping, for which the orthogonal Simon effect tended to reverse. Experiment 2 showed similar results when practice was with high (up) and low (down) pitch tones, though the influence of practice mapping was not as large as that in Experiment 1, implying that the short-term S–R associations acquired in practice are at least in part not modality specific. In Experiment 3, response eccentricity and practice mapping were shown to have separate influences on the orthogonal Simon effect, as expected if both code polarity and acquired S–R associations contribute to performance.     

Processing polarity items: contrastive licensing costs

We describe an experiment that investigated the failure to license polarity items in German using event-related brain potentials (ERPs). The results reveal distinct processing reflexes associated with failure to license positive polarity items in comparison to failure to license negative polarity items. Failure to license both negative and positive polarity items elicited an N400 component reflecting semantic integration cost. Failure to license positive polarity items, however, also elicited a P600 component. The additional P600 in the positive polarity violations may reflect higher processing complexity associated with a negative operator. This difference between the two types of violation suggests that the processing of negative and positive polarity items does not involve identical mechanisms.     

Line bisection-based hemisphericity estimates of university students and professionals: evidence of sorting during higher education and career selection

Recently, hemisphericity has been assessed by six intercorrelated methods. Here, one of these, the "Best Hand Test," a two-hand line bisection-based biophysical method relatively independent of language, culture, or education, was applied to the measurement of hemisphericity distributions within large groups. Entering university students (n=402) enrolled in three lower division courses were chosen as a reference population. Each of these classes contained about 56% left brain-oriented individuals. In contrast, mean student left-brain distributions in four specialized, upper level courses (n=180), ranged from 35 to 68%, suggestive of hemisphericity sorting. Even more pronounced hemisphericity distribution differences were found within university representatives of 15 professions (n=421) and within professional subspecialists (n=45). For example, of biochemists (n=18), 83% were left brain-oriented, while among astronomers (n=21), only 29% were. These results are of intrinsic interest, and demonstrate the capability of the Best Hand Test to estimate hemisphericity in large groups.     

Two-hand line-bisection task outcomes correlate with several measures of hemisphericity

While seeking new functional methods to reassess the concept of hemisphericity, a two-hand line-bisection task was investigated because of reports of large, stable differences among the general population. These were found to be due to hemispheric differences in judgment of the midpoint of horizontal lines, made visible due to the unilateral brain control of each hand. By use of a two-hand line-bisection test (Best-Hand Test), university workers (n=412) were readily sorted into theoretical response categories, resulting in the production of two large groups. These two groups correlated well with those produced by four independent hemisphericity assessments, two physiological and two psychological. This is the third biophysical method whose performance-based group separations significantly correlated with those produced by preference-based hemisphericity-type questionnaires. It is rapid and avoids language, education, or cultural bias.     

Bad–good constraints on a polarity correspondence account for the spatial–numerical association of response codes (SNARC) and markedness association of response codes (MARC) effects

Performance in numerical classification tasks involving either parity or magnitude judgements is quicker when small numbers are mapped onto a left-sided response and large numbers onto a right-sided response than for the opposite mapping (i.e., the spatial–numerical association of response codes or SNARC effect). Recent research by Gevers et al. [Gevers, W., Santens, S., Dhooge, E., Chen, Q., Van den Bossche, L., Fias, W., & Verguts, T. (2010). Verbal-spatial and visuospatial coding of number–space interactions. Journal of Experimental Psychology: General, 139, 180–190] suggests that this effect also arises for vocal “left” and “right” responding, indicating that verbal–spatial coding has a role to play in determining it. Another presumably verbal-based, spatial–numerical mapping phenomenon is the linguistic markedness association of response codes (MARC) effect whereby responding in parity tasks is quicker when odd numbers are mapped onto left-sided responses and even numbers onto right-sided responses. A recent account of both the SNARC and MARC effects is based on the polarity correspondence principle [Proctor, R. W., & Cho, Y. S. (2006). Polarity correspondence: A general principle for performance of speeded binary classification tasks. Psychological Bulletin, 132, 416–442]. This account assumes that stimulus and response alternatives are coded along any number of dimensions in terms of – and + polarities with quicker responding when the polarity codes for the stimulus and the response correspond. In the present study, even–odd parity judgements were made using either “left” and “right” or “bad” and “good” vocal responses. Results indicated that a SNARC effect was indeed present for the former type of vocal responding, providing further evidence for the sufficiency of the verbal–spatial coding account for this effect. However, the decided lack of an analogous SNARC-like effect in the results for the latter type of vocal responding provides an important constraint on the presumed generality of the polarity correspondence account. On the other hand, the presence of robust MARC effects for “bad” and “good” but not “left” and “right” vocal responses is consistent with the view that such effects are due to conceptual associations between semantic codes for odd–even and bad–good (but not necessarily left–right).     

