Klaus Willmes - Profile on Academia.edu (original) (raw)

Papers by Klaus Willmes

Research paper thumbnail of Therapy monitoring

Therapy monitoring

Abstracts of the 65th congress of the German Society of Neurology, 1992

Research paper thumbnail of P 24 Domain-general deficits after stroke lesions in the dorsal and ventral processing stream of the left hemisphere

P 24 Domain-general deficits after stroke lesions in the dorsal and ventral processing stream of the left hemisphere

Clinical Neurophysiology, May 1, 2022

Research paper thumbnail of Modality-specific preparatory influences on the flexibility of cognitive control in task switching

Journal of cognitive psychology, Feb 17, 2017

In the current study, we addressed modality-specificity of the flexibility of cognitive control. ... more In the current study, we addressed modality-specificity of the flexibility of cognitive control. We compared performance in single-task and mixed-tasks blocks between blocked auditory and visual stimuli assessing alternation costs (single vs. mixed). Mixed blocks comprised task switches only. The tasks consisted of numerical parity, magnitude, and distance judgments about numbers between one and nine without five. A cue indicated the relevant task. The cue-stimulus interval was varied (short vs. long interval) to examine preparation effects. The results indicated higher response times (RTs) and error rates (ERs) in mixed-vs. single-tasks blocks. The alternation costs in ERs were larger for auditory compared to visual stimulus presentation. Moreover, the reduction of RT alternation costs based on increased preparation time was more pronounced for the auditory modality compared to the visual modality. These results suggest a modality-specific influence on processes involved in maintaining and updating task sets in working memory.

Research paper thumbnail of Mathematische Leistungen und Akalkulien

Mathematische Leistungen und Akalkulien

Springer-Lehrbuch, 2003

Research paper thumbnail of A Minority pulls the sample mean: on the individual prevalence of robust group-level cognitive phenomena – the instance of the SNARC effect

The aim of cognitive psychology is to obtain insights into human cognition in general. For this p... more The aim of cognitive psychology is to obtain insights into human cognition in general. For this purpose, group-studies are typically conducted on representative samples, such that the results can be generalized to the population. Within this approach, individual differences are typically neglected or considered to be error variance. Little is known about the prevalence of group-level phenomena at the individual level. Such information is nevertheless important for claims about the universality of phenomena, as, in theory, significant effects at the group-level can be driven by a minority of participants. Here we used a uniform analysis of 18 existing data sets revealing a wellreplicated phenomenon in numerical cognition at the group level, the so-called SNARC (Spatial-Numerical Association of Response Codes) effect, to investigate its prevalence at the individual level. Three methods of analyzing the presence of this effect at the individual level were utilized: one psychometric and two bootstrapping methods. The results suggest that the group-level SNARC effect is driven by a minority of individuals (≤ 45%). Our findings are pertinent to an important theoretical question: whether group-level effects are reflecting general principles of cognition. We discuss advantages and drawbacks of the present methods and their utility in investigating the prevalence of other cognitive phenomena. We posit that testing the presence of robust group-level cognitive effects at the individual level, as well as ensuring their reliable measurement, is an important step towards integrating two traditionally separate experimental and correlational approaches of scientific psychology, as previously proposed by Cronbach in the 1950s.

Research paper thumbnail of Influences of cognitive control on number processing: New evidence from switching between two numerical tasks

Influences of cognitive control on number processing: New evidence from switching between two numerical tasks

Quarterly Journal of Experimental Psychology, Mar 7, 2023

A growing body of research suggests that basic numerical abilities such as number magnitude and n... more A growing body of research suggests that basic numerical abilities such as number magnitude and number parity processing are influenced by cognitive control. So far, however, evidence for number processing being influenced by cognitive control came primarily from observed adaptations to stimulus set characteristics (e.g., ratio or order of specific stimulus types) and switches between a numerical and non-numerical task. Complementing this previous research, the present study employed a task switching paradigm exclusively involving numerical tasks (i.e., magnitude comparisons and parity judgements) to examine how cognitive control processes influence number processing. Participants were presented with a single-digit number and had to either judge its parity or compare its magnitude with a standard of 5, depending on a preceding cue. Based on previous results, we expected the numerical distance effect and the spatial–numerical association of response codes (SNARC) effect to be modulated in switch trials requiring the exertion of cognitive control. Partly in line with our expectations, the numerical distance effect was reduced in switch trials. However, no modulation of the SNARC effect was observed. The results pattern suggests that number processing is influenced by cognitive control, depending on task requirements and the type of numerical information (i.e., numerical magnitude vs spatial association of numbers) that is processed. To reconcile the present and previous results, we propose an information prioritisation account, suggesting that cognitive control primarily influences the processing of the information type that requires the most explicit processing.

Research paper thumbnail of Methodological issues in neuropsychological assessment and rehabilitation

Methodological issues in neuropsychological assessment and rehabilitation

Psychology Press eBooks, 1997

K. Willmes, G. Deloche, Methodological Issues in Neuropsychological Assessment and Rehabilitation... more K. Willmes, G. Deloche, Methodological Issues in Neuropsychological Assessment and Rehabilitation. C. Bergego, P. Azouvi, G. Deloche, C. Samuel, A. Louis-Dreyfus, R. Kaschel, K. Willmes, Rehabilitation of Unilateral Neglect: A Controlled Multiple-Baseline-Across-Subjects Trial Using Computerised Training Procedures. E. Capitani, Normative Data and Neurospychological Assessment. Common Problems in Clinical Practice and Research. S. Carlomagno, P. van Eeckhout, V. Blasi, P. Bellin, Y. Samson, G. Deloche, The Impact of Functional Neuroimaging Methods on the Development of a Theory for Cognitive Remediation. R. Castro -Caldas, A. Reis, M. Guerreiro, Neuropsychological Aspects of Illiteracy. R. De Bleser, J. Cholewa, N. Stadie, S. Tabatabaie, Lemo, an Expert System for Single Case Assessment of Word Processing Impairments in Aphasic Patients. S. Della Sala, R.H. Logie, Impairments of Methodology and Theory in Cognitive Neuropsychology: A Case for Rehabilitation? G. Dellatolas, P. Tubert-Bitter, F. Curt, M. de Agostini, Evolution of Degree and Direction of Hand Preference in Children: Methodological and Theoretical Issues. S. Franklin, Designing Single Case Treatment Studies for Aphasic Patients. H. Guyard, V. Masson, R. Quiniou, E. Siou, Expert Knowledge for Aculculia Assessmnet and Rehabilitation. M.J. Watson, S. Horn, B.A. Wilson, A. Shiel, L. McLellan, The Application of a Paired Comparisons Technique to Identify Sequence of Recovery After Severe Head Injury. Contents Listing, Volume 7. Cumulative Author Index. Cumulative Subject Index.

