Fact Retrieval Research Articles

Neurocognitive profiles of learning disabled children with neurofibromatosis type 1.

Neurofibromatosis 1 (NF1) is a genetic condition generally associated with intellectual deficiency and learning disabilities. Although there have been groundbreaking advances in the understanding of the molecular, cellular, and neural systems underlying learning deficits associated to NF1 in animal models, much remains to be learned about the spectrum of neurocognitive phenotype associated with the NF1 clinical syndrome. In the present study, 32 children with NF1 ranging from 7 to 14 years were evaluated with neurocognitive tests dedicated to assess basic capacities which are involved in reading and mathematical achievement. Deficits in lexical and phonological strategies and poor number facts retrieval were found underlying reading and arithmetic disorders, respectively. Additionally, efficiencies in lexical/phonological strategies and mental arithmetic were significant predictors of individual differences in reading attainment and math. However, deficits in core numeric capacities were not found in the sample, suggesting that it is not responsible for calculation dysfluency. The estimated prevalence of Developmental Dyscalculia was 18.8%, and the male:female ratio was 5:1. On the other hand, the prevalence of Developmental Dyslexia was almost 3 times as high (50%), and no gender differences were found (male: female ratio = 1:1). This study offers new evidence to the neurocognitive phenotype of NF1 contributing to an in depth understanding of this condition, but also to possible treatments for the cognitive deficits associated with NF1.

Contributions from specific and general factors to unique deficits: two cases of mathematics learning difficulties

Mathematics learning difficulties are a highly comorbid and heterogeneous set of disorders linked to several dissociable mechanisms and endophenotypes. Two of these endophenotypes consist of primary deficits in number sense and verbal numerical representations. However, currently acknowledged endophenotypes are underspecified regarding the role of automatic vs. controlled information processing, and their description should be complemented. Two children with specific deficits in number sense and verbal numerical representations and normal or above-normal intelligence and preserved visuospatial cognition illustrate this point. Child H.V. exhibited deficits in number sense and fact retrieval. Child G.A. presented severe deficits in orally presented problems and transcoding tasks. A partial confirmation of the two endophenotypes that relate to the number sense and verbal processing was obtained, but a much more clear differentiation between the deficits presented by H.V. and G.A. can be reached by looking at differential impairments in modes of processing. H.V. is notably competent in the use of controlled processing but has problems with more automatic processes, such as nonsymbolic magnitude processing, speeded counting and fact retrieval. In contrast, G.A. can retrieve facts and process nonsymbolic magnitudes but exhibits severe impairment in recruiting executive functions and the concentration that is necessary to accomplish transcoding tasks and word problem solving. These results indicate that typical endophenotypes might be insufficient to describe accurately the deficits that are observed in children with mathematics learning abilities. However, by incorporating domain-specificity and modes of processing into the assessment of the endophenotypes, individual deficit profiles can be much more accurately described. This process calls for further specification of the endophenotypes in mathematics learning difficulties.

Call for Papers: “Developmental Dyscalculia”

