Quantifying the Confidence in fMRI-Based Language Lateralisation Through Laterality Index Deconstruction

Wegrzyn M, Mertens M, Bien C, Woermann FG, Labudda K. Quantifying the Confidence in fMRI-Based Language Lateralisation Through Laterality Index Deconstruction. Frontiers in Neurology. 2019;10: 655.In epilepsy patients, language lateralisation is an important part of the presurgical diagnostic process. Using task-based fMRI, language lateralisation can be determined by visual inspection of activity patterns or by quantifying the difference in left- and right-hemisphere activity using variations of a basic formula [(L-R)/(L+R)]. However, the values of this laterality index (LI) depend on the choice of activity thresholds and regions of interest. The diagnostic utility of the U also depends on how its continuous values are translated into categorical decisions about a patient's language lateralisation. Here, we analysed fMRI data from 712 epilepsy patients who performed a verbal fluency task. Each fMRI data set was evaluated by a trained human rater as depicting left-sided, right-sided, or bilateral lateralisation or as being inconclusive. We used data-driven methods to define the activity thresholds and regions of interest used for LI computation and to define a classification scheme that allowed us to translate the U values into categorical decisions. By deconstructing the LI into measures of laterality (L-R) and strength (L+R), we also modelled the relationship between activation strength and conclusiveness of a data set. In a held-out data set, predictions reached 91% correct when using only conclusive data and 82% when inconclusive data were included. Although only trained on human evaluations of fMRIs, the approach generalised to the prediction of language Wada test results, allowing for significant above-chance accuracies. Compared against different existing methods of U-computation, our approach improved the identification and exclusion of inconclusive cases and ensured that decisions for the remaining data could be made with consistently high accuracies. We discuss how this approach can support clinicians in assessing fMRI data on a single-case level, deciding whether lateralisation can be determined with sufficient certainty or whether additional information is needed

The hidden identity of faces. A case of lifelong prosopagnosia

Wegrzyn M, Garlichs A, Heß RWK, Woermann FG, Labudda K. The hidden identity of faces. A case of lifelong prosopagnosia. BMC Psychology. 2019;7(1): 4.Background Not being able to recognize a person’s face is a highly debilitating condition from which people with developmental prosopagnosia (DP) suffer their entire life. Here we describe the case of J, a 30 year old woman who reports being unable to recognize her parents, her husband, or herself in the mirror. Case presentation We set out to assess the severity of J’s prosopagnosia using tests with unfamiliar as well as familiar faces and investigated whether impaired configural processing explains her deficit. To assess the specificity of the impairment, we tested J’s performance when evaluating emotions, intentions, and the attractiveness and likability of faces. Detailed testing revealed typical brain activity patterns for faces and normal object recognition skills, and no evidence of any brain injury. However, compared to a group of matched controls, J showed severe deficits in learning new faces, and in recognizing familiar faces when only inner features were available. Her recognition of uncropped faces with blurred features was within the normal range, indicating preserved configural processing when peripheral features are available. J was also unimpaired when evaluating intentions and emotions in faces. In line with healthy controls, J rated more average faces as more attractive. However, she was the only one to rate them as less likable, indicating a preference for more distinctive and easier to recognize faces. Conclusions Taken together, the results illustrate both the severity and the specificity of DP in a single case. While DP is a heterogeneous disorder, an inability to integrate the inner features of the face into a whole might be the best explanation for the difficulties many individuals with prosopagnosia experience

Thought experiment: Decoding cognitive processes from the fMRI data of one individual

