Adaptation and attention are two mechanisms by which sensory systems manage limited bioenergetic resources: Whereas adaptation decreases sensitivity to stimuli just encountered, attention increases sensitivity to behaviorally relevant stimuli. In the visual system, these changes in sensitivity are accompanied by a change in the appearance of different stimulus dimensions, such as speed. Adaptation causes an underestimation of speed, whereas attention leads to an overestimation of speed. In the two experiments reported here, we investigated whether the effects of these mechanisms interact and how they affect the appearance of stimulus features. We tested the effects of adaptation and the subsequent allocation of attention on perceived speed. A quickly moving adaptor decreased the perceived speed of subsequent stimuli, whereas a slow adaptor did not alter perceived speed. Attention increased perceived speed regardless of the adaptation effect, which indicates that adaptation and attention affect perceived speed independently. Moreover, the finding that attention can alter perceived speed after adaptation indicates that adaptation is not merely a by-product of neuronal fatigue.
BeckD. M.KastnerS. (2009). Top-down and bottom-up mechanisms in biasing competition in the human brain. Vision Research, 49, 1154–1165.
7.
BlakemoreC.NachmiasJ.SuttonP. (1970). The perceived spatial frequency shift: Evidence for frequency-selective neurones in the human brain. Journal of Physiology, 210, 727–750.
8.
BrainardD. H. (1997). The psychophysics toolbox. Spatial Vision, 10, 433–436.
CarrascoM.LoulaF.HoY. X. (2006). How attention enhances spatial resolution: Evidence from selective adaptation to spatial frequency. Perception & Psychophysics, 68, 1004–1012.
14.
CarrascoM.Penpeci-TalgarC.EcksteinM. (2000). Spatial covert attention increases contrast sensitivity across the CSF: Support for signal enhancement. Vision Research, 40, 1203–1215.
15.
FullerS.CarrascoM. (2006). Exogenous attention and color perception: Performance and appearance of saturation and hue. Vision Research, 46, 4032–4047.
16.
FullerS.ParkY.CarrascoM. (2009). Cue contrast modulates the effects of exogenous attention on appearance. Vision Research, 49, 1825–1837.
17.
GanguliD.SimoncelliE. P. (2010). Implicit encoding of prior probabilities in optimal neural populations. Advances in Neural Information Processing Systems, 23, 658–666.
18.
GanguliD.SimoncelliE. P. (2012, February). Neural implementation of Bayesian inference using efficient population codes. Paper presented at the Computational and Systems Neuroscience meeting, Salt Lake City, UT.
19.
GiordanoA. M.McElreeB.CarrascoM. (2009). On the automaticity and flexibility of covert attention: A speed-accuracy trade-off analysis. Journal of Vision, 9(3), Article 30. Retrieved from http://www.journalofvision.org/content/9/3/30
20.
GobellJ.CarrascoM. (2005). Attention alters the appearance of spatial frequency and gap size. Psychological Science, 16, 644–651.
21.
HerrmannK.Montaser-KouhsariL.CarrascoM.HeegerD. J. (2010). When size matters: Attention affects performance by contrast or response gain. Nature Neuroscience, 13, 1554–1559.
22.
HudsonA. E.SchiffN. D.VictorJ. D.PurpuraK. P. (2009). Attentional modulation of adaptation in V4. European Journal of Neuroscience, 30, 151–171.
23.
JinD. Z.DragoiV.SurM.SeungH. S. (2005). Tilt aftereffect and adaptation-induced changes in orientation tuning in visual cortex. Journal of Neurophysiology, 94, 4038–4050.
24.
KohnA. (2007). Visual adaptation: Physiology, mechanisms, and functional benefits. Journal of Neurophysiology, 97, 3155–3164.
25.
KrekelbergB.van WezelR. J.AlbrightT. D. (2006). Adaptation in macaque MT reduces perceived speed and improves speed discrimination. Journal of Neurophysiology, 95, 255–270.
26.
LankheetM. J.VerstratenF. A. (1995). Attentional modulation of adaptation to two-component transparent motion. Vision Research, 35, 1401–1412.
27.