SNARC效应: 现状、理论与建议

SNARC效应是当对数字进行奇偶判断时,即使数的奇偶性与数的大小无关,但右手（左手）对相对大（小）的数的反应快。首先介绍SNARC效应的起源和理论解释,然后总结SNARC效应的特性,论述SNARC效应和Simon效应以及MARC 效应的关系,并对SNARC效应的脑机制进行了概述,最后提出3个有待深入研究的问题：（1）SNARC效应的加工处理机制;（2）SANRC效应的理论探索;（3）SNARC效应的本质。     

The dimensional arrow: Agreement in directional mapping of dimensions among Mandarin Chinese- and English-speakers

We present evidence that English- and Mandarin-speakers agree about how to map dimensions (e.g., size and clarity) to vertical space and that they do so in a directional way. We first developed visual stimuli for four dimensions—size, clarity, complexity, and darkness—and in each case we varied the stimuli to express a range of the dimension (e.g., there were five total items expressing the range covering big, medium, and small). In our study, English- and Mandarin-speakers mapped these stimuli to an unlabelled vertical scale. Most people mapped dimensional endpoints in similar ways; using size as a standard, we found that the majority of participants mapped the clearest, most complex, and darkest items to the same end of the vertical scale as they mapped the biggest items. This indicates that all four dimensions have a weighted or unmarked end (i.e., all are directional or polar). The strong similarities in polarity across language groups contrasted with group differences on a lexical task, for which there was little cross-linguistic agreement about which comparative words to use to describe stimulus pairs (e.g., “bigger” vs. “smaller”). Thus, we found no evidence in this study that the perception of these dimensions is influenced by language.     

Can conceptual congruency effects between number,time, and space be accounted for by polarity correspondence?

Conceptual congruency effects have been interpreted as evidence for the idea that the representations of abstract conceptual dimensions (e.g., power, affective valence, time, number, importance) rest on more concrete dimensions (e.g., space, brightness, weight). However, an alternative theoretical explanation based on the notion of polarity correspondence has recently received empirical support in the domains of valence and morality, which are related to vertical space (e.g., good things are up). In the present study we provide empirical arguments against the applicability of the polarity correspondence account to congruency effects in two conceptual domains related to lateral space: number and time. Following earlier research, we varied the polarity of the response dimension (left-right) by manipulating keyboard eccentricity. In a first experiment we successfully replicated the congruency effect between vertical and lateral space and its interaction with response eccentricity. We then examined whether this modulation of a concrete-concrete congruency effect can be extended to two types of concrete-abstract effects, those between left-right space and number (in both parity and magnitude judgment tasks), and temporal reference. In all three tasks response eccentricity failed to modulate the congruency effects. We conclude that polarity correspondence does not provide an adequate explanation of conceptual congruency effects in the domains of number and time.     

Rapid communication The mental number line dominates alternative,explicit coding of number magnitude

Numerical judgments are facilitated for left-space responses to a smaller number and right-space responses to a larger number (the spatial–numerical association of response codes, SNARC, effect). Despite support for a mental number line (i.e., spatial) explanation of the SNARC effect, this account has been challenged by an intermediate-coding theory that makes use of a polarity-correspondence principle. The latter is a general explanatory framework whereby stimulus and response dimensions are represented in a categorical, binary manner, with complementary categories coded as having either positive or negative polarity. When stimulus and response polarity match, responding is facilitated. In the present experiment we pitted explicitly presented close–far coding against an implicit mental number line (i.e., left–right coding). Subjects categorized numbers (1, 4, 6, and 9) as greater or less than a standard (5) using keys defined only as close to and far from a starting key. We found that, despite instructing subjects to use a close–far coding scheme, they exhibited a typical SNARC effect, with small-number responses facilitated on the left and large-number responses on the right. These results are discussed in the context of results supporting the polarity explanation and with respect to representational pluralism.     

Grammatical number elicits SNARC and MARC effects as a function of task demands

Despite the robustness of the spatial–numerical association of response codes (SNARC) and linguistic markedness of response codes (MARC) effect, the mechanisms that underlie these effects are still under debate. In this paper, we investigate the extraction of quantity information from German number words and nouns inflected for singular and plural using two alternative forced choice paradigms. These paradigms are applied to different tasks to investigate how access to quantity representation is modulated by task demands. In Experiment 1, we replicated previous SNARC findings for number words—that is, a relative left-hand advantage for words denoting small numbers and a right-hand advantage for words denoting large numbers in semantic tasks (parity decision and quantity comparison). No SNARC effect was obtained for surface or lexical processing tasks (font categorization and lexical decision). In Experiment 2, we found that German words inflected for singular had a relative left-hand advantage, and German words inflected for plural a relative right-hand advantage, showing a SNARC-like effect for grammatical number. The effect interfered, however, with a MARC-like effect based on the markedness asymmetry of singulars and plurals. These two effects appear to be dissociated by response latency rather than task demands, with MARC being more pronounced in early responses and SNARC being more pronounced in late responses. The present findings shed light on the relationship of conceptual number and grammatical number and constrain current accounts of the SNARC and MARC effects.