Limits...
Sensory processing of motor inaccuracy depends on previously performed movement and on subsequent motor corrections: a study of the saccadic system.

Panouillères M, Urquizar C, Salemme R, Pélisson D - PLoS ONE (2011)

Bottom Line: We found that saccadic adaptation and corrective saccade production were both affected by the manipulations of post-saccadic visual information, but in different ways.Finally, the visual mask interfered with the production of corrective saccades only during the voluntary saccades adaptation task.These last observations suggest that post-saccadic perception depends on the previously performed action and that the differences between saccade categories of motor correction and adaptation occur at an early level of visual processing.

View Article: PubMed Central - PubMed

Affiliation: INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, IMPACT (Integrative, Multisensory, Perception, Action and Cognition) Team and University Lyon 1, Lyon, France. muriel.panouilleres@inserm.fr

ABSTRACT
When goal-directed movements are inaccurate, two responses are generated by the brain: a fast motor correction toward the target and an adaptive motor recalibration developing progressively across subsequent trials. For the saccadic system, there is a clear dissociation between the fast motor correction (corrective saccade production) and the adaptive motor recalibration (primary saccade modification). Error signals used to trigger corrective saccades and to induce adaptation are based on post-saccadic visual feedback. The goal of this study was to determine if similar or different error signals are involved in saccadic adaptation and in corrective saccade generation. Saccadic accuracy was experimentally altered by systematically displacing the visual target during motor execution. Post-saccadic error signals were studied by manipulating visual information in two ways. First, the duration of the displaced target after primary saccade termination was set at 15, 50, 100 or 800 ms in different adaptation sessions. Second, in some sessions, the displaced target was followed by a visual mask that interfered with visual processing. Because they rely on different mechanisms, the adaptation of reactive saccades and the adaptation of voluntary saccades were both evaluated. We found that saccadic adaptation and corrective saccade production were both affected by the manipulations of post-saccadic visual information, but in different ways. This first finding suggests that different types of error signal processing are involved in the induction of these two motor corrections. Interestingly, voluntary saccades required a longer duration of post-saccadic target presentation to reach the same amount of adaptation as reactive saccades. Finally, the visual mask interfered with the production of corrective saccades only during the voluntary saccades adaptation task. These last observations suggest that post-saccadic perception depends on the previously performed action and that the differences between saccade categories of motor correction and adaptation occur at an early level of visual processing.

Show MeSH

Related in: MedlinePlus

Schematic representation of the results.This schema represents the differences in error signal processing between saccade categories and between adaptation and corrective saccade generation. Each square indicates the minimal target duration leading to optimal adaptation or to optimal generation of corrective saccades, for both saccade categories. The shading of the square represents the masking condition in which this target duration is required: grey square for the mask condition and black square for the no-mask condition (bicolour square when the same target duration is required in both masking conditions). The grey rectangles “Mask” symbolise the fact that when the mask is presented, a longer duration of stepped target is necessary to induce optimal adaptation and corrective saccade generation.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3044175&req=5

pone-0017329-g006: Schematic representation of the results.This schema represents the differences in error signal processing between saccade categories and between adaptation and corrective saccade generation. Each square indicates the minimal target duration leading to optimal adaptation or to optimal generation of corrective saccades, for both saccade categories. The shading of the square represents the masking condition in which this target duration is required: grey square for the mask condition and black square for the no-mask condition (bicolour square when the same target duration is required in both masking conditions). The grey rectangles “Mask” symbolise the fact that when the mask is presented, a longer duration of stepped target is necessary to induce optimal adaptation and corrective saccade generation.

Mentions: The main finding of this study was that these manipulations affected saccadic adaptation and corrective saccades generation in different ways and that these effects differed between reactive and voluntary saccades. First, we found that applying a visual mask just after target presentation led to increase the minimum target duration necessary to get optimal adaptation. Second, under both the mask and no-mask conditions, the adaptation of reactive saccades unexpectedly required a shorter target duration than the adaptation of voluntary saccades. Third, the mask interfered with the generation of secondary corrective saccades only for voluntary saccades. Finally, although saccadic adaptation and corrective saccades production both depended on visual masking and saccade type, corrective saccades production was quantitatively less affected by these factors than saccadic adaptation (see Figure 6).


