Honors & Awards
the Santen Pharmaceutical Travel Grant, the Association for Research in Vision and Ophthalmology (ARVO) (2010)
Boards, Advisory Committees, Professional Organizations
Councilor, Japanese Neuro-Ophthalmology Society (2015 - Present)
Doctor of Philosophy, Kyoto University (2017)
Doctor of Medicine, Kyoto University (2007)
Jeffrey Goldberg, Postdoctoral Faculty Sponsor
Community and International Work
International Blind Tennis Association
Opportunities for Student Involvement
Effect of Microtubule Disruption on Dynamics of Acidic Organelles in the Axons of Primary Cultured Retinal Ganglion Cells.
Current eye research
2018; 43 (1): 77–83
Axonal transport is fundamental to autophagy in neuronal cells. To understand its biological significance in various conditions, it is necessary to monitor the process of autophagy. However, monitoring methods are often limited to static analyses, such as protein expression and histological observations. Autophagy has multistep process and is highly dynamic; therefore, additional techniques are necessary to study autophagy. In this study, we quantified the dynamics of autophagy-related organelle transport under conditions of dynamic instability and catastrophic disruption of microtubules using in vitro live imaging.Retinal ganglion cells (RGCs) were isolated from postnatal day 3 Sprague-Dawley rats by immunopanning. After 7 days of culture, acidic organelles were stained by LysoTracker. Dynamics of acidic organelles was quantified using kymographs. Colchicine was used to induce microtubule disruption. Movement of acidic organelles was observed at five time points: before, and at 6, 24, 72, and 120 h after colchicine stimulation. Ethidium homodimer-1 (EthD-1) was used to determine cell viability.The status of axonal transport of acidic organelles (n = 363) from 27 RGCs was classified into four categories: anterograde (1.4%), retrograde (90%), stationary (8.0%), and fluttering (0.28%). Six hours after the induction of microtubule disruption in 14 of 27 RGCs, almost all acidic organelles (n = 236) were stationary. All acidic components had completely stopped moving 24 h later. At 72 h after stimulation, axonal fragmentation, and shrinking and disappearance of soma were observed in 71% of RGCs. Finally, the remaining RGCs became positive for EthD-1. In the control (13 of 27 RGCs), axonal transport was maintained for 120 h and EthD-1-positive RGCs were not observed.Almost all acidic organelles were transported retrogradely along the axon, which was inhibited by colchicine. Understanding the dynamics of acidic organelles may provide useful parameters for characterizing autophagy of neuronal cells in pathophysiological conditions.
View details for PubMedID 28937869
Altered Transport Velocity of Axonal Mitochondria in Retinal Ganglion Cells After Laser-Induced Axonal Injury In Vitro
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
2015; 56 (13): 8019-8025
Axonal damage precedes retinal ganglion cell (RGC) apoptosis in glaucomatous optic neuropathy. Because mitochondria in RGC axons are damaged before cell death, we examined axonal mitochondrial transport dynamics after axonal injury.Mitochondria in rat-cultivated RGCs were stained with rhodamine 123. After axonal injury induced using a laser microdissection system, axonal transport was evaluated by time-lapse imaging. The RGC apoptosis was detected using ethidium homodimer-1 on day 3 after axonal injury.The rate of stationary mitochondria in RGC axons significantly increased from 37.6% before axonal injury to 70.6% at 5 minutes (P < 0.001) and 63.6% at 18 hours (P < 0.001) after axonal injury. The mean axonal mitochondrial transport velocity in RGCs transiently deteriorated from 0.48 ± 0.01 μm/s before axonal injury to 0.37 ± 0.02 μm/s at 5 minutes after axonal injury (P < 0.001). However, 23.5% of RGCs showed recovered axonal transport velocity at 18 hours after injury. On day 3 after axonal injury, RGCs with the recovery of axonal transport did not undergo apoptosis, whereas 69.2% of RGCs without the recovery of axonal transport underwent apoptosis (P = 0.029).Axonal injury disrupts mitochondrial transport in RGC axons. Irreversible decreased axonal mitochondrial transport velocity may be useful to predict RGC apoptosis after axonal injury.