Research paper thumbnail of Modern Interdisciplinary and Interhospital Acute Stroke Therapy—What Patients Think About It and What They Really Understand

Journal of stroke and cerebrovascular diseases, Oct 1, 2018

Background: Access to reperfusion therapies in patients with large vessel occluding acute ischemi... more Background: Access to reperfusion therapies in patients with large vessel occluding acute ischemic stroke demands process reorganization and optimization. Neurovascular networks are being built up to provide 24/7 endovascular stroke therapy service. In times of an increasingly complex stroke rescue chain little is known about patients' and their relatives' treatment awareness. Methods: All patients, who received any kind of acute reperfusion treatment between January and August 2017 in the university hospital Aachen, and their proxies, were included in the survey. Patients were either primarily or secondarily transferred. Results: For all questions regarding stroke treatment patients and their caregivers provided concurring answers. 40% of both patients and caregivers did not understand the treatment that was performed. Finally, patients who perceived on their own that stroke detection was delayed had significantly longer onset to door times than patients who did not have this impression. Conclusions: This study showed that patients' and proxies' answers correlated significantly. In case of patients' unavailability extrapolation of treatment satisfaction from answers by proxies might be permitted. High percentages of patients and caregivers do not understand relevant information, possibly due to limits of communication in an emergency setting or deficits in communication during the hospital stay. More emphasis should be laid on providing further information during the hospital stay. T a g g e d P

Research paper thumbnail of Fourth metting of the European Neurological Society 25–29 June 1994 Barcelona, Spain

Journal of Neurology, 1994

Cytomegalovirus (CMV) causes several neurological diseases in the late stages of AIDS, but their ... more Cytomegalovirus (CMV) causes several neurological diseases in the late stages of AIDS, but their ante-mortem diagnosis is problematic. Clinical criteria (defining a presumptive diagnosis) and polymerase chain reaction $4 (PCR) assay from cerebrospinal fluid (CSF) were blindly used to predict the involvement of CMV in neurological disorders of 164 consecutive AIDS patients undergoing a lumbar puncture. During the follow-up, a definite diagnosis based on viral culture of CSF, clinical outcome and/or CNS histology was allowed in 88 patients, 27 (16 %) of whom had a proven CMV related neurological disease. The concordance between the presumptive and definite diagnosis was of 60 %, inducing a moderate agreement kappa index of 0.40. In contrast, the sensitivity and specificity of PCR were respectively of 89 and 94 %, with a positive and negative predictive values of 86 and 95 %. Cytomegalovirus related neurological diseases appeared thus as a frequent complication of AIDS, and detection of viral DNA in CSF by means of PCR seems a reliable tool for their diagnosis, allowing its use for therapeutic decisions 20 99mTC-HMPAO LEUCOCYTE SCINTIGRAPHY IN DIAGNOSIS OF

Research paper thumbnail of Qualität des Trinkverhaltens bei Frühgeborenen

Qualität des Trinkverhaltens bei Frühgeborenen

Sprache-stimme-gehor, Jun 16, 2015

Research paper thumbnail of Einfluß morphologischer Veränderungen auf Durchblutung und Stoffwechsel bei zerebraler Mikroangiopathie

Einfluß morphologischer Veränderungen auf Durchblutung und Stoffwechsel bei zerebraler Mikroangiopathie

Nuklearmedizin-nuclear Medicine, 1995

Zusammenfassung51 Patienten mit zerebraler Mikroangiopathie wurden mittels Kernspintomographie, 1... more Zusammenfassung51 Patienten mit zerebraler Mikroangiopathie wurden mittels Kernspintomographie, 18FDG-PET und 99mTc-HMPAO-SPECT untersucht. Die genaue Zuordnung funktioneller zu den morphologischen Befunden wurde durch ein spezielles Kopf-halterungssystem für PET, SPECT- und KST-Untersuchungen hergestellt. Patienten mit weniger als vier lakunären Infarkten (LI) und ohne bis geringfügigen Deep White Matter Lesions (DWML) im KST wiesen keine signifikant veränderten Werte für rMRGIu und rCBF in grauer oder weißer Substanz auf im Vergleich zu Patienten mit vier oder mehr LI und ausgedehnten DWML. Eine semiquantitative Einteilung der Atrophie (A: keine bis geringfügige; B: mäßige bis schwere) erbrachte für B) im Vergleich zu A) signifikant erniedrigte rCBF- und rMRGIu-Werte in grauer und weißer Substanz. Somit sind bei Patienten mit ZMA nur die Hirnatrophie, jedoch nicht die charakteristischen LI und DWML mit einer meßbaren Erniedrigung von rCBF und rMRGIu korreliert.