Free AccessNews and AnnouncementsCall for Papers: “Developmental Dyscalculia”A Topical Issue of the Zeitschrift für PsychologieJörg-Tobias KuhnJörg-Tobias Kuhn University of Münster, Germany Guest Editor Search for more papers by this authorPublished Online:February 28, 2015https://doi.org/10.1027/2151-2604/a000158PDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinkedInRedditE-Mail SectionsMoreThe past three decades have seen a significant expansion of research on developmental dyscalculia (DD), which is a specific learning disorder affecting mathematical abilities such as calculation, basic number processing, or mathematical fact retrieval. Although substantial scientific progress has been made in the field, a full account of the causal mechanisms of DD is still elusive, and several controversial research issues remain. The aim of this topical issue of the Zeitschrift für Psychologie on “Developmental dyscalculia” is to highlight some of these controversial topics. This may include both state-of-the-art reviews that are concerned with a specific and well-defined aspect of DD (also in the form of a meta-analysis) and original empirical articles with a background in neuroscience, developmental psychology, educational psychology, psychological assessment, or applied research. In addition, shorter research notes and opinion papers are also encouraged. We invite researchers from various areas of psychology, education, and medicine to submit their abstracts on potential papers electronically.How to submit: Interested authors should submit a letter of intent including: (1) a working title for the manuscript, (2) names, affiliations, and contact information for all authors, and (3) an abstract detailing the content of the proposed manuscript to guest editor Jörg-Tobias Kuhn (mailto:t.kuhn@uni-muenster.de).There is a two-stage submissions process. Initially, authors are requested to submit only abstracts of their proposed papers. Authors requested to submit full papers should then do so. All papers will undergo full peer review.Deadline for submission of abstracts is April 15, 2014.Deadline for submission of full papers is August 15, 2014.The journal seeks to maintain a short turnaround time, with the final version of the accepted papers being due by November 15, 2014. The topical issue will be published as issue 2 (2015).For additional information, please contact:Jörg-Tobias Kuhn (mailto:t.kuhn@uni-muenster.de)About the journalThe Zeitschrift für Psychologie, founded in 1890, is the oldest psychology journal in Europe and the second oldest in the world. One of the founding editors was Hermann Ebbinghaus. Since 2007 it is published in English and devoted to publishing topical issues that provide state-of-the-art reviews of current research in psychology.Guidelines for Article PreparationOnly English-language submissions can be considered.Contributions must be original (not published previously or currently under review for publication elsewhere).Review and orginal articles should not exceed 45,000 characters and spaces in length, including references, figures, and tables (allowances for figures and tables should be deducted on the basis of size – approximately 1,250 characters for a quarter-page figure/table).Other submission formats (research summaries, opinion pieces, etc.) may be considered, please contact the guest editor for details.Reference citations in the text and in the reference list should be in accordance with the principles set out in the Publication Manual of the American Psychological Association (6th ed.) – see also any recent issue of the journal.For detailed author guidelines, please see the journal’s website at www.hogrefe.com/journals/zfp/FiguresReferencesRelatedDetails Volume 222Issue 1January 2014ISSN: 2190-8370eISSN: 2151-2604 InformationZeitschrift für Psychologie (2014), 222, pp. 67-67 https://doi.org/10.1027/2151-2604/a000158.© 2014Hogrefe PublishingPDF download

Left fronto-parietal white matter correlates with individual differences in children's ability to solve additions and multiplications: A tractography study

Functional neuroimaging data have pointed to the activation of a fronto-parietal network during calculation tasks, the activity of which is modulated by arithmetic operation and arithmetical competence. As the cortical brain regions of this network are distant, it is crucial to investigate the white matter connections between them and to examine how these connections are related to different arithmetic operations and individual differences in arithmetical competence. By using diffusion tensor imaging (DTI) tractography in eighteen 12-year-olds, we tested whether white matter pathways connecting these distant regions were related to children's arithmetical competence and how this association was modulated by operation. For each child, we delineated the three subcomponents of the arcuate fasciculus, a bundle of pathways linking frontal and temporo-parietal regions that are commonly active during calculation tasks. Fractional anisotropy in the left anterior portion of the arcuate fasciculus was positively correlated with addition and multiplication, but not with subtraction and division, suggesting a specific role of this left anterior segment in the solution of those problems that are expected to be solved with fact retrieval. The observed correlation was not explained by age, intelligence and working memory. Follow-up control analyses using different types of reading measures revealed that the observed correlation only disappeared when measures that draw heavily on phonological processing, such as non-word reading, were controlled for, suggesting that the association between the left arcuate fasciculus-anterior and addition/multiplication reflects the involvement of phonological processing. These results are the first to demonstrate that individual differences in fronto-parietal white matter are associated with arithmetical competence in typically developing children of a very narrow age range and indicate that this association is modulated by arithmetic operation.

