Perception of Upright: Multisensory Convergence and the Role of Temporo-Parietal Cortex

Abstract

We inherently maintain a stable perception of the world despite frequent changes in the head, eye, and body positions. Such "orientation constancy" is a prerequisite for coherent spatial perception and sensorimotor planning. As a multimodal sensory reference, perception of upright represents neural processes that subserve orientation constancy through integration of sensory information encoding the eye, head, and body positions. Although perception of upright is distinct from perception of body orientation, they share similar neural substrates within the cerebral cortical networks involved in perception of spatial orientation. These cortical networks, mainly within the temporo-parietal junction, are crucial for multisensory processing and integration that generate sensory reference frames for coherent perception of self-position and extrapersonal space transformations. In this review, we focus on these neural mechanisms and discuss (i) neurobehavioral aspects of orientation constancy, (ii) sensory models that address the neurophysiology underlying perception of upright, and (iii) the current evidence for the role of cerebral cortex in perception of upright and orientation constancy, including findings from the neurological disorders that affect cortical function.

Body orientation contributes to modelling the effects of gravity for target interception in humans

“…; Alberts et al . ; Kheradmand & Winnick ). Also, the perception of static body tilt results from multisensory fusion, vestibular inputs being integrated with proprioceptive inputs (Bringoux et al .…”

“…Also, the perception of static body tilt results from multisensory fusion, vestibular inputs being integrated with proprioceptive inputs (Bringoux et al . ), although the perception of body orientation is considered to be independent of the perception of vertical direction, with systematic errors smaller than those in SVV (Kaptein & Van Gisbergen, ; Kheradmand & Winnick ).…”

“…Also, SVV tasks engage temporo‐parietal‐insular cortices (Fiori et al . ; Kheradmand & Winnick ), although temporal and spatial processing of gravity may not necessarily co‐localize in the same regions (Maffei et al . ).…”

Gravity estimation and verticality perception

“…Within the human cerebral cortex, the processing of vestibular information occurs in regions in and around the temporoparietal junction, neighboring parietal cortex, and the posterior insula (Brandt et al, 1994; Perennou et al, 2008; Baier et al, 2012; Lopez et al, 2012). Interfering with activity in the human temporoparietal junction through repetitive transcranial magnetic stimulation can systematically bias SVV (Kheradmand et al, 2015; for review, see Kheradmand and Winnick, 2017). For detailed reviews of the contributions of specific brain regions to the processing of vestibular information, see Barmack (2003), Lopez and Blanke (2011), and Kheradmand and Winnick (2017).…”

“…Interfering with activity in the human temporoparietal junction through repetitive transcranial magnetic stimulation can systematically bias SVV (Kheradmand et al, 2015; for review, see Kheradmand and Winnick, 2017). For detailed reviews of the contributions of specific brain regions to the processing of vestibular information, see Barmack (2003), Lopez and Blanke (2011), and Kheradmand and Winnick (2017).…”