Research paper thumbnail of Sucking patterns are not predictive of further feeding development in healthy preterm infants

Sucking patterns are not predictive of further feeding development in healthy preterm infants

Infant Behavior & Development, Feb 1, 2020

Preterm infants are at risk of experiencing difficulties in their feeding development. For a poss... more Preterm infants are at risk of experiencing difficulties in their feeding development. For a possible early identification of these, we examined the association between sucking patterns, assisted spoon feeding, and chewing skills in 40 healthy preterm infants, and the role of experience in the acquisition of these skills in a prospective longitudinal study. Sucking patterns were evaluated at 34, 37, and 44 weeks postmenstrual age (PMA), assisted spoon feeding was evaluated at 6, 9, and 12 months PMA, and chewing was evaluated at 9, 12, and 24 months PMA. Sucking patterns were rated using the Neonatal Oral Motor Assessment Scale, assisted spoon feeding was rated using the Observation List Spoon Feeding, and chewing was evaluated using the Mastication Observation and Evaluation Instrument. All infants showed progression in their oral motor skills during the study period, but not all demonstrated a stable progression of skills. Quality of sucking patterns was not associated with skill level achievement of assisted spoon feeding or with chewing. Length of experience in sucking was significantly associated with duration of supplemental tube feeding but not with the quality of the sucking pattern. Length of chewing experience was significantly associated with chewing abilities at 9 and 12 months PMA. No clinical characteristics were sufficiently predictive of oral motor skill development. Results show that sucking patterns are not predictive of subsequent feeding development in healthy preterm infants. The food consistency offered and the length of feeding experience influenced the acquisition and quality of oral motor skills differently.

Research paper thumbnail of Kompendium der akademischen Sprachtherapie und Logopädie

Kompendium der akademischen Sprachtherapie und Logopädie

Research paper thumbnail of Phonological picture–word interference in language mapping with transcranial magnetic stimulation: an objective approach for functional parcellation of Broca’s region

Brain Structure & Function, May 22, 2019

Functional imaging data suggest different regions for semantic, syntactic, and phonological proce... more Functional imaging data suggest different regions for semantic, syntactic, and phonological processing in an anterior-toposterior direction along the inferior frontal gyrus. Language mapping by use of neuro-navigated transcranial magnetic stimulation (TMS) is frequently applied in clinical research to identify language-related cortical regions. Recently, we proposed a high spatial resolution approach for more detailed language mapping of cortical sub-areas such as Broca's region. Here, we employed a phonological picture-word interference paradigm in healthy subjects to reveal functional specialization in Broca's region for phonological processing. The behavioral phonological priming effect is characterized by accelerated naming responses to target pictures accompanied by phonologically related auditory distractor words. We hypothesized that the inhibitory effects of TMS on language processing would reduce phonological priming only at stimulation sites involved in phonological processing. In active as compared to sham TMS, we found reduced phonological facilitation specifically at sites overlapping with the probabilistic cytoarchitectonic area 44. Our findings complemented functional imaging data by revealing structure-function relationship in Broca's region. The introduction of a reaction time based interference paradigm into TMS language mapping increases the objectivity of the method and allows to explore functional specificity with high temporal resolution. Findings may help to interpret results in clinical applications.

Research paper thumbnail of <title>Unsupervised time course analysis of functional magnetic resonance imaging (fMRI) using self-organizing maps (SOMs)</title>

Unsupervised time course analysis of functional magnetic resonance imaging (fMRI) using self-organizing maps (SOMs)

Proceedings of SPIE, May 20, 1999

ABSTRACT Functional Magnetic Resonance Imaging (fMRI) data of the brain includes activated parenc... more ABSTRACT Functional Magnetic Resonance Imaging (fMRI) data of the brain includes activated parenchymal voxels, corresponding to the paradigm performed, non-activated parenchymal voxels and background voxels. Statistical tests, e.g. using the general linear model approach of SPM or the Kolmogorov-Smirnov (KS) non-parametric statistic, are common &#39;supervised&#39; techniques to look for activation in functional brain MRI. Selection of voxel type by comparing the voxel time course with a model of the expected hemodynamic response function (HRF) from the task paradigm has proven to be difficult due to individual and spatial variance of the measured HRF. For the functional differentiation of brain voxels we introduce a method separating brain voxels based on their features in the time domain using a self-organizing map (SOM) neural network technique without modeling the HRF. Since activation measured by fMRI is related to magnetic susceptibility changes in venous blood which represents only 2 - 5% of brain matter, preprocessing is required to remove the majority of non- activated voxels which dominate learning instead of real activation patterns. Using the auto-correlation function one can select voxels which are candidates of being activated. Features of the time course of the selected voxels can be learned with the SOM. In the first step the SOM is trained by the voxels time course, fitting its neurons to the input. After learning, the neurons have adapted to the intrinsic features space of the voxel time courses. Using the trained SOM, voxel time courses are presented again, now labeled by the neuron having the smallest Euclidean distance to the presented voxel time course. The result of the labeling and the learned feature time course vectors are compared visually with the p-value map of the KS statistic. With the SOM map one can visually separate the voxels based on their features in the time domain into different functional task related classes.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Research paper thumbnail of The novel cognitive flexibility in aphasia therapy (CFAT): A combined treatment of aphasia and executive functions to improve communicative success

International Journal of Speech-Language Pathology, Apr 30, 2020

Purpose: Over and above language deficits, persons with aphasia can present with impairments in e... more Purpose: Over and above language deficits, persons with aphasia can present with impairments in executive functions, including deficits in cognitive flexibility. Cognitive flexibility constitutes the ability to update behaviour quickly and flexibly in a changing environment. Its deficits can restrict communicative ability, e. g. the ability to change a topic. To date, these deficits have been neglected in aphasia therapy, even though their consideration regarding language treatment may be beneficial for the persons affected. The present study aimed to evaluate whether aphasia therapy including cognitive flexibility leads to more improvement than conventional aphasia therapy. Method: A pilot group study with ten patients was conducted. The patients received both the novel Cognitive Flexibility in Aphasia Therapy (CFAT) and conventional aphasia therapy in a cross-over design. Each therapy method was delivered for 20 sessions within two weeks. An assessment battery was applied five times, including language skills, communicative ability and verbal/nonverbal cognitive flexibility. Result: Patients profited from CFAT regarding language skills, communicative ability and verbal cognitive flexibility. Furthermore, compared to conventional therapy, CFAT was more effective for verbal cognitive flexibility. Conclusion: This pilot study indicates that CFAT offers a novel opportunity to directly train cognitive flexibility in communicative settings and complements conventional therapy for optimal patient outcome.