Fact Retrieval and Memory Consolidation for a Movement Sequence: Bidirectional Effects of 'Unrelated' Cognitive Tasks on Procedural Memory

The generation of long-term memory for motor skills can be modulated by subsequent motor experiences that interfere with the consolidation process. Recent studies suggest that even a non-motor task may adversely affect some aspects of motor sequence memory. Here we show that motor sequence memory can be either enhanced or reduced, by different cognitive tasks. Participants were trained in performing finger movement sequences. Fully explicit instructions about the target sequence were given before practice. The buildup of procedural knowledge was tested at three time-points: immediately before training (T1), after practice (T2), and 24 hours later (T3). Each participant performed the task on two separate occasions; training on a different movement sequence on each occasion. In one condition, interference, participants performed a non-motor task immediately after T2. Half the participants solved simple math problems and half performed a simple semantic judgment task. In the baseline condition there was no additional task. All participants improved significantly between T1 and T2 (within-session gains). In addition, in the baseline condition, performance significantly improved between T2 and T3 (delayed 'off-line' gains). Solving math problems significantly enhanced these delayed gains in motor performance, whereas performing semantic decisions significantly reduced delayed gains compared to baseline. Thus, procedural motor memory consolidation can be either enhanced or inhibited by subsequent cognitive experiences. These effects do not require explicit or implicit new learning. The retrieval of unrelated, non-motor, well established knowledge can modulate procedural memory.

Number Sense in Siblings of Children with Mathematical Learning Disabilities: A Longitudinal Study

Number sense, counting and logical thinking were assessed in 14 siblings of children with Mathematical Learning Disabilities (MLD) and in 41 age matched children without family members with MLD. The children were tested in kindergarten and followed up in grade 1. A 0-100 number line estimation paradigm with three formats (Arabic digits, dots and number) was used as a measure of number sense. Results reveal that siblings of children with MLD are less proficient in number line placements compared to non-siblings, with both groups having a logarithmic representation in kindergarten and grade 1. Siblings also differ from non siblings on procedural and conceptual counting knowledge and logical thinking in kindergarten. In addition, our findings suggest that nnumber line estimation in kindergarten is especially predictive for untimed procedural calculation performances in grade 1, whereas procedural counting knowledge is related to timed fact retrieval skills in grade 1. Our findings also reveal that MLD had a familial aggregation. Clinical siblings especially differ from non-clinical siblings on the estimation with Arabic numbers (in kindergarten and grade 1) and number words (in grade 1), pointing to the fact that especially symbolic number line estimation tasks on a 0-100 scale can be used as screeners for MLD. Implications for the understanding and diagnosis of MLD are discussed.

P 53. The functional relevance of the posterior parietal cortex in arithmetic learning and performance

Introduction The successful acquisition of mathematical competence is one of the key aims of institutional learning and has meanwhile also moved into the center of neuroscientific investigations. Recent research has revealed a potential key role of the left posterior parietal cortex (PPC), in particular the angular gyrus, in arithmetic learning and problem solving. Specifically, the acquisition and retrieval of arithmetic facts (such as multiplication facts) were found to be associated with activation increases in this brain region. However, it remained unclear, whether the function of the left PPC is causally related to arithmetic learning and problem solving. Moreover, there is first evidence that the application of anodal transcranial direct current stimulation (tDCS) supports the acquisition of new numerical symbols and improves performance in a subtraction task. However, it is unclear whether these findings can be generalized to more demanding arithmetic learning processes. Objectives In the present tDCS study, we addressed two research questions: First, is the activation of the left PPC causally related to the successful acquisition and retrieval of arithmetic facts? Second, can arithmetic learning or performance be enhanced by means of tDCS at the left PPC? Materials and methods The study comprised 80 adult students who participated in two test sessions. In the first test session (learning session) participants underwent a 45 min training of a small set of arithmetic facts (5 multiplication and 5 subtraction problems). One day later, in the second test session (performance session), participants were presented with the trained as well as untrained arithmetic problems for 30 min. The participants were divided into 4 experimental groups as depicted in Fig. 1. In anodal and cathodal conditions, tDCS of 1.5 mA was applied over the left PPC for 30 min during training and problem solving. Results Presently, the data of 53 participants have been collected and analyzed. The preliminary analyses revealed a more pronounced effect of tDCS in the performance compared to the learning session. Specifically, the group who received sham stimulation during learning and anodal stimulation during retrieval revealed the best performance in terms of response latencies and solution rates. In the learning session, anodal stimulation was slightly more beneficial for the learning progress than cathodal stimulation. Conclusions The preliminary data analysis provides first evidence for a causal functional role of the left PPC in the retrieval rather than in the acquisition of arithmetic facts. In addition, results suggest that the retrieval performance can be enhanced by means of brain stimulation, whereas neither anodal nor cathodal tDCS seem to have a strong beneficial effect during the learning of arithmetic facts. Overview of stimulation protocols. The break between learning and performance session was 24 h.

