Face Part 2.pdf

Are Faces Special?Part 2: NeuroscienceBiological Basis of BehaviourPSY2304 3What we know so far•Specificity Account: Larger inversion effect for faces than for other stimuli (Yin, 1969)•Expertise Account: Robust inversion effect for dog images and Greebles (Diamond & Carey, 1986)•According to the e...

Are Faces Special?Part 2: NeuroscienceBiological Basis of BehaviourPSY2304 3What we know so far•Specificity Account: Larger inversion effect for faces than for other stimuli (Yin, 1969)•Expertise Account: Robust inversion effect for dog images and Greebles (Diamond & Carey, 1986)•According to the expertise account it is possible to obtain a robust inversion effect for all those stimuli that share a configuration for which we are familiar with. 4Agenda •fMRI Studies: Brain activation on the Face Fusiform Area (FFA)•EEG Studies: the inversion effect on the event-related potential (ERP) component called the N170. •Transcranial Direct Current Stimulation (tDCS) applied to perceptual learning (indexed by the Checkerboard Inversion Effect). Cognitive Neuroscience TechniquesElectroencephalography (EEG)Sheldon’s EEG, the Big Bang Theory episode 13 from season 8https://www.youtube.com/watch?v=4K-YSqlx93Ifunctional Magnetic Resonance Imaging (fMRI)5Brain Stimulation What is an fMRI?6•FMRI is a non-invasive imaging technique that detects brain activity by detecting changes in oxygen levels in the blood (blood-oxygen-level-dependent [BOLD]).•FMRI relies on cerebral blood flow and neuronal activation beingcoupled. When an area of the brain is in use/active, blood flow to that region also increases. A brain area is more active when its neurons start sending out more electrical signals than they did before. For instance, if a certain brain area is more “active” when you raise your leg, then that part of the brain is considered responsible for that movement. •An MRI scan is looking to make sure everything is the right size or is in the right place. For instance, are there any signs of damage, such as bruising? If so, there might be a concussion.•In contrast, an fMRI takes images of brain’s activity while performing a function, creating a functional map on top of the brain images (Logothetis et al., 2001) fMRI advantages and limitations7•fMRI is readily available to both clinical and academic researchers, is non-invasive, and can provide high resolution anatomic scans in the same session to use for localization•Poor temporal resolution Kanwisher et al., (1997): PA R T I8Figure 1a. Examples of the stimuli used in Kanwisher et al. (1997). Figure 1b. Example of the brain images in color the voxelsthat produced a significantly higher MR signal intensity during the epochs containing faces than during those containing objects. Kanwisher et al., (1997): PA R T I I9Figure 2a. Examples of the normal and scrambled faces used in Kanwisher et al. (1997). Figure 2b. Examples of the house stimuli used in Kanwisher et al. (1997). Kanwisher et al., (1997): PA R T I I I10Figure 3. Examples of the face and hand stimuli used in Kanwisher et al. (1997). The Face Fusiform Area (FFA)•The FFAis a cortical region in the fusiform gyrus that is found to be more highly activated when participants are presented with faces than when they viewed sets of non-face stimuli (Kanwisher, McDermott, & Chun, 1997)11Face Fusiform Area (FFA) Gauthier et al., (1999): FFA activated by Greeble expertise12 13Example of activation maps for three novices and three experts with faces and Greebles (Gauthier et., 1999). 14Main Findings: •Kanwisher et al (1997):higher activation for faces than other sets of stimuli on a cortical region then named the Face Fusiform Area (FFA), supporting the specificity account of face recognition mechanisms•Gauthier et al (1999): Similar FFA activation for faces and Greebles for Greeble experts supporting the expertise account of face recognition mechanismsPadlet Wallpaper QR-Code What is Electroencephalography (EEG)?15•The EEG measures electrical activity generated by the synchronized activity of thousands of neurons (in volts). It provides excellent time resolution, allowing you to detect activity within cortical areas -even at sub-second timescales. What are Event-Related Potentials (ERPs)?16•ERPsare small voltages generated in the brain structures in response to specific stimuli. They are EEG changes that are time locked to sensory, motor or cognitive events.