Research paper thumbnail of Neuropsychological effects of occupational exposure to polychlorinated biphenyls

Neuropsychological effects of occupational exposure to polychlorinated biphenyls

Neurotoxicology, Dec 1, 2017

HighlightsA significant effect of PCBs on word fluency and sensorimotor processing is described.L... more HighlightsA significant effect of PCBs on word fluency and sensorimotor processing is described.Lower chlorinated PCBs (LPCBS) have a negative impact on word generation.LPCBs are associated with a time‐on‐task effect in word fluency.Higher chlorinated PCBs and dioxin‐like PCBs show adverse effects on motor function.PCB‐induced neurotoxic effects on dopamine and norepinephrine are suggested. &NA; In the context of a health surveillance program for former PCB‐exposed workers of a transformer and capacitor recycling company in Germany, their family members, employees of surrounding companies and area residents a broad range of cognitive functions covering attention, executive processing, reasoning, memory and motor performance was examined. The study aimed at identifying potential adverse effects of PCB load on cognitive functions. Detailed analysis of PCB burden of the participants revealed rather high correlations of lower and higher chlorinated as well as dioxin‐like PCBs. Nearly one half of the participants exhibited increased burden in all three PCB classes whereas only 33 out of 237 participants did not show any increased PCB burden. Thus, data analysis followed a two‐fold strategy: (1) Based on studies providing data on PCB exposure of the German general population the PCB burden of every participant was classified as normal (percentile rank PR <95) or increased (PR ≥95). Increased burden with respect to lower (LPCBs) and higher chlorinated (HPCBs) as well as dioxin‐like (dlPCBs) PCBs was assumed if a participant showed at least one congener surpassing the PR95 criterion for the respective congener class and (2) Overall plasma PCB level per congener class was used as measure of PCB load. In a multivariate approach using structural equation modelling and multiple regression analysis we found a significant impact of PCBs on word fluency and sensorimotor processing irrespective of the measure of PCB burden (PR95 criterion or overall plasma level). However, no effect of PCB burden on memory, attention, and cognitive flexibility could be demonstrated. Particularly, an increase of LPCBs was associated with an overall reduction of verbal fluency of letter and semantic word generation as well as word production based on a single or two alternating criteria. In addition, participants with increased burden of LPCBs exhibited a time‐on‐task effect in terms of a stronger decline of performance with increasing duration of the verbal fluency task. Moreover, we found adverse effects of HPCBs on Aiming and of dlPCBs on Line Tracking. Results are discussed in terms of (1) a decrease of cerebral dopamine (DA) with non‐coplanar PCBs resulting in an impact on fronto‐striatal cerebral structures subserving verbal fluency and motor processing, (2) a PCB‐induced reduction of norepinephrine leading to the time‐on‐task effect with verbal fluency, and (3) adverse effects of PCBs on dopaminergic receptors in the cerebellum resulting in impaired fine motor function.

Research paper thumbnail of Dissociating frontal and temporal correlates of phonological and semantic fluency in a large sample of left hemisphere stroke patients

NeuroImage: Clinical, 2019

Previous lesion studies suggest that semantic and phonological fluency are differentially subserv... more Previous lesion studies suggest that semantic and phonological fluency are differentially subserved by distinct brain regions in the left temporal and the left frontal cortex, respectively. However, as of yet, this often implied double dissociation has not been explicitly investigated due to mainly two reasons: (i) the lack of sufficiently large samples of brain-lesioned patients that underwent assessment of the two fluency variants and (ii) the lack of tools to assess interactions in factorial analyses of non-normally distributed behavioral data. In addition, previous studies did not control for task resource artifacts potentially introduced by the generally higher task difficulty of phonological compared to semantic fluency. We addressed these issues by task-difficulty adjusted assessment of semantic and phonological fluency in 85 chronic patients with ischemic stroke of the left middle cerebral artery. For classical region-based lesion-behavior mapping patients were grouped with respect to their primary lesion location. Building on the extension of the non-parametric Brunner-Munzel rank-order test to multi-factorial designs, ANOVA-type analyses revealed a significant two-way interaction for cue type (semantic vs. phonological) by lesion location (left temporal vs. left frontal vs. other as stroke control group). Subsequent contrast analyses further confirmed the proposed double dissociation by demonstrating that (i) compared to stroke controls, left temporal lesions led to significant impairments in semantic but not in phonological fluency, whereas left frontal lesions led to significant impairments in phonological but not in semantic fluency, and that (ii) patients with frontal lesions showed significantly poorer performance in phonological than in semantic fluency, whereas patients with temporal lesions showed significantly poorer performance in semantic than in phonological fluency. The anatomical specificity of these findings was further assessed in voxel-based lesion-behavior mapping analyses using the multi-factorial extension of the Brunner-Munzel test. Voxel-wise ANOVA-type analyses identified circumscribed parts of left inferior frontal gyrus and left superior and middle temporal gyrus that significantly double-dissociated with respect to their differential contribution to phonological and semantic fluency, respectively. Furthermore, a main effect of lesion with significant impairments in both fluency types was found in left inferior frontal regions adjacent to but not overlapping with those showing the differential effect for phonological fluency. The present study hence not only provides first explicit evidence for the anatomical double dissociation in verbal fluency at the group level but also clearly underlines that its formulation constitutes an oversimplification as parts of left frontal cortex appear to contribute to both semantic and phonological fluency.

Research paper thumbnail of Can Simple Numerical Magnitude Judgments be Influenced by Cross-Modal Selective Attention?

Can Simple Numerical Magnitude Judgments be Influenced by Cross-Modal Selective Attention?

