Ways to investigate vestibular contributions to cognitive processes.

Abstract

Originally conceived as a primary system embedded into reflex generation for spinal and ocular-motor control, there is now an exciting and rapidly growing line of research showing that the vestibular system—which is intrinsically highly convergent with other sensory and motor signals (Angelaki and Cullen, 2008)—interacts with various cognitive processes such as spatial navigation (Angelaki et al., 2009), space perception (Ferre et al., 2013a), body representation (Lopez et al., 2010; Ferre et al., 2013c), mental imagery (Lenggenhager et al., 2008; Falconer and Mast, 2012; Van Elk and Blanke, 2014), attention (e.g., Figliozzi et al., 2005), memory (e.g., Smith et al., 2010), risk perception (Mckay et al., 2013), and even social cognition (Lopez et al., 2013). Insight in this area has mostly been gained through the use of standardized clinical equipment such as caloric, galvanic, and vestibular evoked myogenic potential (VEMP) devices. While these techniques bear several advantages, it is important to recall that they stimulate the vestibular organ in an unnatural and non-physiological way. Such artificial stimulation might be exploited for specific questions, but might hamper the investigation of others. Below we will briefly describe the advantages and disadvantages of various stimulation techniques for investigating specific research questions from cognitive neuroscience (see Figure ​Figure11 for a summary). Emphasis will be put on those stimulation methods that best approximate natural movement, i.e., whole-body motion platforms. We will provide evidence that even though these highly sophisticated apparatus are technically demanding and hence not routinely available, they are indispensable for investigating certain vestibular-cognitive interactions. Figure 1 Summary of the most common methods to stimulate the vestibular system and their suitability for testing specific cognitive research questions. aTypical subject position during CVS, predominantly stimulating the horizontal semicircular canals. Note that ...