Effects of Awareness on Numerosity Adaptation

Abstract

Numerosity perception is a process involving several stages of visual processing. This study investigated whether distinct mechanisms exist in numerosity adaptation under different awareness conditions to characterize how numerosity perception occurs at each stage. The status of awareness was controlled by masking conditions, in which monoptic and dichoptic masking were proposed to influence different levels of processing. Numerosity adaptation showed significant aftereffects when the participants were aware (monoptic masking) and unaware (dichoptic masking) of adaptors. The interocular transfer for numerosity adaptation was distinct under the different awareness conditions. Adaptation was primarily binocular when participants were aware of stimuli and was purely monocular when participants were unaware of adaptors. Moreover, numerosity adaptation was significantly reduced when the adaptor dots were clustered into chunks with awareness, whereas clustering had no effect on unaware adaptation. These results show that distinct mechanisms exist in numerosity processing under different awareness conditions. It is suggested that awareness is crucial to numerosity cognition. With awareness, grouping (by clustering) influences numerosity coding through altered object representations, which involves higher-level cognitive processing.

Numerosity adaptation along the Y-Axis affects numerosity perception along the X-Axis: does numerosity adaptation activate MNLs?

“…Based on the activation of MNLs, the aftereffect of numerosity adaptation in the vertical direction can be revealed in a particular area beyond where the adaptors were presented according to an abstract association, namely, the association of the top with the right and the bottom with the left. In recent studies, numerosity adaptation was shown to be a cross-modal and cross-format adaptation (Burr, 2013), and it was shown to be a process that unfolded across several levels of visual processing (Liu et al, 2013). This evidence supports the view that numerosity adaptation occurred in IPS.…”

“…The perception along the vertical orientation also changed greatly (e.g., 30 dots could be perceived as 100 dots after adaptation; Burr & Ross, 2008a;Liu et al, 2013). Although we proposed that vertical adaptors could simultaneously activate the vertical and horizontal MNLs, we should note that the dramatic change in vertical perception may be more attributable to the retinotopic adaptation of local visual neurons rather than the effect of the change in the vertical MNL.…”

“…More studies need to be conducted before we can describe the adaptation as a Bnumerosity adaptation.^Previous studies (Burr & Ross, 2008b;Burr, Turi, & Anobile, 2010) investigated the influencing factors of numerosity adaptation, confirming that it could occur independently of other, nonnumerical visual properties (e.g., contrast, orientation, or density). Our group has demonstrated that numerosity adaptation is based on numerosity perception (Liu, et al, 2012;Liu, Zhang, Zhao, Liu, & Li, 2013). In our 2012 study, we induced a perceptual grouping by controlling the color and distribution of dots: 9 dots with the same color were constructed into a bigger Bchunk,^and 405 dots were divided into 45 chunks.…”

Peer Review #2 of "Faces in commonly experienced configurations enter awareness faster due to their curvature relative to fixation (v0.1)"

“…Furthermore, another recent study by the same group observed that attentional orienting due to threat stimuli is completely absent when threatening stimuli were rendered completely invisible (Hedger, Adams & Garner, 2015b). Other studies have cast doubt on whether invisible words can be processed (Heyman & Moors, 2014), numerosity can be extracted during suppression (Liu et al, 2013;, or integration between a suppressed visual looming stimulus and a supraliminal auditory stimulus can occur . In sum, the results of this study provide evidence that stimuli that are more strongly represented in the visual cortex break suppression faster than other stimuli.…”

Unbiased Measures of Interocular Transfer of Motion Adaptation

“…For example, adaptation to bright light is largely retinal, and so does not transfer between the eyes (Auerbach & Peachey, 1984). On the other hand, adaptation to numerosity presumably occurs at a cortical level beyond the point of binocular combination, and so transfers almost completely (Liu et al, 2013). For contrast adaptation to grating stimuli, transfer of around 60% is typically reported, though this may be reduced at low spatial frequencies (Baker & Meese, 2012).…”