Mathematical Difficulties in Nonverbal Learning Disability or Co-Morbid Dyscalculia and Dyslexia

The main goal of the present study was to shed further light on the weaknesses of children with different profiles of mathematical difficulties, testing children with nonverbal learning disability (NLD), co-morbid dyscalculia and dyslexia (D&D), or typical development (TD). Sixteen children with NLD, 15 with D&D, and 16 with TD completed tasks derived from Butterworth (2003) and divided into: a capacity subscale (i.e., a number–dots comparison task, a number comparison task, and a dots comparison task); and an achievement subscale (i.e., mental calculations and arithmetical fact retrieval). Children with NLD were impaired in the dots comparison task, children with D&D in the mental calculation and arithmetical facts.

The contribution of general cognitive abilities and number abilities to different aspects of mathematics in children

This study examined the relative contributions of general cognitive abilities and number abilities to word problem solving, calculation, and arithmetic fact retrieval in a sample of 134 children aged 10 to 13years. The following tasks were administered: listening span, visual matrix span, verbal fluency, color naming, Raven’s Progressive Matrices, enumeration, number line estimation, and digit comparison. Hierarchical multiple regressions demonstrated that number abilities provided an independent contribution to fact retrieval and word problem solving. General cognitive abilities contributed to problem solving and calculation. All three number tasks accounted for a similar amount of variance in fact retrieval, whereas only the number line estimation task contributed unique variance in word problem solving. Verbal fluency and Raven’s matrices accounted for an equal amount of variance in problem solving and calculation. The current findings demonstrate, in accordance with Fuchs and colleagues’ developmental model of mathematical learning (Developmental Psychology, 2010, Vol. 46, pp. 1731–1746), that both number abilities and general cognitive abilities underlie 10- to 13-year-olds’ proficiency in problem solving, whereas only number abilities underlie arithmetic fact retrieval. Thus, the amount and type of cognitive contribution to arithmetic proficiency varies between the different aspects of arithmetic. Furthermore, how closely linked a specific aspect of arithmetic is to the whole number representation systems is not the only factor determining the amount and type of cognitive contribution in 10- to 13-year-olds. In addition, the mathematical complexity of the task appears to influence the amount and type of cognitive support.

Identifying Subtypes Among Children With Developmental Coordination Disorder and Mathematical Learning Disabilities, Using Model-Based Clustering

A relationship between motor and mathematical skills has been shown by previous research. However, the question of whether subtypes can be differentiated within developmental coordination disorder (DCD) and/or mathematical learning disability (MLD) remains unresolved. In a sample of children with and without DCD and/or MLD, a data-driven model-based clustering was used to identify subgroups of individuals with relatively homogeneous profiles on measures associated with motor and mathematical skills. One subgroup of children with motor problems was found based on motor variables. Based on mathematical variables, two clinical clusters were found: a subtype with number fact retrieval problems and a subtype with procedural calculation problems. Clustering with motor and mathematical skills revealed two clinical clusters: a cluster with number fact retrieval as well as procedural calculation problems and below average motor and visual-motor integration skills. A second cluster of children had only procedural calculation and visual-motor problems. Our results raise questions about the usefulness of placing children who have below average mathematical skills into a single diagnostic category. Furthermore, we inform ongoing debates about the overlap between DCD and MLD, as below average motor skills were found in both MLD subgroups, although a different motor profile is linked to a different mathematical profile.

