Ec Cieslik

Shall we do this together? Social gaze influences action control in a comparison group, but not in individuals with high-functioning autism:

Perceiving someone else’s gaze shift toward an object can influence how this object will be manipulated by the observer, suggesting a modulatory effect of a gaze-based social context on action control. High-functioning autism (HFA) is characterized by impairments of social interaction, which may be associated with an inability to automatically integrate socially relevant nonverbal cues when generating actions. To explore these hypotheses, we made use of a stimulus-response compatibility paradigm in which a comparison group and patients with HFA were asked to generate spatially congruent or incongruent motor responses to changes in a face, a face-like and an object stimulus. Results demonstrate that while in the comparison group being looked at by a virtual other leads to a reduction of reaction time costs associated with generating a spatially incongruent response, this effect is not present in the HFA group. We suggest that this modulatory effect of social gaze on action control might play an important role in direct social interactions by helping to coordinate one’s actions with those of someone else. Future research should focus on these implicit mechanisms of interpersonal alignment (‘online’ social cognition), which might be at the very heart of the difficulties individuals with autism experience in everyday social encounters.

Dynamic interactions in the fronto-parietal network during a manual stimulus–response compatibility task

Attentional orienting can be modulated by stimulus-driven bottom-up as well as task-dependent top-down processes. In a recent study we investigated the interaction of both processes in a manual stimulus-response compatibility task. Whereas the intraparietal sulcus (IPS) and the dorsal premotor cortex (dPMC) were involved in orienting towards the stimulus side facilitating congruent motor responses, the right temporoparietal junction (TPJ), right dorsolateral prefrontal cortex (DLPFC) as well as the preSMA sustained top-down control processes involved in voluntary reorienting. Here we used dynamic causal modelling to investigate the contributions and task-dependent interactions between these regions. Thirty-six models were tested, all of which included bilateral IPS, dPMC and primary motor cortex (M1) as a network transforming visual input into motor output as well as the right TPJ, right DLPFC and the preSMA as task-dependent top-down regions influencing the coupling within the dorsal network. Our data showed the right temporoparietal junction to play a mediating role during attentional reorienting processes by modulating the inter-hemispheric balance between both IPS. Analysis of connection strength supported the proposed role of the preSMA in controlling motor responses promoting or suppressing activity in primary motor cortex. As the results did not show a clear tendency towards a role of the right DLPFC, we propose this region, against the usual interpretation of an inhibitory influence in stimulus-response compatibility tasks, to subserve generic monitoring processes. Our DCM study hence provides evidence for context-dependent top-down control of right TPJ and DLPFC as well as the preSMA in stimulus-response compatibility.

Transdiagnostic commonalities and differences in resting state functional connectivity of the default mode network in schizophrenia and major depression

Schizophrenia and depression are prevalent psychiatric disorders, but their underlying neural bases remains poorly understood. Neuroimaging evidence has pointed towards the relevance of functional connectivity aberrations in default mode network (DMN) hubs, dorso-medial prefrontal cortex and precuneus, in both disorders, but commonalities and differences in resting state functional connectivity of those two regions across disorders has not been formally assessed. Here, we took a transdiagnostic approach to investigate resting state functional connectivity of those two regions in 75 patients with schizophrenia and 82 controls from 4 scanning sites and 102 patients with depression and 106 controls from 3 sites. Our results demonstrate common dysconnectivity patterns as indexed by a significant reduction of functional connectivity between precuneus and bilateral superior parietal lobe in schizophrenia and depression. Furthermore, our findings highlight diagnosis-specific connectivity reductions of the parietal operculum in schizophrenia relative to depression. In light of evidence that points towards the importance of the DMN for social cognitive abilities and well documented impairments of social interaction in both patient groups, it is conceivable that the observed transdiagnostic connectivity alterations may contribute to interpersonal difficulties, but this could not be assessed directly in our study as measures of social behavior were not available. Given the operculums role in somatosensory integration, diagnosis-specific connectivity reductions may indicate a pathophysiological mechanism for basic self-disturbances that is characteristic of schizophrenia, but not depression.

