The Experts below are selected from a list of 8457 Experts worldwide ranked by ideXlab platform
Romeo Chua - One of the best experts on this subject based on the ideXlab platform.
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cognitive constraint on the Automatic Pilot for the hand movement intention influences the hand s susceptibility to involuntary online corrections
Consciousness and Cognition, 2009Co-Authors: Brendan D. Cameron, Ian M. Franks, Erin K. Cressman, Romeo ChuaAbstract:Research suggests that the reaching hand Automatically deviates toward a target that changes location (jumps) during the reach. In the current study, we investigated whether movement intention can influence the target jump’s impact on the hand. We compared the degree of trajectory deviation to a jumped target under three instruction conditions: (1) GO, in which participants were told to go to the target if it jumped, (2) STOP, in which participants were told to immediately stop their movement if the target jumped, and (3) IGNORE, in which participants were told to ignore the target if it jumped and to continue to its initial location. We observed a reduced response to the jump in the IGNORE condition relative to the other conditions, suggesting that the response to the jump is contingent on the jump being a task-relevant event.
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the hand s Automatic Pilot can update visual information while the eye is in motion
Experimental Brain Research, 2009Co-Authors: Brendan D. Cameron, Ian M. Franks, James T. Enns, Romeo ChuaAbstract:When participants reach for a target, their hand can adjust to a change in target position that occurs while their eyes are in motion (the hand’s Automatic Pilot) even though they are not aware of the target’s displacement (saccadic suppression of perceptual experience). However, previous studies of this effect have displayed the target without interruption, such that the new target position remains visible during the fixation that follows the saccade. Here we test whether a change in target position that begins and ends during the saccade can be used to update aiming movements. We also ask whether such information can be acquired from two targets at a time. The results showed that participants responded to single and double target jumps even when these targets were extinguished prior to saccade termination. The results imply that the hand’s Automatic Pilot is updated with new visual information even when the eye is in motion.
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Dual-target interference for the 'Automatic Pilot' in the dorsal stream.
Experimental brain research, 2007Co-Authors: Brendan D. Cameron, Ian M. Franks, James T. Enns, Romeo ChuaAbstract:When a target moves to a new location during a rapid aiming movement, the hand follows it, even when the participant intends not to. Pisella et al. (Nat Neurosci 3:729–736, 2000) claim that the posterior parietal cortex, in the dorsal visual stream, is responsible for this ‘Automatic Pilot’. Here we study the limits of Automaticity in the dorsal stream through analysis of aiming movements to two targets in sequence. Participants were given a goal of moving rapidly to two targets, with the first movement being completed within approximately 200 ms. On 30% of trials, the first or the second target jumped unpredictably to a new location at movement onset, allowing us to measure the Automatic capture of the hand. The results showed that hand movements were less responsive to target jumps in a 2-target condition than in a 1-target control condition. This indicates that the ‘Automatic Pilot’ is susceptible to interference from multiple visual inputs, implying that the dorsal stream is less effective at guiding actions online when multiple targets are attended.
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No Automatic Pilot for visually guided aiming based on colour
Experimental Brain Research, 2006Co-Authors: Erin K. Cressman, James T. Enns, Ian M. Franks, Romeo ChuaAbstract:It has been claimed that visually guided limb movements are Automatically corrected in response to a change in target location but not when the same change in target is cued through a colour switch (Pisella et al. 2000 ). These findings were based solely on limb endpoint data. Here we examine the kinematic trajectory of the hand during the entire movement. Participants pointed rapidly to a target object that could change position either by changing spatial location, or by switching colour with a second object. Participants performed in two instructional conditions: a “go” condition to index intentional movements and a “stop” condition in which failures to stop pointing indexed Automatic limb guidance. Kinematic analysis indicated efficient intentional pointing in both location and colour change conditions. However, only targets that changed spatial location elicited involuntary limb modifications and these occurred within 150 ms of the change. This conclusion held even after baseline differences in the efficiency of processing colour-defined targets were taken into account, thereby strengthening the claim of a strongly Automatic Pilot for visually guided limb movements.
Laure Pisella - One of the best experts on this subject based on the ideXlab platform.
