References of "Lochy, Aliette 50029933"
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See detailThe acquisition of arithmetic knowledge - an FMRI study.
Delazer, Margarete; Domahs, Frank; Lochy, Aliette UL et al

in Cortex; a journal devoted to the study of the nervous system and behavior (2004), 40(1), 166-7

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See detailNumber processing and basal ganglia dysfunction: a single case study.
Delazer, Margarete; Domahs, Frank; Lochy, Aliette UL et al

in Neuropsychologia (2004), 42(8), 1050-62

Numerical processing has never been investigated in a case of Fahr's disease (FD) and only rarely in cases of basal ganglia dysfunction. The study describes the cognitive decline of a pre-morbidly high ... [more ▼]

Numerical processing has never been investigated in a case of Fahr's disease (FD) and only rarely in cases of basal ganglia dysfunction. The study describes the cognitive decline of a pre-morbidly high-functioning patient (medical doctor) affected by FD and his difficulties in number processing. A MRI scan revealed bilateral calcifications in the basal ganglia and a brain PET showed a massive reduction of glucose metabolism in the basal ganglia and both frontal lobes, but no other brain abnormalities. The patient's cognitive deficits included impairments in problem solving, in cognitive set shifting and in mental flexibility, as well as in verbal memory. These deficits are attributed to the disruption of the dorsolateral prefrontal circuit involving the basal ganglia. In number processing, the patient showed a severe deficit in the retrieval of multiplication facts, deficits in all tasks of numerical problem solving and in the execution of complex procedures. Importantly, he also showed a dense deficit in conceptual knowledge, which concerned all test conditions and all operations. The findings confirm the predictions of the triple code model in so far, as a disruption of cortico-subcortical loops involving the basal-ganglia may lead to specific deficits in fact retrieval. However, no verbal deficit, as assumed in the triple code model and reported in similar cases, could be observed. The present findings further add to current knowledge on numerical processing, showing how fronto-executive dysfunction may disrupt conceptual understanding of arithmetic. This study shows that not only parietal lesions may lead to severe deficits in conceptual understanding, but that basal ganglia lesions leading to frontal dysfunction may have a devastating effect. [less ▲]

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See detailSpecific order impairment in arabic number writing: A case-study.
Lochy, Aliette UL; Domahs, Frank; Bartha, Lisa et al

in Cognitive neuropsychology (2004), 21(5), 555-75

The present study examines the transitory deficit in transcoding verbal to Arabic numbers in an aphasic patient, TM. She showed a mild syntactic impairment in syntactic comprehension of verbal numbers ... [more ▼]

The present study examines the transitory deficit in transcoding verbal to Arabic numbers in an aphasic patient, TM. She showed a mild syntactic impairment in syntactic comprehension of verbal numbers, with preserved performance in comprehension of Arabic numbers, in access to semantic representation, as well as in reading of Arabic numbers, but she committed 75% of errors when required to write numbers in the Arabic format to dictation. In conformity to the previous literature on transcoding deficits, the majority of her errors were syntactic (60%). However, most of them were unusual "order errors" (50%) in which lexical digits (e.g., 1 to 9) were written on the left and zeros on the right of the number, which contained in the majority of the cases the correct number of digits. A similar type of errors has been reported in only one previous case study (Delazer & Denes, 1998), but not specifically studied. We discuss hypotheses concerning its origins as stemming from a syntactic disorder within existing models of transcoding (McCloskey, Caramazza, & Basili, 1985; Power & Dal Martello, 1990). We also report kinematic assessment of the patient's handwriting before and after recovery. At time of the second examination, results show that her pattern of movement fluency parallels that of healthy subjects and supports a distinction between two types of zeros within Arabic numbers, in relation to the verbal code and the rules required to produce them. This paper thus also highlights the potential usefulness of using a digitising tablet in the study of transcoding deficits. [less ▲]

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See detailLearning complex arithmetic--an fMRI study.
Delazer, M.; Domahs, F.; Bartha, L. et al

in Brain research. Cognitive brain research (2003), 18(1), 76-88

Aim of the present functional magnet resonance imaging (fMRI) study was to detect modifications of cerebral activation patterns related to learning arithmetic. Thirteen right-handed subjects were ... [more ▼]

Aim of the present functional magnet resonance imaging (fMRI) study was to detect modifications of cerebral activation patterns related to learning arithmetic. Thirteen right-handed subjects were extensively trained on a set of 18 complex multiplication problems. In the following fMRI session, trained and untrained problems (closely matched for difficulty) were presented in blocked order alternating with a number matching task and a fact retrieval task. Importantly, left hemispheric activations were dominant in the two contrasts between untrained and trained condition, suggesting that learning processes in arithmetic are predominantly supported by the left hemisphere. Contrasting untrained versus trained condition, the left intraparietal sulcus showed significant activations, as well as the inferior parietal lobule. A further significant activation was found in the left inferior frontal gyrus. This activation may be accounted for by higher working memory demands in the untrained as compared to the trained condition. Contrasting trained versus untrained condition a significant focus of activation was found in the left angular gyrus. Following the triple-code model [Science 284 (1999) 970], the shift of activation within the parietal lobe from the intraparietal sulcus to the left angular gyrus suggests a modification from quantity-based processing to more automatic retrieval. The present study shows that the left angular gyrus is not only involved in arithmetic tasks requiring simple fact retrieval, but may show significant activations as a result of relatively short training of complex calculation. [less ▲]

