How to Evaluate Phase Differences between Trial Groups in Ongoing Electrophysiological Signals.
A growing number of studies endeavor to reveal periodicities in sensory and cognitive functions, by comparing the distribution of ongoing (pre-stimulus) oscillatory phases between two (or more) trial groups reflecting distinct experimental outcomes. A systematic relation between the phase of spontaneous electrophysiological signals, before a stimulus is even presented, and the eventual result of sensory or cognitive processing for that stimulus, would be indicative of an intrinsic periodicity in the underlying neural process. Prior studies of phase-dependent perception have used a variety of analytical methods to measure and evaluate phase differences, and there is currently no established standard practice in this field. The present report intends to remediate this need, by systematically comparing the statistical power of various measures of "phase opposition" between two trial groups, in a number of real and simulated experimental situations. Seven measures were evaluated: one parametric test (circular Watson-Williams test), and three distinct measures of phase opposition (phase bifurcation index, phase opposition sum, and phase opposition product) combined with two procedures for non-parametric statistical testing (permutation, or a combination of z-score and permutation). While these are obviously not the only existing or conceivable measures, they have all been used in recent studies. All tested methods performed adequately on a previously published dataset (Busch et al., 2009). On a variety of artificially constructed datasets, no single measure was found to surpass all others, but instead the suitability of each measure was contingent on several experimental factors: the time, frequency, and depth of oscillatory phase modulation; the absolute and relative amplitudes of post-stimulus event-related potentials for the two trial groups; the absolute and relative trial numbers for the two groups; and the number of permutations used for non-parametric testing. The concurrent use of two phase opposition measures, the parametric Watson-Williams test and a non-parametric test based on summing inter-trial coherence values for the two trial groups, appears to provide the most satisfactory outcome in all situations tested. Matlab code is provided to automatically compute these phase opposition measures.
Centre National de la Recherche Scientifique, UMR 5549, Faculté de Médecine PurpanToulouse, France; Université de Toulouse, Centre de Recherche Cerveau et Cognition, Université Paul SabatierToulouse, France.
Rufin
R
VanRullen
discrete perception; oscillations; perceptual cycles; phase; phase opposition; rhythmic perception
Hum Brain Mapp. 1999;8(4):194-208
10619414
Science. 2002 Jan 25;295(5555):690-4
11809976
Trends Cogn Sci. 2003 May;7(5):207-213
12757822
Science. 1960 Dec 9;132(3441):1765-6
13689987
Electroencephalogr Clin Neurophysiol. 1965 Apr;18:433-40
14276036
Brain Res Cogn Brain Res. 2004 Aug;20(3):376-83
15268915
Clin Neurophysiol. 2004 Nov;115(11):2593-601
15465449
J Cogn Neurosci. 2004 Nov;16(9):1595-604
