scholarly journals Representing Multiple Observed Actions in the Motor System

2018 ◽  
Author(s):  
Emiel Cracco ◽  
Christian Keysers ◽  
Amanda Clauwaert ◽  
Marcel Brass
Keyword(s):  
Motor Cortex ◽  
Motor System ◽  
Brain Activity ◽  
Third Party ◽  
Potential Mechanism ◽  
Brain Areas ◽  
Fmri Study ◽  
Social Encounters ◽  
The Brain ◽  
Do So

AbstractThere is now converging evidence that others’ actions are represented in the motor system. However, social cognition requires us to represent not only the actions but also the interactions of others. To do so, it is imperative that the motor system can represent multiple observed actions. The current fMRI study investigated whether this is possible by measuring brain activity from 29 participants while they observed two right hands performing sign language gestures. Three key results were obtained. First, brain activity in the premotor and parietal motor cortex was stronger when two hands performed two different gestures than when one hand performed a single gesture. Second, both individual observed gestures could be decoded from brain activity in the same two regions. Third, observing two different gestures compared with two identical gestures activated brain areas related to motor conflict, and this activity was correlated with parietal motor activity. Together, these results show that the motor system is able to represent multiple observed actions, and as such reveal a potential mechanism by which third-party social encounters could be processed in the brain.

scholarly journals Representing Multiple Observed Actions in the Motor System

2018 ◽  
Vol 29 (8) ◽  
pp. 3631-3641 ◽  
Author(s):  
Emiel Cracco ◽  
Christian Keysers ◽  
Amanda Clauwaert ◽  
Marcel Brass
Keyword(s):  
Motor Cortex ◽  
Motor System ◽  
Brain Activity ◽  
Third Party ◽  
Potential Mechanism ◽  
Brain Areas ◽  
Fmri Study ◽  
Social Encounters ◽  
The Brain ◽  
Do So

Abstract There is now converging evidence that others’ actions are represented in the motor system. However, social cognition requires us to represent not only the actions but also the interactions of others. To do so, it is imperative that the motor system can represent multiple observed actions. The current fMRI study investigated whether this is possible by measuring brain activity from 29 participants while they observed 2 right hands performing sign language gestures. Three key results were obtained. First, brain activity in the premotor and parietal motor cortex was stronger when 2 hands performed 2 different gestures than when 1 hand performed a single gesture. Second, both individual observed gestures could be decoded from brain activity in the same 2 regions. Third, observing 2 different gestures compared with 2 identical gestures activated brain areas related to motor conflict, and this activity was correlated with parietal motor activity. Together, these results show that the motor system is able to represent multiple observed actions, and as such reveal a potential mechanism by which third-party social encounters could be processed in the brain.

Cannabidiol Has a Unique Effect on Global Brain Activity: A Pharmacological, Functional MRI Study in Awake Mice 

2021 ◽  
Author(s):  
Aymen Sadaka ◽  
Ana Ozuna ◽  
Richard Ortiz ◽  
Praveen Kulkarni ◽  
Clare Johnson ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Brain Activity ◽  
Stress Disorders ◽  
Functional Coupling ◽  
Specific Information ◽  
Imaging Data ◽  
Post Traumatic Stress ◽  
Brain Areas ◽  
Dose Dependent ◽  
The Brain