EP 58. Examining the right dorsal premotor mosaic: A connectivity-based parcellation approach

Little is known about how several functions are organized or how putative subregions are coupled with wider brain networks in the human right PMd. To address these issues, we performed connectivity-based parcellation (CBP) based on PMd voxels’ coactivations yielded by meta-analytic connectivity modeling (MACM). We additionally search for a similar cluster solution with CBP based on resting-state functional connectivity (RSFC) and probabilistic diffusion tractography. MACM and RSFC assessed FC of the MACM–CBP-derived subregions while functional characterization revealed their behavioral associations. This procedure showed that the right PMd could be divided into five distinct clusters highlighting a cognitive-motor gradient along a rostro-caudal axis including a rostral cluster functionally interacting with prefrontal cortex in supporting high-level cognitive processes and a caudal cluster closely integrated with the motor system. MACM–CBP also revealed a ventral cluster, whose functional profile fits the concept of an eye field, and a dorsal cluster, preferentially hand-related and connected to both cognitive and motor regions. Finally, MACM–CBP yielded a central cluster showing a mixed behavioral profile and FC to parietal regions of the dorsal attention network. Thus, our results showed that the right PMd may be considered as a functional mosaic formed by five subregions.

EP 61. Coactivation-based parcellation of the posterior medial frontal cortex

Introduction The posterior medial frontal cortex (pMFC) is part of the so-called salience network ( Seeley, 2007 ) and involvement of this region has been reported in a number of different tasks. Although usually referred to as dorsal anterior cingulate cortex, pMFC activation found in most studies is not restricted to the (middle) cingulate cortex, but also extends onto the dorsally abutting superior frontal gyrus, which in turn encompasses the pre-supplementary motor area and parts of the supplementary motor area. Using a connectivity-based parcellation approach, we aimed to investigate whether the pMFC can be subdivided with regard to its functional connectivity (FC) profiles and function. Methods A volume of interest (VOI) corresponding to the pMFC was derived by the conjunction of three previous meta-analyses of attention, working memory and action inhibition ( Muller, 2015 ). The whole-brain co-activation patterns for each voxel within the VOI were computed. Based on those co-activation patterns, all voxels of the VOI were grouped into distinct clusters using k-means clustering, and the most stable clustering solution identified. Meta-analytic and resting state FC approaches were then combined to examine the derived clusters’ brain-wide connectivity. Finally, quantitative functional characterization was performed on each cluster in order to identify differentiable functions of the sub-clusters. Results Results supported the segregation of the pMFC-VOI into five clusters: dorsal-anterior (C1), dorsal-posterior (C2), dorsal-middle (C3), ventral-anterior (C4) and ventral-posterior (C5). Importantly, results demonstrate a clustering into cingulate (C4, C5) and non-cingulate clusters (C1, C2, C3). Posterior cingulate cluster C5 was found to be mainly involved in pain processing and strongly connected to regions of the “pain matrix”, while cingulate C4 more strongly relates to behavioral inhibition. Furthermore, within the non-cingulate pMFC, our results reveal an anterior higher order cognitive (C1) and a posterior action (C2) related cluster. Additionally, we found a central cluster (C3) revealing an intermediate connectivity profile and associated with working memory and cognitive flexibility tasks. Conclusion Thus, our results show that, based on their connectivity patterns, cingulate and non-cingulate regions of the pMFC can be distinguished and further demonstrate a motor to cognitive clustering within non-cingulate pMFC and two cingulate clusters differently involved in pain processing and behavioral inhibition.

EP 62. Functional connectivity and characterization of subregions within left intraparietal sulcus

Introduction The intraparietal sulcus (IPS), located at the intersection of visual, auditory and somatosensory association cortices, has been associated with the multi-modal spatial representation of the external world ( Grefkes, 2005 ). Moreover, the IPS has been reported to be involved in higher executive functions such as working memory or cognitive flexibility. In a previous co-activation based parcellation study we could identify five functional subregions within the left IPS ( Cieslik, 2013 ). To characterize the individual clusters we here used meta-analytic connectivity modelling (MACM) for investigation of each cluster‘s functional connectivity (FC) as well as functional profiling using the BrainMap database ( brainmap ). Methods MACM-FC of the IPS’ subregions was investigated by first identifying those experiments in the BrainMap database activating the respective cluster. Performing a meta-analysis over these experiments revealed those regions showing significant co-activation with the cluster. To identify regions in the brain revealing consistent FC with all five IPS subregions, we performed a conjunction analysis across the FC results of the individual clusters. In a next step, specific co-activation patterns for all five clusters were derived by performing a conjunction analysis across the differences between a given cluster and the four other ones. Moreover, forward and reverse inference was performed using the ‘Paradigm Class’ categories of the BrainMap database to characterize differentiable functions of individual clusters. Results The present study reveals consistent FC of all individual subclusters with a bilateral fronto-parietal network that has been associated with multiple demand processes [6,7]. Moreover, when looking at differential FC and behavioural characterization of individual clusters it was found that cluster C1 and C4 - located in the more posterior-lateral fundus of the IPS - were strongly associated with paradigms requiring higher cognitive control, such as the Wisconsin Card Sorting Test and n-back task, respectively. These clusters furthermore showed specific FC with regions in the prefrontal cortex, such as the inferior frontal junction for C1 and the dorsolateral prefrontal cortex and middle frontal gyrus for C4. In contrast, more anterior (C3) and more dorsal – C2 and C5 – clusters were stronger associated with visuo-motor paradigms. C2 showed specific FC with the precentral gyrus while C3 and C5 showed specific FC only with the respective contralateral homotopic region. Conclusion These results hence provide evidence for an anterior-posterior gradient in the left IPS, with more anterior and dorsal clusters strongly involved in linking perception to action and more posterior lateral clusters featuring higher cognitive functions, such as working memory and cognitive flexibility.

