1
|
Song Y, Shahdadian S, Armstrong E, Brock E, Conrad SE, Acord S, Johnson YR, Marks W, Papadelis C. Spatiotemporal dynamics of cortical somatosensory network in typically developing children. Cereb Cortex 2024; 34:bhae230. [PMID: 38836408 PMCID: PMC11151116 DOI: 10.1093/cercor/bhae230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 05/10/2024] [Accepted: 05/15/2024] [Indexed: 06/06/2024] Open
Abstract
Sense of touch is essential for our interactions with external objects and fine control of hand actions. Despite extensive research on human somatosensory processing, it is still elusive how involved brain regions interact as a dynamic network in processing tactile information. Few studies probed temporal dynamics of somatosensory information flow and reported inconsistent results. Here, we examined cortical somatosensory processing through magnetic source imaging and cortico-cortical coupling dynamics. We recorded magnetoencephalography signals from typically developing children during unilateral pneumatic stimulation. Neural activities underlying somatosensory evoked fields were mapped with dynamic statistical parametric mapping, assessed with spatiotemporal activation analysis, and modeled by Granger causality. Unilateral pneumatic stimulation evoked prominent and consistent activations in the contralateral primary and secondary somatosensory areas but weaker and less consistent activations in the ipsilateral primary and secondary somatosensory areas. Activations in the contralateral primary motor cortex and supramarginal gyrus were also consistently observed. Spatiotemporal activation and Granger causality analysis revealed initial serial information flow from contralateral primary to supramarginal gyrus, contralateral primary motor cortex, and contralateral secondary and later dynamic and parallel information flows between the consistently activated contralateral cortical areas. Our study reveals the spatiotemporal dynamics of cortical somatosensory processing in the normal developing brain.
Collapse
Affiliation(s)
- Yanlong Song
- Neuroscience Research Center, Jane and John Justin Institute for Mind Health, Cook Children’s Health Care System, 1500 Cooper St., Fort Worth, TX 76104, United States
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd., Arlington, TX 76010, United States
- Departments of Physical Medicine and Rehabilitation and Radiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390, United States
| | - Sadra Shahdadian
- Neuroscience Research Center, Jane and John Justin Institute for Mind Health, Cook Children’s Health Care System, 1500 Cooper St., Fort Worth, TX 76104, United States
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd., Arlington, TX 76010, United States
| | - Eryn Armstrong
- Neuroscience Research Center, Jane and John Justin Institute for Mind Health, Cook Children’s Health Care System, 1500 Cooper St., Fort Worth, TX 76104, United States
| | - Emily Brock
- Neuroscience Research Center, Jane and John Justin Institute for Mind Health, Cook Children’s Health Care System, 1500 Cooper St., Fort Worth, TX 76104, United States
| | - Shannon E Conrad
- Neuroscience Research Center, Jane and John Justin Institute for Mind Health, Cook Children’s Health Care System, 1500 Cooper St., Fort Worth, TX 76104, United States
| | - Stephanie Acord
- Neuroscience Research Center, Jane and John Justin Institute for Mind Health, Cook Children’s Health Care System, 1500 Cooper St., Fort Worth, TX 76104, United States
| | - Yvette R Johnson
- NEST Developmental Follow-up Center, Neonatology, Cook Children’s Health Care System, 1521 Cooper St., Fort Worth, TX 76104, United States
- Department of Pediatrics, Burnett School of Medicine, Texas Christian University, TCU Box 297085, Fort Worth, TX 76129, United States
| | - Warren Marks
- Neuroscience Research Center, Jane and John Justin Institute for Mind Health, Cook Children’s Health Care System, 1500 Cooper St., Fort Worth, TX 76104, United States
| | - Christos Papadelis
- Neuroscience Research Center, Jane and John Justin Institute for Mind Health, Cook Children’s Health Care System, 1500 Cooper St., Fort Worth, TX 76104, United States
- Department of Bioengineering, University of Texas at Arlington, 500 UTA Blvd., Arlington, TX 76010, United States
- Department of Pediatrics, Burnett School of Medicine, Texas Christian University, TCU Box 297085, Fort Worth, TX 76129, United States
| |
Collapse
|
2
|
Lin L, Qing W, Huang Y, Ye F, Rong W, Li W, Jiao J, Hu X. Comparison of Immediate Neuromodulatory Effects between Focal Vibratory and Electrical Sensory Stimulations after Stroke. Bioengineering (Basel) 2024; 11:286. [PMID: 38534560 DOI: 10.3390/bioengineering11030286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/14/2024] [Accepted: 03/15/2024] [Indexed: 03/28/2024] Open
Abstract