Neural predictors of individual differences in response to math tutoring in primary-grade school children

Now, more than ever, the ability to acquire mathematical skills efficiently is critical for academic and professional success, yet little is known about the behavioral and neural mechanisms that drive some children to acquire these skills faster than others. Here we investigate the behavioral and neural predictors of individual differences in arithmetic skill acquisition in response to 8-wk of one-to-one math tutoring. Twenty-four children in grade 3 (ages 8-9 y), a critical period for acquisition of basic mathematical skills, underwent structural and resting-state functional MRI scans pretutoring. A significant shift in arithmetic problem-solving strategies from counting to fact retrieval was observed with tutoring. Notably, the speed and accuracy of arithmetic problem solving increased with tutoring, with some children improving significantly more than others. Next, we examined whether pretutoring behavioral and brain measures could predict individual differences in arithmetic performance improvements with tutoring. No behavioral measures, including intelligence quotient, working memory, or mathematical abilities, predicted performance improvements. In contrast, pretutoring hippocampal volume predicted performance improvements. Furthermore, pretutoring intrinsic functional connectivity of the hippocampus with dorsolateral and ventrolateral prefrontal cortices and the basal ganglia also predicted performance improvements. Our findings provide evidence that individual differences in morphometry and connectivity of brain regions associated with learning and memory, and not regions typically involved in arithmetic processing, are strong predictors of responsiveness to math tutoring in children. More generally, our study suggests that quantitative measures of brain structure and intrinsic brain organization can provide a more sensitive marker of skill acquisition than behavioral measures.

Modulating arithmetic fact retrieval: A single-blind, sham-controlled tDCS study with repeated fMRI measurements

Transcranial direct current stimulation (tDCS) is a non-invasive technique which has been used to modulate various cognitive functions in healthy participants as well as stroke patients. Despite the increasing number of tDCS studies, it still remains questionable whether tDCS is suitable for modulating performance in arithmetic tasks and whether a single tDCS session may cause brain activity changes that can be detected with functional magnetic resonance imaging (fMRI). We asked healthy participants to repeatedly solve simple multiplication tasks in three conditions: STIMULATION (anodal tDCS over the right angular gyrus, AG), SHAM (identical electrode set-up without stimulation), and CONTROL (no electrodes attached). Before and after tDCS, we used fMRI to examine changes in brain activity. Behavioural results indicate that a single session of tDCS did not modulate task performance significantly. However, fMRI measurements revealed that the neural correlates of multiplication were modified following a single session of anodal tDCS. In the bilateral AG, activity was significantly higher for multiplication problems rehearsed during active tDCS, as compared to multiplication problems rehearsed without tDCS or during sham tDCS. In sum, we present first neuro-functional evidence that tDCS modulates arithmetic processing. Implications of these findings for future tDCS studies and for the rehabilitation of acalculic patients with deficits in arithmetic fact retrieval are discussed.

Strategy Instruction and Maintenance of Basic Multiplication Facts through Digital Game Play

Formative instruction on multiplication primarily focuses on rote memorization. This leads to factual fluency, but also develops a narrow view of multiplication and hinders the development of conceptual understanding. Theory and research recommend the concurrent development of conceptual understanding and factual fluency during the initial stages of learning about multiplication. Woodward (2006) conducted a field study to investigate this instructional approach and found a significant difference between those who received instruction on multiplicative properties and timed-drills of multiplication facts on a conceptual measure than those who only spent time on timed drills. This study investigated the efficacy of integrating the same approach within a digital game. There was a significant decrease between pre- and post- measures of participants timed retrieval of multiplication facts, but no differences were found between conditions on pre- and post-measures of conceptual understanding. These findings indicate that special attention must be paid to intrinsic integration of instructional content in order to address conceptual understanding through digital game play.

