The Experts below are selected from a list of 233058 Experts worldwide ranked by ideXlab platform
Charalambos Papaxanthis - One of the best experts on this subject based on the ideXlab platform.
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The Temporal Structure of vertical arm movements.
PLoS ONE, 2011Co-Authors: Jeremie Gaveau, Charalambos PapaxanthisAbstract:The present study investigates how the CNS deals with the omnipresent force of gravity during arm motor planning. Previous studies have reported direction-dependent kinematic differences in the vertical plane; notably, acceleration duration was greater during a downward than an upward arm movement. Although the analysis of acceleration and deceleration phases has permitted to explore the integration of gravity force, further investigation is necessary to conclude whether feedforward or feedback control processes are at the origin of this incorporation. We considered that a more detailed analysis of the Temporal features of vertical arm movements could provide additional information about gravity force integration into the motor planning. Eight subjects performed single joint vertical arm movements (45° rotation around the shoulder joint) in two opposite directions (upwards and downwards) and at three different speeds (slow, natural and fast). We calculated different parameters of hand acceleration profiles: movement duration (MD), duration to peak acceleration (D PA), duration from peak acceleration to peak velocity (D PA-PV), duration from peak velocity to peak deceleration (D PV-PD), duration from peak deceleration to the movement end (D PD-End), acceleration duration (AD), deceleration duration (DD), peak acceleration (PA), peak velocity (PV), and peak deceleration (PD). While movement durations and amplitudes were similar for upward and downward movements, the Temporal Structure of acceleration profiles differed between the two directions. More specifically, subjects performed upward movements faster than downward movements; these direction-dependent asymmetries appeared early in the movement (i.e., before PA) and lasted until the moment of PD. Additionally, PA and PV were greater for upward than downward movements. Movement speed also changed the Temporal Structure of acceleration profiles. The effect of speed and direction on the form of acceleration profiles is consistent with the premise that the CNS optimises motor commands with respect to both gravitational and inertial constraints.
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The Temporal Structure of Vertical Arm Movements
PLoS ONE, 2011Co-Authors: Jeremie Gaveau, Charalambos PapaxanthisAbstract:The present study investigates how the CNS deals with the omnipresent force of gravity during arm motor planning. Previous studies have reported direction-dependent kinematic differences in the vertical plane; notably, acceleration duration was greater during a downward than an upward arm movement. Although the analysis of acceleration and deceleration phases has permitted to explore the integration of gravity force, further investigation is necessary to conclude whether feedforward or feedback control processes are at the origin of this incorporation. We considered that a more detailed analysis of the Temporal features of vertical arm movements could provide additional information about gravity force integration into the motor planning. Eight subjects performed single joint vertical arm movements (45 degrees rotation around the shoulder joint) in two opposite directions (upwards and downwards) and at three different speeds (slow, natural and fast). We calculated different parameters of hand acceleration profiles: movement duration (MD), duration to peak acceleration (D PA), duration from peak acceleration to peak velocity (D PA-PV), duration from peak velocity to peak deceleration (D PV-PD), duration from peak deceleration to the movement end (D PD-End), acceleration duration (AD), deceleration duration (DD), peak acceleration (PA), peak velocity (PV), and peak deceleration (PD). While movement durations and amplitudes were similar for upward and downward movements, the Temporal Structure of acceleration profiles differed between the two directions. More specifically, subjects performed upward movements faster than downward movements; these direction-dependent asymmetries appeared early in the movement (i.e., before PA) and lasted until the moment of PD. Additionally, PA and PV were greater for upward than downward movements. Movement speed also changed the Temporal Structure of acceleration profiles. The effect of speed and direction on the form of acceleration profiles is consistent with the premise that the CNS optimises motor commands with respect to both gravitational and inertial constraints.
Jeremie Gaveau - One of the best experts on this subject based on the ideXlab platform.
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The Temporal Structure of vertical arm movements.
