Abstract
Neuronal oscillations are ubiquitous in the brain and contribute to perception and attention. However, most associated evidence derives from post-hoc correlations between brain dynamics and behavior. Our previous work (Luo et al., VSS2013), by measuring response time (RT) in a high resolved manner, demonstrates compelling dynamic oscillatory pattern (theta-mediated alpha pulses) directly in behavioral measurement in a precuing task. We speculate that those behavioral oscillations may reflect underlying neuronal oscillatory mechanism in multi-object attention. Here, we examined whether the spectro-temporal dynamics could also be observed when using eye movement response instead of motor response. After a peripheral uninformative cue shown at one of the two peripheral boxes, a target was presented in the cued or uncued box at varying SOAs (0.1~1 s in steps of 20 ms), and subjects were asked to make saccade to the target as fast as possible, and to not make saccades in catch trials when target was absent. Eye movements were recorded using Eyelink1000 system, and the saccade latency was recorded for each condition (Valid and Invalid) as a function of cue-to-target SOA. Our preliminary results (N=7) replicate typical IOR effects in low-pass filtered saccade latency time courses. Most importantly, the behavioral measurement, indexed by saccade latency here, shows a similar trend of dynamic oscillatory pattern as observed previously in RTs. Specifically, an uninformative peripheral cue elicits rhythmic alpha pulses (8-20 Hz) in saccade latency time courses, and the elicited alpha pulses for cued and uncued conditions are in a certain temporal relationship. In conclusion, the present eye movement findings, combined with our previous RT results, suggest that behavioral performances actually consist of rich dynamic and may reflect underlying neuronal oscillatory substrates. Our data also suggest the critical role of coordinated alpha-band pulse in sampling multiple objects.
Meeting abstract presented at VSS 2014