Side Effects of Transcranial Magnetic Stimulation Biased Task Performance in a Cognitive Neuroscience Study

Summary:: Transcranial magnetic stimulation (TMS) is increasingly used as a research tool for functional brain mapping in cognitive neuroscience. Despite being mostly tolerable, side effects of TMS could influence task performance in behavioural TMS studies. In order to test this issue, healthy subjects assessed the discomfort caused by the stimulation during a verbal working memory task. We investigated the relation between subjective disturbance and task performance. Subjects were stimulated during the delay period of a delayed-match-to-sample task above cortical areas that had been identified before to be involved in working memory. Task performance and subjective disturbance due to side effects were monitored. The subjects' grade of discomfort correlated with the error rates: the higher the discomfort, the more errors were made. Conclusively, TMS side effects may bias task performance in cognitive neuroscience studies and may thereby lead to misinterpretation of results. We emphasize the importance of controlling side effects of the stimulation as a source of biasing effects in TMS studie

Neural correlates of the perception of dynamic versus static facial expressions of emotion

Aim: This study investigated brain areas involved in the perception of dynamic facial expressions of emotion

Neural Correlates of Social Inclusion in Borderline Personality Disorder

Humans engage in social interactions and have a fundamental need and motivation to establish and maintain social connections. Neuroimaging studies particularly focused on the neural substrates of social exclusion in healthy subjects (HC), borderline personality disorder (BPD), and major depression (MD). However, there is evidence regarding neural alterations also during social inclusion in BPD that we intended to elucidate in our study. Considering that patients with BPD often have comorbid MD, we investigated patients with BPD, and comorbid MD, patients with MD without BPD, and a sample of HC. By investigating these two clinical samples within one study design, we attempted to disentangle potential confounds arising by psychiatric disorder or medication and to relate neural alterations under social inclusion specifically to BPD. We investigated 48 females (15 BPD and MD, 16 MD, and 17 HC) aged between 18 and 40 years by fMRI (3T), using the established cyberball paradigm with social exclusion, inclusion, and passive watching conditions. Significant group-by-condition interaction effects (p < 0.05, FWE-corrected on cluster level) were observed within the dorsolateral (dlPFC) and dorsomedial prefrontal cortex (dmPFC), the temporo-parietal junction (TPJ), the posterior cingulate cortex (PCC), and the precuneus. Comparisons of estimated neural activations revealed that significant interaction effects were related to a relative increase in neural activations during social inclusion in BPD. In detail, we observed a significant increase in differential (social inclusion vs. passive watching) neural activation within the dmPFC and the PCC in BPD compared to both, MD and HC. However, significant interaction effects within the dlPFC and the TPJ could not specifically be linked to BPD considering that they did not differ significantly between the two clinical groups in post-hoc comparisons. Our study supports previous results on effects of social and inclusion in BPD, and provides further evidence regarding disorder specific neural alterations in BPD for brain regions associated with self-referential and mentalizing processes during social inclusion

Resting-state functional connectivity within the reward system mediates subcortical integration during erotic stimulus processing

Objectives: Erotic stimuli lead to activations in various brain regions, including the reward system.Several neuroimaging studies have investigated neurofunctional activations during visual eroticstimulation. Little research has investigated whether these functional activations are characterisedby an intrinsic network architecture in the resting-state. Methods: We therefore examined 37 healthy male heterosexual subjects by combiningresting-state and task-related fMRI. In task-related fMRI, we used an established video clip task(erotic and non-erotic video clips). Vectors comprising different neuronal activations during theprocessing of visual erotic stimuli were then correlated with the strength of resting-state functionalconnectivity between two core regions of the human reward system (NAcc and midbrain). Results: We observed an increase in neurofunctional activations in cortical and subcortical regionspreviously described in task-based fMRI studies during visual erotic stimulation. Increased rs-FCbetween midbrain and NAcc was associated with higher differential neuronal responsiveness insubcortical regions, particularly in the hypothalamus, thalamus and periaqueductal grey. Conclusion: Our results support the role of the mesolimbic reward pathway in the processing oferotic stimuli. In particular they show that a higher rs-FC between midbrain and NAcc facilitatesthe simultaneous activation of subcortical brain regions that are relevant for the integration ofprocesses in sexual behaviour

From uncertainty to reward: BOLD characteristics differentiate signaling pathways

<p>Abstract</p> <p>Background</p> <p>Reward value and uncertainty are represented by dopamine neurons in monkeys by distinct phasic and tonic firing rates. Knowledge about the underlying differential dopaminergic pathways is crucial for a better understanding of dopamine-related processes. Using functional magnetic resonance blood-oxygen level dependent (BOLD) imaging we analyzed brain activation in 15 healthy, male subjects performing a gambling task, upon expectation of potential monetary rewards at different reward values and levels of uncertainty.</p> <p>Results</p> <p>Consistent with previous studies, ventral striatal activation was related to both reward magnitudes and values. Activation in medial and lateral orbitofrontal brain areas was best predicted by reward uncertainty. Moreover, late BOLD responses relative to trial onset were due to expectation of different reward values and likely to represent phasic dopaminergic signaling. Early BOLD responses were due to different levels of reward uncertainty and likely to represent tonic dopaminergic signals.</p> <p>Conclusions</p> <p>We conclude that differential dopaminergic signaling as revealed in animal studies is not only represented locally by involvement of distinct brain regions but also by distinct BOLD signal characteristics.</p

