Where Is Size in the Brain of the Beholder?

in Multisensory Research
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Despite advances in our understanding of how the brain represents visual space, it remains unresolved how the subjective experience of an object’s size arises. While responses in retinotopic cortex correlate with perceived size, this does not imply that those brain regions mediate perceived size differences. Here I describe how the percept of an object’s size could be generated in the brain and outline unanswered questions that future research should seek to address.

Where Is Size in the Brain of the Beholder?

in Multisensory Research



AfrazA.PashkamM. V.CavanaghP. (2010). Spatial heterogeneity in the perception of face and form attributesCurr. Biol. 2021122116.

AnstisS. (1998). Picturing peripheral acuityPerception 27817825.

CaparosS.AhmedL.BremnerA. J.de FockertJ. W.LinnellK. J.DavidoffJ. (2012). Exposure to an urban environment alters the local bias of a remote cultureCognition 1228085.

CassJ. R.SpeharB. (2005). Dynamics of collinear contrast facilitation are consistent with long-range horizontal striate transmissionVision Res. 4527282739.

ChoplinJ. M.MedinD. L. (1999). Similarity of the perimeters in the Ebbinghaus illusionPercept. Psychophys. 61312.

ChouinardP. A.NoultyW. A.SperandioI.LandryO. (2013). Global processing during the Müller-Lyer illusion is distinctively affected by the degree of autistic traits in the typical populationExp. Brain Res. 230219231.

DakinS.FrithU. (2005). Vagaries of visual perception in autismNeuron 48497507.

DayM.LofflerG. (2009). The role of orientation and position in shape perceptionJ. Vis. 9(14) 117.

De FockertJ.DavidoffJ.FagotJ.ParronC.GoldsteinJ. (2007). More accurate size contrast judgments in the Ebbinghaus illusion by a remote cultureJ. Exp. Psychol. Hum. Percept. Perform. 33738742.

De FockertJ. W.CaparosS.LinnellK. J.DavidoffJ. (2011). Reduced distractibility in a remote culturePloS One 6e26337.

De ValoisR. L.De ValoisK. K. (1991). Vernier acuity with stationary moving GaborsVis. Res. 3116191626.

DeniJ. R.BrignerW. L. (1997). Ebbinghaus illusion: effect of figural similarity upon magnitude of illusion when context elements are equal in perceived sizePercept. Mot. Skills 8411711175.

DohertyM. J.TsujiH.PhillipsW. A. (2008). The context sensitivity of visual size perception varies across culturesPerception 3714261433.

DohertyM. J.CampbellN. M.TsujiH.PhillipsW. A. (2010). The Ebbinghaus illusion deceives adults but not young childrenDev. Sci. 13714721.

DumoulinS. O.WandellB. A. (2008). Population receptive field estimates in human visual cortexNeuroImage 39647660.

FangF.BoyaciH.KerstenD.MurrayS. O. (2008). Attention-dependent representation of a size illusion in human V1Curr. Biol. 1817071712.

FischerJ.SpotswoodN.WhitneyD. (2011). The emergence of perceived position in the visual systemJ. Cogn. Neurosci. 23119136.

FranzV. H.GegenfurtnerK. R. (2008). Grasping visual illusions: consistent data and no dissociationCogn. Neuropsychol. 25920950.

FranzV. H.ScharnowskiF.GegenfurtnerK. R. (2005). Illusion effects on grasping are temporally constant not dynamicJ. Exp. Psychol. Hum. Percept. Perform. 3113591378.

GençE.BergmannJ.SingerW.KohlerA. (in press). Surface area of early visual cortex predicts individual speed of traveling waves during binocular rivalryCereb. Cortex.

GoodaleM. A. (2011). Transforming vision into actionVis. Res. 5115671587.

GoodaleM. A.MilnerA. D. (1992). Separate visual pathways for perception and actionTrends Neurosci. 152025.

GregoryR. L. (2008). Emmert’s Law and the moon illusionSpat. Vis. 21407420.

HarveyB. M.DumoulinS. O. (2011). The relationship between cortical magnification factor and population receptive field size in human visual cortex: constancies in cortical architectureJ. Neurosci. 311360413612.

