Effector‐based attention systems

Abstract

Visual processing is known to be enhanced at the end point of eye movements. Feedback within the oculomotor system has been shown to drive these alterations in visual processing. However, we do not simply view the world; we also reach out and interact using our hands. Consequently, it is not surprising that visual processing has also been shown to be altered in near-hand space. A growing body of work documents a myriad of alterations in near-hand visual processing, with little consensus on the neural underpinnings of the effect of the hand. Since movement of the eyes and hands is governed by parallel frontoparietal networks and since within the oculomotor system feedback from these motor control regions has been shown to drive enhanced visual processing at saccade end points, it is plausible that a similar feedback mechanism is at play in near-hand improvements in visual processing. Here, we compare and contrast oculomotor-driven and hand-driven changes in visual processing and provide support for the hypothesis that feedback within the reaching and grasping systems enhances visual processing near the hand in a novel way.

Selective Modulation of Early Visual Cortical Activity by Movement Intention

“…One possible role of top-down projections to early visual areas during planning is to enhance object features critical for motor control (Craighero et al 1999;Bekkering and Neggers 2002;Fagioli et al 2007;Gutteling et al 2011Gutteling et al , 2013Perry and Fallah 2017), which are generally different than those critical for perception (Brouwer et al 2009). For example, prior to an impending reaching movement, there is enhanced processing at the target's spatial location (Baldauf et al 2006;Baldauf and Deubel 2008) and, likewise, prior to object grasping, there is enhanced processing of the target's orientation (Gutteling et al 2011(Gutteling et al , 2013.…”

“…Specifically, sensorimotor prediction of the visual consequences of movement at the level of early visual cortex could enable the more rapid detection of movement errors and their subsequent correction (Wolpert and Ghahramani 2000;Wolpert et al 2011). At the neuroanatomical level, both the motor-related enhancement and sensorimotor filtering of information could, in principle, be mediated by top-down projections to early visual cortex from parietal and frontal areas involved in action planning and attention-orienting (Moore and Fallah 2004;Borra and Rockland 2011;Greenberg et al 2012;Takemura et al 2015;Perry and Fallah 2017).…”

Action-specific feature processing in the human visual cortex

“…The premotor cortex is thought to play a role in 'preparatory set' (pre-cued activation of neurons in anticipation of action), possibly initiating the reentrant propagation of signals through motor-to-sensory areas. This likely included general priming of feature-specific processing mechanisms (Martinez-Trujillo and Treue 2004;, in this case intention-related orientation selectivity (Perry and Fallah 2017). However, we did not observe any action-specific responses during this first delay (Figures 5 and 6), or in the initial visual response before the second delay (not shown).…”

“…Likewise, reentrant pathways could explain reactivation of the visual cortex during the planning and execution of reaching and grasping movements in the dark (Singhal et al 2013;Chen et al 2014;Cappadocia et al 2016). Reentrant feedback for limb control is potentially complex because the hand-arm system is capable of many types of action and interacts physically with the surrounding world (Perry and Fallah 2017). For instance, intrinsic object features are important for grasping, whereas pointing only requires knowledge of the object location (Van Elk et al 2010).…”

The gap effect reduces both manual and saccadic inhibition of return (IOR)

“…As they showed the existence of a perceptual component in saccadic IOR and, therefore, needed to consider it as an attentional process, we provide evidence that manual IOR is related to eye preparation and should be considered a motoric process. Both studies showed that manual and saccadic IORs are more a part of the same kind of effector-based attention systems (Perry and Fallah 2017 ) that were postulated by the PToA (Rizzolatti et al 1987 , 1994 ) than they are part of two separate attention-based and motor-based IORs (Taylor and Klein 2000 ; Hilchey et al 2016 ).…”