The perception of temporal order along the mental number line.

R. Sekuler, P. Tynan, and E. Levinson (1973) found that when 2 characters are presented side-by-side with a short onset asynchrony, subjectively they often appear in a “first-left, then-right” order. The authors of this article conducted 6 experiments in which observers judged the temporal order (TOJs) in which 2 digits were presented. They found a consistent TOJ benefit (larger d`) when the numerically smaller digit was presented first, even though this semantic information was irrelevant to the task and unrelated to the correct response. They concluded that digits located to the left of the mental number line are transmitted faster to a central comparison stage, which represents an “internal counterpart” to the Sekuler et al. (1973) finding regarding external locations. A corresponding benefit is found for letters pairs (e.g., A–Z) and also for mixed digit–letter pairs (e.g., 1–Z). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sequential effects in number comparison.

The modular framework of number processing (e.g., S. Dehaene & R. Akhavein, 1995) was applied to study sequential trial-to-trial effects in a number comparison task. In Experiment 1, numbers were always presented as digits. Responses were faster when the same number was repeated, but this effect was additive with the numerical distance effect. In Experiment 2, numbers were presented either as digits or as words. The authors found significant effects of repeating (a) the same physical stimulus, (b) the same number but in a different notation, and (c) the same notation but a different number. Again, all 3 effects were additive with the numerical distance effect. The authors' results provide strong evidence against accounts according to which, on stimulus repetition trials, the comparison stage is bypassed (as proposed by S. Dehaene, 1996), and the results clearly favor an early, precomparison locus of repetition effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modulating the interference effect in timing with varying stimulus onset asynchrony.

The interference effect on time judgments, when subjects are also required to perform a concurrent nontemporal task, is one of the most reliable findings in the time perception literature. In the present study, the interference between a time discrimination task (short or long tone) and a digit classification task (even or odd digit) was analysed using the overlapping tasks paradigm. Reaction times in the digit task were shorter at longer values of stimulus onset asynchrony (SOA) in Experiment 1, showing a clear modulation of interference with varying the relative position of the tasks. Using longer tone durations in Experiment 2, reaction times in the digit task were affected not only by the overlap between the tasks but also by the temporal proximity of responses in the timing and digit tasks. In Experiment 3, the effect of varying the SOA on performance on the digit task was abolished when the auditory tone was irrelevant, thus eliminating an interpretation in terms of distraction from the tone offset. We conclude that the interference effect in concurrent time discrimination and digit classification may be modulated by the degree of overlap between the tasks as well as by the overlap between late processing stages related to decision and response components in the 2 tasks. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Interactive Effects of Numerical Surface Form and Operand Parity in Cognitive Arithmetic.

In Experiment 1, adults (n = 48) performed simple addition, multiplication, and parity (i.e., odd-even) comparisons on pairs of Arabic digits or English number words. For addition and comparison, but not multiplication, response time increased with the number of odd operands. For addition, but not comparison, this parity effect was greater for words than for digits. In Experiment 2, adults (n = 50) solved simple addition problems in digit and word format and reported their strategies (i.e., retrieval or procedures). Procedural strategies were used more for odd than even addends and much more for word than digit problems. The results indicate that problem encoding and answer retrieval processes for cognitive arithmetic are interactive rather than strictly additive stages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Context-dependent semantic priming in number naming.

Previous research has shown that time to name single-digit Arabic numbers is about 15 ms slower when naming trials are interleaved with simple multiplication (e.g., state product of 2 × 3) than when naming digits is interleaved with magnitude comparison (e.g., state larger; 2 ↑ 3). To explain this phenomenon, J. I. D. Campbell and A. W. S. Metcalfe (2008) proposed that the comparison context enables both semantic and asemantic pathways for digit naming but that number-fact retrieval inhibits the semantic route and slows digit naming relative to the comparison context. To test this hypothesis, the authors modified the naming context paradigm by introducing a semantic priming manipulation. They replicated the digit-naming response time advantage for comparison relative to the multiplication context and observed semantic priming only in the comparison context. In comparison blocks, digit naming was 8 ms faster immediately after naming near digit primes (±1) compared to far primes (≥3), but in multiplication blocks there was no priming. The results reinforce the theory that number-fact retrieval can inhibit the semantic route for digit naming (L. Cohen & S. Dehaene, 1995) and thereby reconfigure the cognitive architecture for naming digits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Is numerical comparison digital? Analogical and symbolic effects in two-digit number comparison.