Processing pathways in mental arithmetic--evidence from probabilistic fiber tracking.

Numerical cognition is a case of multi-modular and distributed cerebral processing. So far neither the anatomo-functional connections between the cortex areas involved nor their integration into established frameworks such as the differentiation between dorsal and ventral processing streams have been specified. The current study addressed this issue combining a re-analysis of previously published fMRI data with probabilistic fiber tracking data from an independent sample. We aimed at differentiating neural correlates and connectivity for relatively easy and more difficult addition problems in healthy adults and their association with either rather verbally mediated fact retrieval or magnitude manipulations, respectively. The present data suggest that magnitude- and fact retrieval-related processing seem to be subserved by two largely separate networks, both of them comprising dorsal and ventral connections. Importantly, these networks not only differ in localization of activation but also in the connections between the cortical areas involved. However, it has to be noted that even though seemingly distinct anatomically, these networks operate as a functionally integrated circuit for mental calculation as revealed by a parametric analysis of brain activation.

The N3 is sensitive to odd–even congruency information in arithmetic fact retrieval

This study investigated the behavioral and electrophysiological effects elicited by adults' simple addition verification when false answers agree or disagree with the odd-even status of the correct sum (parity congruency vs. parity incongruency), while they are near or far from correct (small vs. large splits). Event-related brain potentials were recorded from 18 students using a first-answer-then-problem paradigm. The results showed that odd-even congruency had a significant effect on the N3 latency with a small, but not a large split. Specifically, odd-even congruent answers with a small split elicited an N3 with a longer latency. Analyses of RT similarly indicated a bigger parity-congruency effect with small-split answers compared with large-split answers. This pattern parallels the corresponding effects on N3 and confirms that the N3 is sensitive to odd-even information in arithmetic fact retrieval and that there are clear links between the event-related brain potential pattern and behavioral effects.

Kanji Retrieval by Recursive Location of Elements Using HyperCard

There are a number of Japanese-English computer dictionaries. However, they do not provide the Japanese language student with an adequate means of retrieving kanji (Chinese characters). The study here outlines the implementation and evaluation of a computer-based kanji finder. The electronic kanji finder was implemented on a Macintosh using HyperCard, with regard to student needs, based on sound pedagogical and human factor principles. An evaluation of the implementation based on a comparison of the retrieval methods of a traditional dictionary was made, giving students access to both the computer-based dictionary and Nelson's paper kanji dictionary. The two retrieval methods were compared based on human factors criteria. The results of the comparison show that the electronic dictionary has several features which are better than the traditional paper dictionary. The findings go against previous research which show that electronic fact retrieval is worse than traditional retrieval using reference books (B. Shneiderman, 1987). The conclusion discusses some of the implications of the results for students of Japanese.

Why Mental Arithmetic Counts: Brain Activation during Single Digit Arithmetic Predicts High School Math Scores

Do individual differences in the brain mechanisms for arithmetic underlie variability in high school mathematical competence? Using functional magnetic resonance imaging, we correlated brain responses to single digit calculation with standard scores on the Preliminary Scholastic Aptitude Test (PSAT) math subtest in high school seniors. PSAT math scores, while controlling for PSAT Critical Reading scores, correlated positively with calculation activation in the left supramarginal gyrus and bilateral anterior cingulate cortex, brain regions known to be engaged during arithmetic fact retrieval. At the same time, greater activation in the right intraparietal sulcus during calculation, a region established to be involved in numerical quantity processing, was related to lower PSAT math scores. These data reveal that the relative engagement of brain mechanisms associated with procedural versus memory-based calculation of single-digit arithmetic problems is related to high school level mathematical competence, highlighting the fundamental role that mental arithmetic fluency plays in the acquisition of higher-level mathematical competence.

