The Role of Haptic Expectations in Reaching to Grasp: From Pantomime to Natural Grasps and Back Again

Whitwell, Robert L.; Katz, Nathan J.; Goodale, Melvyn A.; Enns, James T.

doi:10.3389/fpsyg.2020.588428

Cited by 10 publications

(7 citation statements)

References 87 publications

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“…Conversely, if we included control orientations for the easy structural grasps, instead, it would not only result in a more asymmetric design, wherein only a subset of trials (for the demanding functional grasp, only) would require substantial hand rotations, but could also put it into question why disparate object orientations (or alternatively, demanding hand rotations) were not included for the reach-to-move actions. Finally, although the use of pantomime is well established in neuroimaging studies of praxis skills, especially the ones concerned with the planning processes, any differences in the outcomes of real and pantomimed grasping of tools and/or subsequent actions with tools, be it functional or not, can be revealed only when they are simultaneously studied (Hermsdorfer et al 2007 ; Króliczak et al 2007 ; see also Kithu et al 2019 ; Whitwell et al 2020 ). Future research could/should also address representations of disparate action goals in other handedness groups, and/or in individuals with atypically represented praxis skills (Kroliczak et al 2021 ).…”

Section: Discussionmentioning

confidence: 99%

Action goals and the praxis network: an fMRI study

et al. 2022

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The praxis representation network (PRN) of the left cerebral hemisphere is typically linked to the control of functional interactions with familiar tools. Surprisingly, little is known about the PRN engagement in planning and execution of tool-directed actions motivated by non-functional but purposeful action goals. Here we used functional neuroimaging to perform both univariate and multi-voxel pattern analyses (MVPA) in 20 right-handed participants who planned and later executed, with their dominant and non-dominant hands, disparate grasps of tools for different goals, including: (1) planning simple vs. demanding functional grasps of conveniently vs. inconveniently oriented tools with an intention to immediately use them, (2) planning simple—but non-functional—grasps of inconveniently oriented tools with a goal to pass them to a different person, (3) planning reaching movements directed at such tools with an intention to move/push them with the back of the hand, and (4) pantomimed execution of the earlier planned tasks. While PRN contributed to the studied interactions with tools, the engagement of its critical nodes, and/or complementary right hemisphere processing, was differently modulated by task type. E.g., planning non-functional/structural grasp-to-pass movements of inconveniently oriented tools, regardless of the hand, invoked the left parietal and prefrontal nodes significantly more than simple, non-demanding functional grasps. MVPA corroborated decoding capabilities of critical PRN areas and some of their right hemisphere counterparts. Our findings shed new lights on how performance of disparate action goals influences the extraction of object affordances, and how or to what extent it modulates the neural activity within the parieto-frontal brain networks.

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Section: Discussionmentioning

confidence: 99%

Action goals and the praxis network: an fMRI study

et al. 2022

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“…The barrier in our study could have modulated anticipation of the potential for somatosensory feedback. After all, the mere expectation of haptic feedback is sufficient to modulate grasping kinematics toward real objects ( Whitwell, Katz, Goodale, & Enns, 2020). Nevertheless, it is unclear whether expectations of haptic feedback are sufficient to modulate perception of real objects and pictures when the task does not explicitly involve grasping.…”

Section: Why Does a Transparent Barrier Modulate Earlymentioning

confidence: 99%

Graspability Modulates the Stronger Neural Signature of Motor Preparation for Real Objects vs. Pictures

