Spatial properties of non-retinotopic reference frames in human vision

Abstract

Many visual attributes of a target stimulus are computed according to dynamic, non-retinotopic reference frames. For example, the motion trajectory of a reflector on a bicycle wheel is perceived as orbital, even though it is in fact cycloidal in retinal, as well as spatial coordinates. We cannot perceive the cycloidal motion because the linear motion of the bike is discounted for. In other words, the linear motion common to all bicycle components serves as a non-retinotopic reference frame, with respect to which the residual (orbital) motion of the reflector is computed. Very little is known about the underlying mechanisms involved in formation and operation of non-retinotopic reference frames. Here, we investigate spatial properties of non-retinotopic reference frames. We show that reference frames are not restricted within the boundaries of moving stimuli but extend over space. By using a variation of the Ternus-Pikler paradigm, we show that the spatial extent of a non-retinotopic reference frame is independent of the size of the inducing elements and the target position near the object boundary. While dynamic reference-frames interact with each other significantly, a static reference-frame has no effect on a dynamic one. The magnitude of interactions between two neighboring dynamic reference-frames increases as the distance between them reduces. Finally, our results indicate that the reference-frame strength is significantly attenuated if the locus of attention is shifted to the elements of the neighboring reference instead of the main reference. We suggest that these results can be conceptualized as reference frames that act and interact as fields.

A New Conceptualization of Human Visual Sensory-Memory

“…Our results supported the predictions of the non-retinotopic motion- based memory hypothesis ( 5D -right). Additional results supporting this finding (with multiple vernier's inserted at multiple locations) can be found in Öğmen et al ( 2006 ), Scharnowski et al ( 2007 ), Otto et al ( 2008 ), Boi et al ( 2009 , 2011 ), and Noory et al ( 2015a , b ).…”

“…The inability of the sensory memory to operate under normal viewing conditions not only challenged any role it may have in information processing, but also positioned it as a “road block” to information flow from external inputs to the rest of the modal model. However, during the last decade, evidence has been accumulating on non-retinotopic processing for various stimulus attributes such as form (Nishida, 2004 ; Öğmen et al, 2006 ; Otto et al, 2006 ; Öğmen and Herzog, 2010 ), luminance (Shimozaki et al, 1999 ), color (Nishida et al, 2007 ), size (Kawabe, 2008 ), and motion (Boi et al, 2009 ; Noory et al, 2015a ). We suggest that this non-retinotopic processing extends to sensory memory in the form of non-retinotopic sensory memory ( nr SM).…”

Field-like interactions between motion-based reference frames

“…Previously, we have shown that the perceived motion of a target stimulus can be influenced by nearby motion of another object, and that this object need not be surrounding the target stimulus, as in the induced-motion paradigm (Agaoglu et al, 2015;Noory et al, 2015). In this study, we started off by replicating our previous findings that each local motion vector has a reference field associated with it, and this is manifested by increased illusory percepts of backward motion with decreasing distance to this moving reference frame.…”

The reference frame for encoding and retention of motion depends on stimulus set size

“…The difference between fixation and SPEM performance in terms of a spatiotopic reference frame was not significant at stimulus encoding and VSTM stages, but it was significant for the sensory memory stage. As mentioned before, whereas earlier studies found that sensory memory uses a retinotopic reference frame, more recent studies using sequential metacontrast and Ternus-Pikler displays indicate that sensory memory can also use a motion-based nonretinotopic reference frame (Noory et al, 2015;Ogmen et al, 2006;Otto, Öğmen, & Herzog, 2006;Scharnowski, Hermens, Kammer, Öğmen, & Herzog, 2007). Because performance in sensory memory in terms of a spatiotopic reference frame was superior to that in terms of a retinotopic reference frame and because spatiotopic performance showed the typical exponential delay observed in sensory memory (see Fig.…”

“…For example, the point lights placed on a person in the biological motion paradigm (Johansson, 1973) creates a very complex stimulus; however, by grouping these points into a meaningful Gestalt (Yantis, 1992), the visual system is capable of computing a common reference frame, which can be used to simplify the relative motions of various point lights. Several studies showed that when the stimulus allows grouping of parts, motion groupings based nonretinotopic reference frames (relative motion) account for perceived direction of motion (Agaoglu et al, 2015a(Agaoglu et al, , 2015bBoi, Öğmen, Krummenacher, Otto, & Herzog, 2009;Duncker, 1929Duncker, /1938Johansson, 1973;Noory et al, 2015). In fact, Agaoglu et al (2015b) quantified the contributions of retinotopic, spatiotopic, and relative-motion reference frames and showed that relative motion dominated both during fixation and SPEM, with a contribution more than 80% when the distance between the stimuli was 2 degrees.…”