View details for DOI 10.1167/iovs.15-17876
View details for Web of Science ID 000368243800049
View details for PubMedID 26720449
Association of Bruch's membrane opening and optic disc morphology to axial length and visual field defects in eyes with primary open-angle glaucoma
GRAEFES ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
2018; 256 (3): 599–610
To examine the morphology of Bruch's membrane opening (BMO), optic disc, and peripapillary atrophy (PPA) by scanning laser ophthalmoscopy (SLO) and spectral-domain optical coherence tomography (SD-OCT), and to determine their association with the axial length and visual field defects.This was a cross-sectional study of 94 eyes of 56 subjects; 77 eyes were diagnosed with primary open-angle glaucoma and 17 eyes as normal. The margins of the optic disc were determined in the SLO images, and that of the BMO in the SD-OCT images. The ovality and area of the BMO and the optic disc were measured. The beta and gamma-PPA areas were also measured. The association of each parameter with the axial length and the mean deviation (MD) of the visual field tests was determined by generalized estimating equations (GEEs).The optic disc ovality was associated with the axial length and the MD (β = -0.47, P = 7.6 × 10-4 and β = 0.12, P = 0.040). The BMO ovality was not significantly associated with the axial length and the MD. The BMO area was associated with the axial length (β = 0.30, P = 0.029). A larger BMO area was associated with a thinner BMO-based neuroretinal rim width (BMO-MRW) after adjustments for the MD (β = -0.30, P = 2.1 × 10-4). The beta- and gamma-PPA areas were associated with the axial length (β = 0.50, P = 7.4 × 10-5 and β = 0.62, P = 4.2 × 10-6).The optic disc ovality was associated with both the axial length and MD, whereas BMO ovality was not. Attention should be paid to the influence of the axial length-related enlargement of the BMO.
View details for PubMedID 29305731
Structural and Functional Analyses in Nonarteritic Anterior Ischemic Optic Neuropathy: Optical Coherence Tomography Angiography Study.
Journal of neuro-ophthalmology
2017; 37 (2): 140-148
Retinal and optic disc perfusion in nonarteritic anterior ischemic optic neuropathy (NAION) is incompletely understood. Our aim was to investigate the characteristics of the microvascular structures at the peripapillary area and optic disc, and their associations with retinal structure and function in patients with NAION.We conducted a prospective, observational case series study. Thirty-four eyes, consisting of 15 NAION eyes and 19 normal eyes, were included. Optical coherence tomography (OCT) angiography was used to measure the vessel densities in the peripapillary superficial retina and whole-depth mode inside the optic disc. Measurement of circumpapillary retinal nerve fiber layer (cpRNFL) thickness was performed using OCT. Sectorial division analysis of cpRNFL was performed by eliminating the influences of the difference in disc rotation between OCT images and OCT angiography images.The vessel densities of peripapillary retina and inside the optic disc were significantly reduced in the NAION compared to the normal (both P < 0.001). Both the severity of visual field defect and cpRNFL thinning were significantly associated with the peripapillary vessel density (P = 0.006, P = 0.046), but not with the optic disc vessel density (P = 0.981, P = 0.856). cpRNFL and peripapillary vessel density showed reduction predominantly in the superior sectors, corresponding to the visual field defect. However, the correlations showed discrepancy of the sectors.The microvascular structures in the peripapillary retina and optic disc were reduced, but the cpRNFL thinning was associated with vessel density only in the peripapillary retina, indicating that the vessel densities in the peripapillary retina and optic disc may be differently affected in the pathological process of NAION.
View details for DOI 10.1097/WNO.0000000000000470
View details for PubMedID 27984351
Circumpapillary retinal nerve fiber layer thickness, anterior lamina cribrosa depth, and lamina cribrosa thickness in neovascular glaucoma secondary to proliferative diabetic retinopathy: a cross-sectional study
To compare the lamina cribrosa between eyes with and without neovascular glaucoma (NVG) using enhanced depth imaging spectral-domain optical coherence tomography.Forty-six patients with proliferative diabetic retinopathy were enrolled in this cross-sectional study. The patients were divided into two groups based on the absence or presence of NVG (the non-NVG group and the NVG group, respectively). The intraocular pressure (IOP), circumpapillary retinal nerve fiber layer (cpRNFL) thickness, anterior lamina cribrosa depth (ALD), and laminar thickness (LT) were compared between the groups.In the non-NVG group, the mean age was 66.2 ± 2.4 (mean ± standard error) years, mean maximum IOP was 18.8 ± 1.8 mmHg, mean cpRNFL thickness was 91.2 ± 3.9 μm, mean ALD was 407.0 ± 22.9 μm, and mean LT was 155.0 ± 4.7 μm. In the NVG group, the mean age was 61.4 ± 2.1 years, mean maximum IOP was 33.1 ± 1.6 mmHg, mean cpRNFL thickness was 73.6 ± 3.4 μm, mean ALD was 403.9 ± 20.1 μm, and mean LT was 156.9 ± 4.2 μm. The IOP was significantly higher and the cpRNFL was significantly thinner in the NVG group (P < 0.001 and P = 0.002, respectively). However, the age, ALD, and LT were not statistically different between the groups (P = 0.151, 0.919, and 0.757, respectively).Although the cpRNFL was thinner, the structure of the lamina cribrosa was unchanged in the NVG eyes. Axonal loss of the retinal ganglion cells in NVG patients was prior to lamina cribrosa deformation.