Focal vibratory stimulation (FVS) and neuromuscular electrical stimulation (NMES) are promising technologies for sensory rehabilitation after stroke. However, the differences between these techniques in immediate neuromodulatory effects on the poststroke cortex are not yet fully understood. In this research, cortical responses in persons with chronic stroke (n = 15) and unimpaired controls (n = 15) were measured by whole-brain electroencephalography (EEG) when FVS and NMES at different intensities were applied transcutaneously to the forearm muscles. Both FVS and sensory-level NMES induced alpha and beta oscillations in the sensorimotor cortex after stroke, significantly exceeding baseline levels (p < 0.05). These oscillations exhibited bilateral sensory deficiency, early adaptation, and contralesional compensation compared to the control group. FVS resulted in a significantly faster P300 response (p < 0.05) and higher theta oscillation (p < 0.05) compared to NMES. The beta desynchronization over the contralesional frontal-parietal area remained during NMES (p > 0.05), but it was significantly weakened during FVS (p < 0.05) after stroke. The results indicated that both FVS and NMES effectively activated the sensorimotor cortex after stroke. However, FVS was particularly effective in eliciting transient involuntary attention, while NMES primarily fostered the cortical responses of the targeted muscles in the contralesional motor cortex.
Collapse
Affiliation(s)
- Legeng Lin
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
- Research Institute for Smart Ageing (RISA), The Hong Kong Polytechnic University, Hong Kong, China
| | - Wanyi Qing
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
- Research Institute for Smart Ageing (RISA), The Hong Kong Polytechnic University, Hong Kong, China
| | - Yanhuan Huang
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
- Research Institute for Smart Ageing (RISA), The Hong Kong Polytechnic University, Hong Kong, China
| | - Fuqiang Ye
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
- Research Institute for Smart Ageing (RISA), The Hong Kong Polytechnic University, Hong Kong, China
| | - Wei Rong
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Waiming Li
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Jiao Jiao
- Department of Sport, Physical Education and Health, Hong Kong Baptist University, Hong Kong, China
| | - Xiaoling Hu
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
- Research Institute for Smart Ageing (RISA), The Hong Kong Polytechnic University, Hong Kong, China
- University Research Facility in Behavioral and Systems Neuroscience (UBSN), The Hong Kong Polytechnic University, Hong Kong, China
- Joint Research Centre for Biosensing and Precision Theranostics, The Hong Kong Polytechnic University, Hong Kong, China
- Research Centre on Data Science and Artificial Intelligence, The Hong Kong Polytechnic University, Hong Kong, China
| |
Collapse
|
3
|
Jiang Y. White noise insole: an artificial evoked sensation device that can be expected to improve plantar sensation of diabetic foot. Sci Rep 2023; 13:20687. [PMID: 38001103 PMCID: PMC10673850 DOI: 10.1038/s41598-023-47263-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
Diabetic foot is a common severe complication of diabetes, and its main symptom is diabetic foot ulcer. The production of plantar diabetic foot ulcers is usually affected by two factors, namely neuropathy or vascular disease. While previous studies proved that stochastic resonance (SR) could effectively enhance the plantar touch of patients with diabetic feet, the potential impact of SR on neural circuit feedback, especially on the input of the tactile nerves of the lower limbs, is less clear. This study aims to explore the potential impact on the tactile threshold of the human foot when using vibrating insoles. We study a white noise vibration insole based on SR mechanism. We compare and analyze the tactile threshold voltage (TTV) triggered by an electrical stimulation device in three main plantar pressure-bearing areas (the second metatarsal (M2), the fourth metatarsal (M4), and the heel (H) area) of 8 participants using EEG and self-developed vibration insole. Significance found in M2 and M4 areas, white noise signal (WNS) lowered the tactile threshold in these areas, and had a potentially positive impact on patients with diabetic feet, especially in the M4 area. The influence of WNS on the plantar heel area was still controversial. This study showed that WNS applied to the sole could improve the plantar tactile sensing ability of patients with diabetic feet, but it did not cover all areas. The application of WNS showed better benefits for the forefoot area than for the hindfoot area, which was speculated that may be related to the difference in the distribution density of blood vessels in plantar areas. Due to the impaired natural touch in participants with diabetic foot, using artificial evoked sensation WNS intervention, would be a feasible approach to improve plantar sensation.
Collapse
Affiliation(s)
- Yangzheng Jiang
- Women's Hospital, Zhejiang University School of Medicine, Xueshi Rd. 1, Hangzhou, China.
