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Motion Perception Under Mesopic Vision Journal of Vision (2016) 16(1):16, 1–15 1 Motion perception under mesopic vision Department of Psychology, Japan Women’s University, Kanagawa, Japan # Sanae Yoshimoto Japan Society for the Promotion of Science, Tokyo, Japan $ Faculty of Environment and Information Sciences, # Katsunori Okajima Yokohama National University, Kanagawa, Japan $ Department of Psychology, Japan Women’s University, # Tatsuto Takeuchi Kanagawa, Japan $ Mesopic and scotopic vision extend over an illuminance deals with this broad dynamic range by switching range of 106. The goal of the present study was to between two different types of photoreceptors: cones, determine the effect of decreasing light level on the which function at higher levels of illumination, and underlying motion mechanism that integrates rods, which function at lower levels. Photopic, mesopic, spatiotemporally separated motion signals. To and scotopic regions are defined according to whether accomplish this, we took advantage of the phenomenon cones operate alone, cones and rods operate together, of visual motion priming, in which the perceived or rods operate alone, respectively. In our daily lives, direction of a directionally ambiguous test stimulus is mesopic and scotopic vision extends over an illumina- influenced by the directional movement of a preceding tion range as wide as 106. Therefore, understanding the priming stimulus. After terminating a drifting priming effect of light levels on visual perception is scientifically stimulus, a 180 phase-shifted grating was presented as a 8 and practically crucial (Hess, 1990; Hess, Sharpe, & test stimulus. The priming and test stimuli were Nordby, 1990). separately presented to the central and peripheral retinas, respectively. The participants judged the Although rods project into all retinogeniculate perceived direction of this test stimulus at various light pathways, they primarily project into the magnocellular levels from photopic to scotopic levels. We found that lateral geniculate nucleus (LGN) layers (Purpura, the effects of motion priming disappeared over 1 log unit Kaplan, & Shapley, 1988; Zele & Cao, 2015). Because of mesopic light levels. When the test stimulus was motion-selective areas, such as the middle temporal presented before the offset of the priming stimulus to area, receive dominant inputs from the magnocellular compensate for the temporal delay in the rod pathway LGN layers, visual motion processing could be or when both stimuli were presented at the same selectively influenced by rod-based inputs (Hadjikhani location in the periphery, a motion-priming effect & Tootell, 2000; Maunsell, Nealey, & DePriest, 1990; appeared at mesopic light levels. These results suggest Maunsell & van Essen, 1983). In fact, various aspects of that different temporal characteristics between the cone human motion perception are known to change as light pathway and rod pathway disturb the function of the intensity decreases. Velocity perception (Gegenfurtner, putative motion mechanism responsible for the Mayser, & Sharpe, 2000; Hammett, Champion, spatiotemporal integration of motion signals, which Thompson, & Morland, 2007; Pritchard & Hammett, leads to specific modulation of motion perception over a 2012; Vaziri-Pashkam & Cavanagh, 2008), velocity wide range of mesopic vision. discrimination thresholds (Takeuchi & De Valois, 2000), short-range motion perception (Dawson & Di Lollo, 1990), complex-motion perception (Billino, Bremmer, & Gegenfurtner, 2008), biological motion Introduction perception (Billino et al., 2008; Grossman & Blake, 1999), perception of static-motion illusions (Hisakata & Ambient light levels may vary by a factor of up to Murakami, 2008), perception of interstimulus-interval 1011 in natural environments (Hood & Finkelstein, (ISI) reversal (Sheliga, Chen, FitzGibbon, & Miles, 1986; Stockman & Sharpe, 2006). The visual system 2006; Takeuchi & De Valois, 1997, 2009; Takeuchi, De Citation: Yoshimoto, S., Okajima, K., & Takeuchi, T. (2016). Motion perception under mesopic vision. Journal of Vision, 16(1):16, 1–15, doi:10.1167/16.1.16. doi: 10.1167/16.1.16 Received February 13, 2015; published January 27, 2016 ISSN 1534-7362 Downloaded from jov.arvojournals.orgThis work ison licensed 10/01/2021 under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. Journal of Vision (2016) 16(1):16, 1–15 Yoshimoto, Okajima, & Takeuchi 2 Valois, & Motoyoshi, 2001), perception of two-stroke the spatially center-surround antagonistic motion- motion (Challinor & Mather, 2010; Mather & Challi- contrast sensing system (Allman, Miezin, & McGuin- nor, 2009), the coherent-motion threshold (Billino et ness, 1985; Born & Tootell, 1992; Eifuku & Wurtz, al., 2008; Lankheet, van Doorn, & van de Grind, 2002; 