RESEARCH 5/27/11 11:13 AM 5 UCLA USJ | VOLUME 24, SPRING 2011 24, SPRING | VOLUME UCLA USJ the Aspects of Gender and Age and Aspects of Gender the Optical illusions can reveal the remarkable vulnerabilities of human of human vulnerabilities Optical illusions can reveal the remarkable these visual perception as well as the populations most susceptible to with the link to the opti- An online survey attached tricks. perceptual purpose The responder. each to e-mails through was sent illusions cal and faculty responses of 2,000 UCLA the survey was to collect of the types of optical il- and graduate) to different students (undergraduate and shape. appearance color, motion, lusions, such as those involving tend to be more that females The results of the survey demonstrated illusions than optical motion, and appearance susceptible to color, optical viewing in no difference was there interestingly, But males. findings these Collectively participants. younger and older in illusions illusion on optical effect and physiological psychological suggest that depending on the gender but not necessarily the age. may differ Investigation of Optical Illusions on of Optical Investigation o Research L ai Statistics/ Ch Neuroscience a Department of Department Dr. Ivo Dinov Dinov Ivo Dr. K R1 11-16.indd 5 R1 1-6 .ind 6 RESEARCH they se objctin al., 201 optical usnehr(Swzkf per with alr imagn (fMRI),therscoudpl INT percnt ofhmal ulation, rd10m from theHwadsug hes MdicalInt disea colrbn. importan hesudyfcl. both pysilgcand are lsucptibon. visual con visual ytemhroncd show optical usn.Oherd, with th Acording tGael.,pwhvsuym to helvfsucpibyan. and al., 208) vison frpectad(Gl perciv thwoldnsuaym Universty ofNgpduhal betwn two lines,ughapycdf equal ngth. in theforgud,baly awy fromthebsvdlngi line. foregund aclsthbv lines volunters whaimgfz brain. IoelusmdthPz, was contigephyl noticed hagrfsupbly same op Universty ColgLdhwaf 6 at ti ceivd asmlrf K relymostnpciwk cal iusonthryevd RODUCTIN T are mo a showed way o mstberv,hlinap C No One Ano 1). si h indvuals UCL de atunl,ohpri

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UCLA USJ | VOLUME 24, SPRING 2011 24, SPRING | VOLUME UCLA USJ males study showed that of this results the illusions, optical males than of females was a higher percentage there and survey, the in illusions optical to the susceptible With responses. on the effects minimal had age that shows data Dot, the Disappearing of the exception the that females are five to ten percent on average more Figure 9. Age effects on viewing optical illusions. Survey respon- Age effects on viewing optical illusions. 9. Figure their suscepti- questions to demonstrate dents answered yes-or-no blility to the corresponding optical illusion. This figure shows the in each optical illusion age affected percentage of people in different of the survey. younger group by around 5% (P<0.05) (Figure 9). Illusion and In the motion optical illusions (Pacman similar percentag- Hermann Grid), both groups had optical illusion, sug- es of people who perceived the effect the on influence minimal a has age that gesting afterimage exper of motion optical illusions. In the iment, the responses of both groups gave a bimodal gave a bimodal iment, the responses of both groups perceived in the distribution for the number of birds percent- The older group had a higher afterimage. Checker’s by the age of people who were affected a higher percent- Shadow illusion, while there was compared to the age of people in the younger group illusions (False older group for the two other color the high However, Color and Disappearing Dots). of the age variance source, which p-value of 0.116 is not as is above 0.05, indicates the main effect Therefore, responses grouped significant as gender. by age are generally equal. DISCUSSION ions

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n io t iga t nves I cause the normality of population parameters of the parameters of the cause the normality of population not assumed and the two independent samples was One-way analysis population sizes were not equal. of variance (ANOVA) was selected for the statisti- was selected of variance (ANOVA) among three or more groups. cal difference RESULTS - The response to the optical illu Effects. Gender and female partici- sion tests by male participants pants were significantly different (P<0.05). In this an approximately sample of subjects, males have of females rate, while about 3% 8% color-blindness motion optical illu- are colorblind (Figure 8). In the grid), a higher sions (Pacman illusion and Hermann