HarveyB. M.KleinB. P.PetridouN.DumoulinS. O. (2013). Topographic representation of numerosity in the human parietal cortexScience 34111231126.

HelmholtzH. (1867). Handbuch der Physiologischen Optik. Leopold VossLeipzig, Germany.

HubelD. H.WieselT. N. (1962). Receptive fields, binocular interaction and functional architecture in the cat’s visual cortexJ. Physiol. 160106154.

HubelD. H.WieselT. N. (1968). Receptive fields and functional architecture of monkey striate cortexJ. Physiol. 195215243.

HughesM.Fernandez-DuqueD. (2010). Knowledge influences perception: evidence from the Ebbinghaus illusionJ. Vis. 10954954.

JaegerT.GuenzelN. (2001). Similarity and lightness effects in Ebbinghaus illusion created by keyboard charactersPercept. Mot. Skills 92151156.

JaegerT.KlahsK.NewtonD. (2014). Ebbinghaus illusions with disc figures: effects of contextual size, separation, and lightnessPercept. Mot. Skills 118805817.

JanckeD.ChavaneF.NaamanS.GrinvaldA. (2004). Imaging cortical correlates of illusion in early visual cortexNature 428423426.

JoganM.StockerA. A. (2014). A new two-alternative forced choice method for the unbiased characterization of perceptual bias and discriminabilityJ. Vis. 1420.

KonenC. S.KastnerS. (2008). Two hierarchically organized neural systems for object information in human visual cortexNat. Neurosci. 11224231.

KonkleT.OlivaA. (2012). A real-world size organization of object responses in occipitotemporal cortexNeuron 7411141124.

KravitzD. J.KriegeskorteN.BakerC. I. (2010). High-level visual object representations are constrained by positionCereb. Cortex 2029162925.

LofflerG.WilsonH. R.WilkinsonF. (2003). Local and global contributions to shape discriminationVis. Res. 43519530.

MilnerA. D.GoodaleM. A. (2008). Two visual systems re-viewedNeuropsychologia 46774785.

MorganM.DillenburgerB.RaphaelS.SolomonJ. A. (2012). Observers can voluntarily shift their psychometric functions without losing sensitivityAtten. Percept. Psychophys. 74185193.

MorganM. J.MelmothD.SolomonJ. A. (2013). Linking hypotheses underlying Class A and Class B methodsVis. Neurosci. 30197206.

MuiseJ. G.BrunV.PorelleM. (1997). Salience of central figure in the Ebbinghaus illusion: the Oreo cookie effectPercept. Mot. Skills 8512031208.

MurrayS. O.BoyaciH.KerstenD. (2006). The representation of perceived angular size in human primary visual cortexNat. Neurosci. 9429434.

NiA. M.MurrayS. O.HorwitzG. D. (2014). Object-centered shifts of receptive field positions in monkey primary visual cortexCurr. Biol. 2416531658.

NishidaS.JohnstonA. (1999). Influence of motion signals on the perceived position of spatial patternNature 397610612.

OnatS.NortmannN.RekauzkeS.KönigP.JanckeD. (2011). Independent encoding of grating motion across stationary feature maps in primary visual cortex visualized with voltage-sensitive dye imagingNeuroImage 5517631770.

PalmerC. R.ChenY.SeidemannE. (2012). Uniform spatial spread of population activity in primate parafoveal V1J. Neurophysiol. 10718571867.

PhillipsW. A.ChapmanK. L. S.BerryP. D. (2004). Size perception is less context-sensitive in malesPerception 337986.

PooresmaeiliA.ArrighiR.BiagiL.MorroneM. C. (2013). Blood oxygen level-dependent activation of the primary visual cortex predicts size adaptation illusionJ. Neurosci. 331599916008.

RamachandranV. S.AnstisS. M. (1990). Illusory displacement of equiluminous kinetic edgesPerception 19611616.

SchwarzkopfD. S.ReesG. (2013). Subjective size perception depends on central visual cortical magnification in human v1PloS One 8e60550.

