fMRI Investigation of Monocular Pattern Rivalry

Abstract

In monocular pattern rivalry, a composite image is shown to both eyes. The patient experiences perceptual alternations in which the two stimulus components alternate in clarity or salience. We used fMRI at 3T to image brain activity while participants perceived monocular rivalry passively or indicated their percepts with a task. The stimulus patterns were left/right oblique gratings, face/house composites, or a nonrivalrous control stimulus that did not support the perception of transparency or image segmentation. All stimuli were matched for luminance, contrast, and color. Compared with the control stimulus, the cortical activation for passive viewing of grating rivalry included dorsal and ventral extrastriate cortex, superior and inferior parietal regions, and multiple sites in frontal cortex. When the BOLD signal for the object rivalry task was compared with the grating rivalry task, a similar whole-brain network was engaged, but with significantly greater activity in extrastriate regions, including V3, V3A, fusiform face area (FFA), and parahippocampal place area (PPA). In addition, for the object rivalry task, FFA activity was significantly greater during face-dominant periods whereas parahippocampal place area activity was greater during house-dominant periods. Our results demonstrate that slight stimulus changes that trigger monocular rivalry recruit a large whole-brain network, as previously identified for other forms of bistability. Moreover, the results indicate that rivalry for complex object stimuli preferentially engages extrastriate cortex. We also establish that even with natural viewing conditions, endogenous attentional fluctuations in monocular pattern rivalry will differentially drive object-category-specific cortex, similar to binocular rivalry, but without complete suppression of the nondominant image.

Tagged MEG measures binocular rivalry in a cortical network that predicts alternation rate

“…We presume that similar modulations according to dominance/suppression might be observed for PR if the stimulus components (i.e., red vs. green gratings) not eyes were differentially tagged, and this is planned in a future study. However, we predict that the magnitude of modulations may be still smaller for PR because of the lack of eye-based competition [40, 59], and consistent with previous findings that binocular rivalry is stronger than other types of rivalry [44, 60].…”

“…The lateral occipital cortex has been strongly associated with figure/ground organization, visual segmentation and grouping, e.g. [59, 77]. 2.…”

Distinct dorsal and ventral streams for binocular rivalry dominance and suppression revealed by magnetoencephalography

“…They concluded that modulation of stimulus‐specific activity in occipital/temporal areas 150–270 ms after stimulus onset possibly reflected inhibition of the suppressed image . It may also be relevant that several studies have found robust modulation of ventral stream regions selective for faces or objects when suppressed percepts are contrasted with dominant (e.g., de Jong et al, 2020; Mendola & Buckthought, 2013; Sterzer & Rees, 2008; Tong et al, 2006; see also Zhan et al, 2018).…”

Upright face-preferential high-gamma responses in lower-order visual areas: Evidence from intracranial recordings in children

“…Furthermore, preferential saccades toward an upright face take place within 100-140 ms following presentation (Kirchner and Thorpe, 2006; Crouzet et al, 2010), demonstrating that detection of an upright face occurs quite early in visual processing. Neural correlates of face recognition have been extensively examined using functional MRI (fMRI) (Puce et al, 1995; Kanwisher et al, 1997; Summerfield et al, 2006; Mendola et al, 2013) and electrocorticography (ECoG) (Miller et al, 2009; Engell and McCarthy, 2010; Vidal et al, 2010). These studies have consistently localized regions of face-selectivity around the fusiform gyrus and around the inferior occipital gyrus.…”