Motion‐induced position mis‐localization predicts the severity of Alzheimer's disease

Abstract

Patients with Alzheimer's disease (AD) often exhibit motion processing deficits. It is unclear whether the localization of moving objectsa perceptual process tightly linked to motionis impaired or intact in AD. In this study, we used the phenomenon of illusory shift of position induced by motion as a behavioural paradigm to probe how the spatial representation differs between AD patients and healthy elderly controls. We measured the magnitudes of motion-induced position shift in a group of AD participants (N = 24) and age-matched elderly observers (N = 24). We found that AD patients showed weakened position mis-localization, but only for motion stimuli of slow speeds. For fast motion, the position mis-localization did not differ significantly between groups. Furthermore, we showed that the magnitudes of position mis-localization can predict the severity of AD; that is, patients with more severe symptoms had less preserved position mis-localization. Our results suggest that AD pathology impacts not only motion processing per se, but also the perceptual process related to motion such as the localization of moving objects.

Integration of Position and Predictive Motion Signals in Aging Vision

“…The increased MIPS in older adults is likely a consequence of optimal integration, in which relatively accurate predictive motion signals are given more weight compared with noisy position signals. Notably, recent studies showed that the size of the MIPS in patients with mild Alzheimer's disease was smaller than that in an age-matched control group and the size decreased with the severity of Alzheimer symptoms 47,48 . An intriguing explanation is that the deteriorated visual memory of Alzheimer's patients 49,50 might weaken the influence of predictive motion signals on position perception, resulting in the relatively small MIPS size.…”

Overconfidence in visual perception in parkinson's disease

“…This becomes more difficult as the percentage of coherently moving dots is decreased. Although this is a classic and well‐established paradigm that has been broadly used to test coherent visual motion perception (Britten et al., 1992; Morgan & Ward, 1980; Rajananda et al., 2018; Shadlen & Newsome, 1996; Williams & Sekuler, 1984), and has also been applied in many clinical populations, such as autism (Milne et al., 2002; Robertson et al., 2012) and Alzheimer's disease (Fernandez & Duffy, 2012; Fernandez et al., 2013; Li et al., 2017; Song & Wang, 2020), surprisingly little is known about RDK performance in PD.…”

Overconfidence in visual perception in Parkinson’s disease

“…This becomes more difficult as the percentage of coherently moving dots is decreased. Although this is a classic and well-established paradigm that has been broadly used to test coherent visual motion perception (Morgan and Ward, 1980;Williams and Sekuler, 1984;Britten et al, 1992;Shadlen and Newsome, 1996;Rajananda et al, 2018), and has also been applied in many clinical populations, such as autism (Milne et al, 2002;Robertson et al, 2012) and Alzheimer's disease (Fernandez and Duffy, 2012;Fernandez et al, 2013;Li et al, 2017;Song and Wang, 2019), surprisingly little is known about RDK performance in PD.…”