SchwarzkopfD. S.SongC.ReesG. (2011). The surface area of human V1 predicts the subjective experience of object sizeNat. Neurosci. 142830.

SerenoM. I.DaleA. M.ReppasJ. B.KwongK. K.BelliveauJ. W.BradyT. J.RosenB. R.TootellR. B. (1995). Borders of multiple visual areas in humans revealed by functional magnetic resonance imagingScience 268889893.

SnowdenR. J. (1998). Shifts in perceived position following adaptation to visual motionCurr. Biol. 813431345.

SongC.SchwarzkopfD. S.ReesG. (2011). Interocular induction of illusory size perceptionBMC Neurosci. 1227.

SongC.SchwarzkopfD. S.LuttiA.LiB.KanaiR.ReesG. (2013). Effective connectivity within human primary visual cortex predicts interindividual diversity in illusory perceptionJ. Neurosci. 331878118791.

SperandioI.ChouinardP. A.GoodaleM. A. (2012a). Retinotopic activity in V1 reflects the perceived and not the retinal size of an afterimageNat. Neurosci. 15540542.

SperandioI.LakA.GoodaleM. A. (2012b). Afterimage size is modulated by size-contrast illusionsJ. Vis. 12(18) 110.

ThelenL.WattR. (2010). The Ebbinghaus Illusion as a function of age: complete psychometric functionsJ. Vis. 10487487.

WangY.-Z.HessR. F. (2005). Contributions of local orientation and position features to shape integrationVis. Res. 4513751383.

WhitneyD.BresslerD. W. (2007). Spatially asymmetric response to moving patterns in the visual cortex: re-examining the local sign hypothesisVis. Res. 475059.

WokkeM. E.VandenbrouckeA. R. E.ScholteH. S.LammeV. A. F. (2013). Confuse your illusion: feedback to early visual cortex contributes to perceptual completionPsychol. Sci. 246371.

YoonJ. H.MaddockR. J.RokemA.SilverM. A.MinzenbergM. J.RaglandJ. D.CarterC. S. (2010). GABA concentration is reduced in visual cortex in schizophrenia and correlates with orientation-specific surround suppressionJ. Neurosci. 3037773781.

ZuiderbaanW.HarveyB. M.DumoulinS. O. (2012). Modeling center-surround configurations in population receptive fields using fMRIJ. Vis. 1210.


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    Contextual illusions in which the perceived size of objects differs from the physical size. (A) Ebbinghaus illusion. The size of the two blue circles is identical but the left one appears smaller. (B) Delboeuf illusion. The size of the two blue circles is identical but the left one appears larger. (C, D) Ponzo and tunnel illusion. The length of the two horizontal lines is identical but the top one appears longer. (E) By free fusing the left and right images, one should see two coins at different distances. The coin seen as closer to the observer should also appear larger. (F) Müller-Lyer illusion. The length of the two horizontal lines is identical but it appears longer in the top figure.

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    Interactions between the profile of contextual interactions between visual stimuli and the macroscopic surface area of V1. Each surface represents the V1 of an individual. The color code denotes the retinotopic organization (e.g., eccentricity). In an individual with a large V1 (top), the same amount of visual space is represented with a greater cortical territory than in an individual with a small V1 (bottom). The sombrero-shaped profile illustrates a putative center-surround profile of contextual interactions [e.g., the peak region may denote increases in perceived size while the troughs denote perceived shrinkage as suggested by Schwarzkopf and Rees (2013)]. If this effect is constant in terms of cortical space, for instance because it is mediated by intrinsic lateral connections in V1, in an individual with a small V1 the perceptual effect will extend farther in visual space (bottom left). Conversely, if the effect is calibrated to the retinotopic map, possibly because it is mediated by feedback connections from higher brain regions, the effect in visual space will be constant (bottom right) and therefore not correlated with V1 surface area. Yet for both kinds of effect the magnitude of the percept will be reflected by responses in V1 neurons.

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    Orientation exerts a strong influence on perceived location. The grating patches in all three panels are positioned on perfect circles. However, the orientation of each patch affects whether one perceives a circle (A), a square (B), or a diamond (C).

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