Wegrzyn M, Aust J, Barnstorf L, et al. Thought experiment: Decoding cognitive processes from the fMRI data of one individual. PLOS ONE. 2018;13(9): e0204338.Cognitive processes, such as the generation of language, can be mapped onto the brain using fMRI. These maps can in turn be used for decoding the respective processes from the brain activation patterns. Given individual variations in brain anatomy and organization, analyzes on the level of the single person are important to improve our understanding of how cognitive processes correspond to patterns of brain activity. They also allow to advance clinical applications of fMRI, because in the clinical setting making diagnoses for single cases is imperative. In the present study, we used mental imagery tasks to investigate language production, motor functions, visuo-spatial memory, face processing, and resting-state activity in a single person. Analysis methods were based on similarity metrics, including correlations between training and test data, as well as correlations with maps from the NeuroSynth meta-analysis. The goal was to make accurate predictions regarding the cognitive domain (e.g. language) and the specific content (e.g. animal names) of single 30-second blocks. Four teams used the dataset, each blinded regarding the true labels of the test data. Results showed that the similarity metrics allowed to reach the highest degrees of accuracy when predicting the cognitive domain of a block. Overall, 23 of the 25 test blocks could be correctly predicted by three of the four teams. Excluding the unspecific rest condition, up to 10 out of 20 blocks could be successfully decoded regarding their specific content. The study shows how the information contained in a single fMRI session and in each of its single blocks can allow to draw inferences about the cognitive processes an individual engaged in. Simple methods like correlations between blocks of fMRI data can serve as highly reliable approaches for cognitive decoding. We discuss the implications of our results in the context of clinical fMRI applications, with a focus on how decoding can support functional localization

Profil und Verlauf kognitiver Störungen bei Patienten mit alkoholbedingtem Korsakowsyndrom und alkoholabhängigen Personen ohne amnestisches Syndrom

Labudda K, Matthias B. Profil und Verlauf kognitiver Störungen bei Patienten mit alkoholbedingtem Korsakowsyndrom und alkoholabhängigen Personen ohne amnestisches Syndrom. In: Fachverband S, ed. Wirksame Therapie? Wissenschaftlich fundierte Suchtbehandlung. Neuland; 2007: 266-275

Neuropsychological correlates of decision-making in ambiguous and risky situations

Brand M, Labudda K, Markowitsch HJ. Neuropsychological correlates of decision-making in ambiguous and risky situations. NEURAL NETWORKS. 2006;19(8):1266-1276.Decision-making situations in real life differ regarding their explicitness of positive and negative consequences as well as regarding the directness of probabilities for reward and punishment. In neuropsychological research, decisions under ambiguity and decisions under risk are differentiated. To assess decisions under ambiguity the Iowa Gambling Task (IGT) is one of the most frequently used tasks. Decisions under risk can be measured by a task that offers explicit rules for gains and losses and stable winning probabilities, as the Game of Dice Task (GDT) does. In this contribution we firstly summarize studies that investigated decision-making in various groups of patients using the IGT or the GDT. We also propose a new model of decision-making in risky situations and describe differences between decisions under ambiguity and decisions under risk from a theoretical and clinical perspective. (c) 2006 Elsevier Ltd. All rights reserved

Interictal dysphoric disorder: Further doubts about its epilepsy-specificity and its independency from common psychiatric disorders

Labudda K, Illies D, Bien C, Neuner F. Interictal dysphoric disorder: Further doubts about its epilepsy-specificity and its independency from common psychiatric disorders. EPILEPSY RESEARCH. 2018;141:13-18.Purpose: The interictal dysphoric disorder (IDD) is a proposed epilepsy-specific psychiatric condition characterized by a conglomerate of symptoms such as depression, irritability, euphoria, and anxiety. However, there are doubts about IDD as an independent entity and about its presumed epilepsy-specific nature. Methods: Here, we investigated the association between psychiatric disorders and IDD in 120 patients with epilepsy, also analyzing potential associations between IDD symptoms and epilepsy-related variables. To test the epilepsy-specificity of IDD, we also studied IDD rates in 28 patients with pure psychogenic non-epileptic seizures. For the assessment of psychopathology, we used a structured clinical interview to determine the presence and nature of Axis I disorders and clinical questionnaires to assess psychopathological symptoms (anxiety, depression and severity of global distress). In accordance with most previous studies, we used the Interictal Dysphoric Disorder Inventory to assess IDD symptoms. Results: In our epilepsy group, we observed an IDD in 33% (42 of 120) of the patients. We diagnosed IDD in 39% (11 of 28) of the patients with psychogenic non-epileptic seizures without epilepsy. The majority of the patients with epilepsy with IDD have or had a psychiatric disorder (33 with a current, 6 with a past Axis I diagnosis). Patients with epilepsy with IDD had higher scores on all psychopathology questionnaires compared to the epilepsy patients without IDD. Conclusion: Our findings suggest that IDD is not epilepsy-specific in nature, but occurs with the same frequency and the same pattern of symptoms in a purely psychiatric sample. We found a large overlap of IDD and common psychiatric comorbidities, mainly depression and anxiety disorders. This result calls the presumed nosological independency of IDD into question