PLoS ONE, 2011Co-Authors: Jeremie Gaveau, Charalambos PapaxanthisAbstract:The present study investigates how the CNS deals with the omnipresent force of gravity during arm motor planning. Previous studies have reported direction-dependent kinematic differences in the vertical plane; notably, acceleration duration was greater during a downward than an upward arm movement. Although the analysis of acceleration and deceleration phases has permitted to explore the integration of gravity force, further investigation is necessary to conclude whether feedforward or feedback control processes are at the origin of this incorporation. We considered that a more detailed analysis of the Temporal features of vertical arm movements could provide additional information about gravity force integration into the motor planning. Eight subjects performed single joint vertical arm movements (45° rotation around the shoulder joint) in two opposite directions (upwards and downwards) and at three different speeds (slow, natural and fast). We calculated different parameters of hand acceleration profiles: movement duration (MD), duration to peak acceleration (D PA), duration from peak acceleration to peak velocity (D PA-PV), duration from peak velocity to peak deceleration (D PV-PD), duration from peak deceleration to the movement end (D PD-End), acceleration duration (AD), deceleration duration (DD), peak acceleration (PA), peak velocity (PV), and peak deceleration (PD). While movement durations and amplitudes were similar for upward and downward movements, the Temporal Structure of acceleration profiles differed between the two directions. More specifically, subjects performed upward movements faster than downward movements; these direction-dependent asymmetries appeared early in the movement (i.e., before PA) and lasted until the moment of PD. Additionally, PA and PV were greater for upward than downward movements. Movement speed also changed the Temporal Structure of acceleration profiles. The effect of speed and direction on the form of acceleration profiles is consistent with the premise that the CNS optimises motor commands with respect to both gravitational and inertial constraints.
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The Temporal Structure of Vertical Arm Movements
PLoS ONE, 2011Co-Authors: Jeremie Gaveau, Charalambos PapaxanthisAbstract:The present study investigates how the CNS deals with the omnipresent force of gravity during arm motor planning. Previous studies have reported direction-dependent kinematic differences in the vertical plane; notably, acceleration duration was greater during a downward than an upward arm movement. Although the analysis of acceleration and deceleration phases has permitted to explore the integration of gravity force, further investigation is necessary to conclude whether feedforward or feedback control processes are at the origin of this incorporation. We considered that a more detailed analysis of the Temporal features of vertical arm movements could provide additional information about gravity force integration into the motor planning. Eight subjects performed single joint vertical arm movements (45 degrees rotation around the shoulder joint) in two opposite directions (upwards and downwards) and at three different speeds (slow, natural and fast). We calculated different parameters of hand acceleration profiles: movement duration (MD), duration to peak acceleration (D PA), duration from peak acceleration to peak velocity (D PA-PV), duration from peak velocity to peak deceleration (D PV-PD), duration from peak deceleration to the movement end (D PD-End), acceleration duration (AD), deceleration duration (DD), peak acceleration (PA), peak velocity (PV), and peak deceleration (PD). While movement durations and amplitudes were similar for upward and downward movements, the Temporal Structure of acceleration profiles differed between the two directions. More specifically, subjects performed upward movements faster than downward movements; these direction-dependent asymmetries appeared early in the movement (i.e., before PA) and lasted until the moment of PD. Additionally, PA and PV were greater for upward than downward movements. Movement speed also changed the Temporal Structure of acceleration profiles. The effect of speed and direction on the form of acceleration profiles is consistent with the premise that the CNS optimises motor commands with respect to both gravitational and inertial constraints.
Uri Hasson - One of the best experts on this subject based on the ideXlab platform.
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Learning Naturalistic Temporal Structure in the Posterior Medial Network.