PsycEXTRA Dataset, 2013

Research paper thumbnail of Cross-modal Selective Attention in Numerical and Spatial Task Switching

Cross-modal Selective Attention in Numerical and Spatial Task Switching

PsycEXTRA Dataset, 2013

Research paper thumbnail of Therapy monitoring

Therapy monitoring

Abstracts of the 65th congress of the German Society of Neurology, 1992

Research paper thumbnail of P 24 Domain-general deficits after stroke lesions in the dorsal and ventral processing stream of the left hemisphere

P 24 Domain-general deficits after stroke lesions in the dorsal and ventral processing stream of the left hemisphere

Clinical Neurophysiology, May 1, 2022

Research paper thumbnail of Modality-specific preparatory influences on the flexibility of cognitive control in task switching

Journal of cognitive psychology, Feb 17, 2017

In the current study, we addressed modality-specificity of the flexibility of cognitive control. ... more In the current study, we addressed modality-specificity of the flexibility of cognitive control. We compared performance in single-task and mixed-tasks blocks between blocked auditory and visual stimuli assessing alternation costs (single vs. mixed). Mixed blocks comprised task switches only. The tasks consisted of numerical parity, magnitude, and distance judgments about numbers between one and nine without five. A cue indicated the relevant task. The cue-stimulus interval was varied (short vs. long interval) to examine preparation effects. The results indicated higher response times (RTs) and error rates (ERs) in mixed-vs. single-tasks blocks. The alternation costs in ERs were larger for auditory compared to visual stimulus presentation. Moreover, the reduction of RT alternation costs based on increased preparation time was more pronounced for the auditory modality compared to the visual modality. These results suggest a modality-specific influence on processes involved in maintaining and updating task sets in working memory.

Research paper thumbnail of Mathematische Leistungen und Akalkulien

Mathematische Leistungen und Akalkulien

Springer-Lehrbuch, 2003

Research paper thumbnail of A Minority pulls the sample mean: on the individual prevalence of robust group-level cognitive phenomena – the instance of the SNARC effect

The aim of cognitive psychology is to obtain insights into human cognition in general. For this p... more The aim of cognitive psychology is to obtain insights into human cognition in general. For this purpose, group-studies are typically conducted on representative samples, such that the results can be generalized to the population. Within this approach, individual differences are typically neglected or considered to be error variance. Little is known about the prevalence of group-level phenomena at the individual level. Such information is nevertheless important for claims about the universality of phenomena, as, in theory, significant effects at the group-level can be driven by a minority of participants. Here we used a uniform analysis of 18 existing data sets revealing a wellreplicated phenomenon in numerical cognition at the group level, the so-called SNARC (Spatial-Numerical Association of Response Codes) effect, to investigate its prevalence at the individual level. Three methods of analyzing the presence of this effect at the individual level were utilized: one psychometric and two bootstrapping methods. The results suggest that the group-level SNARC effect is driven by a minority of individuals (≤ 45%). Our findings are pertinent to an important theoretical question: whether group-level effects are reflecting general principles of cognition. We discuss advantages and drawbacks of the present methods and their utility in investigating the prevalence of other cognitive phenomena. We posit that testing the presence of robust group-level cognitive effects at the individual level, as well as ensuring their reliable measurement, is an important step towards integrating two traditionally separate experimental and correlational approaches of scientific psychology, as previously proposed by Cronbach in the 1950s.

Research paper thumbnail of Influences of cognitive control on number processing: New evidence from switching between two numerical tasks

Influences of cognitive control on number processing: New evidence from switching between two numerical tasks

Quarterly Journal of Experimental Psychology, Mar 7, 2023

A growing body of research suggests that basic numerical abilities such as number magnitude and n... more A growing body of research suggests that basic numerical abilities such as number magnitude and number parity processing are influenced by cognitive control. So far, however, evidence for number processing being influenced by cognitive control came primarily from observed adaptations to stimulus set characteristics (e.g., ratio or order of specific stimulus types) and switches between a numerical and non-numerical task. Complementing this previous research, the present study employed a task switching paradigm exclusively involving numerical tasks (i.e., magnitude comparisons and parity judgements) to examine how cognitive control processes influence number processing. Participants were presented with a single-digit number and had to either judge its parity or compare its magnitude with a standard of 5, depending on a preceding cue. Based on previous results, we expected the numerical distance effect and the spatial–numerical association of response codes (SNARC) effect to be modulated in switch trials requiring the exertion of cognitive control. Partly in line with our expectations, the numerical distance effect was reduced in switch trials. However, no modulation of the SNARC effect was observed. The results pattern suggests that number processing is influenced by cognitive control, depending on task requirements and the type of numerical information (i.e., numerical magnitude vs spatial association of numbers) that is processed. To reconcile the present and previous results, we propose an information prioritisation account, suggesting that cognitive control primarily influences the processing of the information type that requires the most explicit processing.

Research paper thumbnail of Methodological issues in neuropsychological assessment and rehabilitation

Methodological issues in neuropsychological assessment and rehabilitation

Psychology Press eBooks, 1997

K. Willmes, G. Deloche, Methodological Issues in Neuropsychological Assessment and Rehabilitation... more K. Willmes, G. Deloche, Methodological Issues in Neuropsychological Assessment and Rehabilitation. C. Bergego, P. Azouvi, G. Deloche, C. Samuel, A. Louis-Dreyfus, R. Kaschel, K. Willmes, Rehabilitation of Unilateral Neglect: A Controlled Multiple-Baseline-Across-Subjects Trial Using Computerised Training Procedures. E. Capitani, Normative Data and Neurospychological Assessment. Common Problems in Clinical Practice and Research. S. Carlomagno, P. van Eeckhout, V. Blasi, P. Bellin, Y. Samson, G. Deloche, The Impact of Functional Neuroimaging Methods on the Development of a Theory for Cognitive Remediation. R. Castro -Caldas, A. Reis, M. Guerreiro, Neuropsychological Aspects of Illiteracy. R. De Bleser, J. Cholewa, N. Stadie, S. Tabatabaie, Lemo, an Expert System for Single Case Assessment of Word Processing Impairments in Aphasic Patients. S. Della Sala, R.H. Logie, Impairments of Methodology and Theory in Cognitive Neuropsychology: A Case for Rehabilitation? G. Dellatolas, P. Tubert-Bitter, F. Curt, M. de Agostini, Evolution of Degree and Direction of Hand Preference in Children: Methodological and Theoretical Issues. S. Franklin, Designing Single Case Treatment Studies for Aphasic Patients. H. Guyard, V. Masson, R. Quiniou, E. Siou, Expert Knowledge for Aculculia Assessmnet and Rehabilitation. M.J. Watson, S. Horn, B.A. Wilson, A. Shiel, L. McLellan, The Application of a Paired Comparisons Technique to Identify Sequence of Recovery After Severe Head Injury. Contents Listing, Volume 7. Cumulative Author Index. Cumulative Subject Index.

