Temporal Integration Windows in Neural Processing and Perception Aligned to Saccadic Eye Movements.
When processing dynamic input, the brain balances the opposing needs of temporal integration and sensitivity to change. We hypothesized that the visual system might resolve this challenge by aligning integration windows to the onset of newly arriving sensory samples. In a series of experiments, human participants observed the same sequence of two displays separated by a brief blank delay when performing either an integration or segregation task. First, using magneto-encephalography (MEG), we found a shift in the stimulus-evoked time courses by a 150-ms time window between task signals. After stimulus onset, multivariate pattern analysis (MVPA) decoding of task in occipital-parietal sources remained above chance for almost 1 s, and the task-decoding pattern interacted with task outcome. In the pre-stimulus period, the oscillatory phase in the theta frequency band was informative about both task processing and behavioral outcome for each task separately, suggesting that the post-stimulus effects were caused by a theta-band phase shift. Second, when aligning stimulus presentation to the onset of eye fixations, there was a similar phase shift in behavioral performance according to task demands. In both MEG and behavioral measures, task processing was optimal first for segregation and then integration, with opposite phase in the theta frequency range (3-5 Hz). The best fit to neurophysiological and behavioral data was given by a dampened 3-Hz oscillation from stimulus or eye fixation onset. The alignment of temporal integration windows to input changes found here may serve to actively organize the temporal processing of continuous sensory input.
Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto (TN) 38068, Italy; Picower Institute for Learning and Memory, Massachusetts Institute of Technology (MIT), Cambridge, MA 02139, USA.
Andreas
A
Wutz
Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto (TN) 38068, Italy.
Evelyn
E
Muschter
Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto (TN) 38068, Italy; Italian Institute of Technology (IIT), University of Trento, Rovereto (TN) 38068, Italy.
Martijn G
MG
van Koningsbruggen
Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto (TN) 38068, Italy; Centre for Cognitive Neuroscience, University of Salzburg, Salzburg 5020, Austria.
Nathan
N
Weisz
Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto (TN) 38068, Italy. Electronic address: david.melcher@unitn.it.
David
D
Melcher
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011930:Reaction Time; D012438:Saccades; D013998:Time Perception; D014796:Visual Perception; D055815:Young Adult