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An ‘Automatic Pilot’ for the hand in human posterior parietal cortex: toward reinterpreting optic ataxia
Nature Neuroscience, 2000Co-Authors: Laure Pisella, G Gréa, C. Tilikete, A. Vighetto, D Desmurget, G. Rode, D. Boisson, Y. Rossetti, H. GréaAbstract:We designed a protocol distinguishing between Automatic and intentional motor reactions to changes in target location triggered at movement onset. In response to target jumps, but not to a similar change cued by a color switch, normal subjects often could not avoid Automatically correcting fast aiming movements. This suggests that an 'Automatic Pilot' relying on spatial vision drives fast corrective arm movements that can escape intentional control. In a patient with a bilateral posterior parietal cortex (PPC) lesion, motor corrections could only be slow and deliberate. We propose that 'on-line' control is the most specific function of the PPC and that optic ataxia could result from a disruption of Automatic hand guidance.
Brendan D. Cameron - One of the best experts on this subject based on the ideXlab platform.
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cognitive constraint on the Automatic Pilot for the hand movement intention influences the hand s susceptibility to involuntary online corrections
Consciousness and Cognition, 2009Co-Authors: Brendan D. Cameron, Ian M. Franks, Erin K. Cressman, Romeo ChuaAbstract:Research suggests that the reaching hand Automatically deviates toward a target that changes location (jumps) during the reach. In the current study, we investigated whether movement intention can influence the target jump’s impact on the hand. We compared the degree of trajectory deviation to a jumped target under three instruction conditions: (1) GO, in which participants were told to go to the target if it jumped, (2) STOP, in which participants were told to immediately stop their movement if the target jumped, and (3) IGNORE, in which participants were told to ignore the target if it jumped and to continue to its initial location. We observed a reduced response to the jump in the IGNORE condition relative to the other conditions, suggesting that the response to the jump is contingent on the jump being a task-relevant event.
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the hand s Automatic Pilot can update visual information while the eye is in motion
Experimental Brain Research, 2009Co-Authors: Brendan D. Cameron, Ian M. Franks, James T. Enns, Romeo ChuaAbstract:When participants reach for a target, their hand can adjust to a change in target position that occurs while their eyes are in motion (the hand’s Automatic Pilot) even though they are not aware of the target’s displacement (saccadic suppression of perceptual experience). However, previous studies of this effect have displayed the target without interruption, such that the new target position remains visible during the fixation that follows the saccade. Here we test whether a change in target position that begins and ends during the saccade can be used to update aiming movements. We also ask whether such information can be acquired from two targets at a time. The results showed that participants responded to single and double target jumps even when these targets were extinguished prior to saccade termination. The results imply that the hand’s Automatic Pilot is updated with new visual information even when the eye is in motion.
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Dual-target interference for the 'Automatic Pilot' in the dorsal stream.
Experimental brain research, 2007Co-Authors: Brendan D. Cameron, Ian M. Franks, James T. Enns, Romeo ChuaAbstract:When a target moves to a new location during a rapid aiming movement, the hand follows it, even when the participant intends not to. Pisella et al. (Nat Neurosci 3:729–736, 2000) claim that the posterior parietal cortex, in the dorsal visual stream, is responsible for this ‘Automatic Pilot’. Here we study the limits of Automaticity in the dorsal stream through analysis of aiming movements to two targets in sequence. Participants were given a goal of moving rapidly to two targets, with the first movement being completed within approximately 200 ms. On 30% of trials, the first or the second target jumped unpredictably to a new location at movement onset, allowing us to measure the Automatic capture of the hand. The results showed that hand movements were less responsive to target jumps in a 2-target condition than in a 1-target control condition. This indicates that the ‘Automatic Pilot’ is susceptible to interference from multiple visual inputs, implying that the dorsal stream is less effective at guiding actions online when multiple targets are attended.
Ian M. Franks - One of the best experts on this subject based on the ideXlab platform.
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cognitive constraint on the Automatic Pilot for the hand movement intention influences the hand s susceptibility to involuntary online corrections
Consciousness and Cognition, 2009Co-Authors: Brendan D. Cameron, Ian M. Franks, Erin K. Cressman, Romeo ChuaAbstract:Research suggests that the reaching hand Automatically deviates toward a target that changes location (jumps) during the reach. In the current study, we investigated whether movement intention can influence the target jump’s impact on the hand. We compared the degree of trajectory deviation to a jumped target under three instruction conditions: (1) GO, in which participants were told to go to the target if it jumped, (2) STOP, in which participants were told to immediately stop their movement if the target jumped, and (3) IGNORE, in which participants were told to ignore the target if it jumped and to continue to its initial location. We observed a reduced response to the jump in the IGNORE condition relative to the other conditions, suggesting that the response to the jump is contingent on the jump being a task-relevant event.