View details for DOI 10.1186/s12886-017-0456-9
View details for Web of Science ID 000400240200004
View details for PubMedID 28446148
View details for PubMedCentralID PMC5407001
Retinal Blood Flow Velocity Change in Parafoveal Capillary after Topical Tafluprost Treatment in Eyes with Primary Open-angle Glaucoma.
2017; 7 (1): 5019
Although ocular circulation at the retina and optic disc is known to be associated with the pathology of glaucoma, direct measurement of blood flow velocity has been difficult to obtain. This prospective observational study enrolled 11 consecutive patients with treatment-naïve primary open-angle glaucoma (POAG) and 11 healthy subjects, and the effects of topical tafluprost treatment on ocular circulation were examined at baseline and at 1, 4, and 12 weeks after initiating treatment with topical tafluprost on POAG patients using multiple modalities, which include adaptive optics scanning laser ophthalmoscopy (AOSLO). Baseline mean intraocular pressure (IOP) was significantly higher and mean parafoveal blood flow velocity (pBFV) was significantly lower in POAG eyes than in healthy eyes. Mean IOP was significantly decreased (1 week, -19.1%; 4 weeks, -17.7%; and 12 weeks, -23.5%; all P < 0.001) and mean pBFV was significantly increased from the baseline at all follow-up periods after initiating treatment (1 week, 14.9%, P = 0.007; 4 weeks, 21.3%, P < 0.001; and 12 weeks, 14.3%, P = 0.002). These results reveal that tafluprost may not only lower IOP but may also improve retinal circulation in POAG eyes and AOSLO may be useful to evaluate retinal circulatory change after treatment.
View details for PubMedID 28694501
View details for PubMedCentralID PMC5504003
Prospective observational study of conjunctival scarring after phacoemulsification
2016; 94 (7): E541-E549
To examine whether anterior segment-optical coherence tomography (AS-OCT) can detect conjunctival scarring after transscleral phacoemulsification and whether temporal transscleral phacoemulsification causes scarring in the superior conjunctiva.Transscleral phacoemulsification was performed in the superior conjunctiva (superior incision group) or the temporal conjunctiva (temporal incision group). Anterior segment-optical coherence tomography (AS-OCT) images of the superior conjunctiva were obtained before and after surgery. We quantified the thickness of the conjunctiva and preservation rates of the borderlines among the subconjunctival layers. The relationship between the AS-OCT images and histology was evaluated in rabbit eyes with phacoemulsification.Each group comprised 25 patients. At ≤1 month after surgery, the superior conjunctiva was significantly thicker in the superior incision group than the temporal incision group (1 day, 7 days, and 1 month after surgery; p < 0.0001, p < 0.0001, and p < 0.001 respectively); however, there were no significant differences between the two groups at ≥2 months. The borderline of the conjunctival stroma/Tenon's capsule and the borderline of the Tenon's capsule/sclera were preserved significantly better in the temporal incision group after surgery (p < 0.0001). The cell densities in the conjunctiva of the rabbit temporal incision group were unchanged after surgery, whereas the rabbit superior incision group had significantly more neutrophils (p = 0.0001) and myofibroblasts (p < 0.0001) in the superior conjunctiva than the temporal incision group.Anterior segment-optical coherence tomography (AS-OCT) images can detect conjunctival scarring after transscleral phacoemulsification. The layer structures in the superior conjunctiva are unaffected by temporal transscleral incision.