Abstract Background: The phytocannabinoid cannabidiol (CBD) is a potential treatment for post-traumatic stress disorders. How does CBD interact with the brain to alter behavior? We hypothesized that CBD would produce a dose-dependent reduction in brain activity and functional coupling in neural circuitry associated with fear and defense. Methods: During the scanning session awake mice were given vehicle or CBD (3, 10, or 30 mg/kg I.P.) and imaged for 10 min post treatment. Mice were also treated with the 10 mg/kg dose of CBD and imaged one hr later for resting state BOLD functional connectivity (rsFC). Imaging data were registered to a 3D MRI mouse atlas providing site-specific information on 138 different brain areas. Blood samples were collected for CBD measurements.Results: CBD produced a dose-dependent polarization of activation along the rostral-caudal axis of the brain. The olfactory bulb and prefrontal cortex showed an increase in positive BOLD whereas the brainstem and cerebellum showed a decrease in BOLD signal. This negative BOLD affected many areas connected to the ascending reticular activating system (ARAS). The ARAS was decoupled to much of the brain but was hyperconnected to the olfactory system and prefrontal cortex. The pattern of ARAS connectivity closely overlapped with brain areas showing high levels N-acyl-phosphatidylethanolamines-specific phospholipase D (NAPE-PLD) messenger RNA.Conclusion: The CBD-induced decrease in ARAS activity is consistent with an emerging literature suggesting that CBD reduces autonomic arousal under conditions of emotional and physical stress. The putative target and mechanism of action is NAPE-PLD the enzyme responsible for the biosynthesis of lipid signaling molecules like anandamide.

P18-3 Odors activate selectively the brain areas related on the memory and emotion, by an fMRI study

2010 ◽  
Vol 121 ◽  
pp. S208
Author(s):  
M. Tonoike ◽  
T. Uno ◽  
T. Yoshida ◽  
L.Q. Wang
Keyword(s):  
Brain Areas ◽  
Fmri Study ◽  
The Brain

scholarly journals Stopping a response has global or nonglobal effects on the motor system depending on preparation

2012 ◽  
Vol 107 (1) ◽  
pp. 384-392 ◽  
Author(s):  
Ian Greenhouse ◽  
Caitlin L. Oldenkamp ◽  
Adam R. Aron
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Motor System ◽  
Primary Motor Cortex ◽  
Stop Signal ◽  
Stop Signal Task ◽  
Proactive Control ◽  
The Subject ◽  
Do So

Much research has focused on how people stop initiated response tendencies when instructed by a signal. Stopping of this kind appears to have global effects on the motor system. For example, by delivering transcranial magnetic stimulation (TMS) over the leg area of the primary motor cortex, it is possible to detect suppression in the leg when the hand is being stopped (Badry R et al. Suppression of human cortico-motoneuronal excitability during the stop-signal task. Clin Neurophysiol 120: 1717–1723, 2009). Here, we asked if such “global suppression” can be observed proactively, i.e., when people anticipate they might have to stop. We used a conditional stop signal task, which allows the measurement of both an “anticipation phase” (i.e., where proactive control is applied) and a “stopping” phase. TMS was delivered during the anticipation phase ( experiment 1) and also during the stopping phase ( experiments 1 and 2) to measure leg excitability. During the anticipation phase, we did not observe leg suppression, but we did during the stopping phase, consistent with Badry et al. (2009) . Moreover, when we split the subject groups into those who slowed down behaviorally (i.e., exercised proactive control) and those who did not, we found that subjects who slowed did not show leg suppression when they stopped, whereas those who did not slow did show leg suppression when they stopped. These results suggest that if subjects prepare to stop, then they do so without global effects on the motor system. Thus, preparation allows them to stop more selectively.

scholarly journals Different mechanisms of contralateral- or ipsilateral-acupuncture to modulate the brain activity in patients with unilateral chronic shoulder pain: a pilot fMRI study

2018 ◽  
Vol Volume 11 ◽  
pp. 505-514 ◽  
Author(s):  
Shuai Zhang ◽  
Xu Wang ◽  
Chao-Qun Yan ◽  
Shang-Qing Hu ◽  
Jian-Wei Huo ◽  
...  
Keyword(s):  
Shoulder Pain ◽  
Brain Activity ◽  
Fmri Study ◽  
The Brain ◽  
Chronic Shoulder Pain

scholarly journals Dissociating Neural Correlates of Action Monitoring and Metacognition of Agency

