Motion-induced blindness measured objectively

Abstract

During central fixation, a moving pattern of nontargets induces repeated temporary blindness to even salient peripheral targets: motion-induced blindness (MIB). Hitherto, behavioral measures of MIB have relied on subjective judgments. Here, we offer an objective alternative that builds on earlier findings regarding the effects of MIB on the detectability of physical target offsets. We propose a small modification of regular MIB displays: Following a variable duration (lead time), one of the targets is physically removed. Subjects are to respond immediately afterward. We hypothesize that illusory target offsets, caused by MIB, are mistaken for physical target offsets and that errors should thus increase with lead time. Indeed, for both nonsalient and salient targets, we found that detection accuracy for physical target offsets dramatically decreased with lead time. We conclude that target offset detection accuracy is a valid objective measure of MIB. With our method, effects of guessing are minimal, and the fitting of psychometric functions is straightforward. In principle, a staircase extensionfor more efficient data collection-is also possible.

The relation between cognitive-perceptual schizotypal traits and the Ebbinghaus size-illusion is mediated by judgment time

“…Given that a processing tendency should be more flexible than a processing disability, with a deadline experiment (an experiment in which subjects are forced to respond before a variable deadline; e.g., Kramer et al, 2013) these two accounts can be pitted against each other. At a long deadline, some may have a large Ebbinghaus illusion and some may have a small one.…”

Direct behavioral and neural evidence for an offset-triggered conscious perception

“…Those results indicate that the offset does not always trigger consciousness; it should be given at the right time just before a (spontaneous) emergence of a conscious percept. In the previous studies using MIB and Troxler fading (Klotz & Ansorge, 2007;Kramer et al, 2013;Lleras & Moore, 2006;Montaser-Kouhsari et al, 2004), an offset was introduced at a random time in an "invisible" period during which a strength of perceptual suppression fluctuated over time. If the offset had been constantly provided at the end of the invisible period (when the perceptual suppression was weak and the disinhibition was in progress), they might have observed the offsettriggered consciousness as the present study.…”

“…Time dependency of the offset-triggered conscious perception While we used CFS (inter-ocular suppression) to create a unique situation in which an invisible stimulus physically disappeared from a screen, several studies have tested similar situations using other psychophysical techniques to render a stimulus invisible, such as motion-induced blindness (MIB) (Klotz & Ansorge, 2007;Kramer, Massaccesi, Semenzato, Cecchetto, & Bressan, 2013;Montaser-Kouhsari, Moradi, Zandvakili, & Esteky, 2004) and Troxler fading (Lleras & Moore, 2006). Those studies, however, consistently reported no evidence for the offset-triggered conscious perception; subjects failed to detect an offset of an invisible stimulus because it induced no perceptual change.…”

“…The time dependency of the offsettriggered conscious perception described above suggests a mechanism of this phenomenon. We presume that the offset facilitates consciousness by interacting with a temporal integration window (preconscious time window) of visual perception Krekelberg et al, 2000).…”

Elucidating unconscious processing with instrumental hypnosis

“…Different subliminal approaches reveal that suppression hardly affects superficial level of visual processing, such as spatial frequency, motion-direction, color, and orienting (Long and Toppino, 2004; Breitmeyer and Ögmen, 2006; Breitmeyer, 2007; Whitney and Levi, 2011; Yang and Blake, 2012; Kramer et al, 2013). A more complex picture has emerged concerning deeper levels of subliminal processing (van Gaal and Lamme, 2012).…”