Altered visual perception near the hands: A critical review of attentional and neurophysiological models

Abstract

Visual perception changes as a function of hand proximity. While various theoretical accounts have been offered for this alteration (attentional prioritisation, bimodal cell involvement, detailed evaluation, and magnocellular neuron input enhancement), the current literature lacks consensus on these mechanisms. The purpose of this review, therefore, is to critically review the existing body of literature in light of these distinct theoretical accounts. We find that a growing number of results support the magnocellular (M-cell) enhancement account, and are difficult to reconcile with general attention-based explanations. Despite this key theoretical development in the field, there has been some ambiguity with interpretations offered in recent papers, for example, equating the existing attentional and M-cell based explanations, when in fact they make contrasting predictions. We therefore highlight the differential predictions arising from the distinct theoretical accounts. Importantly, however, we also offer novel perspectives that synthesises the role of attention and neurophysiological mechanisms in understanding altered visual perception near the hands. We envisage that this theoretical development will ensure that the field can progress from documenting behavioural differences, to a consensus on the underlying visual and neurophysiological mechanisms.

Testing the generality of the zoom-lens model: Evidence for visual-pathway specific effects of attended-region size on perception

“…For example, processes such as emotion and hand proximity were initially thought to be nonspecifically beneficial to visual perception, due to a generic effect of attention (Phelps, Ling, & Carrasco, 2006;Reed et al, 2006). It is now understood that emotion (Bocanegra & Zeelenberg, 2011) and hand proximity (Goodhew et al, 2015;Gozli et al, 2012) can both improve and impair performance, dependent on the nature of the task, as encapsulated within the dual-channel framework.…”

“…That is, when observers place their hands in a power grasp (palm pointing inwards, fingers uncurled) on either side of the computer monitor, visual perception is changed compared with identical stimuli presented when the hands are held away from the screen (for a review, see Goodhew, Edwards, Ferber, & Pratt, 2015). While initial explanations for this focussed on non-pathway-specific attentional explanations, which predicted nonspecific perceptual enhancement (Reed, Grubb, & Steele, 2006) or nonspecific disadvantage due to difficulty with attentional disengagement (Abrams, Davoli, Du, Knapp, & Paull, 2008), more recent evidence implies that is the nature of the stimulus, in particular whether it is optimally suited to be processed by M or P cells, that determines whether hand proximity improves or impairs perception.…”

“…While initial explanations for this focussed on non-pathway-specific attentional explanations, which predicted nonspecific perceptual enhancement (Reed, Grubb, & Steele, 2006) or nonspecific disadvantage due to difficulty with attentional disengagement (Abrams, Davoli, Du, Knapp, & Paull, 2008), more recent evidence implies that is the nature of the stimulus, in particular whether it is optimally suited to be processed by M or P cells, that determines whether hand proximity improves or impairs perception. That is, when participants hold their hands in a power grasp near visual stimuli, they demonstrate enhanced M-cell-mediated visual processing at the expense of P-cellmediated perception (Abrams & Weidler, 2013;Goodhew et al, 2015;Goodhew, Fogel, & Pratt, 2014;Goodhew, Gozli, Ferber, & Pratt, 2013;Gozli, West, & Pratt, 2012;Kelly & Brockmole, 2014;Medina, Drebing, Hamilton, & Coslett, 2016). However, several key factors can qualitatively shift this to a pattern of P-cell enhancement near the hands, such as when participants adopt a precision grip (conducive to fine motor interactions with objects), instead of a power grasp (Thomas, 2015).…”

Intentional control of visual processing benefits from referential objects

“…The account suggests an enhancement of the magnocellular pathway (Taylor, Gozli, Chan, Huffman, & Pratt, 2015) due to a disparity in the spatial frequency sensitivities, which could affect perceptual-grouping processes (Huffman, Gozli, Welsh, & Pratt, 2015). According to Goodhew, Edwards, Ferber, and Pratt (2015), these effects implicate Bintegrating dynamic information about the location of the hands in space (body-centred) with visual information about the external world^(p. 227).…”

The conceptual cueing database: Rated items for the study of the interaction between language and attention

“…Embodied semantics There is considerable interaction between abstract cognitive processes on the one hand and one's body and external environment on the other. For example, memory is dramatically enhanced by mentally representing content in familiar spatial locations (Maguire, Valentine, Wilding, & Kapur, 2003), insight problem solving is facilitated by prescribed physical movements (Thomas & Lleras, 2007, 2009, and visual awareness of an object is affected by proximity of the observer's hands (Goodhew, Edwards, Ferber, & Pratt, 2015;Goodhew, Gozli, Ferber, & Pratt, 2013). Furthermore, humans appear to draw on concrete spatial layouts in order to describe and represent concepts (e.g., Boroditsky, Fuhrman, & McCormick, 2011).…”