36 research outputs found

    Exploring the neural correlates of (altered) moral cognition in psychopaths

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    Abstract Research into the neurofunctional mechanisms of psychopathy has gathered momentum over the last years. Previous neuroimaging studies have identified general changes in brain activity of psychopaths. In an exploratory meta‐analysis, we here investigated the neural correlates of impaired moral cognition in psychopaths. Our analyses replicated general effects in the dorsomedial prefrontal cortex, lateral prefrontal cortex, fronto‐insular cortex, and amygdala, which have been reported recently. In addition, we found aberrant brain activity in the midbrain and inferior parietal cortex. Our preliminary findings suggest that alterations in both regions may represent more specific functional brain changes related to (altered) moral cognition in psychopaths. Furthermore, future studies including a more comprehensive corpus of neuroimaging studies on moral cognition in psychopaths should re‐examine this notion

    Improving mentalizing deficits in older age with region-specific transcranial direct current stimulation.

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    Older adults have difficulties to detect the intentions, thoughts, and feelings of others, indicating an age-associated decline of socio-cognitive abilities that are known as "mentalizing". These deficits in mental state recognition are driven by neurofunctional alterations in brain regions that are implicated in mentalizing, such as the right temporo-parietal junction (rTPJ) and the dorso-medial prefrontal cortex (dmPFC). We tested whether focal transcranial current stimulation (tDCS) of the rTPJ and dmPFC has the potential to eliminate mentalizing deficits in older adults. Mentalizing deficits were assessed with a novel mindreading task that required the recognition of mental states in child faces. Older adults (n = 60) performed worse than younger adults (n = 30) on the mindreading task, indicating age-dependent deficits in mental state recognition. These mentalizing deficits were ameliorated in older adults who received sham-controlled andodal tDCS over the rTPJ (n = 30) but remained unchanged in older adults who received sham-controlled andodal tDCS over the dmPFC (n = 30). We, thus, showed for the first time that anodal tDCS over the rTPJ has the potential to remediate age-dependent mentalizing deficits in a region-specific way. This provides a rationale for exploring stimulation-based interventions targeting mentalizing deficits in older age. [Abstract copyright: © 2024. The Author(s).

    Unhealthy yet Avoidable-How Cognitive Bias Modification Alters Behavioral and Brain Responses to Food Cues in Individuals with Obesity

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    Obesity is associated with automatically approaching problematic stimuli, such as unhealthy food. Cognitive bias modification (CBM) could beneficially impact problematic approach behavior. However, it is unclear which mechanisms are targeted by CBM in obesity. Candidate mechanisms include: (1) altering reward value of food stimuli; and (2) strengthening inhibitory abilities. Thirty-three obese adults completed either CBM or sham training during functional magnetic resonance imaging (fMRI) scanning. CBM consisted of implicit training to approach healthy and avoid unhealthy foods. At baseline, approach tendencies towards food were present in all participants. Avoiding vs. approaching food was associated with higher activity in the right angular gyrus (rAG). CBM resulted in a diminished approach bias towards unhealthy food, decreased activation in the rAG, and increased activation in the anterior cingulate cortex. Relatedly, functional connectivity between the rAG and right superior frontal gyrus increased. Analysis of brain connectivity during rest revealed training-related connectivity changes of the inferior frontal gyrus and bilateral middle frontal gyri. Taken together, CBM strengthens avoidance tendencies when faced with unhealthy foods and alters activity in brain regions underpinning behavioral inhibition.Peer reviewe

    A fundamental distinction in early neural processing of implicit social interpretation in schizophrenia and bipolar disorder

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    Background: Social cognition impairment is a key phenomenon in serious mental disorders such as schizophrenia (SCZ) and bipolar disorder (BPD). Although genetic and neurobiological studies have suggested common neural correlates, here we hypothesized that a fundamental dissociation of social processing occurs at an early level in these conditions. Methods: Based on the hypothesis that key structures in the social brain, namely the temporoparietal junction, should present distinctive features in SCZ and BPD during low-level social judgment, we conducted a case-control study in SCZ (n = 20) and BPD (n = 20) patients and controls (n = 20), using task-based fMRI during a Theory of Mind (ToM) visual paradigm leading to interpretation of social meaning based on simple geometric figures. Results: We found opposite neural responses in two core ToM regions: SCZ patients showed social content-related deactivation (relative to controls and BPD) of the right supramarginal gyrus, while the opposite pattern was found in BPD; reverse patterns, relative to controls and SCZ, were found in the left posterior superior temporal gyrus, a region involved in inferring other's intentions. Receiver-operating-characteristic curve analysis showed 88% accuracy in discriminating the two clinical groups based on these neural responses. Conclusions: These contrasting activation patterns of the temporoparietal junction in SCZ and BPD represent mechanistic differences of social cognitive dysfunction that may be explored as biomarkers or therapeutic targets.info:eu-repo/semantics/publishedVersio