Do Ss compare multidigit numbers digit by digit (symbolic model) or do they compute the whole magnitude of the numbers before comparing them (holistic model)? In 4 experiments of timed 2-digit number comparisons with a fixed standard, the findings of J. V. Hinrichs et al (see record 1982-07073-001) were extended with French Ss. Reaction times (RTs) decreased with target-standard distance, with discontinuities at the boundaries of the standard's decade appearing only with standards 55 and 66 but not with 65. The data are compatible with the holistic model. A symbolic interference model that posits the simultaneous comparison of decades and units can also account for the results. To separate the 2 models, the decades and units digits of target numbers were presented asynchronously in Experiment 4. Contrary to the prediction of the interference model, presenting the units before the decades did not change the influence of units on RTs. Pros and cons of the holistic model are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Operation-specific effects of numerical surface form on arithmetic strategy.

Educated adults solve simple addition problems primarily by direct memory retrieval, as opposed to by counting or other procedural strategies, but they report using retrieval substantially less often with problems in written-word format (four + eight) compared with digit format (4 + 8). It was hypothesized that retrieval efficiency is relatively low with word operands compared with digits and that this promotes a shift to procedural backup strategies. Consistent with this hypothesis, Experiment 1 demonstrated greater word-format costs on retrieval usage for addition than subtraction, which was due to increased counting for addition but not subtraction. Experiment 2 demonstrated greater word-format costs on retrieval for division than multiplication, which was due to increased use of multiplication-fact reference to solve division problems. Format-related strategy shifts away from retrieval reflected both the efficiency of retrieval for a given operation and the availability of viable alternative strategies. The results demonstrate that calculation processes are not abstracted away from problem surface form. The authors propose that retrieval efficiency for arithmetic connects diverse performance and strategy-related effects across key arithmetic factors, including arithmetic operation, numerical size, and numeral format. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Across-notation automatic numerical processing.

In this article, the authors explored the existence of across-notation automatic numerical processing using size comparison and same-different paradigms. Participants were Arabic speakers, who used 2 sets of numerical symbols--Arabic and Indian. They were presented with number pairs in the same notation (Arabic or Indian) or in different ones (Arabic and Indian). In the size comparison paradigm, 2 digits differing both numerically and physically were compared on the physical dimension. Nevertheless, there was evidence that participants automatically processed the irrelevant numerical dimension in different notation pairs. In the same-different paradigm, 2 digits were presented either in the same or in different notations. Participants had to indicate whether the 2 digits were physically the same. The results again showed evidence for the automatic processing of numerical magnitude for pairs in different notations. Findings of both experiments suggest that numbers in different notations are automatically translated into a common representation of magnitude, in line with M. McCloskey's (1992) abstract representation model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relative time course of semantic and phonological activation in reading Chinese.

The relative time course of semantic and phonological activation was investigated in the context of whether phonology mediates access to lexical representations in reading Chinese. Compound words (Experiment 1) and single-character words (Experiments 2 and 3) were preceded by semantic and phonological primes. Strong semantic priming effects were found at both short (57 ms) and long (200 ms) stimulus onset asynchrony (SOA), but phonological effects were either absent in lexical decision (Experiment 1), were present only at the longer SOA in character decision (Experiment 2) or were equally strong as semantic effects in naming (Experiment 3). Experiment 4 revealed facilitatory or inhibitory effects, depending on SOA, in phonological judgments to character pairs that were not phonologically but semantically related. It was concluded that, in reading Chinese, semantic information in the lexicon is activated at least as early and just as strongly as phonological information. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Priming by numb3r5 does not involve top-down feedback.