Postepileptic seizure PTSD: A very rare psychiatric condition in patients with epilepsy

Labudda K, Illies D, Bien C, Neuner F. Postepileptic seizure PTSD: A very rare psychiatric condition in patients with epilepsy. EPILEPSY & BEHAVIOR. 2018;78:219-225.Purpose: It has been shown that relatives of patients with epilepsy could experience a seizure as a traumatic event followed by a posttraumatic stress disorder (PTSD). In one questionnaire study, 51% of the patients with epilepsy were reported to have a PTSD caused by a traumatic seizure, termed postepileptic seizure PTSD by the authors. However, it remained unclear whether these patients had further psychiatric comorbidities and if certain seizure features may foster the development of the proposed epilepsy-specific PTSD. Methods: We conducted a structured clinical interview assessing psychiatric disorders in 120 patients with difficult-to-treat epilepsies. We also used a modified version of the Posttraumatic Stress Diagnostic Scale conducted as an interview to assess the number of patients who fulfilled the criteria for a PTSD caused by an epileptic seizure. We additionally compared certain features of traumatic versus nontraumatic seizures. Results: Fifty of the 120 patients identified a seizure that fulfilled the criteria for a traumatic event, whereas 28 patients identified a worst seizure not meeting the trauma definition. Six patients fulfilled all PTSD criteria caused by a traumatic seizure. However, three of these patients also had a regular PTSD, and in two further patients, the results of the clinical interview suggested that the PTSD-like symptoms could be better explained by an adjustment disorder. We could not identify seizure characteristics differentiating traumatic from nontraumatic seizures. Conclusion: Our results showed that it is recommendable to conceptualize an epileptic seizure as being potentially traumatic in nature when assessing PTSD in patients with epilepsy, although we could not identify specific characteristics that could differentiate between traumatic and nontraumatic seizures. However, while using interview-based psychiatric assessment, we found a very low rate of a postepileptic seizure PTSD. It is worth conducting a comprehensive psychiatric diagnostic interview to differentiate PTSD-like symptoms from other comorbidities, such as epilepsy-related adjustment disorder. (c) 2017 Elsevier Inc. All rights reserved

Kognitive Störungen bei Patienten mit Epilepsie

Labudda K, Friedrich G. W. Kognitive Störungen bei Patienten mit Epilepsie. In: Hans J. M, P. C, eds. Kognitive Störungen in Neurologie und Psychiatrie. Hippocampus Verlag; In Press

Investigating the brain basis of facial expression perception unsing multi-voxel pattern analysis of FMRI data

Wegrzyn M, Riehle M, Labudda K, Woermann F, Kißler J. Investigating the brain basis of facial expression perception unsing multi-voxel pattern analysis of FMRI data. Psychophysiology. 2013;50(Special Issue S1):S83-S84

The role of cognitive fMRI in mesial temporal lobe epilepsy

Kirsten L, Friedrich G. W. The role of cognitive fMRI in mesial temporal lobe epilepsy. In: H. L, P. R, P. K, eds. The mesial temporal lobe epilepsies. John Libbey Eurotext; 2010