Object manipulation and motion perception: Evidence of an influence of action planning on visual processing.

2009 ◽  
Vol 35 (4) ◽  
pp. 1062-1071 ◽  
Author(s):  
Oliver Lindemann ◽  
Harold Bekkering
2016 ◽  
Vol 16 (12) ◽  
pp. 23
Author(s):  
Simona Monaco ◽  
Elisa Pellencin ◽  
Malfatti Giulia ◽  
Turella Luca

2019 ◽  
Author(s):  
Evan Cesanek ◽  
Jordan A. Taylor ◽  
Fulvio Domini

AbstractVisual perception often fails to recover the veridical 3D shape of objects in the environment due to ambiguity and variability in the available depth cues. However, we rely heavily on 3D shape estimates when planning movements, for example reaching to pick up an object from a slanted surface. Given the wide variety of distortions that can affect 3D perception, how do our actions remain accurate across different environments? One hypothesis is that the visuomotor system performs selective filtering of 3D information to minimize distortions. Indeed, some studies have found that actions appear to preferentially target stereo information when it is put in conflict with texture information. However, since these studies analyze averages over multiple trials, this apparent preference could be produced by sensorimotor adaptation. In Experiment 1, we create a set of cue-conflict stimuli where one available depth cue is affected by a constant bias. Sensory feedback rapidly aligns the motor output with physical reality in just a few trials, which can make it seem as if action planning selectively relies on the reinforced cue—yet no change in the relative influences of the cues is necessary to eliminate the constant errors. In contrast, when one depth cue becomes less correlated with physical reality, variable movement errors will occur, causing canonical adaptation to fail as the opposite error corrections cancel out. As a result, canonical adaptation cannot explain the preference for stereo found in studies with variable errors. However, Experiment 2 shows that persistent errors can produce a novel form of adaptation that gradually reduces the relative influence of an unreliable depth cue. These findings show that grasp control processes are continuously modified based on sensory feedback to compensate for both biases and noise in 3D visual processing, rather than having a hardwired preference for one type of depth information.


Author(s):  
Matthias Weigelt ◽  
Wilfried Kunde ◽  
Wolfgang Prinz

The present experiment investigated the sensitivity for end-state comfort in a bimanual object manipulation task. Participants were required to simultaneously reach for two bars and to place the objects' ends into two targets on the table. The design of the experiment allowed to dissociate the relative roles of initial means (e.g., the selection of grips) and final postures (e.g., the anticipation of end-states). The question of interest was whether affording different grip patterns for the two hands would introduce a bias away from reaching end-state comfort. Results revealed a strong sensitivity for end-state comfort, independent of the required grip patterns. In particular, end-state comfort was preferred even if this meant selecting different initial means (i.e., different grips) for the two hands. Hence, end-state oriented action planning appears to dominate interaction costs that may result from motor-related, intermanual interference. We infer that movement planning is constrained by action goals (e.g., a comfortable end-posture for both hands), but largely unaffected by the type of motor actions necessary to achieve these goals.


2021 ◽  
Author(s):  
Sunwoo Kwon ◽  
Krystel R. Huxlin ◽  
Jude F. Mitchell

AbstractVisual pathways that guide actions do not necessarily mediate conscious perception. Patients with primary visual cortex (V1) damage lose conscious perception but often retain unconscious abilities (e.g. blindsight). Here, we asked if saccade accuracy and post-saccadic following responses (PFRs) that automatically track target motion upon saccade landing are retained when conscious perception is lost. We contrasted these behaviors in the blind and intact fields of 8 chronic V1-stroke patients, and in 8 visually-intact controls. Saccade accuracy was relatively normal in all cases. Stroke patients also had normal PFR in their intact fields, but no PFR in their blind fields. Thus, V1 damage did not spare the unconscious visual processing necessary for automatic, post-saccadic smooth eye movements. Importantly, visual training that recovered motion perception in the blind field did not restore the PFR, suggesting a clear dissociation between pathways mediating perceptual restoration and automatic actions in the V1-damaged visual system.


2002 ◽  
Vol 9 (1) ◽  
pp. 1-25 ◽  
Author(s):  
D. C. Kiper ◽  
P. Zesiger ◽  
P. Maeder ◽  
T. Deonna ◽  
G. M. Innocenti

We analyzed the visual functions of two patients (MS, FJ) with bilateral lesion of the primary visual cortex, which occurred at gestational age 33 wk in MS and at postnatal month 7 in FJ. In both patients basic visual functions— visual acuity, contrast sensitivity, color, form, motion perception—are similarly preserved or modestly impaired. Functions requiring higher visual processing, particularly figure-ground segregation based on textural cues, are severely impaired. In MS, studied longitudinally, the deficits attenuated between the ages of 4.5 and 8 y, suggesting that the developing visual system can display a considerable degree of adaptive plasticity several years after the occurrence of a lesion. In FJ (age 18:9 to 20:6 y), who is more impaired, the recovery, if any, was less.


2019 ◽  
Vol 45 (Supplement_2) ◽  
pp. S151-S152
Author(s):  
Antigona Martinez ◽  
Russell Tobe ◽  
Melissa Breland ◽  
Alexis Lieval ◽  
Babak Ardekani ◽  
...  

2013 ◽  
Vol 13 (9) ◽  
pp. 21-21
Author(s):  
E. Burton ◽  
J. Wattam-Bell ◽  
K. Nishiguchi ◽  
V. Sundaram ◽  
J. Aboshiha ◽  
...  

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