Using the same–different task, Perea, Du?abeitia, Pollatsek, and Carreiras (2009) showed that digits resembling letters (“leet digits”; e.g., 1 = I, 4 = A) primed pseudoword strings (e.g., V35Z3D–VESZED), but letters resembling digits (“leet letters”) did not prime digit strings (e.g., 9ES7E2–935732), and suggested that this is due to top-down feedback available for letter, but not digit, strings. Here we show that (a) single letters show as much leet priming as 3-letter words (Experiment 1); (b) leet priming is equally robust for digit strings and pseudowords when the string is 4 items long but not when 6 items long (Experiment 2); and (c) with 6-item strings, orthotactically illegal letter strings (e.g., OIAUEQ) behave just like digit strings (Experiment 3). These results indicate that the asymmetry in leet priming is not due to top-down feedback available selectively for letter strings. We offer an alternative explanation based on the Bayesian reader account of masked priming proposed by Norris and Kinoshita (2008), and the role played by the orthotactic knowledge used to extend the functional capacity of visual working memory involved in performing the same–different task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of Prolonged Work on Data Entry Speed and Accuracy.

In 2 experiments, participants used a keyboard to enter 4-digit numbers presented on a computer monitor under conditions promoting fatigue. In Experiment 1, accuracy of data entry declined but response times improved over time, reflecting an increasing speed-accuracy trade-off. In Experiment 2, the (largely cognitive) time to enter the initial digit decreased in the 1st half but increased in the 2nd half of the session. Accuracy and time to enter the remaining digits decreased across though not within session halves. The (largely motoric) time to press a concluding keystroke decreased over the session. Thus, through a combination of facilitation and inhibition, prolonged work affects the component cognitive and motoric processes of data entry differentially and at different points in practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The cuing and priming of cognitive operations.

The effect on performance of advance information about the specific cognitive operations to be performed on a stimulus was investigated in two experiments using cues (information useful and necessary for performance) and primes (information useful but not necessary for performance). In the first experiment, a cue presented prior to a digit stimulus indicated whether the digit was to be classified as odd or even, or low (less than 6) or high (greater than 5). Results showed that performance improved with increasing time between cue and digit and with practice. A Stroop-like asymmetric interference of the low–high operation on the odd–even operation was also observed. In the second experiment, a prime that matched the cue, mismatched it, or was neutral was presented before the cue. Results showed facilitatory and inhibitory priming effects, as well as a distance effect based on the position of a digit relative to the boundary between 5 and 6. The results of both experiments were discussed in terms of a model based on relative processing speeds of the two relevant properties of the digits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the interaction of numerical and size information in digit comparison: a behavioral and event-related potential study

To investigate effects of dimensional congruity in digit comparison processes we recorded response latencies, error rates and event-related potentials (ERPs) in a situation when the relevant and the irrelevant dimension of judgement, the digit's physical size or its numerical value, varied unpredictably from trial to trial. Congruity effects may arise at early processing stages, where both numerical and size information are mapped onto a common, integrated representation. Alternatively, numerical and size information may be processed in functionally independent channels and interact only at a later stage of response activation. For both, numerical and size comparisons, reliable distance effects on ERPs (starting 224 ms post-stimulus at frontal electrode sites) and on behavioral data were observed. Congruity effects follow a timecourse that mirror-images the temporal pattern found for the distance effects: while distance effects on difference potentials start about 64 ms earlier for numerical comparisons, congruity effects due to the irrelevant attribute are seen about 88 ms earlier for size comparisons. While Lateralized Readiness Potentials (LRPs) for incongruent trials are shifted in time, there was no indication of an activation for the incorrect response in incongruent trials, as an account of congruity effects in terms of response competition would predict. The most parsimonious explanation of our results is that numerical and size information are extracted in parallel, are both converted into an integrated representation and potentially interact during these early parallel stages.     

Spontaneous assimilation of continuous values and temporal information in causal induction.

Existing models of causal induction primarily rely on the contingency between the presence and the absence of a causal candidate and an effect. Yet, classification of observations into these four types of covariation data may not be straightforward because (a) most causal candidates, in real life, are continuous with ambiguous, intermediate values and because (b) effects may unfold after some temporal lag, providing ambiguous contingency information. Although past studies suggested various reasons why ambiguous information may not be used during causal induction, the authors examined whether learners spontaneously use ambiguous information through a process called causal assimilation. In particular, the authors examined whether learners willingly place ambiguous observations into one of the categories relevant to the causal hypothesis, in accordance with their current causal beliefs. In Experiment 1, people's frequency estimates of contingency data reflected that information ambiguous along a continuous quantity dimension was spontaneously categorized and assimilated in a causal induction task. This assimilation process was moderated by the strength of the upheld causal hypothesis (Experiment 2), could alter the overall perception of a causal relationship (Experiment 3), and could occur over temporal sequences (Experiment 4). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Issues concerning relative speed of processing hypotheses, schizophrenic performance deficits, and prefrontal function: Comment on Schooler et al. (1997).

