Can't Touch This: Removing haptic feedback of the goal object during visually-guided grasping induces pantomime-like grasps

C. M. Byrne; R. L. Whitwell; T. Ganel; M. A. Goodale

doi:10.1167/13.9.335

Can't Touch This: Removing haptic feedback of the goal object during visually-guided grasping induces pantomime-like grasps

Journal of Vision ◽

10.1167/13.9.335 ◽

2013 ◽

Vol 13 (9) ◽

pp. 335-335 ◽

Cited By ~ 3

Author(s):

C. M. Byrne ◽

R. L. Whitwell ◽

T. Ganel ◽

M. A. Goodale

Keyword(s):

Haptic Feedback ◽

Visually Guided ◽

Goal Object

Download Full-text

Reframing the action and perception dissociation in DF: haptics matters, but how?

Journal of Neurophysiology ◽

10.1152/jn.00396.2012 ◽

2013 ◽

Vol 109 (3) ◽

pp. 621-624 ◽

Cited By ~ 20

Author(s):

Robert L. Whitwell ◽

Gavin Buckingham

Keyword(s):

Haptic Feedback ◽

Careful Consideration ◽

Object Size ◽

Goal Object ◽

Functional Roles ◽

Action And Perception ◽

Vision For Action ◽

Original Interpretation ◽

New Evidence ◽

Core Issues

Goodale and Milner's (1992) “vision-for-action” and “vision-for-perception” account of the division of labor between the dorsal and ventral “streams” has come to dominate contemporary views of the functional roles of these two pathways. Nevertheless, some lines of evidence for the model remain controversial. Recently, Thomas Schenk reexamined visual form agnosic patient DF's spared anticipatory grip scaling to object size, one of the principal empirical pillars of the model. Based on this new evidence, Schenk rejects the original interpretation of DF's spared ability that was based on segregated processing of object size and argues that DF's spared grip scaling relies on haptic feedback to calibrate visual egocentric cues that relate the posture of the hand to the visible edges of the goal-object. However, a careful consideration of the tasks that Schenk employed reveals some problems with his claim. We suspect that the core issues of this controversy will require a closer examination of the role that cognition plays in the operation of the dorsal and ventral streams in healthy controls and in patient DF.

Download Full-text

Coordination between digit forces and positions: interactions between anticipatory and feedback control

Journal of Neurophysiology ◽

10.1152/jn.00754.2013 ◽

2014 ◽

Vol 111 (7) ◽

pp. 1519-1528 ◽

Cited By ~ 11

Author(s):

Qiushi Fu ◽

Marco Santello

Keyword(s):

Feedback Control ◽

Visual Information ◽

Visual Cues ◽

Time Course ◽

Haptic Feedback ◽

Virtual Object ◽

Control Mechanisms ◽

Visually Guided ◽

Force Coordination ◽

Digit Position

Humans adjust digit forces to compensate for trial-to-trial variability in digit placement during object manipulation, but the underlying control mechanisms remain to be determined. We hypothesized that such digit position/force coordination was achieved by both visually guided feed-forward planning and haptic-based feedback control. The question arises about the time course of the interaction between these two mechanisms. This was tested with a task in which subjects generated torque (± 70 N·mm) on a virtual object to control a cursor moving to target positions to catch a falling ball, using a virtual reality environment and haptic devices. The width of the virtual object was varied between large (L) and small (S). These object widths result in significantly different horizontal digit relative positions and require different digit forces to exert the same task torque. After training, subjects were tested with random sequences of L and S widths with or without visual information about object width. We found that visual cues allowed subjects to plan manipulation forces before contact. In contrast, when visual cues were not available to predict digit positions, subjects implemented a “default” digit force plan that was corrected after digit contact to eventually accomplish the task. The time course of digit forces revealed that force development was delayed in the absence of visual cues. Specifically, the appropriate digit force adjustments were made 250–300 ms after initial object contact. This result supports our hypothesis and further reveals that haptic feedback alone is sufficient to implement digit force-position coordination.

Download Full-text