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Deep brain stimulation at the anterior thalamic nuclei modulates frontal alpha asymmetry and emotional responses
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Abstracts / Brain Stimulation 10 (2017) 346e540
Discussion: The techniques described here can examine the multiple pathways from parietal areas to M1, and show their dynamic modulation with learning. Derangement of these pathways are relevant in disorders such as apraxia and focal hand dystonia. Keywords: Motor cortex, Parietal lobe, Premotor cortex, Brain connectivity
condition, different groups of participants received tDCS of the posterior temporal lobe. The results show that tDCS of the ATL during the recognition test does not have an effect on false recognition, which suggests that its role as a semantic hub relates to encoding rather than retrieval processes. Keywords: semantic memory, left temporal lobe, false memory, tDCS
[0149] EEG UNDER TMS-INDUCED SP REVEALS INHIBITORY EFFECTS OF LOWFREQUENCY RTMS ON THE PRIMARY MOTOR CORTEX
[0151] DEEP BRAIN STIMULATION AT THE ANTERIOR THALAMIC NUCLEI MODULATES FRONTAL ALPHA ASYMMETRY AND EMOTIONAL RESPONSES
F. Jin, J. Jin, Y. Li, X. Wang, Z. Liu, T. Yin*. Chinese Academy of Medical Sciences Peking Union Medical College, China
€kyla €, K. Lehtim€ L. Sun*, M. Polvivaara, J. Pera aki, J. Peltola, K.M. Hartikainen. Tampere University Hospital, Finland
Purpose: A number of methods have been employed to investigate the effects of low-frequency transcranial magnetic stimulation (rTMS), such as Silent Period (SP). However, SP cannot directly demonstrate the effects on cortical activity levels. Recent research showed that SP duration was associated with some EEG parameters under TMS-induced SP. Therefore, the objective of this paper is to test the effects of low-frequency rTMS by analyzing EEG during TMS-induced SP. Methods: 10 healthy subjects were enrolled in the study. With the effects being investigated through tests performed before and after rTMS, every subject accepted 1Hz rTMS at 90% RMT over the left primary motor cortex (M1) for 20 minutes. SP and EEG signals were recorded simultaneously when 110% RMT single TMS was performed on the left hotspot under voluntary contraction of the first dorsal interosseous (FDI) muscle. And then EEG signals were processed by ICA and spline interpolation to obtain TMS-evoked potentials (TEPs) and power spectrums. Results: According to our hypothesis, SP durations were shown to be significantly higher in the post-intervention test than that in the pre-intervention test (p¼0.007). N100 and P30 amplitudes on the left motor cortex, as well as the power spectrums of alpha band (p¼0.015) increased significantly (N100, p¼0.05; P30, p¼0.024). EEG results indicated that 1Hz rTMS increased the amount of GABAa and GABAb-ergic, which revealed the inhibitory effects on motor cortex. Furthermore, there was a significant correlation between SP and N100 amplitudes changes on the left motor cortex (r¼0.784, p¼0.007). Conclusion: Analyzing EEG under TMS-induced SP is a new method to investigate the effects of low-frequency rTMS. The results show that EEG under TMS-induced SP can be used as a marker of cortical inhibition. The present finding provides a possibility for the research of inhibitory mechanism and agnostic of some inhibitory impairments. Keywords: TMS-EEG, SP, low-frequency rTMS, N100
Increased right hemispheric activity, as indicated by rightward frontal alpha asymmetry, has been linked with proneness to mood and anxiety disorders. Previously we have shown that deep brain stimulation at the anterior thalamic nuclei (ANT-DBS) increased attentional allocation to threat-related stimuli, as evidenced by both behavioural changes and alteration of brain event-related potentials (Hartikainen et al., 2014; Sun et al., 2015). Here we further investigated the effect of ANT-DBS on the frontal alpha asymmetry during a cognitive task. In line with our previous findings, electrical stimulation at ANT led to increased rightward frontal alpha asymmetry compared to situations when stimulation was off and when the thalamic control location was stimulated. Therefore, ANT-DBS increased relative right hemispheric activity. The current findings, along with our previous findings that ATN-DBS increases attentional allocation to threat, as well as previously reported depression-related symptoms due to ANT-DBS, call for careful consideration of adverse affective effects of this clinical treatment. Furthermore, frontal alpha asymmetry may server as a potential biomarker for the affective effects of neuromodulation techniques including ANT-DBS. Keywords: deep brain stimulation, emotion, frontal alpha asymmetry, anterior thalamic nuclei