View details for DOI 10.1111/aos.13071
View details for Web of Science ID 000386631400003
View details for PubMedID 27167027
The relationship between self-reported habitual exercise and visual field defect progression: a retrospective cohort study
Exercise reduces intraocular pressure (IOP) in the short term. However, it is not known whether exercise contributes to slower glaucomatous visual field defect progression.Twenty-four primary open-angle glaucoma or exfoliation glaucoma patients who were evaluated by the Humphrey Field Analyzer (HFA) 24-2 program ≥ four times in 3 years were enrolled. Patients with a history of intraocular surgery in past 3 years or other eye diseases threatening visual fields were excluded. Patients were classified into two groups whether they had exercise habits or not.Eleven patients had exercise habits. The mean ± standard error of IOP and MD slope were 14.8 ± 0.9 mmHg and +0.20 ± 0.20 dB/year in the exercise group and 13.3 ± 0.8 mmHg and -0.53 ± 0.18 dB/year in the non-exercise group (P = 0.24 and P = 0.01, respectively). Higher IOP [odds ratio (OR) = 0.44/1 mmHg increase; P = 0.02] and habitual exercise (OR = 0.04; P = 0.02) reduced the visual field defect progression risk in logistic regression analyses.Patients with self-reported exercise habits had slower glaucoma progression.
View details for DOI 10.1186/s12886-016-0326-x
View details for Web of Science ID 000383548300001
View details for PubMedID 27553843
View details for PubMedCentralID PMC4995761
Microvascular Density in Glaucomatous Eyes With Hemifield Visual Field Defects: An Optical Coherence Tomography Angiography Study
AMERICAN JOURNAL OF OPHTHALMOLOGY
2016; 168: 237-249
To investigate microcirculation of peripapillary retina and optic disc in eyes with primary open-angle glaucoma (POAG) and hemifield visual field (VF) defects.Prospective observational case series with normal comparison group.Sixty eyes with POAG (41 with superior and 19 with inferior hemifield VF defects) and 21 normal eyes were included in this study. Optical coherence tomography (OCT) angiography was used to acquire 3 × 3-mm optic disc cubes, and circumpapillary retinal nerve fiber layer thickness was also measured using OCT. Vessel densities in the peripapillary superficial retina and whole-signal-mode optic disc were individually analyzed based on the sectorial division.The peripapillary vessel densities were significantly reduced at the corresponding location of the VF defects in both non-highly myopic (P < .001, P = .006) and highly myopic glaucomatous eyes (P < .001, P = .005) compared with the normal eyes. Vessel densities of the optic discs were significantly reduced at locations corresponding to the VF defects in eyes without high myopia but with inferior hemifield VF defects (P = .006), but not in the other eyes. The vessel densities in the peripapillary retina were significantly associated with visual field total deviation values at their corresponding sides. The choroidal microvascular reduction in the peripapillary area extended to the α-peripapillary atrophy (PPA) as well as β-PPA zones.Microvascular reduction was associated with VF defects in a region-specific manner: significantly and partially in the peripapillary retina and optic disc, respectively.
View details for DOI 10.1016/j.ajo.2016.06.009
View details for Web of Science ID 000381166600026
View details for PubMedID 27296492
Clustering of Combined 24-2 and 10-2 Visual Field Grids and Their Relationship With Circumpapillary Retinal Nerve Fiber Layer Thickness
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE
2016; 57 (7): 3203-3210
The purpose of this study was to cluster the test points of the combined 24-2 and 10-2 visual fields (VFs) and circumpapillary retinal nerve fiber layer thickness (cpRNFLT) sectors using explanatory factor analyses (EFAs). The correlations between the VF clusters and cpRNFLT clusters were determined, and a new function-structure relationship map was determined.Two hundred fifty-four eyes of 166 subjects (13 normal eyes and 241 eyes with glaucoma) were studied retrospectively. All eyes had an axial length <27 mm and had undergone 24-2 and 10-2 VF tests using the Swedish Interactive Threshold Algorithm (SITA-standard) and cpRNFLT examinations by spectral domain optical coherence tomography within a 3-month period. Explanatory factor analysis was performed to group the 116 test points of the combined 24-2/10-2 VF test grids into a smaller number of VF clusters. Another EFA was performed to cluster the 24 cpRNFLT sectors. The correlations between the VF clusters and the cpRNFLT clusters were evaluated by Pearson's correlation analysis.The combined 24-2/10-2 VF test grids were grouped into seven VF clusters by EFA. Another EFA grouped the cpRNFLT sectors into 11 clusters. The correlation coefficients between the corresponding VF and cpRNFLT clusters ranged from 0.304 (P < 1 × 10-6) to 0.794 (P < 2.2 × 10-16).Explanatory factor analysis revealed detailed patterns of glaucomatous VF defects and glaucomatous cpRNFL thinning. Their significant correlations indicate that they have common latent factors that might be derived from a developing pattern of glaucomatous optic neuropathy. These findings support the function-structure relationship theory in glaucoma.