Altern und kognitive Handlungskontrolle: Veränderungen der Performanz und funktionellen Konnektivität

Einleitung: Schnelle Wahlreaktionen werden durch raumlich inkompatible Stimulus-Reaktions-(SR) Verknupfungen verlangsamt, da automatisch aktivierte Antworttendenzen durch kognitive Kontrolle uberwunden werden mussen. Fruhere Arbeiten fanden eine starkere Verlangsamung mit hoherem Lebensalter. Hier untersuchten wir, ob dieser Alterseffekt unabhangig ist von potentiellen Mediatorvariablen wie allgemeiner Reaktionsgeschwindigkeit, visuomotorischer Koordination und kognitiver Flexibilitat. Um neuronale Grundlagen des altersabhangigen S-R-Inkompatibilitatseffekts zu untersuchen, testeten wir, ob Altern zu Veranderungen der funktionellen Konnektivitat (FK) zwischen Hirnregionen fuhrt, die mit raumlich inkompatiblen Wahlreaktionen assoziiert sind. Methode: 26 junge (20 – 29J., MW = 24,9) und 27 altere (50 – 73J., MW = 59,4) gesunde Probanden fuhrten eine Wahlreaktionsaufgabe aus, die schnelle links- oder rechtshandige Reaktionen auf lateralisierte visuelle Stimuli erforderte. S-R-Kompatibilitat wurde blockweise variiert. Zusatzlich wurden motorische Geschwindigkeit, visuomotorische Koordination und kognitive Flexibilitat getestet. Fur die FK-Analyse wurden Ruhe-fMRT-Daten von 399 gesunden Probanden (Alters-Range: 18 – 85J.) verwendet. Das aufgabenbezogene Netzwerk fur die FK-Analyse wurde aus einer fruheren fMRT-Studie mit gleicher Aufgabe [1] gewonnen. Es bestand aus bilateralem intraparietalen Sulcus (IPS), dorsalen pramotorischen Kortex, anteriorer Insel, pra-SMA sowie der rechten temporoparietalen Ubergangszone (TPJ) und dem dorsolateralen prafrontalen Kortex (DLPFC). Fur jeden Probanden wurden die BOLD-Signalverlaufe aller 9 Cluster miteinander korreliert. Die daraus resultierenden FK-Mase wurden Fisher-Z-transformiert und mit dem Alter der Probanden korreliert. Ergebnisse: Die Reaktionsverlangsamung bei S-R-Inkompatibilitat war im Alter gesteigert und blieb nach Auspartialisierung der mittleren Reaktionsgeschwindigkeit und Fehlerrate in kompatiblen Aufgabenblocken sowie Masen motorischer Geschwindigkeit, visuomotorischer Koordination und kognitiver Flexibilitat signifikant. Positive FK im Ruhezustand sank mit dem Alter zwischen mehreren Netzwerkknoten, vor allem zwischen bilateraler Insel, pra-SMA und rechtem DLPFC. Ein altersbedingter FK-Anstieg fand sich zwischen pra-SMA und bilateralem IPS. Schlussfolgerungen: Die Verhaltensdaten weisen darauf hin, dass die Verlangsamung bei der Losung von Reaktionskonflikten, die durch raumliche S-R-Inkompatibilitat entstehen, ein spezifisches Defizit kognitiver Kontrolle bei alteren Menschen darstellt und nicht durch globale kognitive Verlangsamung oder Unterschiede in potentiellen Mediatorvariablen erklart wird. Die selektive FK-Abnahme zwischen prafrontalen Netzwerkknoten spricht fur altersbedingte Defizite in der Kommunikation zwischen Regionen, die das relevante Aufgabenschema reprasentieren und konnte zu einer reduzierten Effizienz bei der Durchsetzung von Handlungsabsichten gegen dominante Reaktionstendenzen beitragen. Referenz: [1] Cieslik EC et al. (2010). J Neurophys 104:1472 – 83.