Integration of Target and Effector Information in the Human Brain During Reach Planning

2007 ◽  
Vol 97 (1) ◽  
pp. 188-199 ◽  
Author(s):  
S. M. Beurze ◽  
F. P. de Lange ◽  
I. Toni ◽  
W. P. Medendorp
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Human Subjects ◽  
Premotor Cortex ◽  
Insular Cortex ◽  
Spatial Location ◽  
Posterior Parietal ◽  
The Right ◽  
Integrative Processing ◽  
Reach Planning

To plan a reaching movement, the brain must integrate information about the location of the target with information about the limb selected for the reach. Here, we applied rapid event-related 3-T fMRI to investigate this process in human subjects ( n = 16) preparing a reach following two successive visual instruction cues. One cue instructed which arm to use; the other cue instructed the location of the reach target. We hypothesized that regions involved in the integration of target and effector information should not only respond to each of the two instruction cues, but should respond more strongly to the second cue due to the added integrative processing to establish the reach plan. We found bilateral regions in the posterior parietal cortex, the premotor cortex, the medial frontal cortex, and the insular cortex to be involved in target–arm integration, as well as the left dorsolateral prefrontal cortex and an area in the right lateral occipital sulcus to respond in this manner. We further determined the functional properties of these regions in terms of spatial and effector specificity. This showed that the posterior parietal cortex and the dorsal premotor cortex specify both the spatial location of a target and the effector selected for the response. We therefore conclude that these regions are selectively engaged in the neural computations for reach planning, consistent with the results from physiological studies in nonhuman primates.

scholarly journals Human posterior parietal cortex encodes the movement goal in a pro-/anti-reach task

2015 ◽  
Vol 114 (1) ◽  
pp. 170-183 ◽  
Author(s):  
Hanna Gertz ◽  
Katja Fiehler
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Premotor Cortex ◽  
Imaging Study ◽  
Visual Cue ◽  
Frontoparietal Network ◽  
Electrophysiological Studies ◽  
Posterior Parietal ◽  
Reach Planning ◽  
Premotor Areas

Previous research on reach planning in humans has implicated a frontoparietal network, including the precuneus (PCu), a putative human homolog of the monkey parietal reach region (PRR), and the dorsal premotor cortex (PMd). Using a pro-/anti-reach task, electrophysiological studies in monkeys have demonstrated that the movement goal rather than the location of the visual cue is encoded in PRR and PMd. However, if only the effector but not the movement goal is specified (underspecified condition), the PRR and PMd have been shown to represent all potential movement goals. In this functional magnetic resonance imaging study, we investigated whether the human PCu and PMd likewise encode the movement goal, and whether these reach-related areas also engage in situations with underspecified compared with specified movement goals. By using a pro-/anti-reach task, we spatially dissociated the location of the visual cue from the location of the movement goal. In the specified conditions, pro- and anti-reaches activated similar parietal and premotor areas. In the PCu contralateral to the moving arm, we found directionally selective activation fixed to the movement goal. In the underspecified conditions, we observed activation in reach-related areas of the posterior parietal cortex, including PCu. However, the activation was substantially weaker in parietal areas and lacking in PMd. Our results suggest that human PCu encodes the movement goal rather than the location of the visual cue if the movement goal is specified and even engages in situations when only the visual cue but not the movement goal is defined.

scholarly journals Effector selection precedes reach planning in the dorsal parietofrontal cortex

2012 ◽  
Vol 108 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Pierre-Michel Bernier ◽  
Matthew Cieslak ◽  
Scott T. Grafton
Keyword(s):  
Posterior Parietal Cortex ◽  
Premotor Cortex ◽  
Target Selection ◽  
Movement Planning ◽  
Target Onset ◽  
Posterior Parietal ◽  
Full Knowledge ◽  
Selection For ◽  
The Right ◽  
Reach Planning

Experimental evidence and computational modeling suggest that target selection for reaching is associated with the parallel encoding of multiple movement plans in the dorsomedial posterior parietal cortex (dmPPC) and the caudal part of the dorsal premotor cortex (PMdc). We tested the hypothesis that a similar mechanism also accounts for arm selection for unimanual reaching, with simultaneous and separate motor goal representations for the left and right arms existing in the right and left parietofrontal cortex, respectively. We recorded simultaneous electroencephalograms and functional MRI and studied a condition in which subjects had to select the appropriate arm for reaching based on the color of an appearing visuospatial target, contrasting it to a condition in which they had full knowledge of the arm to be used before target onset. We showed that irrespective of whether subjects had to select the arm or not, activity in dmPPC and PMdc was only observed contralateral to the reaching arm after target onset. Furthermore, the latency of activation in these regions was significantly delayed when arm selection had to be achieved during movement planning. Together, these results demonstrate that effector selection is not achieved through the simultaneous specification of motor goals tied to the two arms in bilateral parietofrontal cortex, but suggest that a motor goal is formed in these regions only after an arm is selected for action.

