A Cortical Parcellation Based Analysis of Ventral Premotor Area Connectivity

2021 ◽  
pp. 1-14
Author(s):  
John R. Sheets ◽  
Robert G. Briggs ◽  
Nicholas B. Dadario ◽  
Isabella M. Young ◽  
Michael Y. Bai ◽  
...  
Keyword(s):  
Premotor Area ◽  
Cortical Parcellation

Neural Encoding Correlates of High and Low Verbal Memory Performance

2006 ◽  
Vol 20 (2) ◽  
pp. 68-78 ◽  
Author(s):  
Sibylle Heinze ◽  
Gudrun Sartory ◽  
Bernhard W. Müller ◽  
Armin de Greiff ◽  
Michael Forsting ◽  
...  
Keyword(s):  
Verbal Memory ◽  
Parietal Lobe ◽  
Functional Neuroimaging ◽  
Memory Performance ◽  
Extrastriate Cortex ◽  
Parahippocampal Gyrus ◽  
Premotor Area ◽  
High Performers ◽  
Rehearsal Strategy ◽  
Common Memory

Neuroimaging studies have indicated involvement of left prefrontal cortex and temporal areas in verbal memory processes. The current study used event-related functional neuroimaging to compare encoding of subsequently recalled and not recalled words in high and low memory performers. Fifteen healthy volunteers were given lists of words to learn with immediate recall and to read as a control condition. High performers reported to have visualized the words whereas low performers used a rehearsal strategy. Compared to reading, unsuccessful encoding was associated with thalamic and left premotor area (BA 6) activity. Comparing successful with unsuccessful learning yielded widespread activity of the left prefrontal and posterior temporal gyrus as well as the left superior parietal lobe in the whole group. Low performers showed activation of the left premotor area throughout learning and additionally of the left middle temporal and parahippocampal gyrus during successful encoding. High performers showed increased activation in the extrastriate cortex throughout learning and additionally in the left parietal post- and paracentral areas as well as in the right precuneus during successful encoding. The results suggest that high verbal memory performance is the result of spatiovisual activation concomitant to imagery and low performance of hippocampal and motor activation, the latter being associated with rehearsal, with a common memory circuit subserving both groups.

Corticospinal Tract Microstructure Correlates With Beta Oscillatory Activity in the Primary Motor Cortex After Stroke

Stroke ◽  
2021 ◽  
Author(s):  
Robert Schulz ◽  
Marlene Bönstrup ◽  
Stephanie Guder ◽  
Jingchun Liu ◽  
Benedikt Frey ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Fractional Anisotropy ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Premotor Cortex ◽  
Motor Impairment ◽  
Motor Area ◽  
Oscillatory Activity ◽  
Premotor Area ◽  
Beta Power

Background and Purpose: Cortical beta oscillations are reported to serve as robust measures of the integrity of the human motor system. Their alterations after stroke, such as reduced movement-related beta desynchronization in the primary motor cortex, have been repeatedly related to the level of impairment. However, there is only little data whether such measures of brain function might directly relate to structural brain changes after stroke. Methods: This multimodal study investigated 18 well-recovered patients with stroke (mean age 65 years, 12 males) by means of task-related EEG and diffusion-weighted structural MRI 3 months after stroke. Beta power at rest and movement-related beta desynchronization was assessed in 3 key motor areas of the ipsilesional hemisphere that are the primary motor cortex (M1), the ventral premotor area and the supplementary motor area. Template trajectories of corticospinal tracts (CST) originating from M1, premotor cortex, and supplementary motor area were used to quantify the microstructural state of CST subcomponents. Linear mixed-effects analyses were used to relate tract-related mean fractional anisotropy to EEG measures. Results: In the present cohort, we detected statistically significant reductions in ipsilesional CST fractional anisotropy but no alterations in EEG measures when compared with healthy controls. However, in patients with stroke, there was a significant association between both beta power at rest ( P =0.002) and movement-related beta desynchronization ( P =0.003) in M1 and fractional anisotropy of the CST specifically originating from M1. Similar structure-function relationships were neither evident for ventral premotor area and supplementary motor area, particularly with respect to their CST subcomponents originating from premotor cortex and supplementary motor area, in patients with stroke nor in controls. Conclusions: These data suggest there might be a link connecting microstructure of the CST originating from M1 pyramidal neurons and beta oscillatory activity, measures which have already been related to motor impairment in patients with stroke by previous reports.