LennieP. (2003). The cost of cortical computation. Current Biology, 13, 493–497.
28.
LevinsonE.SekulerR. (1976). Adaptation alters perceived direction of motion. Vision Research, 16, 779–781.
LingS.CarrascoM. (2007). Transient covert attention does alter appearance: A reply to Schneider (2006). Perception & Psychophysics, 69, 1051–1058.
31.
LingnauA.AshidaH.WallM. B.SmithA. T. (2009). Speed encoding in human visual cortex revealed by fMRI adaptation. Journal of Vision, 9(13), Article 3. Retrieved from http://www.journalofvision.org/content/9/13/3
32.
LiuJ.NewsomeW. T. (2003). Functional organization of speed tuned neurons in visual area MT. Journal of Neurophysiology, 89, 246–256.
33.
LiuJ.NewsomeW. T. (2005). Correlation between speed perception and neural activity in the middle temporal visual area. Journal of Neuroscience, 25, 711–722.
LuckS. J.HillyardS. A.MoulouaM.WoldorffM. G.ClarkV. P.HawkinsH. L. (1994). Effects of spatial cuing on luminance detectability: Psychophysical and electrophysiological evidence for early selection. Journal of Experimental Psychology: Human Perception and Performance, 20, 887–904.
39.
MaW. J.BeckJ. M.LathamP. E.PougetA. (2006). Bayesian inference with probabilistic population codes. Nature Neuroscience, 9, 1432–1438.
40.
Martinez-TrujilloJ.TreueS. (2002). Attentional modulation strength in cortical area MT depends on stimulus contrast. Neuron, 35, 365–370.
41.
MontagnaB.CarrascoM. (2006). Transient covert attention and the perceived rate of flicker. Journal of Vision, 6(9), Article 8. Retrieved from http://www.journalofvision.org/content/6/9/8
OhzawaI.SclarG.FreemanR. D. (1982). Contrast gain control in the cat visual cortex. Nature, 298, 266–268.
45.
PelliD. G. (1997). The VideoToolbox software for visual psychophysics: Transforming numbers into movies. Spatial Vision, 10, 437–442.
46.
PestilliF.VieraG.CarrascoM. (2007). How do attention and adaptation affect contrast sensitivity?Journal of Vision, 7(7), Article 9. Retrieved from http://www.journalofvision.org/content/7/7/9
47.
PriebeN. J.CassanelloC. R.LisbergerS. G. (2003). The neural representation of speed in macaque area MT/V5. Journal of Neuroscience, 23, 5650–5661.
48.
ReynoldsJ. H.ChelazziL. (2004). Attentional modulation of visual processing. Annual Review of Neuroscience, 27, 611–647.
SmithA. T. (1985). Velocity coding: Evidence from perceived velocity shifts. Vision Research, 25, 1969–1976.
51.
StörmerV. S.McDonaldJ. J.HillyardS. A. (2009). Cross-modal cueing of attention alters appearance and early cortical processing of visual stimuli. Proceedings of the National Academy of Sciences, USA, 106, 22456–22461.
52.
ThompsonP. (1981). Velocity after-effects: The effects of adaptation to moving stimuli on the perception of subsequently seen moving stimuli. Vision Research, 21, 337–345.
53.
TreueS. (2003). Climbing the cortical ladder from sensation to perception. Trends in Cognitive Sciences, 7, 469–471.
54.
TurattoM.VescoviM.ValsecchiM. (2007). Attention makes moving objects be perceived to move faster. Vision Research, 47, 166–178.
WeissY.SimoncelliE. P.AdelsonE. H. (2002). Motion illusions as optimal percepts. Nature Neuroscience, 5, 598–604.
57.
WichmannF. A.HillN. J. (2001). The psychometric function: I. Fitting, sampling, and goodness of fit. Perception & Psychophysics, 63, 1293–1313.
58.
WillifordT.MaunsellJ. H. (2006). Effects of spatial attention on contrast response functions in macaque area V4. Journal of Neurophysiology, 96, 40–54.
59.
YeshurunY.CarrascoM. (1998). Attention improves or impairs visual performance by enhancing spatial resolution. Nature, 396, 72–75.
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