A neural disconnection hypothesis on impaired numerical processing

In recent years the number of fMRI studies aiming to pinpoint the neural substrates of number processing increased steadily (e.g., Dehaene et al., 2003; see Dehaene, 2009; Nieder and Dehaene, 2009 for reviews; see Arsalidou and Taylor, 2010 for a meta-analysis). Nevertheless, while considerable progress has been made, the neural correlates and cognitive mechanisms involved in the retrieval of arithmetic facts such as for multiplication (e.g., 2 × 3 = 6) or for addition (e.g., 2 + 3 = 5) fact knowledge is still a matter of debate. According to the currently most influential model of numerical cognition, the Triple Code Model by Dehaene and colleagues (Dehaene and Cohen, 1995, 1997; Dehaene et al., 2003) the retrieval of arithmetic fact knowledge is verbally mediated and subserved by a neural system relying on left-hemispheric perisylvian language areas and the angular gyrus. It is thus assumed that arithmetic facts are retrieved directly from long-term memory without the need of any magnitude manipulations. Instead, the verbally mediated representation format is claimed to trigger the retrieval of a word sequence from memory, which is associated with the AG (e.g., “two times three equals six”). Consistent with this prediction of the Triple Code Model, evidence from neuroimaging (e.g., Rickard et al., 2000; Delazer et al., 2003, 2005; Ischebeck et al., 2006, 2007; Grabner et al., 2009; Zamarian et al., 2009) as well as single-case studies with brain damaged patients (e.g., Hittmair-Delazer et al., 1994; Lee, 2000; Cohen et al., 2000) point to an involvement of the left angular gyrus (AG) in the retrieval of arithmetic facts. Compelling evidence for a functional involvement of the left AG comes from a training study by Delazer et al. (2003). In their study adults were trained on complex multiplication problems (e.g., 17 × 26 =) over 5 days. In a subsequent fMRI session, contrasts between trained and untrained problems revealed stronger activation in the left angular gyrus for the trained than the untrained set interpreted to indicate increased reliance on fact-retrieval to solve trained problems. In contrast, higher activation in frontal cortices and in the lPS for the untrained problems was suggested to reflect higher demands on executive functions and magnitude manipulations, respectively. In sum, these activation differences, in particular between the IPS and the angular gyrus for trained vs. untrained problems indicated a transition from quantity-based processing to direct fact retrieval (for similar results, see Ischebeck et al., 2007). However, there is also contradictory evidence in the literature. For instance, Van Harskamp et al. (2005) reported a patient with a severe multiplication fact-retrieval deficit, although his brain lesion did not involve the left AG. More particularly, a detailed review of single-case studies of patients, for whom neuroradiological images are available, revealed that also the lesion of patient BOO (Dehaene and Cohen, 1997), who presented with a selective impairment for multiplication, did not involve the AG, the supramarginal gyrus (SMG) or perisylvian language areas. This can be seen from the axial lesion drawings in Figure 3 (p. 226). Moreover, in patient ATH who also exhibited a severe impairment for rote multiplication (Cohen and Dehaene, 2000), the posterior part of the angular gyrus seemed spared. Additionally, Van Harskamp and Cipolotti (2001) reported a patient VP who presented with a selective impairment for simple multiplication problems and extended atrophy due to Alzheimer's disease, while the left angular gyrus was relatively spared. Finally, Zaunmueller et al. (2009) reported a patient with a severe multiplication fact-retrieval deficit although his brain lesion did neither involve the left AG or even left-hemispheric language areas. Thus, at a first glance these results do not seem to be in concordance with the notion that the left AG is critical for the retrieval of arithmetic (multiplication) facts nor that this structure in conjunction with temporal, frontal and subcortical areas is indeed critical for arithmetic (multiplication) fact knowledge as suggested by the Triple Code Model.