Research paper thumbnail of Modern Interdisciplinary and Interhospital Acute Stroke Therapy—What Patients Think About It and What They Really Understand

Journal of stroke and cerebrovascular diseases, Oct 1, 2018

Background: Access to reperfusion therapies in patients with large vessel occluding acute ischemi... more Background: Access to reperfusion therapies in patients with large vessel occluding acute ischemic stroke demands process reorganization and optimization. Neurovascular networks are being built up to provide 24/7 endovascular stroke therapy service. In times of an increasingly complex stroke rescue chain little is known about patients' and their relatives' treatment awareness. Methods: All patients, who received any kind of acute reperfusion treatment between January and August 2017 in the university hospital Aachen, and their proxies, were included in the survey. Patients were either primarily or secondarily transferred. Results: For all questions regarding stroke treatment patients and their caregivers provided concurring answers. 40% of both patients and caregivers did not understand the treatment that was performed. Finally, patients who perceived on their own that stroke detection was delayed had significantly longer onset to door times than patients who did not have this impression. Conclusions: This study showed that patients' and proxies' answers correlated significantly. In case of patients' unavailability extrapolation of treatment satisfaction from answers by proxies might be permitted. High percentages of patients and caregivers do not understand relevant information, possibly due to limits of communication in an emergency setting or deficits in communication during the hospital stay. More emphasis should be laid on providing further information during the hospital stay. T a g g e d P

Research paper thumbnail of Fourth metting of the European Neurological Society 25–29 June 1994 Barcelona, Spain

Journal of Neurology, 1994

Cytomegalovirus (CMV) causes several neurological diseases in the late stages of AIDS, but their ... more Cytomegalovirus (CMV) causes several neurological diseases in the late stages of AIDS, but their ante-mortem diagnosis is problematic. Clinical criteria (defining a presumptive diagnosis) and polymerase chain reaction $4 (PCR) assay from cerebrospinal fluid (CSF) were blindly used to predict the involvement of CMV in neurological disorders of 164 consecutive AIDS patients undergoing a lumbar puncture. During the follow-up, a definite diagnosis based on viral culture of CSF, clinical outcome and/or CNS histology was allowed in 88 patients, 27 (16 %) of whom had a proven CMV related neurological disease. The concordance between the presumptive and definite diagnosis was of 60 %, inducing a moderate agreement kappa index of 0.40. In contrast, the sensitivity and specificity of PCR were respectively of 89 and 94 %, with a positive and negative predictive values of 86 and 95 %. Cytomegalovirus related neurological diseases appeared thus as a frequent complication of AIDS, and detection of viral DNA in CSF by means of PCR seems a reliable tool for their diagnosis, allowing its use for therapeutic decisions 20 99mTC-HMPAO LEUCOCYTE SCINTIGRAPHY IN DIAGNOSIS OF

Research paper thumbnail of Qualität des Trinkverhaltens bei Frühgeborenen

Qualität des Trinkverhaltens bei Frühgeborenen

Sprache-stimme-gehor, Jun 16, 2015

Research paper thumbnail of Einfluß morphologischer Veränderungen auf Durchblutung und Stoffwechsel bei zerebraler Mikroangiopathie

Einfluß morphologischer Veränderungen auf Durchblutung und Stoffwechsel bei zerebraler Mikroangiopathie

Nuklearmedizin-nuclear Medicine, 1995

Zusammenfassung51 Patienten mit zerebraler Mikroangiopathie wurden mittels Kernspintomographie, 1... more Zusammenfassung51 Patienten mit zerebraler Mikroangiopathie wurden mittels Kernspintomographie, 18FDG-PET und 99mTc-HMPAO-SPECT untersucht. Die genaue Zuordnung funktioneller zu den morphologischen Befunden wurde durch ein spezielles Kopf-halterungssystem für PET, SPECT- und KST-Untersuchungen hergestellt. Patienten mit weniger als vier lakunären Infarkten (LI) und ohne bis geringfügigen Deep White Matter Lesions (DWML) im KST wiesen keine signifikant veränderten Werte für rMRGIu und rCBF in grauer oder weißer Substanz auf im Vergleich zu Patienten mit vier oder mehr LI und ausgedehnten DWML. Eine semiquantitative Einteilung der Atrophie (A: keine bis geringfügige; B: mäßige bis schwere) erbrachte für B) im Vergleich zu A) signifikant erniedrigte rCBF- und rMRGIu-Werte in grauer und weißer Substanz. Somit sind bei Patienten mit ZMA nur die Hirnatrophie, jedoch nicht die charakteristischen LI und DWML mit einer meßbaren Erniedrigung von rCBF und rMRGIu korreliert.