Integration of Target and Effector Information in Human Posterior Parietal Cortex for the Planning of Action

2005 ◽  
Vol 93 (2) ◽  
pp. 954-962 ◽  
Author(s):  
W. Pieter Medendorp ◽  
Herbert C. Goltz ◽  
J. Douglas Crawford ◽  
Tutis Vilis
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Spatial Information ◽  
Target Location ◽  
Premotor Cortex ◽  
Target Selection ◽  
Right Hand ◽  
Pointing Movements ◽  
Posterior Parietal ◽  
The Right

Recently, using event-related functional MRI (fMRI), we located a bilateral region in the human posterior parietal cortex (retIPS) that topographically represents and updates targets for saccades and pointing movements in eye-centered coordinates. To generate movements, this spatial information must be integrated with the selected effector. We now tested whether the activation in retIPS is dependent on the hand selected. Using 4-T fMRI, we compared the activation produced by movements, using either eyes or the left or right hand, to targets presented either leftward or rightward of central fixation. The majority of the regions activated during saccades were also activated during pointing movements, including occipital, posterior parietal, and premotor cortex. The topographic retIPS region was activated more strongly for saccades than for pointing. The activation associated with pointing was significantly greater when pointing with the unseen hand to targets ipsilateral to the hand. For example, although there was activation in the left retIPS when pointing to targets on the right with the left hand, the activation was significantly greater when using the right hand. The mirror symmetric effect was observed in the right retIPS. Similar hand preferences were observed in a nearby anterior occipital region. This effector specificity is consistent with previous clinical and behavioral studies showing that each hand is more effective in directing movements to targets in ipsilateral visual space. We conclude that not only do these regions code target location, but they also appear to integrate target selection with effector selection.

scholarly journals Attentional bias to threat and gray mater volume morphology in high anxious individuals

2020 ◽  
Author(s):  
Joshua M. Carlson ◽  
Lin Fang
Keyword(s):  
Attentional Bias ◽  
Parietal Cortex ◽  
Gray Matter ◽  
Posterior Parietal Cortex ◽  
Gray Matter Volume ◽  
Anterior Cingulate ◽  
Brain Morphology ◽  
Matter Volume ◽  
Posterior Parietal ◽  
The Right

AbstractIn a sample of highly anxious individuals, the relationship between gray matter volume brain morphology and attentional bias to threat was assessed. Participants performed a dot-probe task of attentional bias to threat and gray matter volume was acquired from whole brain structural T1-weighted MRI scans. The results replicate previous findings in unselected samples that elevated attentional bias to threat is linked to greater gray matter volume in the anterior cingulate cortex, middle frontal gyrus, and striatum. In addition, we provide novel evidence that elevated attentional bias to threat is associated with greater gray matter volume in the right posterior parietal cortex, cerebellum, and other distributed regions. Lastly, exploratory analyses provide initial evidence that distinct sub-regions of the right posterior parietal cortex may contribute to attentional bias in a sex-specific manner. Our results illuminate how differences in gray matter volume morphology relate to attentional bias to threat in anxious individuals. This knowledge could inform neurocognitive models of anxiety-related attentional bias to threat and targets of neuroplasticity in anxiety interventions such as attention bias modification.

Paired pulse TMS over the right posterior parietal cortex modulates visuospatial perception

2006 ◽  
Vol 247 (2) ◽  
pp. 144-148 ◽  
Author(s):  
Brigida Fierro ◽  
Filippo Brighina ◽  
Giuseppe Giglia ◽  
Antonio Palermo ◽  
Margherita Francolini ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Paired Pulse ◽  
Visuospatial Perception ◽  
Posterior Parietal ◽  
The Right

The Role of the Right Posterior Parietal Cortex in Letter Migration between Words

2015 ◽  
Vol 27 (2) ◽  
pp. 377-386 ◽  
Author(s):  
Dario Cazzoli ◽  
René M. Müri ◽  
Christopher Kennard ◽  
Clive R. Rosenthal
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Word Reading ◽  
Letter Position ◽  
Control Group ◽  
Neural Basis ◽  
Specific Effects ◽  
Letter Position Coding ◽  
Posterior Parietal ◽  
The Right

When briefly presented with pairs of words, skilled readers can sometimes report words with migrated letters (e.g., they report hunt when presented with the words hint and hurt). This and other letter migration phenomena have been often used to investigate factors that influence reading such as letter position coding. However, the neural basis of letter migration is poorly understood. Previous evidence has implicated the right posterior parietal cortex (PPC) in processing visuospatial attributes and lexical properties during word reading. The aim of this study was to assess this putative role by combining an inhibitory TMS protocol with a letter migration paradigm, which was designed to examine the contributions of visuospatial attributes and lexical factors. Temporary interference with the right PPC led to three specific effects on letter migration. First, the number of letter migrations was significantly increased only in the group with active stimulation (vs. a sham stimulation group or a control group without stimulation), and there was no significant effect on other error types. Second, this effect occurred only when letter migration could result in a meaningful word (migration vs. control context). Third, the effect of active stimulation on the number of letter migrations was lateralized to target words presented on the left. Our study thus demonstrates that the right PPC plays a specific and causal role in the phenomenon of letter migration. The nature of this role cannot be explained solely in terms of visuospatial attention, rather it involves an interplay between visuospatial attentional and word reading-specific factors.

Far Space Remapping by Tool Use: A rTMS Study Over the Right Posterior Parietal Cortex

2015 ◽  
Vol 8 (4) ◽  
pp. 795-800 ◽  
Author(s):  
Giuseppe Giglia ◽  
Lorenzo Pia ◽  
Alessia Folegatti ◽  
Angela Puma ◽  
Brigida Fierro ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Tool Use ◽  
Posterior Parietal Cortex ◽  
Posterior Parietal ◽  
The Right
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