Reading the Literate Andean Past

Reading the Literate Andean Past Joanne Rappaport (bio) Into the Archive: Writing and Power in Colonial Peru. By Kathryn Burns. Durham, NC: Duke University Press. Pp. xv + 247. $79.95 cloth. $22.95 paper. ISBN: 9780822348573. Indians and Mestizos in the “Lettered City”: Reshaping Justice, Social Hierarchy, and Political Culture in Colonial Peru. By Alcira Dueñas. Boulder: University Press of Colorado, 2010. Pp. xii + 269. $70.00 cloth. ISBN: 9781607320180. In Search of an Inca: Identity and Utopia in the Andes. By Alberto Flores Galindo. Edited and translated by Carlos Aguirre, Charles F. Walker, and Willie Hiatt. New York: Cambridge University Press, 2010. Pp. xxix + 270. $75.00 cloth. $21.99 paper. ISBN: 9780521598613. The Lettered Mountain: A Peruvian Village’s Way with Writing. By Frank Salomon and Mercedes Niño-Murcia. Durham, NC: Duke University Press, 2011. Pp. xv + 368. $94.95 cloth. $25.95 paper. ISBN 9780822350279. Reading the Andean past involves a series of translations. First, like any other historical investigation, we must locate the documents and make sense of them from our own modern vantage point. But, on top of that, when writing the history of native Andeans, we must attempt to read documents from an indigenous perspective, despite the fact that oftentimes they were composed by members of a dominant culture who partially—sometimes completely—obscured the intentions, language, and arguments of the Andeans who participated in some way in their creation. This is an issue upon which many anthropologists, art historians, historians, and literary scholars have fruitfully reflected during the past few decades. In his masterful meditation on the process of writing history, Michel-Rolph Trouillot lists a series of key moments: “the moment of fact creation (the making of sources); the moment of fact assembly (the making of archives); the moment of fact retrieval (the making of narratives); and the moment of retrospective significance (the making of history in the final instance).”1 At each of these moments, the challenge of reading from an Andean vantage point intrudes. Native Andeans have at least partially influenced the sources available to us today, particularly in those instances when they controlled the process of writing documents in their localities. Their archives are different from those of the courts or notarial records of the dominant society because sometimes they include types of information that our society would not accumulate, such as rosters of participants in collective [End Page 213] tasks. Moreover, when native Andeans have had occasion to assemble their own evidence, the criteria by which they did so are unique. The facts retrieved in Andean narratives and the ways they are woven into history are also different from Western models. However, one essential lesson we have learned over the years is that the Andean voice in historical documents is, without question, hybrid. It is the product of transculturation, a process through which cultural referents are transformed by intercultural negotiation, misunderstanding, and reinterpretation by both Andeans and Europeans. It therefore becomes difficult to draw clear boundaries around these two groups in Ecuador, Peru, and Bolivia, particularly with the rise of mestizo populations in the colonial era and the appropriation of Andean symbols in the construction of nationalist discourses. It is, then, impossible to sustain the notion of a pristine and primordial Andean voice. We must instead look for a colonial, republican, or modern Andean voice in historical documentation, and we must question what is Andean, keeping in mind the historical contingencies in which Andean peoples have found themselves and the influences that they have had on others. This is particularly true in the area of history making, where, early on, native Andeans adopted European alphabetic literacy, literary and visual conventions, legal discourses, and theological arguments, and entered into sustained communication with nonnative interlocutors who, in turn, borrowed from Andean sources. This is not to say, of course, that Andean forms of inscription completely disappeared from the literate landscape; the khipu knot record, for instance, adapted to the colonial environment and was transformed by it, surviving in altered form to the present. But we can say that literate communication furnished a prime stage on which transculturation unfolded. The four volumes under review expand our understanding of Andean...

Shared deficits in space, time, and quantity processing in childhood genetic disorders

Shared deficits in space, time, and quantity processing in childhood genetic disorders