View details for DOI 10.1167/iovs.15-18798
View details for Web of Science ID 000381726600035
View details for PubMedID 27309624
Limbus- Versus Fornix-Based Trabeculectomy for Open-Angle Glaucoma Eyes with Prior Ocular Surgery: The Collaborative Bleb-Related Infection Incidence and Treatment Study
We compared the surgical successes of limbus- and fornix-based trabeculectomies in open-angle glaucoma (OAG) eyes that had prior ocular surgery in the Collaborative Bleb-Related Infection Incidence and Treatment Study (CBIITS), Japan. From the 1,098 glaucoma eyes in 34 clinical centers in CBIITS, 195 OAG eyes that had undergone previous trabeculectomy and/or lens extraction were included. Limbus- or fornix-based trabeculectomy with mitomycin C were performed. Surgical failure (IOP ≥ 21, 18, or 15 mmHg for criterion A, B or C, respectively; <20% decrease from baseline; reoperation for glaucoma; or loss of light perception vision) was counted. There were 106 and 89 eyes treated with limbus- and fornix-based trabeculectomies, respectively. At 3 years, IOP (mean ± SD) was 12.5 ± 5.9 and 14.1 ± 6.4 mmHg and the cumulative probabilities of failure during 3 years were 30.2% and 50.5% for criterion A, 40.3% and 57.4% for criterion B, and 57.9% and 65.8% for criterion C in the limbus- and the fornix-based group, respectively. Fornix-based incisions were associated with surgical failure in Cox-proportional multivariable analysis for criterion A [relative risk (RR) = 1.96], and B [RR = 1.60]. Limbus-based trabeculectomy had a higher probability of success in OAG eyes with prior ocular surgery.
View details for Web of Science ID 000351276500006
View details for PubMedID 25786684
Large capsulorhexis with implantation of a 7.0 mm optic intraocular lens during cataract surgery in patients with diabetes mellitus
JOURNAL OF CATARACT AND REFRACTIVE SURGERY
2014; 40 (11): 1850-1856
To evaluate the efficacy of a large capsulorhexis and intraocular lens (IOL) in obtaining a larger anterior capsule opening after cataract surgery in patients with diabetes mellitus (DM).Department of Ophthalmology, University of Fukui, Fukui, Japan.Prospective clinical trial.Patients with DM had bilateral cataract surgery with a 2.8 or 3.0 mm scleral incision, a capsulorhexis with a diameter of approximately 5.0 or 6.0 mm, and implantation of a 6.0 mm optic (Eternity X-60) or 7.0 mm optic (Eternity X-70) IOL. The anterior capsule opening area, aqueous flare intensity, surgically induced astigmatism (SIA), corneal endothelial cell density (ECD), and central corneal thickness (CCT) were measured 1 day, 1 week, and 1, 3, and 6 months after surgery.Thirty-one patients (62 eyes) with DM were enrolled. At all postoperative timepoints, the anterior capsule opening was significantly larger in eyes with the 7.0 mm optic IOL than in eyes with the 6.0 mm optic IOL (P<.05, Mann-Whitney U test). There were no significant differences in postoperative aqueous flare intensity, SIA, ECD, or CCT based on the size of the capsulorhexis and IOL.A larger capsulorhexis and implantation of a 7.0 mm IOL resulted in a larger anterior capsule opening after cataract surgery in patients with DM.No author has a financial or proprietary interest in any material or method mentioned.