The authors have found the data presented in the C. Schooler, E. Neumann, L. J. Caplan, and B. R. Roberts (see record 1997-02838-004) article to be interesting and of potential value in constraining the further development of detailed theoretical models of Stroop performance. However, the authors have found that the relative speed of processing account of stimulus onset asynchrony (SOA) effects given by Schooler et al. in Experiment 1 fails to address several important and vexing issues faced by such accounts, which have been highlighted by existing formal models. The authors also have expressed concerns about Schooler et al.'s, interpretation of the reduction in Stroop interference observed among individuals with schizophrenia in Experiment 2. Whereas the authors have acknowledged that it is plausible to relate this to a dysfunction of prefrontal cortex, they have pointed to equally plausible alternative explanations, which are not addressed by the experiment or in the discussion in the Schooler et al. article. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of stimulus-based and response-based spatial information in sequence learning.

In 4 experiments, relational structures were independently varied in stimulus and response sequences in a serial reaction time task. Moreover, the use of spatial and symbolic stimuli and responses was varied between experiments. In Experiment 1, spatial stimuli (asterisk locations) triggered spatial responses (keystrokes); in Experiment 2, spatial stimuli triggered symbolic responses (verbal digit naming); in Experiment 3, symbolic stimuli (digits) triggered keystrokes; and in Experiment 4, digits triggered verbal responses. The results showed that there is a remarkably stronger effect of relational structures in spatial sequences than in symbolic sequences, irrespective of whether stimulus or response sequences are concerned. This suggests that learning is particularly effective for sequences of spatial locations. It is argued that spatial learning is a critical determinant for the debate on perceptual and motor learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time-course analysis of semantic and orthographic context effects in picture naming.

In Experiment 1, the authors used a picture-word task to investigate the time courses of semantic interference, orthographic facilitation, and their interaction. Five stimulus onset asynchronies (SOAs), from -200 ms (word first) to 200 ms, in steps of 100 ms were used. The results show that the semantic interference effect was restricted to a small SOA range around zero, that the orthographic facilitation effect almost spanned the whole SOA range used, and finally, that the two effects modified each other. The authors present a connectionist model based on W. R. Glaser and M. O. Glaser's (see record 1989-24812-001) model that is able to simulate the experimental results. In Experiment 2, a prediction of the model was tested and supported. The findings support a word-form retrieval account of context effects in picture naming and are discussed in relation to alternative accounts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic and intentional processing of numerical information.

Ss evaluated either numerical size or physical size of stimuli varying along both dimensions. Size congruity, distance, and semantic congruency effects were obtained for numerical comparisons of digit pairs and for comparisons of digits with an internal standard (5). Only the size congruity effect was obtained for physical judgments. It was smaller for pairs in which both stimuli were either both smaller or both larger than 5 than for pairs that contained the digit 5. The results are consistent with the notion that intentional processing is mainly algorithm-based, whereas autonomous processing is mainly memory-based. Implications of the results for models of numerical processing are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processes underlying long-term repetition priming in digit data entry.

Two experiments examined long-term repetition priming in data entry. In each experiment, participants entered 4-digit numbers displayed as either words or numerals, and responded with digits (Experiment 1), or either digits or initial letters (Experiment 2). At test 1 week later, they entered old and new numbers, with the format changed for half of the old stimuli. Implicit memory was evidenced at test by faster entry of the old than the new numbers, regardless of whether the numbers were in the same or different format, suggesting that the abstract numerical meaning, not the surface form, contributes to repetition priming. Numbers presented as words in training had an advantage over numbers presented as numerals, regardless of response format, implying that type of processing also contributes to the effect and ruling out an explanation based on time spent processing numbers in word format. (PsycINFO Database Record (c) 2010 APA, all rights reserved)