- Institute of Rehabilitation Engineering and Technology, University of Shanghai for Science and Technology, Jungong Rd. 516, Shanghai, China.
| |
Collapse
|
4
|
Foldes ST, Chandrasekaran S, Camerone J, Lowe J, Ramdeo R, Ebersole J, Bouton CE. Case Study: Mapping Evoked Fields in Primary Motor and Sensory Areas via Magnetoencephalography in Tetraplegia. Front Neurol 2021; 12:739693. [PMID: 34630308 PMCID: PMC8497881 DOI: 10.3389/fneur.2021.739693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 08/13/2021] [Indexed: 12/02/2022] Open
Abstract
Devices interfacing with the brain through implantation in cortical or subcortical structures have great potential for restoration and rehabilitation in patients with sensory or motor dysfunction. Typical implantation surgeries are planned based on maps of brain activity generated from intact function. However, mapping brain activity for planning implantation surgeries is challenging in the target population due to abnormal residual function and, increasingly often, existing MRI-incompatible implanted hardware. Here, we present methods and results for mapping impaired somatosensory and motor function in an individual with paralysis and an existing brain–computer interface (BCI) device. Magnetoencephalography (MEG) was used to directly map the neural activity evoked during transcutaneous electrical stimulation and attempted movement of the impaired hand. Evoked fields were found to align with the expected anatomy and somatotopic organization. This approach may be valuable for guiding implants in other applications, such as cortical stimulation for pain and to improve implant targeting to help reduce the craniotomy size.
Collapse
Affiliation(s)
- Stephen T Foldes
- Department of Neurology, Barrow Neurological Institute, Phoenix, AZ, United States
| | - Santosh Chandrasekaran
- Neural Bypass and Brain-Computer Interface Laboratory, Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research at Northwell Health, New York, NY, United States
| | - Joseph Camerone
- MEG Center, Overlook Medical Center, Atlantic Health, Summit, NJ, United States
| | - James Lowe
- MEG Center, Overlook Medical Center, Atlantic Health, Summit, NJ, United States
| | - Richard Ramdeo
- Neural Bypass and Brain-Computer Interface Laboratory, Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research at Northwell Health, New York, NY, United States
| | - John Ebersole
- MEG Center, Overlook Medical Center, Atlantic Health, Summit, NJ, United States
| | - Chad E Bouton
- Neural Bypass and Brain-Computer Interface Laboratory, Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research at Northwell Health, New York, NY, United States.,Department of Molecular Medicine, Hofstra-Northwell Medical School, New York, NY, United States
| |
Collapse
|
5
|
Kangas ES, Vuoriainen E, Li X, Lyyra P, Astikainen P. Somatosensory Deviance Detection ERPs and Their Relationship to Analogous Auditory ERPs and Interoceptive Accuracy. J PSYCHOPHYSIOL 2021. [DOI: 10.1027/0269-8803/a000288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Abstract. Automatic deviance detection has been widely explored in terms of mismatch responses (mismatch negativity or mismatch response) and P3a components of event-related potentials (ERPs) under a predictive coding framework; however, the somatosensory mismatch response has been investigated less often regarding the different types of changes than its auditory counterpart. It is not known whether the deviance detection responses from different modalities correlate, reflecting a general prediction error mechanism of the central nervous system. Furthermore, interoceptive functions have been associated with predictive coding theory, but whether interoceptive accuracy correlates with deviance detection brain responses has rarely been investigated. Here, we measured ERPs to changes in somatosensory stimuli’s location and intensity and in sound intensity in healthy adults ( n = 34). Interoceptive accuracy was measured with a heartbeat discrimination task, where participants indicated whether their heartbeats were simultaneous or non-simultaneous with sound stimuli. We found a mismatch response and a P3a response to somatosensory location and auditory intensity changes, but for somatosensory intensity changes, only a P3a response was found. Unexpectedly, there were neither correlations between the somatosensory location deviance and intensity deviance brain responses nor between auditory and somatosensory brain responses. In addition, the brain responses did not correlate with interoceptive accuracy. The results suggest that although deviance detection in the auditory and somatosensory modalities are likely based on similar neural mechanisms at a cellular level, their ERP indexes do not indicate a linear association in sensitivity for deviance detection between the modalities. Furthermore, although sensory deviance detection and interoceptive detection are both associated with predictive coding functions, under these experimental settings, functional relationships were not observed. These results should be taken into account in the future development of theories related to human sensory functions and in extensions of the predictive coding theory in particular.