Fairchild

Marini

Snow

2021

Journal of Cognitive Neuroscience

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The cognitive and neural bases of visual perception are typically studied using pictures rather than real-world stimuli. Unlike pictures, real objects are actionable solids that can be manipulated with the hands. Recent evidence from human brain imaging suggests that neural responses to real objects differ from responses to pictures; however, little is known about the neural mechanisms that drive these differences. Here, we tested whether brain responses to real objects versus pictures are differentially modulated by the “in-the-moment” graspability of the stimulus. In human dorsal cortex, electroencephalography responses show a “real object advantage” in the strength and duration of mu (μ) and low beta (β) rhythm desynchronization—well-known neural signatures of visuomotor action planning. We compared desynchronization for real tools versus closely matched pictures of the same objects, when the stimuli were positioned unoccluded versus behind a large transparent barrier that prevented immediate access to the stimuli. We found that, without the barrier in place, real objects elicited stronger μ and β desynchronization compared to pictures, both during stimulus presentation and after stimulus offset, replicating previous findings. Critically, however, with the barrier in place, this real object advantage was attenuated during the period of stimulus presentation, whereas the amplification in later periods remained. These results suggest that the “real object advantage” is driven initially by immediate actionability, whereas later differences perhaps reflect other, more inherent properties of real objects. The findings showcase how the use of richer multidimensional stimuli can provide a more complete and ecologically valid understanding of object vision.

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“…Second, terminal haptic feedback was available during natural but not pantomime-grasps and this was done so that the latter task matched that used in previous work (Goodale et al, 1994;Holmes et al, 2011;Westwood et al, 2000) and the extant apraxia literature (Liepmann, 1908). That said, we recognize the salience of this issue given work by our group and others showing that haptic feedback on trial N can-in some instances-support an absolute visuo-haptic calibration for trial N + 1 and beyond (Bingham et al, 2007;Davarpanah Jazi & Heath, 2016;Heath et al, 2019;Schenk, 2012;Whitwell et al, 2020). Based on the above, it would be interesting to determine whether a continuum of targets that differ by as little as 0.5 mm provide the requisite feedback for an absolute visuo-haptic calibration.…”

Section: Discussionmentioning

confidence: 90%

Distinct visual resolution supports aperture shaping in natural and pantomime-grasping.

Heath¹,

Ayala²,

Hamidi³

et al. 2022

Canadian Journal of Experimental Psychology / Revue canadienne

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Pantomime-grasping is a "simulated" motor response wherein an individual grasps to an area dissociated from a physical target. The task has been used in the apraxia literature as a proxy for natural grasping (i.e., physically grasping a target); however, it is important to recognize that the task's decoupled spatial relations between stimulus and response renders the top-down processing of target features (e.g., size) that accumulating evidence has shown to be mediated by visual information functionally distinct from natural grasping. Here, we examined whether the visual information supporting pantomime-grasps exhibits a visual resolution power commensurate with natural grasps. Participants were presented with a target and nontarget that differed in size below the perceptual threshold (i.e., 0.5 mm or ∼1.3%) and were asked to make a perceptual judgment about the target (i.e., "smaller" or "larger" than the nontarget) before and after completing natural and pantomime-grasps. Results showed that perceptual judgments "before" and "after" natural and pantomime-grasps did not reliably distinguish between target and nontarget. Natural grasp peak grip apertures (PGAs) scaled to target size and were comparable for "before" and "after" perceptual judgment trials-a result indicating that haptic feedback from physically grasping the target did not "boost" perceptual accuracy. Most notably, pantomime-grasp PGAs were insensitive to target size; that is, responses elicited a visual resolution power less than natural grasps. These results provide convergent evidence that pantomime-grasps are mediated by the same visual information as obligatory perceptions and do not provide a proxy for natural grasps. Public Significance StatementThe visual information we use to identify an apple in a bowl of fruit (i.e., a perception) is distinct from the visual information we use to grasp the apple (i.e., an action). The main finding from the present study is that a simulated grasping response (so-called pantomime) is supported by the same visual information as that supporting perceptions.

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The Role of Haptic Expectations in Reaching to Grasp: From Pantomime to Natural Grasps and Back Again

Cited by 10 publications

References 87 publications

Action goals and the praxis network: an fMRI study

Action goals and the praxis network: an fMRI study

Graspability Modulates the Stronger Neural Signature of Motor Preparation for Real Objects vs. Pictures

Distinct visual resolution supports aperture shaping in natural and pantomime-grasping.

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