Cortical Dynamics of Anticipatory Mechanisms in Interception: A Neuromagnetic Study

2008 ◽  
Vol 20 (10) ◽  
pp. 1827-1838 ◽  
Author(s):  
Patrice Senot ◽  
Sylvain Baillet ◽  
Bernard Renault ◽  
Alain Berthoz

Humans demonstrate an amazing ability for intercepting and catching moving targets, most noticeably in fast-speed ball games. However, the few studies exploring the neural bases of interception in humans and the classical studies on visual motion processing and visuomotor interactions have reported rather long latencies of cortical activations that cannot explain the performances observed in most natural interceptive actions. The aim of our experiment was twofold: (1) describe the spatio-temporal unfolding of cortical activations involved in catching a moving target and (2) provide evidence that fast cortical responses can be elicited by a visuomotor task with high temporal constraints and decide if these responses are task or stimulus dependent. Neuromagnetic brain activity was recorded with whole-head coverage while subjects were asked to catch a free-falling ball or simply pay attention to the ball trajectory. A fast, likely stimulus-dependent, propagation of neural activity was observed along the dorsal visual pathway in both tasks. Evaluation of latencies of activations in the main cortical regions involved in the tasks revealed that this entire network of regions was activated within 40 msec. Moreover, comparison of experimental conditions revealed similar patterns of activation except in contralateral sensorimotor regions where common and catch-specific activations were differentiated.

2012 ◽  
Vol 25 (0) ◽  
pp. 140
Author(s):  
Lore Thaler ◽  
Jennifer Milne ◽  
Stephen R. Arnott ◽  
Melvyn A. Goodale

People can echolocate their distal environment by making mouth-clicks and listening to the click-echoes. In previous work that used functional magnetic resonance imaging (fMRI) we have shown that the processing of echolocation motion increases activity in posterior/inferior temporal cortex (Thaler et al., 2011). In the current study we investigated, if brain areas that are sensitive to echolocation motion in blind echolocation experts correspond to visual motion area MT+. To this end we used fMRI to measure brain activity of two early blind echolocation experts while they listened to recordings of echolocation and auditory source sounds that could be either moving or stationary, and that could be located either to the left or to the right of the listener. A whole brain analysis revealed that echo motion and source motion activated different brain areas in posterior/inferior temporal cortex. Furthermore, the relative spatial arrangement of echo and source motion areas appeared to match the relative spatial arrangement of area MT+ and source motion areas that has been reported for sighted people (Saenz et al., 2008). Furthermore, we found that brain areas that were sensitive to echolocation motion showed a larger response to echo motion presented in contra-lateral space, a response pattern typical for visual motion processing in area MT+. In their entirety the data are consistent with the idea that brain areas that process echolocation motion in blind echolocation experts correspond to area MT+.


2021 ◽  
Author(s):  
Ana Gómez-Granados ◽  
Isaac Kurtzer ◽  
Tarkeshwar Singh

AbstractAn important window into sensorimotor function is how we catch moving objects. Studies that examined catching of free-falling objects report that the timing of the motor response is independent of the momentum of the projectile, whereas the motor response amplitude scales with projectile momentum. However, this pattern may not be a general strategy of catching since objects accelerate under gravity in a characteristic manner (unlike object motion in the horizontal plane) and the human visual motion-processing system is not adept at encoding acceleration. Accordingly, we developed a new experimental paradigm using a robotic manipulandum and augmented reality where participants stabilized against the impact of a virtual object moving at constant velocity in the horizontal plane. Participants needed to apply an impulse that mirrored the object momentum to bring it to rest and received explicit feedback on their performance. In different blocks, object momentum was varied by an increase in its speed or mass. In contrast to previous reports on free falling objects, we observed that increasing object speed caused earlier onset of arm muscle activity and limb force relative to the impending time to contact. Also, arm force increased as a function of target momentum linked to changes in speed or mass. Our results demonstrate velocity-dependent timing to catch objects and a complex pattern of scaling to momentum.


