Sensory memory of structure-from-motion is shape-specific

Abstract

Perceptual priming can stabilize the phenomenal appearance of multistable visual displays (Leopold, Wilke, Maier, & Logothetis, Nature Neuroscience, 5, 605-609, 2002). Prior exposure to such displays induces a sensory memory of their appearance, which persists over long intervals and intervening stimulation, and which facilitates renewed perception of the same appearance. Here, we investigated perceptual priming for the apparent rotation in depth of ambiguous structure-from-motion (SFM) displays. Specifically, we generated SFM objects with different threedimensional shapes and presented them in random order and with intervening blank periods. To assess perceptual priming, we established the probability that a perceived direction of rotation would persist between successive objects. In general, persistence was greatest between identical objects, intermediate between similar objects, and negligible between dissimilar objects. These results demonstrate unequivocally that sensory memory for apparent rotation is specific to three-dimensional shape, contrary to previous reports (e.g., Maier, Wilke, Logothetis, & Leopold, Current Biology, 13, 1076-1085. Because persistence did not depend on presentation order for any pair of objects, it provides a commutative measure for the similarity of object shapes. However, it is not clear exactly which features or aspects of object shape determine similarity. At least, we did not find simple, low-level features (such as volume overlap, heterogeneity, or rotational symmetry) that could have accounted for all observations. Accordingly, it seems that sensory memory of SFM (which underlies priming of ambiguous rotation) engages higher-level representations of object surface and shape.

What you see depends on what you saw, and what else you saw: The interactions between motion priming and object priming

“…It is worth to note that recent studies have suggested a distinction between perceptual priming with a brief interval between the prime and target stimuli (e.g., 100ms in the present study) and those with a longer interval (e.g., >1second), the former is usually named neural persistence or inertia (Anstis & Ramachandran, 1987), while the later is usually termed perceptual/sensory memory (Chen & He, 2004; Maier et al, 2003; Pastukhov et al, 2013). For instance, a mask image between the prime and target stimuli will disrupt neural persistence, but not sensory memory (Pastukhov & Braun, 2013).…”

“…More specifically, we test whether the representations of motion direction and object structure of 3-D SFM stimuli are largely independent from each other, or tightly integrated with each other. For instance, with a longer interval between the prime and target stimuli (>1 second), while some previous studies have suggested that motion priming was unaffected by changes of color or shape between prime and target (e.g., Chen & He, 2004; Maier, Wilke, Logothetis, & Leopold, 2003) – suggesting separated neural representations of the motion and object structure of an SFM stimulus, a very recent study has revealed reduced motion priming when the prime and target stimuli constituted different objects (Pastukhov, Füllekrug, & Braun, 2013) – suggesting a rather integrated neural representation for the motion and object structure of a 3-D dynamic object. To further complicate the scenario, a very recent study of motion aftereffect has found that negative motion aftereffect is shape irrelevant (Pastukhov, Lissner, & Braun, 2014).…”

“…For instance, a mask image between the prime and target stimuli will disrupt neural persistence, but not sensory memory (Pastukhov & Braun, 2013). Nevertheless, both neural persistence/inertia (Jiang et al, 1998; Jiang et al, 2002; Nawrot & Blake, 1993; Pinkus & Pantle, 1997) and sensory memory (Brascamp et al, 2010; Chen & He, 2004; Maier et al, 2003; Pastukhov et al, 2013; Sterzer & Rees, 2008) have been widely used to investigate the processing of 3-D SFM stimulus. In addition, we were not aware of any priming studies with a brief interval (less than half second) have examined the relationship between motion priming and object structure.…”

Transformation priming helps to disambiguate sudden changes of sensory inputs

“…Whereas in the present experiments priming lasted for seconds, other effects induced by recent experience, which may be linked to perception of transformations, retain their influence over far longer time-scales (Klink, Brascamp, Blake, & van Wezel, 2010;Pastukhov & Braun, 2013a;Suzuki & Grabowecky, 2007). Moreover, priming of perceptual states exhibits both facilitatory (Leopold et al, 2002;Orbach, Ehrlich, & Heath, 1963;Pastukhov & Braun, 2013b;Pastukhov, Füllekrug, et al, 2013;Pastukhov, Lissner, Füllekrug, et al, 2014) and inhibitory effects (Pastukhov & Braun, 2011, 2013b operating concurrently on different time-scales. Similarly diverging effects may also exist for priming of transformations.…”

“…or is represented and updated locally. To this end, we used the SFM display in conjunction with a selective adaptation procedure (Pastukhov, Füllekrug, & Braun, 2013; to examine how priming strength is affected by a change in the stimulus location, axis of rotation, or shape (see Fig. 7A).…”