2011 ◽  
Vol 23 (11) ◽  
pp. 3620-3636 ◽  
Author(s):  
David B. Miele ◽  
Tor D. Wager ◽  
Jason P. Mitchell ◽  
Janet Metcalfe
Keyword(s):  
Brain Activity ◽  
Dorsal Striatum ◽  
Neural Correlates ◽  
Action Monitoring ◽  
Fmri Study ◽  
Metacognitive Judgments ◽  
The Right ◽  
Reflective Processing ◽  
Increased Activity ◽  
The Brain

Judgments of agency refer to people's self-reflective assessments concerning their own control: their assessments of the extent to which they themselves are responsible for an action. These self-reflective metacognitive judgments can be distinguished from action monitoring, which involves the detection of the divergence (or lack of divergence) between observed states and expected states. Presumably, people form judgments of agency by metacognitively reflecting on the output of their action monitoring and then consciously inferring the extent to which they caused the action in question. Although a number of previous imaging studies have been directed at action monitoring, none have assessed judgments of agency as a potentially separate process. The present fMRI study used an agency paradigm that not only allowed us to examine the brain activity associated with action monitoring but that also enabled us to investigate those regions associated with metacognition of agency. Regarding action monitoring, we found that being “out of control” during the task (i.e., detection of a discrepancy between observed and expected states) was associated with increased brain activity in the right TPJ, whereas being “in control” was associated with increased activity in the pre-SMA, rostral cingulate zone, and dorsal striatum (regions linked to self-initiated action). In contrast, when participants made self-reflective metacognitive judgments about the extent of their own control (i.e., judgments of agency) compared with when they made judgments that were not about control (i.e., judgments of performance), increased activity was observed in the anterior PFC, a region associated with self-reflective processing. These results indicate that action monitoring is dissociable from people's conscious self-attributions of control.

scholarly journals Resting-state connectivity studies as a marker of the acute and delayed effects of subanaesthetic ketamine administration in healthy and depressed individuals: A systematic review

2021 ◽  
Vol 5 ◽  
pp. 239821282110554
Author(s):  
Vasileia Kotoula ◽  
Toby Webster ◽  
James Stone ◽  
Mitul A Mehta
Keyword(s):  
Resting State ◽  
Emotional Regulation ◽  
Brain Connectivity ◽  
Brain Activity ◽  
Reward Processing ◽  
Brain Areas ◽  
Delayed Effects ◽  
Treatment Naïve ◽  
Resting State Connectivity ◽  
The Brain

Acute ketamine administration has been widely used in neuroimaging research to mimic psychosis-like symptoms. Within the last two decades, ketamine has also emerged as a potent, fast-acting antidepressant. The delayed effects of the drug, observed 2–48 h after a single infusion, are associated with marked improvements in depressive symptoms. At the systems’ level, several studies have investigated the acute ketamine effects on brain activity and connectivity; however, several questions remain unanswered around the brain changes that accompany the drug’s antidepressant effects and how these changes relate to the brain areas that appear with altered function and connectivity in depression. This review aims to address some of these questions by focusing on resting-state brain connectivity. We summarise the studies that have examined connectivity changes in treatment-naïve, depressed individuals and those studies that have looked at the acute and delayed effects of ketamine in healthy and depressed volunteers. We conclude that brain areas that are important for emotional regulation and reward processing appear with altered connectivity in depression whereas the default mode network presents with increased connectivity in depressed individuals compared to healthy controls. This finding, however, is not as prominent as the literature often assumes. Acute ketamine administration causes an increase in brain connectivity in healthy volunteers. The delayed effects of ketamine on brain connectivity vary in direction and appear to be consistent with the drug normalising the changes observed in depression. The limited number of studies however, as well as the different approaches for resting-state connectivity analysis make it very difficult to draw firm conclusions and highlight the importance of data sharing and larger future studies.

scholarly journals Synchronization in the connectome: Metastable oscillatory modes emerge from interactions in the brain spacetime network