    Improving mentalizing deficits in older age with region-specific transcranial direct current stimulation

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    Older adults have difficulties to detect the intentions, thoughts, and feelings of others, indicating an age-associated decline of socio-cognitive abilities that are known as "mentalizing". These deficits in mental state recognition are driven by neurofunctional alterations in brain regions that are implicated in mentalizing, such as the right temporo-parietal junction (rTPJ) and the dorso-medial prefrontal cortex (dmPFC). We tested whether focal transcranial current stimulation (tDCS) of the rTPJ and dmPFC has the potential to eliminate mentalizing deficits in older adults. Mentalizing deficits were assessed with a novel mindreading task that required the recognition of mental states in child faces. Older adults (n = 60) performed worse than younger adults (n = 30) on the mindreading task, indicating age-dependent deficits in mental state recognition. These mentalizing deficits were ameliorated in older adults who received sham-controlled andodal tDCS over the rTPJ (n = 30) but remained unchanged in older adults who received sham-controlled andodal tDCS over the dmPFC (n = 30). We, thus, showed for the first time that anodal tDCS over the rTPJ has the potential to remediate age-dependent mentalizing deficits in a region-specific way. This provides a rationale for exploring stimulation-based interventions targeting mentalizing deficits in older age

    Localizing Pain Matrix and Theory of Mind networks with both verbal and non-verbal stimuli

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    Functional localizer tasks allow researchers to identify brain regions in each individual's brain, using a combination of anatomical and functional constraints. In this study, we compare three social cognitive localizer tasks, designed to efficiently identify regions in the "Pain Matrix," recruited in response to a person's physical pain, and the "Theory of Mind network," recruited in response to a person's mental states (i.e. beliefs and emotions). Participants performed three tasks: first, the verbal false-belief stories task; second, a verbal task including stories describing physical pain versus emotional suffering; and third, passively viewing a non-verbal animated movie, which included segments depicting physical pain and beliefs and emotions. All three localizers were efficient in identifying replicable, stable networks in individual subjects. The consistency across tasks makes all three tasks viable localizers. Nevertheless, there were small reliable differences in the location of the regions and the pattern of activity within regions, hinting at more specific representations. The new localizers go beyond those currently available: first, they simultaneously identify two functional networks with no additional scan time, and second, the non-verbal task extends the populations in whom functional localizers can be applied. These localizers will be made publicly available.National Institutes of Health (U.S.) (Grant 1R01 MH096914-01A1

    The role of the temporoparietal junction in self-other distinction

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    Being able to discriminate between what originates from ourselves and what originates from others is critical for efficient interactions with our social environment. However, it remains an open question whether self-other distinction is a domain-general mechanism that is involved in various social-cognitive functions or whether specific 'self-other distinction mechanisms' exist for each of these functions. On the neural level, there is evidence that self-other distinction is related to a specific brain region at the border of the superior temporal and inferior parietal cortex, the temporoparietal junction (TPJ). Demonstrating that the TPJ plays a role in social processes that require self-other distinction would support the idea of a domain-general mechanism of self-other distinction. In the present paper, we review evidence coming from clinical observations, neuroimaging experiments and a meta-analysis indicating the involvement of the TPJ in various cognitive operations requiring self-other distinction. At the perceptual level, we discuss the human ability to identify one's own body and to distinguish it from others. At the action level, we review research on the human ability to experience agency and the control of imitative response tendencies. Finally, at the mental-state level, we discuss the ability to attribute mental states to others. Based on this integrative review, we suggest that the TPJ, and in particular its dorsal part, supports a domain general ability to enhance task-relevant representations when self-related and other-related representations are in conflict. Finally, this conception allows us to propose a unifying architecture for the emergence of numerous socio-cognitive abilities