[0150] ENCODING/RETRIEVAL DISSOCIATION OF FALSE RECOGNITION WITH TRANSCRANIAL DIRECT CURRENT STIMULATION (TDCS) OF THE LEFT TEMPORAL LOBE 1 mez-Ariza 2, A.M. Díez-Alamo , M.A. Alonso 3, A. E. Díez*1, C.J. Go Fernandez 1. 1 University of Salamanca - INICO, Spain; 2 University of Jaen, Spain; 3 University of La Laguna - INICO, Spain
A dominant view of the role of the anterior temporal lobe (ATL) in semantic memory functioning is that it serves as an integration hub, specialized in binding together information from different kinds to form a coherent whole concept or “gist” (Wong & Gallate, 2012). While different lines of evidence (e.g.., studies with people suffering from ATL damage) support this view, it has not been until recently that brain stimulation techniques have started to be used to explore this issue. In a previous study (Díez et al., in preparation), tDCS was used along with the DRM paradigm (a well-established cognitive task that is widely utilized to experimentally induce semantic-based false memories), with aim of modulating activity in the ATL while participants encoded word lists that were semantically related to unpresented critical words. The results showed that anodal tDCS of the ATL led to reduced false recognition of critical words in lists composed of strong associates. While suggestive of the role that the ATL may play in the creation of semantically related false memories, these findings are uninformative as to whether the effect of anodal tDCS was interfering with encoding, retrieval or both processes. In the present experiment we aimed to shed light into this issue by replicating the previous study except for the delivery of tDCS over the ATL only while participants performed the recognition test. As a control site
[0152] MATCHING ACTION OBSERVATION TO ACTION EXECUTION M. Soriano*1, A. Cavallo 1, C. Becchio 1, 2. 1 University of Turin, Italy; 2 Italian Institute of Technology, Italy Since the seminal work by Fadiga et al. (1995), several studies have documented the activations of one’s corticospinal system during observation of others actions. Despite nearly two decades of research, however, the specificity of this mirror response to action observation remains poorly understood. Specifically, there are at least three aspects of the mirror response that are not yet clear: timing, directionality, and muscle specificity (Naish et al., 2014). The aim of this study was to clarify timing, directionality, and muscle specificity of the mirror response by directly matching data from action observation to those from action execution. To this end, we first recorded the electromyographic (EMG) activity during the execution of grasping movements direct toward small vs. large objects. Next, by combining single pulse TMS and EMG, we recorded Motor Evoked Potentials (MEPs) from FDI and ADM muscles while participants watched videos of the recorded reach-to-grasp movements. Our results demonstrate, first, that the pattern of corticospinal modulation is muscle-specific and, second, that it matches the direction of muscle activity during action execution (although no overall increase in corticospinal excitability was observed during action observation). Only for timing, we found no correspondence between execution and observation. We anticipate that these results will advance our understanding of the mirror mechanism and provide new insights into the functional role of the human mirror response. Keywords: Mirror response, MEPs, Action observation, Action execution [0153] INTERHEMISPHERIC SENSORIMOTOR CONNECTIVITY OF THE UPPER LIMBS €chinger, K.L. Ruddy. ETH Zürich, Switzerland N. Wenderoth*, M. Ba Introduction: Interhemispheric interactions can be measured during both movement and rest. Here we test two new procedures to (i) probe how cutaneous sensory information is transmitted between hemispheres using