Research paper thumbnail of Sucking patterns are not predictive of further feeding development in healthy preterm infants

Sucking patterns are not predictive of further feeding development in healthy preterm infants

Infant Behavior & Development, Feb 1, 2020

Preterm infants are at risk of experiencing difficulties in their feeding development. For a poss... more Preterm infants are at risk of experiencing difficulties in their feeding development. For a possible early identification of these, we examined the association between sucking patterns, assisted spoon feeding, and chewing skills in 40 healthy preterm infants, and the role of experience in the acquisition of these skills in a prospective longitudinal study. Sucking patterns were evaluated at 34, 37, and 44 weeks postmenstrual age (PMA), assisted spoon feeding was evaluated at 6, 9, and 12 months PMA, and chewing was evaluated at 9, 12, and 24 months PMA. Sucking patterns were rated using the Neonatal Oral Motor Assessment Scale, assisted spoon feeding was rated using the Observation List Spoon Feeding, and chewing was evaluated using the Mastication Observation and Evaluation Instrument. All infants showed progression in their oral motor skills during the study period, but not all demonstrated a stable progression of skills. Quality of sucking patterns was not associated with skill level achievement of assisted spoon feeding or with chewing. Length of experience in sucking was significantly associated with duration of supplemental tube feeding but not with the quality of the sucking pattern. Length of chewing experience was significantly associated with chewing abilities at 9 and 12 months PMA. No clinical characteristics were sufficiently predictive of oral motor skill development. Results show that sucking patterns are not predictive of subsequent feeding development in healthy preterm infants. The food consistency offered and the length of feeding experience influenced the acquisition and quality of oral motor skills differently.

Research paper thumbnail of Kompendium der akademischen Sprachtherapie und Logopädie

Kompendium der akademischen Sprachtherapie und Logopädie

Research paper thumbnail of Phonological picture–word interference in language mapping with transcranial magnetic stimulation: an objective approach for functional parcellation of Broca’s region

Brain Structure & Function, May 22, 2019

Functional imaging data suggest different regions for semantic, syntactic, and phonological proce... more Functional imaging data suggest different regions for semantic, syntactic, and phonological processing in an anterior-toposterior direction along the inferior frontal gyrus. Language mapping by use of neuro-navigated transcranial magnetic stimulation (TMS) is frequently applied in clinical research to identify language-related cortical regions. Recently, we proposed a high spatial resolution approach for more detailed language mapping of cortical sub-areas such as Broca's region. Here, we employed a phonological picture-word interference paradigm in healthy subjects to reveal functional specialization in Broca's region for phonological processing. The behavioral phonological priming effect is characterized by accelerated naming responses to target pictures accompanied by phonologically related auditory distractor words. We hypothesized that the inhibitory effects of TMS on language processing would reduce phonological priming only at stimulation sites involved in phonological processing. In active as compared to sham TMS, we found reduced phonological facilitation specifically at sites overlapping with the probabilistic cytoarchitectonic area 44. Our findings complemented functional imaging data by revealing structure-function relationship in Broca's region. The introduction of a reaction time based interference paradigm into TMS language mapping increases the objectivity of the method and allows to explore functional specificity with high temporal resolution. Findings may help to interpret results in clinical applications.

Research paper thumbnail of <title>Unsupervised time course analysis of functional magnetic resonance imaging (fMRI) using self-organizing maps (SOMs)</title>

Unsupervised time course analysis of functional magnetic resonance imaging (fMRI) using self-organizing maps (SOMs)

Proceedings of SPIE, May 20, 1999

ABSTRACT Functional Magnetic Resonance Imaging (fMRI) data of the brain includes activated parenc... more ABSTRACT Functional Magnetic Resonance Imaging (fMRI) data of the brain includes activated parenchymal voxels, corresponding to the paradigm performed, non-activated parenchymal voxels and background voxels. Statistical tests, e.g. using the general linear model approach of SPM or the Kolmogorov-Smirnov (KS) non-parametric statistic, are common &#39;supervised&#39; techniques to look for activation in functional brain MRI. Selection of voxel type by comparing the voxel time course with a model of the expected hemodynamic response function (HRF) from the task paradigm has proven to be difficult due to individual and spatial variance of the measured HRF. For the functional differentiation of brain voxels we introduce a method separating brain voxels based on their features in the time domain using a self-organizing map (SOM) neural network technique without modeling the HRF. Since activation measured by fMRI is related to magnetic susceptibility changes in venous blood which represents only 2 - 5% of brain matter, preprocessing is required to remove the majority of non- activated voxels which dominate learning instead of real activation patterns. Using the auto-correlation function one can select voxels which are candidates of being activated. Features of the time course of the selected voxels can be learned with the SOM. In the first step the SOM is trained by the voxels time course, fitting its neurons to the input. After learning, the neurons have adapted to the intrinsic features space of the voxel time courses. Using the trained SOM, voxel time courses are presented again, now labeled by the neuron having the smallest Euclidean distance to the presented voxel time course. The result of the labeling and the learned feature time course vectors are compared visually with the p-value map of the KS statistic. With the SOM map one can visually separate the voxels based on their features in the time domain into different functional task related classes.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Research paper thumbnail of The novel cognitive flexibility in aphasia therapy (CFAT): A combined treatment of aphasia and executive functions to improve communicative success

International Journal of Speech-Language Pathology, Apr 30, 2020

Purpose: Over and above language deficits, persons with aphasia can present with impairments in e... more Purpose: Over and above language deficits, persons with aphasia can present with impairments in executive functions, including deficits in cognitive flexibility. Cognitive flexibility constitutes the ability to update behaviour quickly and flexibly in a changing environment. Its deficits can restrict communicative ability, e. g. the ability to change a topic. To date, these deficits have been neglected in aphasia therapy, even though their consideration regarding language treatment may be beneficial for the persons affected. The present study aimed to evaluate whether aphasia therapy including cognitive flexibility leads to more improvement than conventional aphasia therapy. Method: A pilot group study with ten patients was conducted. The patients received both the novel Cognitive Flexibility in Aphasia Therapy (CFAT) and conventional aphasia therapy in a cross-over design. Each therapy method was delivered for 20 sessions within two weeks. An assessment battery was applied five times, including language skills, communicative ability and verbal/nonverbal cognitive flexibility. Result: Patients profited from CFAT regarding language skills, communicative ability and verbal cognitive flexibility. Furthermore, compared to conventional therapy, CFAT was more effective for verbal cognitive flexibility. Conclusion: This pilot study indicates that CFAT offers a novel opportunity to directly train cognitive flexibility in communicative settings and complements conventional therapy for optimal patient outcome.