1998; Murakami & Shimojo, 1993; Tadin, Lappin, van de Grind, Koenderink, & van Doorn, 2000), Gilroy, & Blake, 2003). Antagonistic interactions moving texture segregation (Takeuchi, Yokosawa, & between the center and surround would induce a biased De Valois, 2004), and visual motion priming (Takeuchi, perception of motion direction for the directionally Tuladhar, & Yoshimoto, 2011; Yoshimoto & Takeuchi, ambiguous test stimulus in the peripheral visual field 2013; Yoshimoto, Uchida-Ota, & Takeuchi, 2014b) when the unidirectionally drifting stimulus is presented have all been shown to vary with the light level. in the central visual field. Since the priming and test Most of these studies have shown that motion stimuli were temporally separated in the visual motion- sensitivity decreases as light levels are reduced, priming display, the hypothesized mechanism should suggesting that changes in underlying temporal mech- be able to integrate motion signals separated by several anisms under low light levels affect motion perception. hundreds of milliseconds. However, Billino et al. (2008) measured the thresholds Then, we measured the effects of motion priming for the detection of biological motion under three under two lower light levels, presumably corresponding conditions of luminance corresponding to photopic, to mesopic (0.048 cd/m2) and scotopic levels (0.0048 cd/ mesopic, and scotopic light levels and found that m2). We found that under the mesopic level, the effects threshold was exclusively increased in the mesopic of motion priming completely disappeared. Under the condition, whereas the threshold under the scotopic scotopic level, however, negative motion priming was condition was identical to that under the photopic observed in a similar degree to that observed under the condition. The authors argued that in the mesopic photopic level (Yoshimoto & Takeuchi, 2013). As the condition, the mismatch of cone- and rod-mediated density of cones is higher in the central retina whereas velocity information led to impaired integration of the density of rods is higher in the periphery (Curcio, spatiotemporally separated motion signals, producing Sloan, Packer, Hendrickson, & Kalina, 1987; Oster- the largest threshold increase. Inspired by this finding, berg, 1935), our finding suggests that such a hypoth- we employed visual motion priming to examine a esized motion-contrast mechanism could not integrate motion mechanism under low light levels (Yoshimoto signals originated from cones at the center and rods at & Takeuchi, 2013). the periphery under mesopic vision. Visual motion priming is a phenomenon in which the We examined only one light level from the broad perceived direction of a directionally ambiguous test mesopic range extending over an illuminance range of stimulus is influenced by the direction of movement of 103–104 in our previous study (Yoshimoto & Takeuchi, the preceding priming stimulus. Examination of the 2013). However, motion information processing might effect of visual motion priming could reveal a be different even under mesopic vision because of the mechanism that integrates temporally separate motion complex nature of cone-rod interaction and the signals (Kanai & Verstraten, 2005; Pantle, Gallogly, & different amount of rod contribution across light levels Piehler, 2000; Pavan, Campana, Maniglia, & Casco, (Bloomfield & Dacheux, 2001; Cao, Pokorny, Smith, & 2010; Pinkus & Pantle, 1997). In these previous studies, Zele, 2008; Stockman & Sharpe, 2006; Zele & Cao, both priming and test stimuli were presented at the 2015; Zele, Maynard, Joyce, & Cao, 2014). Thus, in same location in the central visual field. Our previous Experiment 1 of the present study, we measured the work (Yoshimoto & Takeuchi, 2013) differed from strength of negative motion priming at various mesopic these studies by separately presenting the priming and light levels following our previous experimental method test stimuli in the central and peripheral visual fields in order to examine the effect of light levels on the under different light levels. The rationale for this integration of spatiotemporally separated visual inputs. manipulation was to create a situation in which the In our previous study (Yoshimoto & Takeuchi, induction of visual motion priming reflects a function 2013), we also found that negative priming reappeared of the underlying motion mechanism that integrates not at the mesopic light level when the test stimulus was only temporally, but also spatially, separate visual presented before the offset of the priming stimulus, inputs to induce motion perception. Our data showed causing a temporary overlap between the priming and that when the spatial distance between the priming and test stimuli. This indicates that the temporal
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