Abstracts / Brain Stimulation 10 (2017) 346e540
Discussion: The techniques described here can examine the multiple pathways from parietal areas to M1, and show their dynamic modulation with learning. Derangement of these pathways are relevant in disorders such as apraxia and focal hand dystonia. Keywords: Motor cortex, Parietal lobe, Premotor cortex, Brain connectivity
condition, different groups of participants received tDCS of the posterior temporal lobe. The results show that tDCS of the ATL during the recognition test does not have an effect on false recognition, which suggests that its role as a semantic hub relates to encoding rather than retrieval processes. Keywords: semantic memory, left temporal lobe, false memory, tDCS
[0149] EEG UNDER TMS-INDUCED SP REVEALS INHIBITORY EFFECTS OF LOWFREQUENCY RTMS ON THE PRIMARY MOTOR CORTEX
[0151] DEEP BRAIN STIMULATION AT THE ANTERIOR THALAMIC NUCLEI MODULATES FRONTAL ALPHA ASYMMETRY AND EMOTIONAL RESPONSES
F. Jin, J. Jin, Y. Li, X. Wang, Z. Liu, T. Yin*. Chinese Academy of Medical Sciences Peking Union Medical College, China
€kyla €, K. Lehtim€ L. Sun*, M. Polvivaara, J. Pera aki, J. Peltola, K.M. Hartikainen. Tampere University Hospital, Finland
Purpose: A number of methods have been employed to investigate the effects of low-frequency transcranial magnetic stimulation (rTMS), such as Silent Period (SP). However, SP cannot directly demonstrate the effects on cortical activity levels. Recent research showed that SP duration was associated with some EEG parameters under TMS-induced SP. Therefore, the objective of this paper is to test the effects of low-frequency rTMS by analyzing EEG during TMS-induced SP. Methods: 10 healthy subjects were enrolled in the study. With the effects being investigated through tests performed before and after rTMS, every subject accepted 1Hz rTMS at 90% RMT over the left primary motor cortex (M1) for 20 minutes. SP and EEG signals were recorded simultaneously when 110% RMT single TMS was performed on the left hotspot under voluntary contraction of the first dorsal interosseous (FDI) muscle. And then EEG signals were processed by ICA and spline interpolation to obtain TMS-evoked potentials (TEPs) and power spectrums. Results: According to our hypothesis, SP durations were shown to be significantly higher in the post-intervention test than that in the pre-intervention test (p¼0.007). N100 and P30 amplitudes on the left motor cortex, as well as the power spectrums of alpha band (p¼0.015) increased significantly (N100, p¼0.05; P30, p¼0.024). EEG results indicated that 1Hz rTMS increased the amount of GABAa and GABAb-ergic, which revealed the inhibitory effects on motor cortex. Furthermore, there was a significant correlation between SP and N100 amplitudes changes on the left motor cortex (r¼0.784, p¼0.007). Conclusion: Analyzing EEG under TMS-induced SP is a new method to investigate the effects of low-frequency rTMS. The results show that EEG under TMS-induced SP can be used as a marker of cortical inhibition. The present finding provides a possibility for the research of inhibitory mechanism and agnostic of some inhibitory impairments. Keywords: TMS-EEG, SP, low-frequency rTMS, N100
Increased right hemispheric activity, as indicated by rightward frontal alpha asymmetry, has been linked with proneness to mood and anxiety disorders. Previously we have shown that deep brain stimulation at the anterior thalamic nuclei (ANT-DBS) increased attentional allocation to threat-related stimuli, as evidenced by both behavioural changes and alteration of brain event-related potentials (Hartikainen et al., 2014; Sun et al., 2015). Here we further investigated the effect of ANT-DBS on the frontal alpha asymmetry during a cognitive task. In line with our previous findings, electrical stimulation at ANT led to increased rightward frontal alpha asymmetry compared to situations when stimulation was off and when the thalamic control location was stimulated. Therefore, ANT-DBS increased relative right hemispheric activity. The current findings, along with our previous findings that ATN-DBS increases attentional allocation to threat, as well as previously reported depression-related symptoms due to ANT-DBS, call for careful consideration of adverse affective effects of this clinical treatment. Furthermore, frontal alpha asymmetry may server as a potential biomarker for the affective effects of neuromodulation techniques including ANT-DBS. Keywords: deep brain stimulation, emotion, frontal alpha asymmetry, anterior thalamic nuclei