Involvement of subareas within the dorsal premotor area (PMd) in a conceptually demanding visuomotor task

2009 ◽  
Vol 65 ◽  
pp. S168
Author(s):  
Yoshihisa Nakayama ◽  
Nariko Arimura ◽  
Tomoko Yamagata ◽  
Jun Tanji ◽  
Eiji Hoshi
Keyword(s):  
Premotor Area ◽  
Visuomotor Task

scholarly journals A sub+ cortical fMRI-based surface parcellation

2019 ◽  
Author(s):  
John D. Lewis ◽  
Gleb Bezgin ◽  
Vladimir S. Fonov ◽  
D. Louis Collins ◽  
Alan C. Evans
Keyword(s):  
Individual Differences ◽  
Functional Connectivity ◽  
Life Span ◽  
Brain Volume ◽  
Subcortical Structures ◽  
Common Space ◽  
Cortical Parcellation ◽  
Connectivity Patterns ◽  
Deep Gray Matter ◽  
Volumetric Registration

AbstractBoth the cortex and the subcortical structures are organized into a large number of distinct areas reflecting functional and cytoarchitectonic differences. Mapping these areas is of fundamental importance to neuroscience. A central obstacle to this task is the inaccuracy associated with mapping results from individuals into a common space. The vast individual differences in morphology pose a serious problem for volumetric registration. Surface-based approaches fare substantially better, but have thus far been used only for cortical parcellation. We extend this surface-based approach to include also the subcortical deep gray-matter structures. Using the life-span data from the Enhanced Nathan Klein Institute - Rockland Sample, comprised of data from 590 individuals from 6 to 85 years of age, we generate a functional parcellation of both the cortical and subcortical surfaces. To assess this extended parcellation, we show that our extended functional parcellation provides greater homogeneity of functional connectivity patterns than do arbitrary parcellations matching in the number and size of parcels. We also show that our subcortical parcels align with known subnuclei. Further, we show that this parcellation is appropriate for use with data from other modalities; we generate cortical and subcortical white/gray contrast measures for this same dataset, and draw on the fact that areal differences are evident in the relation of white/gray contrast to age, to sex, to brain volume, and to interactions of these terms; we show that our extended functional parcellation provides an improved fit to the complexity of the life-span changes in the white/gray contrast data compared to arbitrary parcellations matching in the number and size of parcels. We provide our extended functional parcellation for the use of the neuroimaging community.

Parcellation-based modeling of the dorsal premotor area

2020 ◽  
Vol 415 ◽  
pp. 116907
Author(s):  
John R. Sheets ◽  
Robert G. Briggs ◽  
Michael Y. Bai ◽  
Anujan Poologaindran ◽  
Isabella M. Young ◽  
...  
Keyword(s):  
Premotor Area

Functional Properties of Grasping-Related Neurons in the Dorsal Premotor Area F2 of the Macaque Monkey

2004 ◽  
Vol 92 (4) ◽  
pp. 1990-2002 ◽  
Author(s):  
Vassilis Raos ◽  
Maria-Alessandra Umiltá ◽  
Vittorio Gallese ◽  
Leonardo Fogassi
Keyword(s):  
Motor Neurons ◽  
Discharge Rate ◽  
Macaque Monkey ◽  
3 Dimensional ◽  
Premotor Area ◽  
Neuron Response ◽  
Behavioral Paradigm ◽  
Fixation Task ◽  
Object Fixation ◽  
Almost All

We investigated the properties of neurons located in the distal forelimb field of dorsal premotor area F2 of macaque monkey using a behavioral paradigm for studying the neuronal discharge during observation (object fixation condition) and grasping of different 3-dimensional objects with and without visual guidance of the movement (movement in light and movement in dark conditions, respectively). The main result is that almost all studied neurons were selective for both the type of prehension and the wrist orientation required for grasping an object. Three categories of neurons were found: purely motor, visually modulated, and visuomotor neurons. The discharge of purely motor neurons was not affected by either object presentation or by the visual feedback of the hand approaching to and interacting with the object. Visually modulated neurons presented a different discharge in the 2 movement conditions, this determining a decrease in selectivity for the grip and wrist orientation in the movement in dark condition. Visuomotor neurons typically discharged during the object fixation task even in the absence of any grasping movement. Nine of them also displayed a different discharge rate between the 2 movement conditions. Congruence was observed between the neuron response during the most effective type of prehension and the neuron response during observation of the object requiring that particular prehension. These results indicate an important role of F2 in the control of goal-related hand movements.

Sign in / Sign up

Export Citation Format

Share Document