rate of females perceived these optical illusions based on the survey responses. For the afterimage illusion, the number of birds that were seen in the afterimage for males was binomially distributed; they tended to see either the most number or the least number of birds. In the color optical illusions there were also Shadow and False Color, Checker’s a higher percentage of females that perceived the optical illusions. Age Effects. Survey responders were separated into groups based on the sample size me- two different group over thirty years old The thirty. of age dian the than colorblindness of percentage higher a had centage of people affected in each optical illusion of the survey in each optical of people affected centage (n=158). Figure 8. Gender effects on viewing optical illusions. The per effects on viewing 8. Gender Figure R1 11-16.indd 9 R1 11-16.indd 10 RESEARCH susceptible to the optical illusions presented, The finding of this study strengthens the ideathat the males andfemalesbehave andsolvequestionsdiffer strengthens study this of finding The influence. minimal has age while perception illusion optical affects significantly gender that suggest study difference in task-solvingstrategy. The resultsofthis to optical illusions ness isgenetic (Kelly, 1973),thegreatersusceptibility the optimalrangeofresponders. data, whichoccurswhenthecollecteddataisnotwithin quarter tocanminimizesuchnon-responsebiasofthe responding. Sendingemailsconstantlythroughoutthe have beenbiasedbythesurveyrecipientssimplynot a large amountofresponses;however, thedatacould data throughonlinesurveywasaneffective waytogain more abletoperceivetheopticalillusion.Collecting http://socr.ucla.edu/docs/surveys/SOCR_Survey_VisualIllusions_2010.html next totheopticalillusionsmorecloselyandthuswere SurveyURL: because femalesfollowedtheinstructionsprovided vey wasnotcontrolled. SOCRURL:http://www.socr.ucla.edu These resultscouldhavearisen voluntary, thetimethateachsubjectspentonsur of responderstothesurvey. Becausethissurveywas factor istheresponseerror, whichinvolvestheattitude influenced have could that rors tibility infemalestoopticalillusions. strategy; this difference could explain a highersuscep- complement this hypothesisofadifference in spatial solve thetask(Miller 2001). The results ofthisstudy the spatial strategy used bythe two gender groups to actions to thePonzoIllusionbetween gender isdueto difference re- the in that dependent. implies field This Figures Test (EFT),suggestingthat females were more more, females had slowerresponsestothe Embedded line to bemuchlonger than the bottom line. Further 2001). Females tendedtoperceivethetophorizontal susceptible to the Ponzo Illusion than males (Miller, more significantly are females that stated illusion zo lusion susceptibility. Onestudyexamining the Pon- suggested thatagehasminimal effect onoptical il- thirty yearsoldandonebelow(Figure9),which sponses ofthe two age groups examined, one above is notanoticeable difference between thesurveyre- ing thoseinvolving color and motion (Figure 8). There 10 K a Ch While thereasonforamalebiasincolorblind There aretwoimportantpossiblesourcesofer UCLA USJUCLA |VOLUME 24,SPRING 2011 ai L o in females seems to be caused by a these results. The first first The results. these includ------jective experienceofobjectsize.NatNeurosci.14:28-30. Schwarzkopf, D. S.et al. (2011). The surface area of human V1 predicts the sub - Spatial StrategyandSexRatio.Roles.44:209-225. of Influence The Response: Illusion in Differences Gender (2001). J. R. Miller, Luckiesh, M.(1965). Visual Illusions(New York: DoverPress). 228: 55-72. Kelly, D. H.(1973). Lateral inhibition in human colour mechanisms. J Physiol. the Contextof Visual Illusions.PsychologicalScience.19:221-225. Ganel, T. et al. (2008). A Double Dissociation Between Action and Perception in See Them? PLoSComputBiol.3:180. Corney, D.andLotto, R.B.(2007) What Are LightnessIllusionsand Why Do We New GraphicalStatisticsEducational Toolkit. JSS.30:1-19. Che, A. etal. (2009). SOCR Analyses: Implementation and Demonstration of a cal Analysis Toolkit. JOLT. 5:1-19. Che, A. etal.(2009).SOCR Analyses –anInstructional Java Web-based Statisti REFERENCES This research is fundedinpart for hiscontinual guidance and supportinthisresearch. ACKNOWLEDGEMENTS other behaviorsbetweenthetwosexes. illusions promptsfuturestudiesonthedifference in ently. Potential gender biasintheperception of optical 10-21 andNSFgrants07160551023115. I would like to sincerely thank Prof. Ivo Dinov I wouldliketosincerelythankProf. by UCLA OIDgrant 5/27/11 11:14 AM -