Somatosensory Stimulus Intensity Encoding in Borderline Personality Disorder

Borderline Personality Disorder (BPD) is clinically characterized by emotional instability, interpersonal disturbances and dysfunctional behavior such as non-suicidal self-injury (NSSI). During NSSI, patients with BPD typically report analgesic or hypoalgesic phenomena, and pain perception and pain processing in BPD have been repeatedly investigated. Most of the studies so far focused on affective-motivational and cognitive-evaluative neural components of pain within categorial study designs. By contrast, rather basic somatosensory aspects such as neural intensity-encoding of somatosensory stimuli were not examined in further details. Thus, we investigated patients with BPD and healthy controls (HC) by functional magnetic resonance imaging (fMRI) during an unpleasant sensory stimulation task with parametrically increasing stimulus intensities. 15 females diagnosed with BPD and 15 HCs were investigated with fMRI during four individually adjusted levels of electrical stimulus intensities. Ratings of stimulus intensity were assessed by button presses during fMRI. fMRI-data were analyzed by analyses of variances (ANOVA) at a statistical threshold of p &lt; 0.05 FWE-corrected on cluster level. Subjective ratings of stimulus intensities were alike between BPD and HC, and intensity levels identified with equal accuracy. Significant intensity-encoding neural activations were observed within the primary and secondary somtasensory cortex, the posterior insula, the posterior midcingulate cortex (pMCC) and the supplementary motor area (SMA) in both, HC and BPD. Notably, there were no significant between-groups differences in intensity-encoding neural activations, even at lowered significance thresholds. Present results suggest a similar neural somatosensory stimulus intensity encoding in BPD as previously observed on a behavioral level. The alterations in neural affective-motivational or cognitive-evaluative components reported so far may be restricted to pain rather than unpleasant stimulus processing and were absent in our study

The STAR collaborative nonsuicidal self-injury study: methods and sample description of the face-to-face sample

Background Nonsuicidal self-injury (NSSI) is highly prevalent in adolescents and young adults worldwide. It is linked to a broad variety of mental disorders and an increased suicide risk. Despite its high prevalence, research on the underlying mechanisms and on potential risk and resilience factors for maintaining or quitting NSSI remains scarce. This manuscript presents an overview of the “Self-injury: Treatment-Assessment-Recovery” (STAR) collaboration, which aimed to address these gaps. Methods We investigated the natural course of NSSI as well as its social, psychological, and neurobiological predictors (observational study; OS). OS data collection occurred at four timepoints (baseline [T0], 4 [post, T1], 12 [follow-up (FU), T2], and 18 [FU, T3] months after baseline) for the NSSI group, which was compared to a healthy control (HC) group at T0 only. Online self-report was used at all timepoints, while semi-structured interviews (face-to-face (f2f)) were conducted at T0 and T3. At T0 only, we conducted ecological momentary assessment and neurobiological investigations. Here, we present the general methodology and sample characteristics of the completed OS including the f2f subprojects, while other subprojects are not within the scope of this paper. Sample description The OS sample consists of 343 participants at T0 (180 NSSI, 163 HC). Mean age in the NSSI group (T0) was 18.1 years (SD = 2.09, range: 15–25), gender-related data is available for 166: 156 = female, 7 = male, 3 = transgender, 10 = not disclosed). In the HC group, mean age (T0) was 19.1 years (SD = 2.35, range: 15–25) (142 = female, 21 = male). At T1, 128 (71.11%) of the NSSI participants completed the questionnaires, at T2 125 (69.44%) and at T3 104 (57.78%). In the fMRI subproject, 126 adolescents participated (NSSI = 66, HC = 60, 100% female; mean age (T0): NSSI = 18.10 years, SD = 2.21; HC = 19.08, SD = 2.36). Conclusion Understanding predictors is of utmost importance for adequate diagnosis and intervention for NSSI. Our OS applied a multimodal investigation of social, psychological, and neurobiological parameters and is the largest sample of adolescents with NSSI to date including follow-up assessments. As health care providers require specific knowledge to develop new treatments, we believe that our in-depth assessments can potentially enhance care for youths engaging in NSSI

The STAR collaborative nonsuicidal self-injury study: methods and sample description of the face-to-face sample.

