Attention to object files defined by transparent motion.

Abstract

Two interspersed and differently colored sets of dots were rotated in opposite directions and were perceived as superimposed transparent surfaces. Probes consisting of brief changes in dot motion direction were reported. Two probes affecting the same surface were discriminated accurately. The 2nd probe was discriminated poorly if it affected a surface different from the 1st and if the time between probes was less than 600 ms. This reflects a difficulty in switching attention rapidly between surfaces. Spatial proximity increased the interference. Controls were incompatible with traditional spatial mechanisms (2- or 3-dimensional) or with simple sensory filters. Instead, probes were apparently selected by object files. The interference is not simply due to an inability to process 2 objects at once but requires close spatial proximity of incompatible motion signals.

Stimulus-specific competitive selection in macaque extrastriate visual area V4

“…One proposal is that the CRF shifts toward or shrinks around the selected stimulus (1,(8)(9)(10)(11). This model, however, cannot account for the obligatory spread of attention across surfaces (12) or for selective processing of one of two spatially superimposed stimuli (13)(14)(15)(16)(17)(18). Such findings suggest that selection can be surface-or object-based.…”

“…These studies thus could not distinguish between selection of a retinotopic location and selection of the stimulus at that location. To overcome this limitation, we adapted a paradigm used in human psychophysical studies (15,(17)(18)(19), which used virtual surfaces defined by rigidly rotating patterns of dots. Retinotopically based selection was ruled out by superimposing two dot fields, rotating in opposite directions.…”

The Selectivity of Task-Dependent Attention Varies with Surrounding Context

“…The effect of task on the spread of attention One might also wonder why attention did not spread within a perceptually grouped object (Duncan, 1984;He and Nakayama, 1995;Driver and Baylis, 1998;Valdes-Sosa et al, 2000;Driver et al, 2001) as in the in-phase center-surround configuration. Such object-based attention may be useful if the task is to detect a change at an unknown location within the object Nakayama, 1992, 1995).…”

“…Studies that have examined the interaction between object segmentation and attention indicate that attention spreads within a perceptually linked surface (Duncan, 1984;He and Nakayama, 1995;Valdes-Sosa et al, 2000;Driver et al, 2001). Here we investigate whether spatial attention can be more selective when observers perform a demanding task at the center of a uniform surface.…”

Pupil size reflects the focus of feature-based attention

“…Some authors have suggested that shifts of spatial attention are tightly linked to eye movements (Corbetta 1998;Kowler et al 1995;Moore and Fallah 2004), so much that the two may rely on the same neural circuits (Kustov and Robinson 1996;Rizzolatti et al 1994), although there is evidence against this (Gregoriou et al 2012;Ignashchenkova et al 2004;Juan et al 2004). However, attention can also be deployed based on nonspatial criteria, as in "global feature-based attention" (Martinez-Trujillo and Treue 2004;Saenz et al 2002;Serences and Boynton 2007;Treue and Martinez Trujillo 1999) or "surface/ object-based attention" (Ernst et al 2013;He and Nakayama 1995;O'Craven et al 1997;Valdes-Sosa et al 2000;Wannig et al 2007). Being spatially distributed, this type of attention is fundamentally distinct from eye movements, and its control likely depends on separate neural circuits (Greenberg et al 2010;Maunsell and Treue 2006;Runeson et al 2013), although different types of attention may ultimately affect visual responses through similar mechanisms (Maunsell and Treue 2006;McAdams and Maunsell 1999;Reynolds and Chelazzi 2004).…”