Poster #43 - The Role of Motion Parallax in Infants' Visual Preference for Real Objects

• In Event: Poster Session 11

Abstract

From early in life, infants encounter real, physical objects in their environment as well as pictorial representations of those objects. When presented with both object formats at the same time, 7-month-old infants looked significantly longer at real objects than matched pictures, thus demonstrating a visual preference for real objects over pictures (DeLoache et al., 1979; Gerhard et al., 2016). While many studies have addressed what this advantage is good for, such as that real objects provide greater affordances for actions compared to pictures (Gibson, 1979; Snow et al., 2014), it remains unclear what depth cue infants use that transports information about whether a stimulus is a 3D object or just an image of it. To study this question we investigated the relative contribution of motion parallax (MP) which infants use as a cue for depth perception of real objects from 4 months on (Nawrot et al., 2009). We presented real objects paired with their pictures using iPads simulating MP. If MP is a contributing factor in infants’ preference for real objects, we expected them to prefer looking at pictorial representations with MP over pictorial representations without MP, similar to how they prefer looking at real objects over pictorial representations without MP.
We tested 7- 8-month-old infants (N = 24, data collection is still ongoing), using 4 real objects and their pictorial counterparts as stimuli. The pictorial counterparts were presented on an iPad Pro 11 using an application that allowed MP to be switched on or off. Each infant viewed each of the four objects in every possible pair combination of the three object formats (real object, iPad with MP, iPad without MP) for 15 seconds, with left-right position counterbalanced within the pair (total of 24 pairs). Accumulated looking times for each object format served as dependent measure.
A repeated measures ANOVA revealed a significant effect of object format, F(2) = 11.93, p < .001, with the longest looking times to the real objects (M = 73.8226 s, SD = 23.4143 s), followed by the looking times to the iPad with MP (M = 59.3270 s, SD = 17.2040 s), and those to the iPad without MP (M = 52.6248, SD = 17.5361 s). Post-hoc comparisons showed significantly longer looking times to the real object compared to the iPad presentations without MP (p < .001). Looking times to the iPad presentations with MP were nearly significantly longer than those to the iPad presentations without MP (p = .06). However, looking times to the real objects still significantly exceeded those to the iPad presentations with MP (p < 0.05).
Thus, besides confirming the often reported real-object preference, our preliminary results provide first evidence that the use of MP seems to contribute to this preference given the nearly significant preference for iPad presentations with MP over those without. Nevertheless, as infants still looked longer at real objects than iPad presentations with MP, it seems that further factors might be responsible for the real object preference – binocular disparity being the most likely candidate.

Authors

• Gudrun Schwarzer, University of Giessen
  Presenting Author

• Lucie Preißler, Justus-Liebig-Universität Gießen

• Nikolaus Friedrich Troje, York University, Toronto