Collapse
Affiliation(s)
| | - Elisa Vuoriainen
- Human Information Processing Laboratory, Faculty of Social Sciences/Psychology, Tampere University, Finland
| | - Xueqiao Li
- Department of Psychology, University of Jyvaskyla, Finland
| | - Pessi Lyyra
- Department of Psychology, University of Jyvaskyla, Finland
| | | |
Collapse
|
6
|
Xu Q, Ye C, Hämäläinen JA, Ruohonen EM, Li X, Astikainen P. Magnetoencephalography Responses to Unpredictable and Predictable Rare Somatosensory Stimuli in Healthy Adult Humans. Front Hum Neurosci 2021; 15:641273. [PMID: 33935671 PMCID: PMC8079819 DOI: 10.3389/fnhum.2021.641273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/19/2021] [Indexed: 11/13/2022] Open
Abstract
Mismatch brain responses to unpredicted rare stimuli are suggested to be a neural indicator of prediction error, but this has rarely been studied in the somatosensory modality. Here, we investigated how the brain responds to unpredictable and predictable rare events. Magnetoencephalography responses were measured in adults frequently presented with somatosensory stimuli (FRE) that were occasionally replaced by two consecutively presented rare stimuli [unpredictable rare stimulus (UR) and predictable rare stimulus (PR); p = 0.1 for each]. The FRE and PR were electrical stimulations administered to either the little finger or the forefinger in a counterbalanced manner between the two conditions. The UR was a simultaneous electrical stimulation to both the forefinger and the little finger (for a smaller subgroup, the UR and FRE were counterbalanced for the stimulus properties). The grand-averaged responses were characterized by two main components: one at 30-100 ms (M55) and the other at 130-230 ms (M150) latency. Source-level analysis was conducted for the primary somatosensory cortex (SI) and the secondary somatosensory cortex (SII). The M55 responses were larger for the UR and PR than for the FRE in both the SI and the SII areas and were larger for the UR than for the PR. For M150, both investigated areas showed increased activity for the UR and the PR compared to the FRE. Interestingly, although the UR was larger in stimulus energy (stimulation of two fingers at the same time) and had a larger prediction error potential than the PR, the M150 responses to these two rare stimuli did not differ in source strength in either the SI or the SII area. The results suggest that M55, but not M150, can possibly be associated with prediction error signals. These findings highlight the need for disentangling prediction error and rareness-related effects in future studies investigating prediction error signals.
Collapse
Affiliation(s)
- Qianru Xu
- Institute of Brain and Psychological Sciences, Sichuan Normal University, Chengdu, China.,Jyväskylä Centre for Interdisciplinary Brain Research, Department of Psychology, Faculty of Education and Psychology, University of Jyväskylä, Jyväskylä, Finland
| | - Chaoxiong Ye
- Institute of Brain and Psychological Sciences, Sichuan Normal University, Chengdu, China.,Jyväskylä Centre for Interdisciplinary Brain Research, Department of Psychology, Faculty of Education and Psychology, University of Jyväskylä, Jyväskylä, Finland
| | - Jarmo A Hämäläinen
- Jyväskylä Centre for Interdisciplinary Brain Research, Department of Psychology, Faculty of Education and Psychology, University of Jyväskylä, Jyväskylä, Finland
| | - Elisa M Ruohonen
- Human Information Processing Laboratory, Psychology, Faculty of Social Sciences, Tampere University, Tampere, Finland
| | - Xueqiao Li
- Jyväskylä Centre for Interdisciplinary Brain Research, Department of Psychology, Faculty of Education and Psychology, University of Jyväskylä, Jyväskylä, Finland
| | - Piia Astikainen
- Jyväskylä Centre for Interdisciplinary Brain Research, Department of Psychology, Faculty of Education and Psychology, University of Jyväskylä, Jyväskylä, Finland
| |
Collapse
|
7
|
Kim MY, Kwon H, Yang TH, Kim K. Vibration Alert to the Brain: Evoked and Induced MEG Responses to High-Frequency Vibrotactile Stimuli on the Index Finger of Dominant and Non-dominant Hand. Front Hum Neurosci 2020; 14:576082. [PMID: 33250728 PMCID: PMC7674801 DOI: 10.3389/fnhum.2020.576082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 10/12/2020] [Indexed: 11/13/2022] Open
Abstract