View details for DOI 10.1016/j.jcrs.2014.02.039
View details for Web of Science ID 000344580800015
View details for PubMedID 25201533
Objective Assessment of Foveal Cone Loss Ratio in Surgically Closed Macular Holes Using Adaptive Optics Scanning Laser Ophthalmoscopy
2013; 8 (5)
To use adaptive optics scanning laser ophthalmoscopy (AO-SLO) to quantify cone loss ratio in the foveola in order to assess foveal cone status and to investigate relationships between foveal structural abnormalities and visual function in patients with macular hole (MH) after surgery.We evaluated 10 normal eyes of 10 healthy volunteers and 19 eyes of 18 patients in whom anatomically successful MH closure had been performed. All subjects underwent a comprehensive ophthalmologic examination that included measurements of spectral-domain optical coherence tomography and AO-SLO.On AO-SLO regular cone mosaic was seen in all normal eyes whereas dark regions suggesting cone loss were seen in all eyes after MH repair. Visual acuity was better in eyes without dark regions at the center of the fovea than in eyes with them (P = 0.001). Cone loss ratio in the foveola correlated with postoperative visual acuity (P<0.001), mean foveal sensitivity (P = 0.029), thinner inner and outer segments at the center of the fovea (P = 0.002), larger size of the disrupted inner and outer segment junction line (P = 0.018), and cone outer segment tip line (P<0.001). Cone loss ratio in the foveola was significantly greater in eyes that had moderately reflective foveal lesions after surgery (P = 0.006).AO-SLO is a useful means of assessing foveal cone damage objectively and quantitatively. The location and extent of cone damage, especially if it involves the foveola, is an important factor determining visual function after MH surgery.
View details for DOI 10.1371/journal.pone.0063786
View details for Web of Science ID 000319385300033
View details for PubMedID 23717484
Focal macular photopic negative response in patients with optic neuritis
2011; 25 (3): 358-364
To investigate, by focal macular electroretinography (ERG), the change of photopic negative response (PhNR) in the recovery of visual function in patients with optic neuritis.Focal macular ERG was recorded from nine patients with acute optic neuritis (38.6 ± 10.2 years). The photostimulator device projected 15° visual angle spotlight onto the macula. Focal macular ERG recording was performed at the onset and at 1 month and 6 months after the onset of optic neuritis. The results were compared between each recording for seven of the patients.All patients decreased in the vision below 20/100 and had central scotoma. Vision improved more than 20/20 within 1 month and full-visual field recovered within 6 months after the onset in all patients. The amplitude of the a-wave, b-wave, and PhNR of focal macular ERG at the onset was significantly attenuated in eyes with optic neuritis (66.8 ± 15.5, 65.8 ± 17.7, and 65.2 ± 14.4% of normal control, respectively). The amplitude of the a-wave and b-wave increased gradually after steroid pulse therapy. The increase in a-wave amplitude was significant at 6 months (P = 0.046), whereas the PhNR amplitude did not show any significant change over 6 months after the onset of optic neuritis.Our results suggest that inflammation at the onset of optic neuritis leads to functional deficits that extend to at least the inner nuclear layers of the retina, and that all but the ganglion cell layers of retina recover.
View details for DOI 10.1038/eye.2010.205
View details for Web of Science ID 000288240500012
View details for PubMedID 21212800
View details for PubMedCentralID PMC3171782
Posterior parietal negativity preceding self-paced praxis movements
EXPERIMENTAL BRAIN RESEARCH
2005; 163 (4): 535-539
Studies of movement-related cortical potentials (MRCPs) for simple movements have shown a slowly rising negativity (Bereitschaftspotential, or BP) about 2 s prior to movement onset, centered in the bilateral sensorimotor area. However, complex movements may elicit a different temporal and spatial distribution of this pre-movement activity. In this study, 64-channel electroencephalography (EEG) was recorded while normal volunteers were asked to perform a simple thumb adduction once every 10--15 s for three 10--15 min blocks. Following this, they were asked to make tool-use movements (hammer, scissor, and screwdriver pantomime) in the same manner. Surface electromyography (EMG) was recorded on the thumb adductor and forearm flexor. MRCP was analyzed for the beginning part of the epoch (from 3.5 s to 1.5 s before EMG onset, with 0.5 s time bins) for differences in the amplitude and spatial distribution of the BP. Significant differences were seen from 3.0 s to 2.0 s before EMG onset, where the amplitude was greater for the more complex movements. On average, negativity began at 3.0 s before onset for praxis movements, and only 1.7 s before onset for thumb adduction. Additionally, the negativity seen for the complex movements had a distribution beginning over the left hemisphere posterior parietal area, whereas, thumb adduction movements had a more anterior distribution, over the bilateral sensorimotor area. The posterior parietal negativity (PPN) suggests that early parietal activity is essential for tool-use movements and is not a part of preparing simple movements.
View details for DOI 10.1007/s00221-005-2314-x
View details for Web of Science ID 000229972500012
View details for PubMedID 15883800