15601521
Neurosci Lett. 2005 Feb 25;375(1):64-8
15664124
Proc Natl Acad Sci U S A. 2006 Feb 21;103(8):2948-52
16473952
J Neurosci. 2006 Sep 13;26(37):9494-502
16971533
Electroencephalogr Clin Neurophysiol. 1991 Jul-Aug;80(4):241-50
1713834
Hum Brain Mapp. 2007 Dec;28(12):1318-33
17274017
Int J Psychophysiol. 2007 Jul;65(1):58-68
17428561
Neuroscience. 2007 Jun 8;146(4):1435-44
17459593
Neuroimage. 2007 Oct 1;37(4):1465-73
17706433
J Neurosci. 2008 Feb 20;28(8):1816-23
18287498
J Neurosci. 2009 Mar 4;29(9):2725-32
19261866
J Neurosci. 2009 Jun 17;29(24):7869-76
19535598
Neuron. 2009 Aug 13;63(3):386-96
19679077
Proc Natl Acad Sci U S A. 2009 Dec 15;106(50):21341-6
19926847
Neuroimage. 2010 May 15;51(1):112-22
20114076
Proc Natl Acad Sci U S A. 2010 Sep 14;107(37):16048-53
20805482
J Neurosci. 2011 Mar 9;31(10):3813-20
21389236
J Neurosci. 2011 Mar 23;31(12):4698-708
21430168
Cereb Cortex. 2012 Jan;22(1):221-31
21625011
Front Psychol. 2011 Apr 09;2:60
21716580
J Neurosci. 2011 Aug 17;31(33):11889-93
21849549
J Neurosci. 2012 May 16;32(20):7034-41
22593071
Proc Natl Acad Sci U S A. 2012 Jun 26;109(26):10599-604
22689974
J Neurosci. 2012 Aug 29;32(35):12268-76
22933808
Curr Biol. 2012 Oct 23;22(20):1969-74
23041197
Neuron. 2012 Nov 21;76(4):847-58
23177968
Neuroimage. 2013 Apr 1;69:126-37
23186917
Cereb Cortex. 2014 May;24(5):1278-88
23300109
Neuron. 2013 Feb 20;77(4):750-61
23439126
Front Psychol. 2013 May 14;4:262
23717293
J Neurosci. 2013 Jul 17;33(29):11878-87
23864677
Front Neuroinform. 2013 Feb 15;7:3
23919088
Curr Biol. 2013 Nov 18;23(22):2273-2278
24184106
J Neurophysiol. 2014 Feb;111(3):513-9
24198325
Front Psychol. 2013 Nov 18;4:845
24302913
J Neurophysiol. 2014 Mar;111(6):1300-7
24381028
Neurosci Lett. 2014 Mar 6;562:79-84
24440121
Nat Neurosci. 2014 Apr;17(4):612-8
24609466
Cereb Cortex. 2015 Sep;25(9):3077-85
24846147
J Neurosci. 2014 Jun 4;34(23):7735-43
24899697
Neuroimage. 2014 Dec;103:119-129
25219334
Brain Topogr. 2015 Jan;28(1):47-61
25228153
Proc Natl Acad Sci U S A. 2014 Oct 14;111(41):14935-40
25267634
J Cogn Neurosci. 2015 May;27(5):945-58
25390199
PLoS One. 2014 Nov 18;9(11):e112974
25405521
Neuroimage. 2015 Feb 15;107:34-45
25482267
J Neurosci. 2015 Feb 18;35(7):3256-62
25698760
J Cogn Neurosci. 2015 Aug;27(8):1573-86
25774428
Cogn Neurodyn. 2015 Apr;9(2):103-12
25852778
J Cogn Neurosci. 2015 Sep;27(9):1811-22
25941871
J Cogn Neurosci. 2015 Oct;27(10):1887-94
26042505
Proc Natl Acad Sci U S A. 2015 Jul 7;112(27):8457-62
26100868
Proc Natl Acad Sci U S A. 2015 Jul 7;112(27):8439-44
26100913
Curr Biol. 2015 Aug 31;25(17):2332-7
26279231
Proc Natl Acad Sci U S A. 2015 Sep 29;112(39):12187-92
26324922
Cell Rep. 2015 Nov 10;13(6):1272-1282
26527004
J Neurosci. 2016 Jan 27;36(4):1401-9
26818525
J Cogn Neurosci. 2016 Sep;28(9):1318-30
27082046
Sci Rep. 2016 Jul 11;6:29335
27403937
Trends Cogn Sci. 2016 Oct;20(10):723-735
27567317
Percept Mot Skills. 1989 Oct;69(2):451-7
2812990
Sci Rep. 2017 Mar 06;7:43573
28262824
Psychophysiology. 1974 May;11(3):294-303
4421317
Neuropsychologia. 1981;19(5):675-86
7312152
J Neurosci. 1996 Jul 1;16(13):4240-9
8753885
Int J Neurosci. 1998 Feb;93(1-2):101-15
9604173