-
the hand s Automatic Pilot can update visual information while the eye is in motion
Experimental Brain Research, 2009Co-Authors: Brendan D. Cameron, Ian M. Franks, James T. Enns, Romeo ChuaAbstract:When participants reach for a target, their hand can adjust to a change in target position that occurs while their eyes are in motion (the hand’s Automatic Pilot) even though they are not aware of the target’s displacement (saccadic suppression of perceptual experience). However, previous studies of this effect have displayed the target without interruption, such that the new target position remains visible during the fixation that follows the saccade. Here we test whether a change in target position that begins and ends during the saccade can be used to update aiming movements. We also ask whether such information can be acquired from two targets at a time. The results showed that participants responded to single and double target jumps even when these targets were extinguished prior to saccade termination. The results imply that the hand’s Automatic Pilot is updated with new visual information even when the eye is in motion.
-
Dual-target interference for the 'Automatic Pilot' in the dorsal stream.
Experimental brain research, 2007Co-Authors: Brendan D. Cameron, Ian M. Franks, James T. Enns, Romeo ChuaAbstract:When a target moves to a new location during a rapid aiming movement, the hand follows it, even when the participant intends not to. Pisella et al. (Nat Neurosci 3:729–736, 2000) claim that the posterior parietal cortex, in the dorsal visual stream, is responsible for this ‘Automatic Pilot’. Here we study the limits of Automaticity in the dorsal stream through analysis of aiming movements to two targets in sequence. Participants were given a goal of moving rapidly to two targets, with the first movement being completed within approximately 200 ms. On 30% of trials, the first or the second target jumped unpredictably to a new location at movement onset, allowing us to measure the Automatic capture of the hand. The results showed that hand movements were less responsive to target jumps in a 2-target condition than in a 1-target control condition. This indicates that the ‘Automatic Pilot’ is susceptible to interference from multiple visual inputs, implying that the dorsal stream is less effective at guiding actions online when multiple targets are attended.
-
No Automatic Pilot for visually guided aiming based on colour
Experimental Brain Research, 2006Co-Authors: Erin K. Cressman, James T. Enns, Ian M. Franks, Romeo ChuaAbstract:It has been claimed that visually guided limb movements are Automatically corrected in response to a change in target location but not when the same change in target is cued through a colour switch (Pisella et al. 2000 ). These findings were based solely on limb endpoint data. Here we examine the kinematic trajectory of the hand during the entire movement. Participants pointed rapidly to a target object that could change position either by changing spatial location, or by switching colour with a second object. Participants performed in two instructional conditions: a “go” condition to index intentional movements and a “stop” condition in which failures to stop pointing indexed Automatic limb guidance. Kinematic analysis indicated efficient intentional pointing in both location and colour change conditions. However, only targets that changed spatial location elicited involuntary limb modifications and these occurred within 150 ms of the change. This conclusion held even after baseline differences in the efficiency of processing colour-defined targets were taken into account, thereby strengthening the claim of a strongly Automatic Pilot for visually guided limb movements.
H. Gréa - One of the best experts on this subject based on the ideXlab platform.
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An ‘Automatic Pilot’ for the hand in human posterior parietal cortex: toward reinterpreting optic ataxia
Nature Neuroscience, 2000Co-Authors: Laure Pisella, G Gréa, C. Tilikete, A. Vighetto, D Desmurget, G. Rode, D. Boisson, Y. Rossetti, H. GréaAbstract:We designed a protocol distinguishing between Automatic and intentional motor reactions to changes in target location triggered at movement onset. In response to target jumps, but not to a similar change cued by a color switch, normal subjects often could not avoid Automatically correcting fast aiming movements. This suggests that an 'Automatic Pilot' relying on spatial vision drives fast corrective arm movements that can escape intentional control. In a patient with a bilateral posterior parietal cortex (PPC) lesion, motor corrections could only be slow and deliberate. We propose that 'on-line' control is the most specific function of the PPC and that optic ataxia could result from a disruption of Automatic hand guidance.