2022 ◽  
Author(s):  
Joana Cabral ◽  
Francesca Castaldo ◽  
Jakub Vohryzek ◽  
Vladimir Litvak ◽  
Christian Bick ◽  
...  
Keyword(s):  
Coupled Oscillators ◽  
Brain Activity ◽  
Power Spectra ◽  
Brain Areas ◽  
Neural Mass ◽  
Spatially Distributed ◽  
Weakly Stable ◽  
Human Brains ◽  
The Brain

A rich repertoire of oscillatory signals is detected from human brains with electro- and magnetoencephalography (EEG/MEG). However, the principles underwriting coherent oscillations and their link with neural activity remain unclear. Here, we hypothesise that the emergence of transient brain rhythms is a signature of weakly stable synchronization between spatially distributed brain areas, occurring at network-specific collective frequencies due to non-negligible conduction times. We test this hypothesis using a phenomenological network model to simulate interactions between neural mass potentials (resonating at 40Hz) in the structural connectome. Crucially, we identify a critical regime where metastable oscillatory modes emerge spontaneously in the delta (0.5-4Hz), theta (4-8Hz), alpha (8-13Hz) and beta (13-30Hz) frequency bands from weak synchronization of subsystems, closely approximating the MEG power spectra from 89 healthy individuals. Grounded in the physics of delay-coupled oscillators, these numerical analyses demonstrate the role of the spatiotemporal connectome in structuring brain activity in the frequency domain.

The Neurobiology of Sleep

2013 ◽  
pp. 1127-1143
Author(s):  
Giulio Tononi ◽  
Chiara Cirelli
Keyword(s):  
Sleep Deprivation ◽  
Brain Activity ◽  
Negative Consequences ◽  
Brain Areas ◽  
Environmental Stimuli ◽  
Essential Function ◽  
The Brain ◽  
Dreamless Sleep

Sleep is a state of reduced responsiveness to environmental stimuli, usually associated with immobility and stereotyped postures. It is universal and tightly regulated, suggesting that it is likely to serve some essential function. However, that function remains unclear. In this chapter we examine how sleep is traditionally subdivided into different stages that alternate in the course of the night, discuss the brain areas that determine whether we are asleep or awake, and summarize the negative consequences of sleep deprivation. We then discuss how brain activity changes between sleep and wakefulness and consider how this leads to the characteristic modifications of consciousness experienced during dreaming and dreamless sleep. Finally, we turn to the paramount but still mysterious question of sleep function.

scholarly journals Abnormal Baseline Brain Activity in Patients with Pulsatile Tinnitus: A Resting-State fMRI Study

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Lv Han ◽  
Liu Zhaohui ◽  
Yan Fei ◽  
Li Ting ◽  
Zhao Pengfei ◽  
...  
Keyword(s):  
Resting State ◽  
Structural Changes ◽  
Brain Activity ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Resting State Fmri ◽  
Pulsatile Tinnitus ◽  
Spontaneous Brain Activity ◽  
Fmri Study ◽  
The Brain

Numerous investigations studying the brain functional activity of the tinnitus patients have indicated that neurological changes are important findings of this kind of disease. However, the pulsatile tinnitus (PT) patients were excluded in previous studies because of the totally different mechanisms of the two subtype tinnitus. The aim of this study is to investigate whether altered baseline brain activity presents in patients with PT using resting-state functional magnetic resonance imaging (rs-fMRI) technique. The present study used unilateral PT patients (n=42) and age-, sex-, and education-matched normal control subjects (n=42) to investigate the changes in structural and amplitude of low-frequency (ALFF) of the brain. Also, we analyzed the relationships between these changes with clinical data of the PT patients. Compared with normal controls, PT patients did not show any structural changes. PT patients showed significant increased ALFF in the bilateral precuneus, and bilateral inferior frontal gyrus (IFG) and decreased ALFF in multiple occipital areas. Moreover, the increased THI score and PT duration was correlated with increased ALFF in precuneus and bilateral IFG. The abnormalities of spontaneous brain activity reflected by ALFF measurements in the absence of structural changes may provide insights into the neural reorganization in PT patients.

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