Background: In recent years, vibrotactile haptic feedback technology has been widely used for user interfaces in the mobile devices. Although functional neuroimaging studies have investigated human brain responses to different types of tactile inputs, the neural mechanisms underlying high-frequency vibrotactile perception are still relatively unknown. Our aim was to investigate neuromagnetic brain responses to high-frequency vibrotactile stimulation, using magnetoencephalography (MEG). Methods: We measured 152-channel whole-head MEG in 30 healthy, right-handed volunteers (aged 20–28 years, 15 females). A total of 300 vibrotactile stimuli were presented at the tip of either the left index finger or the right index finger in two separate sessions. Sinusoidal vibrations at 150 Hz for 200 ms were generated with random inter-stimulus intervals between 1.6 and 2.4 s. Both time-locked analysis and time-frequency analysis were performed to identify peak responses and oscillatory modulations elicited by high-frequency vibrations. The significance of the evoked and induced responses for dominant and non-dominant hand stimulation conditions was statistically tested, respectively. The difference in responses between stimulation conditions was also statistically evaluated. Results: Prominent peak responses were observed at 56 ms (M50) and at 100 ms (M100) for both stimulation conditions. The M50 response revealed clear dipolar field patterns in the contralateral side with significant cortical activations in the contralateral primary sensorimotor area, whereas the M100 response was not as prominent as the M50. Vibrotactile stimulation induced significant suppression of both alpha (8–12 Hz) and beta (20–30 Hz) band activity during the mid-latency period (0.2–0.4 s), primarily in sensorimotor areas contralateral to the stimulation side. In addition, a significant alpha enhancement effect in posterior regions was accompanied with alpha suppressions in sensorimotor regions. The alpha suppression was observed in a broader distribution of cortical areas for the non-dominant hand stimulation. Conclusion: Our data demonstrate that high-frequency tactile vibrations, which is known to primarily activate Pacinian corpuscles, elicit somatosensory M50 and M100 responses in the evoked fields and induce modulations of alpha and beta band oscillations during mid-latency periods. Our study is also consistent with that the primary sensorimotor area is significantly involved in the processing of high-frequency vibrotactile information with contralateral dominance.
Collapse
Affiliation(s)
- Min-Young Kim
- Quantum Technology Institute, Korea Research Institute of Standards and Science, Daejeon, South Korea
| | - Hyukchan Kwon
- Quantum Technology Institute, Korea Research Institute of Standards and Science, Daejeon, South Korea
| | - Tae-Heon Yang
- Department of Electronic Engineering, Korea National University of Transportation, Chungju-si, South Korea
| | - Kiwoong Kim
- Quantum Technology Institute, Korea Research Institute of Standards and Science, Daejeon, South Korea.,Department of Medical Physics, University of Science and Technology, Daejeon, South Korea
| |
Collapse
|
8
|
Hautasaari P, McLellan S, Koskio M, Pesonen H, Tarkka IM. Acute Exercise Modulates Pain-induced Response on Sensorimotor Cortex ∼20 Hz Oscillation. Neuroscience 2020; 429:46-55. [DOI: 10.1016/j.neuroscience.2019.12.044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 12/13/2019] [Accepted: 12/28/2019] [Indexed: 01/29/2023]
|
9
|
Single subject and group whole-brain fMRI mapping of male genital sensation at 7 Tesla. Sci Rep 2020; 10:2487. [PMID: 32051426 PMCID: PMC7015912 DOI: 10.1038/s41598-020-58966-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 01/13/2020] [Indexed: 01/07/2023] Open
Abstract
Processing of genital sensations in the central nervous system of humans is still poorly understood. Current knowledge is mainly based on neuroimaging studies using electroencephalography (EEG), magneto-encephalography (MEG), and 1.5- or 3- Tesla (T) functional magnetic resonance imaging (fMRI), all of which suffer from limited spatial resolution and sensitivity, thereby relying on group analyses to reveal significant data. Here, we studied the impact of passive, yet non-arousing, tactile stimulation of the penile shaft using ultra-high field 7T fMRI. With this approach, penile stimulation evoked significant activations in distinct areas of the primary and secondary somatosensory cortices (S1 & S2), premotor cortex, insula, midcingulate gyrus, prefrontal cortex, thalamus and cerebellum, both at single subject and group level. Passive tactile stimulation of the feet, studied for control, also evoked significant activation in S1, S2, insula, thalamus and cerebellum, but predominantly, yet not exclusively, in areas that could be segregated from those associated with penile stimulation. Evaluation of the whole-brain activation patterns and connectivity analyses indicate that genital sensations following passive stimulation are, unlike those following feet stimulation, processed in both sensorimotor and affective regions.
Collapse
|