peer reviewedBACKGROUND: Nonsuicidal self-injury (NSSI) is highly prevalent in adolescents and young adults worldwide. It is linked to a broad variety of mental disorders and an increased suicide risk. Despite its high prevalence, research on the underlying mechanisms and on potential risk and resilience factors for maintaining or quitting NSSI remains scarce. This manuscript presents an overview of the "Self-injury: Treatment-Assessment-Recovery" (STAR) collaboration, which aimed to address these gaps. METHODS: We investigated the natural course of NSSI as well as its social, psychological, and neurobiological predictors (observational study; OS). OS data collection occurred at four timepoints (baseline [T0], 4 [post, T1], 12 [follow-up (FU), T2], and 18 [FU, T3] months after baseline) for the NSSI group, which was compared to a healthy control (HC) group at T0 only. Online self-report was used at all timepoints, while semi-structured interviews (face-to-face (f2f)) were conducted at T0 and T3. At T0 only, we conducted ecological momentary assessment and neurobiological investigations. Here, we present the general methodology and sample characteristics of the completed OS including the f2f subprojects, while other subprojects are not within the scope of this paper. SAMPLE DESCRIPTION: The OS sample consists of 343 participants at T0 (180 NSSI, 163 HC). Mean age in the NSSI group (T0) was 18.1 years (SD = 2.09, range: 15-25), gender-related data is available for 166: 156 = female, 7 = male, 3 = transgender, 10 = not disclosed). In the HC group, mean age (T0) was 19.1 years (SD = 2.35, range: 15-25) (142 = female, 21 = male). At T1, 128 (71.11%) of the NSSI participants completed the questionnaires, at T2 125 (69.44%) and at T3 104 (57.78%). In the fMRI subproject, 126 adolescents participated (NSSI = 66, HC = 60, 100% female; mean age (T0): NSSI = 18.10 years, SD = 2.21; HC = 19.08, SD = 2.36). CONCLUSION: Understanding predictors is of utmost importance for adequate diagnosis and intervention for NSSI. Our OS applied a multimodal investigation of social, psychological, and neurobiological parameters and is the largest sample of adolescents with NSSI to date including follow-up assessments. As health care providers require specific knowledge to develop new treatments, we believe that our in-depth assessments can potentially enhance care for youths engaging in NSSI

Neural correlates of human fear conditioning and sources of variability in 2199 individuals

Pavlovian fear conditioning is a fundamental process in both health and disease. We investigate its neural correlates and sources of variability using harmonized functional magnetic resonance imaging data from 2199 individuals across nine countries, including 1888 healthy individuals and 311 with anxiety-related or depressive disorders. Using mega-analysis and normative modeling, we show that fear conditioning consistently engages brain regions within the “central autonomic–interoceptive” or “salience” network. Several task variables strongly modulate activity in these regions, contributing to variability in neural responses. Additionally, brain activation patterns differ between healthy individuals and those with anxiety-related or depressive disorders, with distinct profiles characterizing specific disorders such as post-traumatic stress disorder and obsessive-compulsive disorder. While the neural correlates of fear conditioning are highly generalizable at the population level, variability arises from differences in task design and clinical status, highlighting the importance of methodological diversity in capturing fear learning mechanisms

Untersuchung des Arbeitsgedächtnisses mit funktioneller Magnetresonanztomographie und neuronavigierter transkranieller Magnetstimulation

In der vorliegenden Studie wurden funktionelle Magnetresonanztomographie (fMRT) und transkranielle Magnetstimulation (TMS) im Rahmen einer Arbeitsgedächtnisuntersuchung kombiniert. Gemäß der Hypothese beeinträchtigt TMS über nach fMRT aktiven Gehirnarealen die Gedächtnisfunktion. Mit Hilfe der fMRT wurden bei 8 Probanden individuell Gehirnareale identifiziert, die im Merkintervall bei Durchführung einer modifizierten Sternberg-Aufgabe aktiv waren. Die Stimulation erfolgte anschließend während des Merkintervalls einer vergleichbaren Aufgabe, wobei die TMS-Spule neuronavigiert über den jeweiligen Aktivierungen positioniert wurde. Es wurden eine Kontrollstimulation über der nichtaktiven Gegenseite des Kortex und eine Scheinstimulation ohne Kontakt zur Kopfoberfläche durchgeführt. Die Probanden wurden mit einem kurzen Fragebogen zur subjektiven Beeinträchtigung durch die Stimulation befragt. Gemäß fMRT fanden sich Aktivierungen insbesondere im linken präfrontalen, prämotorischen und parietalen Kortex. Bei Stimulation der individuellen prämotorischen Aktivierungen wurden signifikant höhere Fehlerraten im Vergleich zur Kontrollbedingung festgestellt, nicht aber bei präfrontaler und parietaler TMS. Gegenüber der schmerzfreien Scheinstimulation wurden signifikant erhöhte Fehlerraten in der präfrontalen TMS-Bedingung gemessen. Die Auswertung der Fragebögen ergab, dass sich die Probanden besonders bei präfrontaler TMS durch den Schmerzreiz bei der Stimulation beeinträchtigt fühlten. Hohe durchschnittliche Fehlerraten waren hier korreliert mit hoher subjektiver Schmerzempfindung. Die Beeinträchtigung des Arbeitsgedächtnisses bei prämotorischer Stimulation kann bestehende Hypothesen zur Einbindung dieses Kortexareals in den Gedächtnisprozess stützen. Daneben weisen die Ergebnisse der präfrontalen Stimulation im Vergleich zur Scheinstimulation in Verbindung mit der Einschätzung der subjektiven Beeinträchtigung auf die Bedeutung der Kontrolle von Stimulationsnebenwirkungen hin