•Reliable ERP is obtained by averaging EEG fragments in multiple trials•ERPs provide anon-invasive approach to study psychophysiological correlates of mental processes with high temporal resolution. Face Inversion Effect on the N170: The Specificity Account17Example from Itier& Taylor (2004) of N170 to upright and inverted faces and seven object categories recorded at temporal parietal sites P7/P8.Notethe larger N170 for faces than objects and the delayed and larger N170 to inverted than upright faces.Inversion Effect Inversion Effect on the N170: The expertise account18•Rossion et al (2002), showed that ERPs recorded before the training phase revealed a larger inversion effect on the N170 component for faces compared to that found for Greebles. Critically, that was not the case for the results after the training phase with the categories of Greebles where the inversion effect on the N170 was comparable for the two stimulus’s types. •Buseyand Vanderkolk(2005) showed that fingerprint experts exhibited a delayed (but not larger) N170 for inverted fingerprints similar to that exhibited with inverted faces. C2Categorization phase: to categorise a set of checkerboards from two different categories A & C.Prototype APrototype CA1A2C1A65InvertedA67UprightB67UprightB65InvertedStudy phase:to memorize a set of checkerboards presented upright or inverted.Old/new recognition task: To press “.” if they had seen the checkerboard before or “x” if not.The Behavioural Task: Old/New Recognition Task19A67UprightA80UprightOldNewCivile, Zhao et al (2014): CheckerboardInversion Effect on the N170 Results: A robust Checkerboard Inversion Effect 20 -2.4 -2.2 -2.0 -1.8 -1.6 -1.4 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0. 0 0. 2 0. 4 0. 6 0. 8 1. 0 1. 2 1. 4 1. 6 1. 8 2. 0 2. 2 [µV] 0 100 200 300 400 500 600 700 800 900 [ms] PO8 Grand Av erage Grand Av erage Grand Av erage Familiar InvertedFamiliar UprightNovel InvertedNovel UprightN1701.0100200300-1.0P08PO8[µV] -0.15-0.1-0.0500.050.10.150.20.250.30.35Fam iliar In vert edFam iliar Upr igh tNove l Inve rt edNove l Upr ightFamiliar InvertedFamiliar UprightNovel InvertedNovel Uprightsensitivity measure d’N=32P = .004P = .025InteractionCheckerboard Inversion EffectP = .025Upright Familiar vs Novel Behavioural ResultsEEG/ERP Results Romanphysician,ClaudiusGalen(130-210A.D.),afterfailingtoalleviatepainusingadeadfish,herealizedthekeywasapplyingthefishalive,whileitwasstillproducinganelectricalcurrent.Theelectricray—ortorpedofish—canoutputupto30ampsofcurrent.Romanphysician,ScriboniusLargusexperimented(43A.D.)withtheuseoftheseelectricfishforthetreatmentofheadaches.Brief History of Brain Stimulation21 GiovanniAldini(1762-1834),completedthefirststudyinwhichheusedthisearlyformoftDCStoimprovethemoodsofsubjectssufferingfrom“melancholia,”whichmodern-dayphysicianswoulddiagnoseasdepression.AlessandroVo l t a(1745-1827),createdthefirstelectricbattery.Thisbatteryproducedaconstant,directcurrent,andwouldpavethewayforthefirststudiesondirectcurrentstimulationandmusclemovementinanimals.Cathode -Anode +22 Transcranial Direct Current Stimulation (tDCS) today23 tDCS System (neuroConnDC Stimulator)tDCS Fp3 montage AnodalReferenceczAnodal1.5mA10 min+-Sham1.5mA30 secFp3Civile et al (2016); Civile et al., (2018): tDCS on the inversion effect24 00.10.20.30.40.50.60.70.80.91UprightAnodalInvert edAnodalUprightShamInvert edShamd’ sensitivity (d’ of 0 = 50% Accuracy)Overall Results:Civile, McLaren, McLaren (2018) Neuropsychologia;Civile, Obhi, Mclaren(2019) Vision Research;Civile, Cooke et al., (2020) Journal of Experimental Psychology: Animal Learning and Cognition.b) Civile et al (2018): TDCS reduces the face inversion effectInteractionP<.001P<.001P<.001N=192-0.3-0.2-0.100.10.20.30.40.50.60.70.80.91Ano da l Upr igh tAno da l In ve rt edSh am U p r i g htSh am I nv er t edUprightAnodalInvertedAnodalUprightShamInvertedShamOverall Results:Civileet al., (2016) Journal of Experimental Psychology: Animal Learning and Cognition.InteractionP=.045P<.001N=104a) Civile et al (2016): TDCS reduces