Ongoing Slow Fluctuations in V1 Impact on Visual Perception

Abstract

The human brain’s ongoing activity is characterized by intrinsic networks of coherent fluctuations, measured for example with correlated functional magnetic resonance imaging signals. So far, however, the brain processes underlying this ongoing blood oxygenation level dependent (BOLD) signal orchestration and their direct relevance for human behavior are not sufficiently understood. In this study, we address the question of whether and how ongoing BOLD activity within intrinsic occipital networks impacts on conscious visual perception. To this end, backwardly masked targets were presented in participants’ left visual field only, leaving the ipsi-lateral occipital areas entirely free from direct effects of task throughout the experiment. Signal time courses of ipsi-lateral BOLD fluctuations in visual areas V1 and V2 were then used as proxies for the ongoing contra-lateral BOLD activity within the bilateral networks. Magnitude and phase of these fluctuations were compared in trials with and without conscious visual perception, operationalized by means of subjective confidence ratings. Our results show that ipsi-lateral BOLD magnitudes in V1 were significantly higher at times of peak response when the target was perceived consciously. A significant difference between conscious and non-conscious perception with regard to the pre-target phase of an intrinsic-frequency regime suggests that ongoing V1 fluctuations exert a decisive impact on the access to consciousness already before stimulation. Both effects were absent in V2. These results thus support the notion that ongoing slow BOLD activity within intrinsic networks covering V1 represents localized processes that modulate the degree of readiness for the emergence of visual consciousness.

Neural and metabolic basis of dynamic resting state fMRI

“…Early work with human subjects (using stimulus detection tasks and event-driven fMRI paradigms) linked performance on tasks to resting BOLD amplitude in various brain regions (Boly et al, 2007; Eichele et al, 2008; Sadaghiani et al, 2009). Using dynamic rsfMRI, fluctuations in correlation between brain regions or networks have shown similar effects within a variety of tasks (Cassidy et al, 2016; Gonzalez-Castillo et al, 2015; Jia et al, 2014; Madhyastha et al, 2015; Mooneyham et al, 2017; Sadaghiani et al, 2015; Telesford et al, 2016; Thompson et al, 2013a; Weissman et al, 2006), as have amplitudes within resting state networks themselves (Wohlschlager et al, 2016). Presentation of stimuli (Nummenmaa et al, 2014; Raz et al, 2012), as well as spontaneous state changes including eye closures (Wang et al, 2016), daydreaming (Kucyi and Davis, 2014), sleep state (Tagliazucchi and Laufs, 2014; Wilson et al, 2015) and deprivation (Kaufmann et al, 2016) all alter dynamic rsfMRI measurements.…”

Slow Endogenous Fluctuations in Cortical fMRI Signals Correlate with Reduced Performance in a Visual Detection Task and Are Suppressed by Spatial Attention

“…Within the frequency range we have studied (<0.1 Hz), stimulus detection is predicted by spontaneous slow negative cortical shifts in EEG signals (Devrim, Demiralp, Kurt, & Yücesir, 1999) and by the phase of ongoing EEG oscillations in the infraslow range (Monto et al, 2008). Additionally, previous studies have demonstrated relationships between performance on visual detection tasks and prestimulus fMRI activity recorded a few seconds before stimulus onset (Coste & Kleinschmidt, 2016; Wohlschläger et al, 2016; Schölvinck, Friston, & Rees, 2012; Hesselmann et al, 2008), and fMRI connectivity between brain regions at very slow frequencies is significantly correlated with performance across participants in an executive control task (Xu et al, 2014) and a visual attention task (Griffis, Elkhetali, Burge, Chen, & Visscher, 2015). Our results extend these findings by showing that spatial attention suppresses slow endogenous fluctuations in occipital and parietal cortex and that reduced endogenous activity predicts performance on a visual detection task.…”

“…Perceptual performance is affected by intrinsic neural activity immediately before stimulus presentation (Busch, Dubois, & VanRullen, 2009; Mathewson, Gratton, Fabiani, Beck, & Ro, 2009; Supèr, van der Togt, Spekreijse, & Lamme, 2003), including very slow (<0.1 Hz) fluctuations in activity (Monto, Palva, Voipio, & Palva, 2008). In addition, ongoing fMRI signals before initiation of visual perceptual tasks predict behavior (Coste & Kleinschmidt, 2016; Wohlschläger et al, 2016; Hesselmann, Kell, & Kleinschmidt, 2008; Weissman, Roberts, Visscher, & Woldorff, 2006).…”

Segregated Co-activation Patterns in the Emergence of Decision Confidence During Visual Perception

“…A backward-masked visual perception task ( Figure 1A ) was adapted from (Wohlschläger et al, 2016 ; Glim et al, 2020 ; see also, Haynes et al, 2005 ) to measure visual confidence. fMRI data were concurrently recorded during the task.…”