    Neuronal and behavioral mechanisms of Gestalt perception

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    Principles of Gestalt perception have fundamentally influenced our understanding of visual cognition. In the past century, Gestalt psychologists postulated that the human brain determines single elements with common features as a single entity rather than a sum of separate parts. The importance of Gestalt perception is emphasized by the neuropsychological syndrome simultanagnosia. Patients suffering from this condition have lost the ability to integrate single elements into a superior entity. Simultanagnosia is usually associated with bilateral posterior temporo-parietal brain lesions but the exact neuroanatomy of global Gestalt perception and functions of areas already associated with this perceptual quality are still a matter of lively debates. Further, not much is known about behavioral characteristics of wellexplored perceptual processes, like visual constancy, in the context of Gestalt perception. The present work aimed at investigating neuronal and behavioral properties of Gestalt perception applying psychophysical methods and functional magnetic resonance imaging (fMRI). In previous neuroimaging studies the temporoparietal junction (TPJ) was identified as a crucial brain structure involved in Gestalt perception. However, its specific role in Gestalt perception is still unclear. The functions attributed to this brain region range from attentional selection between the local and the global level of hierarchically organized stimuli to mere perceptual mechanisms of global processing. The neuroimaging studies included into this work explore mainly TPJ related perceptual functions. In the first study, neuronal properties of TPJ in Gestalt perception were investigated. Based on observations in simultanagnosia patients that are able to perceive familiar complex stimulus arrangements but fail in recognition of novel stimulus configurations, it was hypothesized that TPJ areas mainly contribute to processing of novel object arrangements. A training study was conducted where subjects had to learn the perception of complex stimulus arrangements in order to examine this hypothesis. Neuronal processes of Gestalt perception in bilateral TPJ regions were assessed pre- and posttraining. It was demonstrated that an anterior right hemispheric TPJ region responded to perceptual training with global stimuli. The results indicated fundamentally changed TPJ contributions with increasing familiarity suggesting a different strategy of the brain for processing of highly familiar object arrangements. In the second study, involvements of bilateral TPJ areas in global processing were investigated with an approach taking advantage of visual expertise. During presentation of specific chess arrangements TPJ signals of chess experts and novices were examined. As a consequence, it was possible to compare neuronal TPJ correlates for holistic perception in experts and serial perceptual strategies in novices. The result showed higher signals in bilateral TPJ areas for chess experts compared to novices while inspecting specific chess configurations. With this method a lot of the typical stimulus confounds in research about Gestalt perception, like size differences or differences in spatial frequencies between global/local stimulus levels, were avoided. Moreover, the nature of the stimuli and experimental tasks argues for a TPJ involvement during perception rather than for functions of attentional selection. In the third study perceptual properties of visual size constancy were investigated in the context of Gestalt perception. While size constancy is a well-known phenomenon for regular objects this visual mechanism has not been investigated for stimuli forming a global Gestalt. Therefore, the perceptual performance for a global stimulus arrangement placed on different locations of a visual scene containing a 3D perspective was tested. For the first time, influences of size constancy were demonstrated also for global stimuli. Effects of size constancy on Gestalt perception suggest a perceptual hierarchy of global scenes even on stimuli that have to be integrated themselves. Taken together the results show that the TPJ is involved in mere perceptual processes of Gestalt perception and that an anterior section of this structure has a specific role in processing of novel object arrangements. It was also demonstrated that Gestalt perception itself underlies visual top-down processes of visual constancy suggesting a superior role of global scene processing influencing even local grouping processes.Zu Beginn des letzten Jahrhunderts formulierte die Gestaltpsychologie bestimmte GesetzmĂ€ĂŸigkeiten, die der menschlichen Wahrnehmung zu Grunde liegen. Die sog. Gestaltgesetzte besagen, dass einzelne Elemente mit systematischen Gemeinsamkeiten eher als ganzheitliche EntitĂ€t aufgefasst werden denn als Summe einzelner Teile. Die besondere Bedeutung der Gestaltwahrnehmung wird durch das neuropsychologische Störungsbild