the checkerboard inversion effect 128 trials+S1S2ISI1s1.5s≤ 2sDifferentSameTDCS applied during a Face Matching Taskoften used to study prosopagnosiaC2Prototype APrototype CA1A2C1Categorisation Task (pre-exposure phase)128 trials1s1.5s≤ 2sDifferentSame+S1S2ISI1sCheckerboard Matching TaskExp 1aExp 1bCivile, Quaglia et al (2021): tDCS on the inversion effect 2.12.32.52.72.93.13.3AnodalUprightAnodalInvert edShamUprightShamInvert edd’ sensitivity (d’ of 0 = 50% Accuracy)InteractionP=.006P<.001P<.001N=48Exp 1a) Matching Task with Faces2.12.32.52.72.93.13.3AnodalUprightAnodalInvert edShamUprightShamInvert edInteractionP=.010P<.001N=48Exp 1b) Matching Task with CheckerboardsAnodal Face vs Checkerboard Inversion Effect p=.00827Civile, Quaglia, Waguri, Ward, McLaren and McLaren (2021) Scientific Reports 28To s u m u p : A r e F a c e s S p e c i a l ? Ye s a n d N o !•Using a specific tDCS procedure we provided evidence of a causal link between the robust inversion effect found for faces and that obtained for non-face stimuli.•The tDCSeliminates the checkerboard inversion effect index of expertise. Similarly, it reduces significantly the face inversion effect indicating that a component of it is based on expertise. Importantly, the fact that the tDCSdoes not reduce entirely the face inversion effect suggest that the remaining effect could be due to specificity. Padlet Wallpaper QR-Code ***Earn £7 in Cash(or 1 credit) oncampus***Face recognition study using tDCSWe are looking for participants to take part in a study investigating the processes involved in face recognition.Experience the tDCS technique in action!The experiment runs in the Washington Singer Building on Streatham Campus. It takes about 45 minutes –you get £7 or 1 credit (Psychology 1styear/MSc Conversionstudents).Eligibility: You must be 18 or older, right handedand be generally healthy.To view the medical safety screening questionnaire: email the researcher, scan below or go to: http://people.exeter.ac.uk/wb221/tDCSInfoPack.pdfWhat is tDCS?Transcranial direct current stimulation is the application of a weak current via two electrodes placed on the head. The stimulation feels slightly warm and tingly. Interested?Email Siobhan McCourt:[email protected] find out more information and to arrange a time.Orsign up on SONA“Face recognition and brain stimulation through tDCS (credits or cash available)” •Civile, C., Zhao, D., Ku, Y., Elchlepp, H., Lavric, A., & McLaren, I. P. L. (2014). Perceptual learning and inversion effects: Recognition of prototype-defined familiar checkerboards. Journal of Experimental Psychology: Animal Learning and Cognition, 40, 144–161.•Civile, C., Ve r b r u g g e n, F., McLaren, R., Zhao, D., Ku, Y., and McLaren, I.P.L. (2016). Switching off perceptual learning: Anodal transcranial direct current stimulation (tDCS) at Fp3 eliminates perceptual learning in humans. Journal of Experimental Psychology: Animal Learning and Cognition, 42, 290-296.•Civile, C., McLaren, R., and McLaren, I.P.L. (2018). How we can change your mind: Anodal tDCSto Fp3 alters human stimulus representation and learning. Neuropsychologia, 11 9 , 2 4 1-246.•Civile, C., Quaglia, S., Waguri, E., Ward, W., McLaren, R., and McLaren, I.P.L. (2021) Using transcranial Direct Current Stimulation (tDCS) to investigate why Faces are and are Not Special. Scientific Reports, 11 , 4 3 8 0.•Eimer, M. (2011). “The face-sensitive N170 component of the event-related potentials,” inThe Oxford Handbook of Face Perception, eds A. J. Calder, G. Rhoades, M. N. Johnson, and J. V. Haxby(Oxford: Oxford University Press), 329–344.•Gauthier I, Ta r rM.J, Anderson A.W, SkudlarskiP, & Gore J.C. (1999). Activation of the middle fusiform ‘face area’ increases with expertise in recognizing novel objects.Nature Neuroscience, 2, 568–573.•Kanwisher N,McDermott J,& Chun MM.(1997).The fusiform face area: a module in human extrastriatecortex specialized for face perception.Journal of Neuroscience,17, 4302–78. •Sarmiento CI, San-Juan D, Prasath VBS. Letter to the Editor: Brief history of transcranial direct current stimulation (tDCS): from electric fishes to microcontrollers (2016). Psychological Medicine, 46:3259–61Main References (suggested readings inbold)