Research paper thumbnail of Neuropsychological effects of occupational exposure to polychlorinated biphenyls

Neuropsychological effects of occupational exposure to polychlorinated biphenyls

Neurotoxicology, Dec 1, 2017

HighlightsA significant effect of PCBs on word fluency and sensorimotor processing is described.L... more HighlightsA significant effect of PCBs on word fluency and sensorimotor processing is described.Lower chlorinated PCBs (LPCBS) have a negative impact on word generation.LPCBs are associated with a time‐on‐task effect in word fluency.Higher chlorinated PCBs and dioxin‐like PCBs show adverse effects on motor function.PCB‐induced neurotoxic effects on dopamine and norepinephrine are suggested. &NA; In the context of a health surveillance program for former PCB‐exposed workers of a transformer and capacitor recycling company in Germany, their family members, employees of surrounding companies and area residents a broad range of cognitive functions covering attention, executive processing, reasoning, memory and motor performance was examined. The study aimed at identifying potential adverse effects of PCB load on cognitive functions. Detailed analysis of PCB burden of the participants revealed rather high correlations of lower and higher chlorinated as well as dioxin‐like PCBs. Nearly one half of the participants exhibited increased burden in all three PCB classes whereas only 33 out of 237 participants did not show any increased PCB burden. Thus, data analysis followed a two‐fold strategy: (1) Based on studies providing data on PCB exposure of the German general population the PCB burden of every participant was classified as normal (percentile rank PR <95) or increased (PR ≥95). Increased burden with respect to lower (LPCBs) and higher chlorinated (HPCBs) as well as dioxin‐like (dlPCBs) PCBs was assumed if a participant showed at least one congener surpassing the PR95 criterion for the respective congener class and (2) Overall plasma PCB level per congener class was used as measure of PCB load. In a multivariate approach using structural equation modelling and multiple regression analysis we found a significant impact of PCBs on word fluency and sensorimotor processing irrespective of the measure of PCB burden (PR95 criterion or overall plasma level). However, no effect of PCB burden on memory, attention, and cognitive flexibility could be demonstrated. Particularly, an increase of LPCBs was associated with an overall reduction of verbal fluency of letter and semantic word generation as well as word production based on a single or two alternating criteria. In addition, participants with increased burden of LPCBs exhibited a time‐on‐task effect in terms of a stronger decline of performance with increasing duration of the verbal fluency task. Moreover, we found adverse effects of HPCBs on Aiming and of dlPCBs on Line Tracking. Results are discussed in terms of (1) a decrease of cerebral dopamine (DA) with non‐coplanar PCBs resulting in an impact on fronto‐striatal cerebral structures subserving verbal fluency and motor processing, (2) a PCB‐induced reduction of norepinephrine leading to the time‐on‐task effect with verbal fluency, and (3) adverse effects of PCBs on dopaminergic receptors in the cerebellum resulting in impaired fine motor function.

Research paper thumbnail of Dissociating frontal and temporal correlates of phonological and semantic fluency in a large sample of left hemisphere stroke patients

NeuroImage: Clinical, 2019

Previous lesion studies suggest that semantic and phonological fluency are differentially subserv... more Previous lesion studies suggest that semantic and phonological fluency are differentially subserved by distinct brain regions in the left temporal and the left frontal cortex, respectively. However, as of yet, this often implied double dissociation has not been explicitly investigated due to mainly two reasons: (i) the lack of sufficiently large samples of brain-lesioned patients that underwent assessment of the two fluency variants and (ii) the lack of tools to assess interactions in factorial analyses of non-normally distributed behavioral data. In addition, previous studies did not control for task resource artifacts potentially introduced by the generally higher task difficulty of phonological compared to semantic fluency. We addressed these issues by task-difficulty adjusted assessment of semantic and phonological fluency in 85 chronic patients with ischemic stroke of the left middle cerebral artery. For classical region-based lesion-behavior mapping patients were grouped with respect to their primary lesion location. Building on the extension of the non-parametric Brunner-Munzel rank-order test to multi-factorial designs, ANOVA-type analyses revealed a significant two-way interaction for cue type (semantic vs. phonological) by lesion location (left temporal vs. left frontal vs. other as stroke control group). Subsequent contrast analyses further confirmed the proposed double dissociation by demonstrating that (i) compared to stroke controls, left temporal lesions led to significant impairments in semantic but not in phonological fluency, whereas left frontal lesions led to significant impairments in phonological but not in semantic fluency, and that (ii) patients with frontal lesions showed significantly poorer performance in phonological than in semantic fluency, whereas patients with temporal lesions showed significantly poorer performance in semantic than in phonological fluency. The anatomical specificity of these findings was further assessed in voxel-based lesion-behavior mapping analyses using the multi-factorial extension of the Brunner-Munzel test. Voxel-wise ANOVA-type analyses identified circumscribed parts of left inferior frontal gyrus and left superior and middle temporal gyrus that significantly double-dissociated with respect to their differential contribution to phonological and semantic fluency, respectively. Furthermore, a main effect of lesion with significant impairments in both fluency types was found in left inferior frontal regions adjacent to but not overlapping with those showing the differential effect for phonological fluency. The present study hence not only provides first explicit evidence for the anatomical double dissociation in verbal fluency at the group level but also clearly underlines that its formulation constitutes an oversimplification as parts of left frontal cortex appear to contribute to both semantic and phonological fluency.

Research paper thumbnail of Can Simple Numerical Magnitude Judgments be Influenced by Cross-Modal Selective Attention?

Can Simple Numerical Magnitude Judgments be Influenced by Cross-Modal Selective Attention?

PsycEXTRA Dataset, 2013

Research paper thumbnail of Cross-modal Selective Attention in Numerical and Spatial Task Switching

Cross-modal Selective Attention in Numerical and Spatial Task Switching

PsycEXTRA Dataset, 2013