Journal of cognitive neuroscience, 2018Co-Authors: Mariam Aly, Janice Chen, Nicholas B. Turk-browne, Uri HassonAbstract:The posterior medial network is at the apex of a Temporal integration hierarchy in the brain, integrating information over many seconds of viewing intact, but not scrambled, movies. This has been interpreted as an effect of Temporal Structure. Such Structure in movies depends on preexisting event schemas, but Temporal Structure can also arise de novo from learning. Here, we examined the relative role of schema-consistent Temporal Structure and arbitrary but consistent Temporal Structure on the human posterior medial network. We tested whether, with repeated viewing, the network becomes engaged by scrambled movies with Temporal Structure. Replicating prior studies, activity in posterior medial regions was immediately locked to stimulus Structure upon exposure to intact, but not scrambled, movies. However, for Temporally Structured scrambled movies, functional coupling within the network increased across stimulus repetitions, rising to the level of intact movies. Thus, Temporal Structure is a key determinant of network dynamics and function in the posterior medial network.
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Learning naturalistic Temporal Structure in the posterior medial network
2017Co-Authors: Mariam Aly, Janice Chen, Nicholas B. Turk-browne, Uri HassonAbstract:The posterior medial network is at the apex of a Temporal integration hierarchy in the brain, integrating information over many seconds of viewing intact, but not scrambled, movies. This has been interpreted as an effect of Temporal Structure. Such Structure in movies depends on pre-existing event schemas, but Temporal Structure can also arise de novo from learning. Here we examined the relative role of schema-consistent Temporal Structure and arbitrary but consistent Temporal Structure on the human posterior medial network. We tested whether, with repeated viewing, the network becomes engaged by scrambled movies with Temporal Structure. Replicating prior studies, posterior medial regions were immediately locked to stimulus Structure upon exposure to intact but not scrambled movies. However, for Temporally Structured scrambled movies, functional coupling within the network increased across stimulus repetitions, rising to the level of intact movies. Thus, Temporal Structure is a key determinant of network dynamics and function.
David Poeppel - One of the best experts on this subject based on the ideXlab platform.
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the role of Temporal Structure in the investigation of sensory memory auditory scene analysis and speech perception a healthy aging perspective
International Journal of Psychophysiology, 2015Co-Authors: Johanna Maria Rimmele, Elyse Sussman, David PoeppelAbstract:Abstract Listening situations with multiple talkers or background noise are common in everyday communication and are particularly demanding for older adults. Here we review current research on auditory perception in aging individuals in order to gain insights into the challenges of listening under noisy conditions. Informationally rich Temporal Structure in auditory signals – over a range of time scales from milliseconds to seconds – renders Temporal processing central to perception in the auditory domain. We discuss the role of Temporal Structure in auditory processing, in particular from a perspective relevant for hearing in background noise, and focusing on sensory memory, auditory scene analysis, and speech perception. Interestingly, these auditory processes, usually studied in an independent manner, show considerable overlap of processing time scales, even though each has its own ‘privileged’ Temporal regimes. By integrating perspectives on Temporal Structure processing in these three areas of investigation, we aim to highlight similarities typically not recognized.
Kazuo Hiraki - One of the best experts on this subject based on the ideXlab platform.
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The relative importance of spatial versus Temporal Structure in the perception of biological motion: an event-related potential study.
Cognition, 2005Co-Authors: Masahiro Hirai, Kazuo HirakiAbstract:We investigated how the spatioTemporal Structure of animations of biological motion (BM) affects brain activity. We measured event-related potentials (ERPs) during the perception of BM under four conditions: normal spatial and Temporal Structure; scrambled spatial and normal Temporal Structure; normal spatial and scrambled Temporal Structure; and scrambled spatial and Temporal Structure. As in a previous study, we identified two negative components at both occipitoTemporal regions: N210 reflected general motion processing while N280 reflected the processing of BM. We analyzed the averaged ERPs in the 200-300 ms response time window and found that spatial Structure had a substantial effect on the magnitude of the averaged response amplitude in both hemispheres. This finding suggests that spatial Structure of point-lights elicits a stronger response in the occipitoTemporal region than Temporal Structure for the BM perception.
