Small subitizing range in people with Williams syndrome

Recent evidence suggests that the rapid apprehension of small numbers of objects—often called subitizing—engages a system which allows representation of up to 4 objects but is distinct from other aspects of numerical processing. We examined subitizing by studying people with Williams syndrome (WS), a genetic deficit characterized by severe visuospatial impairments, and normally developing children (4–6.5 years old). In Experiment 1, participants first explicitly counted displays of 1 to 8 squares that appeared for 5 s and reported “how many”. They then reported “how many” for the same displays shown for 250 ms, a duration too brief to allow explicit counting, but sufficient for subitizing. All groups were highly accurate up to 8 objects when they explicitly counted. With the brief duration, people with WS showed almost perfect accuracy up to a limit of 3 objects, comparable to 4-year-olds but fewer than either 5- or 6.5-year-old children. In Experiment 2, participants were asked to report “how many” for displays that were presented for an unlimited duration, as rapidly as possible while remaining accurate. Individuals with WS responded as rapidly as 6.5-year-olds, and more rapidly than 4-year-olds. However, their accuracy was as in Experiment 1, comparable to 4-year-olds and lower than older children. These results are consistent with previous findings, indicating that people with WS can simultaneously represent multiple objects, but that they have a smaller capacity than older children, on par with 4-year-olds. This pattern is discussed in the context of normal and abnormal development of visuospatial skills, in particular those linked to the representation of numerosity.     

Age-related changes in the appreciation of novel metaphoric semantic relations

ABSTRACT

In the present study we tested the possibility that older adults differ from younger adults in their appreciation of metaphoric semantic relations, and that age-related changes occur due to the perception of novel metaphors. In the first experiment 35 younger (mean age?=?23.1) and 35 older adults (mean age?=?75.3) were asked to rate the plausibility of metaphoric, literal, and unrelated word pairs. Relative to young participants, older participants rated fewer expressions as metaphorically plausible. The second experiment was conducted to examine whether the findings of the first experiment could be accounted for by an age-associated difference in the appreciation of metaphors with different levels of familiarity. In the second experiment, 25 younger (mean age?=?24.4) and 25 older adults (mean age?=?77.5) were asked to rate the familiarity level of the plausible metaphoric expressions. Relative to young participants, older participants rated fewer expressions as novel and more expressions as familiar. The results suggest that novelty plays an important role in appreciating the plausibility of semantic relationships, and age-related changes are associated with the appreciation of the novelty of expressions.     

Invariance on a reading comprehension test in European Portuguese: A differential item functioning analysis between students from rural and urban areas

The aim of this study was to determine whether the items from a reading comprehension test in European Portuguese function differently across students from rural and urban areas, which biases the test validity and the equity in assessment. The sample was composed of 653 students from second, third and fourth grades. The presence of differential item functioning (DIF) was analysed using logistic regression and the Mantel–Haenszel procedure. Although 17 items were flagged with DIF, only five items showed non-negligible DIF in all effect-size measures. The evidence of invariance across students with rural or urban backgrounds for most of the items supports the validity of the test though the five identified items should be further investigated.     

Participant recruitment methods and statistical reasoning performance

Optimal Bayesian reasoning performance has reportedly been elusive, and a variety of explanations have been suggested for this situation. In a series of experiments, it is demonstrated that these difficulties with replication can be accounted for by differences in participant-sampling methodologies. Specifically, the best performances are obtained with students from top-tier, national universities who were paid for their participation. Performance drops significantly as these conditions are altered regarding inducements (e.g., using unpaid participants) or participant source (e.g., using participants from a second-tier, regional university). Honours-programme undergraduates do better than regular undergraduates within the same university, paid participation creates superior performance, and top-tier university students do better than students from lower ranked universities. Pictorial representations (supplementing problem text) usually have a slight facilitative effect across these participant manipulations. These results indicate that studies should take account of these methodological details and focus more on relative levels of performance rather than absolute performance.     

Time,number and length: Similarities and differences in discrimination in adults and children

The aim of this study was to focus on similarities in the discrimination of three different quantities—time, number, and line length—using a bisection task involving children aged 5 and 8 years and adults, when number and length were presented nonsequentially (Experiment 1) and sequentially (Experiment 2). In the nonsequential condition, for all age groups, although to a greater extent in the younger children, the psychophysical functions were flatter, and the Weber ratio higher for time than for number and length. Number and length yielded similar psychophysical functions. Thus, sensitivity to time was lower than that to the other quantities, whether continuous or not. However, when number and length were presented sequentially (Experiment 2), the differences in discrimination performance between time, number, and length disappeared. Furthermore, the Weber ratio values as well as the bisection points for all quantities presented sequentially appeared to be close to that found for duration in the nonsequential condition. The results are discussed within the framework of recent theories suggesting a common mechanism for all analogical quantities.     

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.     

Working memory demands of exact and approximate addition

We compared the working memory requirements of two forms of mental addition: exact calculation (e.g., 63 + 49 = 112) and approximation (e.g., 63 + 49 is about 110). In two experiments, participants solved two-digit addition problems (e.g., 63 + 49) alone and in combination with a working memory task (i.e., remembering four consonants). In Experiment 1, participants chose an answer from two alternatives (e.g., exact: 112 vs. 122; approximate: 110 vs. 140). In Experiment 2, participants responded verbally with exact or approximate answers. In both experiments, the working memory load impaired exact and approximate addition performance, but exact addition was affected more. Load also impaired performance on problems with a carry operation in the units (e.g., 28 + 59 or 76 + 57) more than on problems without a unit carry (e.g., 24 + 53 or 76 + 52). These results identify the carry operation as the source of the working memory demands in multidigit addition.     

Internal number magnitude representation is not holistic,either

Over the last years, evidence has accumulated that the magnitude of two-digit numbers is not only represented as one holistic entity, but also decomposed for tens and units. Recently, Zhang and Wang (2005) suggested such separate processing may be due to the presence of external representations of numbers, whereas holistic processing became more likely when one of the to-be-compared numbers was already internalised. The latter conclusion essentially rested on unit-based null effects. However, Nuerk and Willmes (2005) argued that unfavourable stimulus selection may provoke such null effects and misleading conclusions. Therefore, we tested the conclusion of Zhang and Wang for internal standards with a modified stimulus set. We observed reliable unit-based effects in all conditions contradicting the holistic model. Thus, decomposed representations of tens and units can also be demonstrated for internal standards. We conclude that decomposed magnitude processing of multidigit numbers does not rely on external representations. Rather, even when two-digit numbers are internalised, the magnitudes of tens and units seem to be (also) represented separately.     

Why do people disagree with a statement they do not understand? Relations between comprehension and evaluation of a simple assertion

This article presents the results of a quasi-experimental study that examined the relation between the metacomprehension (i.e., understand/do not understand) and evaluative (i.e., agree/disagree) response to a simple one-sentence statement to compare the relative timing in which these two responses are generated in the course of sentence processing. In the study, participants were asked to provide metacomprehension and evaluative judgements to simple one-sentence assertions, and their response times were measured. Two of the main findings are: first, the response time for the evaluative judgement is faster than the response time for the metacomprehension judgement and, second, the faster response time of the evaluative judgement relative to the metacomprehension judgement is more pronounced either when they are not sure about whether they understand a statement or when they feel they do not understand a statement. The findings are analysed in relation to a multiple constraint satisfaction model of sentence comprehension to generate a possible processing model of a simple one-sentence assertion underlying the generation of metacomprehension and evaluative responses.