[0150] ENCODING/RETRIEVAL DISSOCIATION OF FALSE RECOGNITION WITH TRANSCRANIAL DIRECT CURRENT STIMULATION (TDCS) OF THE LEFT TEMPORAL LOBE 1 mez-Ariza 2, A.M. Díez-Alamo , M.A. Alonso 3, A. E. Díez*1, C.J. Go Fernandez 1. 1 University of Salamanca - INICO, Spain; 2 University of Jaen, Spain; 3 University of La Laguna - INICO, Spain
A dominant view of the role of the anterior temporal lobe (ATL) in semantic memory functioning is that it serves as an integration hub, specialized in binding together information from different kinds to form a coherent whole concept or “gist” (Wong & Gallate, 2012). While different lines of evidence (e.g.., studies with people suffering from ATL damage) support this view, it has not been until recently that brain stimulation techniques have started to be used to explore this issue. In a previous study (Díez et al., in preparation), tDCS was used along with the DRM paradigm (a well-established cognitive task that is widely utilized to experimentally induce semantic-based false memories), with aim of modulating activity in the ATL while participants encoded word lists that were semantically related to unpresented critical words. The results showed that anodal tDCS of the ATL led to reduced false recognition of critical words in lists composed of strong associates. While suggestive of the role that the ATL may play in the creation of semantically related false memories, these findings are uninformative as to whether the effect of anodal tDCS was interfering with encoding, retrieval or both processes. In the present experiment we aimed to shed light into this issue by replicating the previous study except for the delivery of tDCS over the ATL only while participants performed the recognition test. As a control site
[0152] MATCHING ACTION OBSERVATION TO ACTION EXECUTION M. Soriano*1, A. Cavallo 1, C. Becchio 1, 2. 1 University of Turin, Italy; 2 Italian Institute of Technology, Italy Since the seminal work by Fadiga et al. (1995), several studies have documented the activations of one’s corticospinal system during observation of others actions. Despite nearly two decades of research, however, the specificity of this mirror response to action observation remains poorly understood. Specifically, there are at least three aspects of the mirror response that are not yet clear: timing, directionality, and muscle specificity (Naish et al., 2014). The aim of this study was to clarify timing, directionality, and muscle specificity of the mirror response by directly matching data from action observation to those from action execution. To this end, we first recorded the electromyographic (EMG) activity during the execution of grasping movements direct toward small vs. large objects. Next, by combining single pulse TMS and EMG, we recorded Motor Evoked Potentials (MEPs) from FDI and ADM muscles while participants watched videos of the recorded reach-to-grasp movements. Our results demonstrate, first, that the pattern of corticospinal modulation is muscle-specific and, second, that it matches the direction of muscle activity during action execution (although no overall increase in corticospinal excitability was observed during action observation). Only for timing, we found no correspondence between execution and observation. We anticipate that these results will advance our understanding of the mirror mechanism and provide new insights into the functional role of the human mirror response. Keywords: Mirror response, MEPs, Action observation, Action execution [0153] INTERHEMISPHERIC SENSORIMOTOR CONNECTIVITY OF THE UPPER LIMBS €chinger, K.L. Ruddy. ETH Zürich, Switzerland N. Wenderoth*, M. Ba Introduction: Interhemispheric interactions can be measured during both movement and rest. Here we test two new procedures to (i) probe how cutaneous sensory information is transmitted between hemispheres using