Fluctuations of fMRI activation patterns in visual object priming

Abstract

Prior information shapes how the brain processes sensory inputs (e.g., priming effects). Recent studies of "behavioral oscillation” have demonstrated that the effects of visual object primes are temporally coordinated in the theta band to guide perception efficiently. However, the neural mechanism underlying this dynamic processing remains unclear. Here, we combine functional magnetic resonance imaging (fMRI) and a time-resolved paradigm to access high-temporal-resolution profiles of brain activation fluctuations corresponding to "behavioral oscillation" in visual object priming. Specifically, multivoxel activity patterns in the fusiform face area (FFA) and the parahippocampal place area (PPA) show temporal fluctuations in the theta band (~ 5 Hz). Importantly, the theta-band power in the FFA negatively correlates with reaction time, further indicating the critical role of the observed fluctuations in brain activation. By finely mapping the temporal dynamics of cortical responses, our fMRI results demonstrate that category-selective brain areas underlie the rhythmic coordination of visual object processing.

Predictive visuo-motor communication through neural oscillations

“…However, the response was not modulated by the visuo-motor delay (Figures S2E and S2H) at any time of the hemodynamic response (Figures S2F and S2I), contrary to reported evidence when reaction times are also measured. 21 The absence of M1 BOLD modulations with visual delay is consistent with the fact that motor cortex does not activate in response to visual stimuli. However, synchronous oscillatory activity may be present in M1 and shared with V1.…”

“…However, the response was not modulated by the visuo-motor delay ( Figures S2 E and S2H) at any time of the hemodynamic response ( Figures S2 F and S2I), contrary to reported evidence when reaction times are also measured. 21 …”

Predictive visuo-motor communication through neural oscillations

“…The haemodynamic responses of M1 and S1 to vision and action events are different from those in V1 (compare panel A to panels D&G in Figure S2): the response occurred earlier (reflecting activity during action preparation 20 ), and had a more pronounced negative lobe. However, the response was not modulated by the visuo-motor delay (Figure S2, panels E&H), at any time of the haemodynamic response (Figure S2, panels F&I), contrary to reported evidence when reaction times are also measured 21 .…”

“…This is to be expected, given that M1 and S1 do not respond to visual stimuli, so a visual stimulus will not be an adequate probe of cortical excitability. Interestingly, using a similar time-resolved fMRI approach, and measuring reaction-times, Guo et al 62 observed rhythmic modulations of M1, consistently with previous report 63 . We interpret their oscillation in M1 to be related to the programming of speeded responses, whose latency oscillates with a theta rhythm 20,56,62 , like behavioural sensitivity.…”

Evidence for a theta‐band behavioural oscillation in rapid face detection

“…What is the origin of the observed fluctuation in rapid detection performance as a function of ISI? A possible mechanism is suggested by a recent investigation of the neural substrates of behavioural oscillations in the priming effect (Guo et al, 2020). The authors in that study presented pairs of congruent or incongruent primes and probes (faces/houses) separated by densely sampled ISIs during fMRI recording.…”