Low-level mechanisms do not explain paradoxical motion percepts.
Classic psychophysical studies have shown that increasing the size of low-contrast moving stimuli increases their discriminability, indicating spatial summation mechanisms. More recently, a number of studies have reported that for moderate and high contrasts, size increases yield substantial deteriorations of motion perception-a result described as psychophysical spatial suppression. While this result resembles known characteristics of suppressive center-surround neural mechanisms, a recent study (C. R. Aaen-Stockdale, B. Thompson, P. C. Huang, & R. F. Hess, 2009) argued that observed size-dependent changes in motion perception might be explained by differences in contrast sensitivity for stimuli of different sizes. Here, we tested this hypothesis using duration threshold measurements-an experimental approach used in several spatial suppression studies. The results replicated previous reports by demonstrating spatial suppression at a fixed, high contrast. Importantly, we observed strong spatial suppression even when stimuli were normalized relative to their contrast thresholds. While the exact mechanisms underlying spatial suppression still need to be adequately characterized, this study demonstrates that a low-level explanation proposed by Aaen-Stockdale et al. (2009) cannot account for spatial suppression results.
Glasser
Davis M
DM
Center for Visual Science and Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY 14627, USA. dglasser@cvs.rochester.edu
Tadin
Duje
D
D015350:Contrast Sensitivity / Q000502:physiology*; D004192:Discrimination, Psychological / Q000502:physiology*; D006801:Humans; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D013028:Space Perception / Q000502:physiology*
J Neurosci. 2008 Mar 19;28(12):3017-29
18354005
Vision Res. 1980;20(4):341-7
7414966
Nature. 2003 Jul 17;424(6946):312-5
12867982
Vision Res. 1995 Feb;35(3):325-36
7892728
J Neurosci. 1994 Dec;14(12):7367-80
7996182
J Neurosci. 1991 Sep;11(9):2768-85
1880548
Neuron. 2000 Jun;26(3):725-34
10896167
J Vis. 2009 Jan 22;9(1):30.1-14
19271900
J Vis. 2009 Apr 20;9(4):15.1-15
19757924
J Vis. 2008 May 26;8(7):9.1-11
19146242
Vision Res. 2005 Jul;45(16):2059-64
15845238
Perception. 1985;14(2):105-26
4069941
J Neurophysiol. 2005 Mar;93(3):1809-15
15483068
J Neurosci. 2000 Feb 1;20(3):1157-69
10648720
Vision Res. 2005 Sep;45(20):2642-9
15998529
J Neurophysiol. 1993 Jan;69(1):19-39
8433131
Percept Psychophys. 2001 Nov;63(8):1314-29
11800459
Vision Res. 2002 Dec;42(28):3005-17
12480071
J Neurosci. 1999 Aug 15;19(16):7162-74
10436069
Vision Res. 2004;44(14):1635-9
15136000
Annu Rev Neurosci. 1985;8:407-30
3885829
Science. 2003 May 2;300(5620):812-5
12730605
J Opt Soc Am A. 1984 Aug;1(8):876-84
6470838
J Neurophysiol. 2000 Nov;84(5):2658-69
11068007
J Neurosci. 2009 Jul 15;29(28):9072-7
19605644
Percept Psychophys. 1983 Feb;33(2):113-20
6844102
J Neurosci. 2002 Nov 1;22(21):9475-89
12417672
J Clin Psychopharmacol. 2003 Dec;23(6):601-40
14624191
J Vis. 2009 Jan 21;9(1):25.1-15
19271895
Proc R Soc Lond B Biol Sci. 1981 Mar 11;211(1184):321-39
6111803
Neuron. 2005 Feb 3;45(3):361-6
15694323
J Neurosci. 2006 Nov 1;26(44):11403-12
17079669
J Neurophysiol. 2009 Nov;102(5):2594-602
19726727
Curr Biol. 2008 Oct 14;18(19):R904-6
18957232
Spat Vis. 1997;10(4):437-42
9176953
J Neurosci. 2006 Mar 15;26(11):2941-50
16540571
J Exp Psychol Hum Percept Perform. 2007 Apr;33(2):257-70
17469967
J Opt Soc Am A. 1991 Aug;8(8):1330-9
1919836
Nature. 1992 Jun 11;357(6378):497-9
1608448
Vision Res. 2006 Mar;46(5):599-604
16005041
Percept Psychophys. 2001 Nov;63(8):1293-313
11800458
Depress Anxiety. 2007;24(7):495-517
17117412
Curr Biol. 2008 Nov 25;18(22):R1051-2
19036331
Neuron. 2003 Aug 14;39(4):681-91
12925281
Spat Vis. 1997;10(4):433-6
9176952
J Vis. 2005 Jul 06;5(6):571-8
16097869
J Neurophysiol. 2005 May;93(5):2908-21
15574800
Vision Res. 1976;16(2):161-8
1266056
J Neurosci. 2006 Mar 8;26(10):2614-22
16525040
Spat Vis. 1997;10(4):369-77
9176946
Eur J Neurosci. 2009 Sep;30(6):1172-82
19723288
Neuron. 2000 Jun;26(3):715-24
10896166
J Vis. 2009 May 13;9(5):9.1-14
19757887
J Physiol. 1975 Sep;250(2):347-66
1177145