Head and body space to left and right, front and rear—II. Visuotactual and kinesthetic studies and left-side underestimation

Asymmetric prefrontal cortex functions predict asymmetries in number space

“…This advantage is proposed to be equivalent to the one enjoyed by left-sided items in a horizontal arrangement of visually or haptically presented stimuli [Bradshaw, Nathan, Nettleton, Wilson, & Pierson (1987): rod centering] and referred to, alternatively, as "initial exploration asymmetry" (Ebersbach et al, 1996;Hättig, 1992), "left-side underestimation" (Bradshaw, Nettleton, Nathan, & Wilson, 1983), "right hemispatial inattention" (Weintraub & Mesulam, 1988) or "pseudoneglect" (Bowers & Heilman, 1980). Pseudoneglect along the mental number line was originally demonstrated in the bisection of numerical intervals (Oliveri et al, 2004).…”

Pseudoneglect: a review and meta-analysis of performance factors in line bisection tasks

“…In seven tactile and visuotactile studies Bradshaw et al [15] found greater leftward errors when stimuli were presented in left hemispace.…”

“…In addition, Sampaio and Chokron [108] found the eect only with the right hand and only in dextral (right-handed) subjects in both a tactile and a kinesthetic task. In seven tactile and visuotactile (i.e., tactile rod bisection under normal vision) experiments Bradshaw et al [15] found that both hands erred to the left of veridical, with the left hand erring farther to the left than the right hand.…”

“…An upright control condition produced the greatest leftwards error. Bradshaw et al [15] had subjects turn their head either to the left or the right while keeping their eyes forward. The right head turn condition produced rightward errors while the left head turn condition produced leftward errors.…”

Spatial biases in peripersonal space in sighted and blind individuals revealed by a haptic line bisection paradigm.

“…Despite these differences, the direction of the horizontal bias in the visual and haptic modality tends to be similar, with neurologically normal individuals bisecting to the left of the veridical midpoint ( Jewell & McCourt, 2000; see also Gallace, Auvray, & Spence, 2007, on the possible involvement of higher order multisensory/amodal processes in bisection tasks). It is important to note, however, that the extent of pseudoneglect in the haptic modality depends on numerous modality-specific factors, such as the way the rod is explored (one search vs. multiple searches; see Baek et al, 2002), whether the left or right hand is used for scanning (e.g., Brodie & Pettigrew, 1995), tactile versus kinesthetic scanning ( Sampaio & Philip, 1991), participants' handedness (e.g., Sampaio & Chokron, 1992), and the spatial position of the line with respect to the head-body axis ( Bradshaw, Nettleton, Nathan, & Wilson, 1983). Conversely, the bias reported in the haptic modality for rods presented in the vertical and radial planes is the opposite of that observed with visually presented lines; that is, toward the body in the radial plane and in the downward direction in the vertical plane ( Baek et al, 2002;Chewning et al, 1998;Shelton et al, 1990).…”