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See detailTranscoding zeros within complex numerals.
Grana, Alessia; Lochy, Aliette UL; Girelli, Luisa et al

in Neuropsychologia (2003), 41(12), 1611-8

This paper describes a patient (LD) showing a selective syntactic deficit in the production of Arabic numerals. Unlike in previously reported cases, LD's syntactic difficulties result in deletions rather ... [more ▼]

This paper describes a patient (LD) showing a selective syntactic deficit in the production of Arabic numerals. Unlike in previously reported cases, LD's syntactic difficulties result in deletions rather than insertions of zeros, with a reduction of the number magnitude. The pattern of errors highlighted a distinction between "lexical zeros", i.e. the zeros in tens, that are semantically derived, and "syntactic zeros" that are syntactically produced as the result of specific production rules. In LD, only syntactic zeros were affected. Furthermore, the processing of numerals with final zeros was found to be easier than the processing of numerals with internal zeros. This pattern of errors is compatible with the lexical-semantic model of Power and Dal Martello. In this model, in fact, lexical zeros originate from a numerical concept, while syntactic zeros originate from a concatenation operation, plus an overwriting operation leaving one or more intermediary zeros. Thus, lexical zeros may be easier to manipulate than syntactic zeros that merely represent a null quantity associated to a specific power of 10. [less ▲]

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See detailWhen writing 0 (zero) is easier than writing O (o): a neuropsychological case study of agraphia.
Delazer, M.; Lochy, Aliette UL; Jenner, C. et al

in Neuropsychologia (2002), 40(12), 2167-77

Though a few case studies reported a dissociation between intact writing of Arabic and impaired writing of alphabetical script, a detailed experimental analysis of such a dissociation is still lacking. We ... [more ▼]

Though a few case studies reported a dissociation between intact writing of Arabic and impaired writing of alphabetical script, a detailed experimental analysis of such a dissociation is still lacking. We report a follow-up study of a patient with a parieto-occipital lesion who is affected by severe peripheral agraphia for letters, but not for Arabic digits. While letters in writing to dictation are frequently illegible, distorted, or consist in meaningless strokes, Arabic digits are well-formed and fluently produced. In a series of tasks, including copying of letters with tachistoscopic presentation and handwriting on a digitizing tablet, several processing levels are assessed in order to localize JS' functional writing impairment and to determine different processing routes for letters and for numbers. Overall, the results of the experimental investigation suggest a notation specific deficit in the activation of graphomotor patterns for letters, but not for digits. The study thus adds evidence to the so far reported dissociations between Arabic and alphabetical scripts. [less ▲]

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See detailVerbal structure of numerals and digits handwriting: new evidence from kinematics.
Lochy, Aliette UL; Pillon, Agnesa; Zesiger, Pascal et al

in The Quarterly journal of experimental psychology. A, Human experimental psychology (2002), 55(1), 263-88

Two experiments used a digitizing tablet to analyse the temporal, spatial, and kinematic characteristics of handwritten production of arabic numbers. They addressed a specific issue of the numerical ... [more ▼]

Two experiments used a digitizing tablet to analyse the temporal, spatial, and kinematic characteristics of handwritten production of arabic numbers. They addressed a specific issue of the numerical domain: Does the lexical and syntactic structure of verbal numerals influence the production of arabic numerals (Experiments 1 and 2), even after enforced semantic processing in a comparison task (Experiment 2)? Subjects had to write multi-digit arabic numerals (e.g., 1200) presented in two different verbal structures: a multiplicative one (e.g., teen-hundred, douze cents (twelve hundred)) or an additive one (e.g., thousand-unit-hundred, mille deux cents (one thousand two hundred)). Results show differences in the inter-digit jumps that reflect the influence of the structure of verbal numerals, even after the semantic task. This finding is discussed with regard to different models of number transcoding (McCloskey, Caramazza, & Basili, 1985; Power & Dal Martello, 1990, 1997). [less ▲]

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See detailThe odd-even effect in multiplication: parity rule or familiarity with even numbers?
Lochy, Aliette UL; Seron, X.; Delazer, M. et al

in Memory & cognition (2000), 28(3), 358-65

This study questions the evidence that a parity rule is used during the verification of multiplication. Previous studies reported that products are rejected faster when they violate the expected parity ... [more ▼]

This study questions the evidence that a parity rule is used during the verification of multiplication. Previous studies reported that products are rejected faster when they violate the expected parity, which was attributed to the use of a rule (Krueger, 1986; Lemaire & Fayol, 1995). This experiment tested an alternative explanation of this effect: the familiarity hypothesis. Fifty subjects participated in a verification task with contrasting types of problems (even x even, odd x odd, mixed). Some aspects of our results constitute evidence against the use of the parity rule: False even answers were rejected slowly, even when the two operands were odd. We suggest that the odd-even effect in verification of multiplication could not be due to the use of the parity rule, but rather to a familiarity with even numbers (three quarters of products are indeed even). [less ▲]

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