Sensory processing of motor inaccuracy depends on previously performed movement and on subsequent motor corrections: a study of the saccadic system.

Panouillères M, Urquizar C, Salemme R, Pélisson D - PLoS ONE (2011)

Schematic representation of the results.This schema represents the differences in error signal processing between saccade categories and between adaptation and corrective saccade generation. Each square indicates the minimal target duration leading to optimal adaptation or to optimal generation of corrective saccades, for both saccade categories. The shading of the square represents the masking condition in which this target duration is required: grey square for the mask condition and black square for the no-mask condition (bicolour square when the same target duration is required in both masking conditions). The grey rectangles “Mask” symbolise the fact that when the mask is presented, a longer duration of stepped target is necessary to induce optimal adaptation and corrective saccade generation.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3044175&req=5

pone-0017329-g006: Schematic representation of the results.This schema represents the differences in error signal processing between saccade categories and between adaptation and corrective saccade generation. Each square indicates the minimal target duration leading to optimal adaptation or to optimal generation of corrective saccades, for both saccade categories. The shading of the square represents the masking condition in which this target duration is required: grey square for the mask condition and black square for the no-mask condition (bicolour square when the same target duration is required in both masking conditions). The grey rectangles “Mask” symbolise the fact that when the mask is presented, a longer duration of stepped target is necessary to induce optimal adaptation and corrective saccade generation.
Mentions: The main finding of this study was that these manipulations affected saccadic adaptation and corrective saccades generation in different ways and that these effects differed between reactive and voluntary saccades. First, we found that applying a visual mask just after target presentation led to increase the minimum target duration necessary to get optimal adaptation. Second, under both the mask and no-mask conditions, the adaptation of reactive saccades unexpectedly required a shorter target duration than the adaptation of voluntary saccades. Third, the mask interfered with the generation of secondary corrective saccades only for voluntary saccades. Finally, although saccadic adaptation and corrective saccades production both depended on visual masking and saccade type, corrective saccades production was quantitatively less affected by these factors than saccadic adaptation (see Figure 6).

Bottom Line: We found that saccadic adaptation and corrective saccade production were both affected by the manipulations of post-saccadic visual information, but in different ways.Finally, the visual mask interfered with the production of corrective saccades only during the voluntary saccades adaptation task.These last observations suggest that post-saccadic perception depends on the previously performed action and that the differences between saccade categories of motor correction and adaptation occur at an early level of visual processing.

View Article: PubMed Central - PubMed

Affiliation: INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, IMPACT (Integrative, Multisensory, Perception, Action and Cognition) Team and University Lyon 1, Lyon, France. muriel.panouilleres@inserm.fr

ABSTRACT
When goal-directed movements are inaccurate, two responses are generated by the brain: a fast motor correction toward the target and an adaptive motor recalibration developing progressively across subsequent trials. For the saccadic system, there is a clear dissociation between the fast motor correction (corrective saccade production) and the adaptive motor recalibration (primary saccade modification). Error signals used to trigger corrective saccades and to induce adaptation are based on post-saccadic visual feedback. The goal of this study was to determine if similar or different error signals are involved in saccadic adaptation and in corrective saccade generation. Saccadic accuracy was experimentally altered by systematically displacing the visual target during motor execution. Post-saccadic error signals were studied by manipulating visual information in two ways. First, the duration of the displaced target after primary saccade termination was set at 15, 50, 100 or 800 ms in different adaptation sessions. Second, in some sessions, the displaced target was followed by a visual mask that interfered with visual processing. Because they rely on different mechanisms, the adaptation of reactive saccades and the adaptation of voluntary saccades were both evaluated. We found that saccadic adaptation and corrective saccade production were both affected by the manipulations of post-saccadic visual information, but in different ways. This first finding suggests that different types of error signal processing are involved in the induction of these two motor corrections. Interestingly, voluntary saccades required a longer duration of post-saccadic target presentation to reach the same amount of adaptation as reactive saccades. Finally, the visual mask interfered with the production of corrective saccades only during the voluntary saccades adaptation task. These last observations suggest that post-saccadic perception depends on the previously performed action and that the differences between saccade categories of motor correction and adaptation occur at an early level of visual processing.

Show MeSH
Related in: MedlinePlus