Simultanagnosie deutlich. Patienten, die an dieser Störung leiden, haben die FĂ€higkeit einzelne Elemente zu einer ĂŒbergeordneten Einheit zu verbinden verloren. Normalerweise treten Symptome der Simultanagnosie nach bilateralen temporo-parietalen GehirnlĂ€sionen auf. Die genaue Neuroanatomie der Gestaltwahrnehmung und klar definierte Funktionen von Gehirnarealen, die bereits mit globaler Wahrnehmung in Verbindung gebracht werden konnten, sind jedoch noch nicht eindeutig definiert. DarĂŒber hinaus ist auf Verhaltensebene wenig ĂŒber Funktionen der visuellen Wahrnehmung, z.B. hinsichtlich des PhĂ€nomens der GrĂ¶ĂŸenkonstanz, im Zusammenhang mit Gestaltwahrnehmung bekannt. Das Ziel der vorliegenden Arbeit ist die Erforschung neuronaler und behavioraler Mechanismen der Gestaltwahrnehmung mit Hilfe psychophysischer und bildgebender Methoden. In bisherigen Bildgebungsstudien konnte die temporo-parietale Übergangsregion (temporo-parietal junction, TPJ) als neuronales Korrelat der Gestaltwahrnehmung identifiziert werden. Die genaue Bedeutung dieser Hirnregion fĂŒr die Gestaltwahrnehmung ist jedoch noch unklar, wobei bisher vor allem Aufmerksamkeits- und reine Wahrnehmungsfunktionen damit in Verbindung gebracht werden konnten. Die Bildgebungsstudien dieser Arbeit konzentrieren sich daher vornehmlich auf perzeptuelle Funktionen bilateraler TPJ-Areale. In der ersten Studie dieser Arbeit wurden spezifische Eigenschaften der temporo-parietalen Übergangsregion fĂŒr die Gestaltwahrnehmung untersucht. Die Motivation fĂŒr diese Studie wurde von Beobachtungen bei Simultanagnosie-Patienten abgeleitet, die vor allem Schwierigkeiten bei der Verarbeitung neuartiger komplexer Reizanordnungen haben, aber gelĂ€ufige komplexe visuelle Inhalte erkennen können. Daher wurde die Hypothese untersucht, dass bilaterale TPJ-Regionen hauptsĂ€chlich in die Verarbeitung neuartiger komplexer Strukturen involviert sind. Zur Untersuchung dieser Hypothese wurde eine Lernstudie durchgefĂŒhrt. Im Rahmen dieser Studie wurde die Wahrnehmung fĂŒr komplexe Gestalt-Stimuli trainiert und die neuronalen Mechanismen der Gestaltwahrnehmung vor und nach dem Training mittels funktionaler Magnet Resonanztomographie (fMRT) gemessen. Es zeigte sich, dass hauptsĂ€chlich das anteriore rechtshemisphĂ€rische TPJ-Areal signifikant auf Wahrnehmungstraining reagierte. Dieses Ergebnis bestĂ€tigte die Hypothese, dass TPJ hauptsĂ€chlich fĂŒr die Verarbeitung neuartiger Objekt-Arrangements zustĂ€ndig ist bzw. komplexe Stimuli mit hohem Bekanntheitsgrad ĂŒber andere neuronale KanĂ€le verarbeitet werden. In der zweiten Studie wurde der Beitrag bilateraler TPJ-Areale auf die Gestaltwahrnehmung durch die Untersuchung von Schach-Experten realisiert. Dabei wurden TPJ-Signale von Schach-Experten und Novizen bei der Betrachtung komplexer Schach-Arrangements mittels fMRT gemessen. Auf diese Weise war es möglich neuronale TPJ-Aktivierungen wĂ€hrend einer ganzheitlichen Wahrnehmung in Experten und einer seriellen Strategie in Novizen zu vergleichen. Die Ergebnisse zeigten stĂ€rkere Signale in bilateralen TPJ-Regionen fĂŒr Experten im Vergleich zu Novizen wĂ€hrend der Betrachtung komplexer Schach-Arrangements. Mit Hilfe dieses Ansatzes konnten einige Störvariablen, die bei der Erforschung der Gestaltwahrnehmung auftreten, wie z.B. Unterschiede zwischen lokalen und globalen Stimuli hinsichtlich GrĂ¶ĂŸe oder rĂ€umlicher Frequenz, umgangen werden. DarĂŒber hinaus weisen der Aufbau der Stimuli und die verwendeten Testparadigmen auf TPJ-EinflĂŒsse wĂ€hrend der perzeptuellen Verarbeitung komplexer Stimuli hin und sprechen gegen TPJ-gesteuerte Aufmerksamkeitsmechanismen der perzeptuellen Auswahl von globalen oder lokalen Ebenen. Die dritte Studie untersuchte perzeptuelle Eigenschaften der GrĂ¶ĂŸenkonstanz im Kontext der Gestaltwahrnehmung. WĂ€hrend die GrĂ¶ĂŸenkonstanz ein gut erforschtes PhĂ€nomen im Rahmen der Objektwahrnehmung darstellt, ist bisher nicht bekannt, ob dieser visuelle Mechanismus auch globale Gestalt-Stimuli betrifft. Diese Fragestellung wurde durch ein Experiment, in dem globale Gestalt-Stimuli in einer visuellen Szene mit 3D-Perspektive platziert wurden, untersucht. Es zeigte sich, dass auch die Verarbeitung globaler Stimuli Mechanismen der GrĂ¶ĂŸenkonstanz unterliegt. Effekte der GrĂ¶ĂŸenkonstanz auf die Wahrnehmung globaler Gestalt-Stimuli weisen auf eine Hierarchie der visuellen Verarbeitung hin, der zufolge eine ĂŒbergeordnete globale Szene auch visuelle Inhalte beeinflusst, die selbst der Gestaltwahrnehmung unterliegen. Zusammenfassend zeigen die dargestellten Arbeiten, dass das TPJ-Areal hauptsĂ€chlich an der perzeptuellen Verarbeitung komplexer visueller Reizanordnungen beteiligt ist und dabei speziell fĂŒr neuartige Reizkonfigurationen zustĂ€ndig ist. DarĂŒber hinaus konnte gezeigt werden, dass Gestaltwahrnehmung selbst Top-down-Prozessen der visuellen GrĂ¶ĂŸenkonstanz unterliegt und die globale Wahrnehmung einer visuellen Szene lokale Prozesse der Gestaltwahrnehmung beeinflussen kann
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