2014 ◽  
Vol 111 (1) ◽  
pp. 112-127 ◽  
Author(s):  
L. Thaler ◽  
J. L. Milne ◽  
S. R. Arnott ◽  
D. Kish ◽  
M. A. Goodale

We have shown in previous research (Thaler L, Arnott SR, Goodale MA. PLoS One 6: e20162, 2011) that motion processing through echolocation activates temporal-occipital cortex in blind echolocation experts. Here we investigated how neural substrates of echo-motion are related to neural substrates of auditory source-motion and visual-motion. Three blind echolocation experts and twelve sighted echolocation novices underwent functional MRI scanning while they listened to binaural recordings of moving or stationary echolocation or auditory source sounds located either in left or right space. Sighted participants' brain activity was also measured while they viewed moving or stationary visual stimuli. For each of the three modalities separately (echo, source, vision), we then identified motion-sensitive areas in temporal-occipital cortex and in the planum temporale. We then used a region of interest (ROI) analysis to investigate cross-modal responses, as well as laterality effects. In both sighted novices and blind experts, we found that temporal-occipital source-motion ROIs did not respond to echo-motion, and echo-motion ROIs did not respond to source-motion. This double-dissociation was absent in planum temporale ROIs. Furthermore, temporal-occipital echo-motion ROIs in blind, but not sighted, participants showed evidence for contralateral motion preference. Temporal-occipital source-motion ROIs did not show evidence for contralateral preference in either blind or sighted participants. Our data suggest a functional segregation of processing of auditory source-motion and echo-motion in human temporal-occipital cortex. Furthermore, the data suggest that the echo-motion response in blind experts may represent a reorganization rather than exaggeration of response observed in sighted novices. There is the possibility that this reorganization involves the recruitment of “visual” cortical areas.


1988 ◽  
Vol 60 (3) ◽  
pp. 940-965 ◽  
Author(s):  
M. R. Dursteler ◽  
R. H. Wurtz

1. Previous experiments have shown that punctate chemical lesions within the middle temporal area (MT) of the superior temporal sulcus (STS) produce deficits in the initiation and maintenance of pursuit eye movements (10, 34). The present experiments were designed to test the effect of such chemical lesions in an area within the STS to which MT projects, the medial superior temporal area (MST). 2. We injected ibotenic acid into localized regions of MST, and we observed two deficits in pursuit eye movements, a retinotopic deficit and a directional deficit. 3. The retinotopic deficit in pursuit initiation was characterized by the monkey's inability to match eye speed to target speed or to adjust the amplitude of the saccade made to acquire the target to compensate for target motion. This deficit was related to the initiation of pursuit to targets moving in any direction in the visual field contralateral to the side of the brain with the lesion. This deficit was similar to the deficit we found following damage to extrafoveal MT except that the affected area of the visual field frequently extended throughout the entire contralateral visual field tested. 4. The directional deficit in pursuit maintenance was characterized by a failure to match eye speed to target speed once the fovea had been brought near the moving target. This deficit occurred only when the target was moving toward the side of the lesion, regardless of whether the target began to move in the ipsilateral or contralateral visual field. There was no deficit in the amplitude of saccades made to acquire the target, or in the amplitude of the catch-up saccades made to compensate for the slowed pursuit. The directional deficit is similar to the one we described previously following chemical lesions of the foveal representation in the STS. 5. Retinotopic deficits resulted from any of our injections in MST. Directional deficits resulted from lesions limited to subregions within MST, particularly lesions that invaded the floor of the STS and the posterior bank of the STS just lateral to MT. Extensive damage to the densely myelinated area of the anterior bank or to the posterior parietal area on the dorsal lip of the anterior bank produced minimal directional deficits. 6. We conclude that damage to visual motion processing in MST underlies the retinotopic pursuit deficit just as it does in MT. MST appears to be a sequential step in visual motion processing that occurs before all of the visual motion information is transmitted to the brainstem areas related to pursuit.(ABSTRACT TRUNCATED AT 400 WORDS)


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