The changing face of face research Vicki Bruce School of Psychology Newcastle University and many, many more...... Bruce & Young (1986) EXPRESSION ANALYSIS FACIAL SPEECH ANALYSIS DIRECTED VISUAL PROCESSING COGNITIVE SYSTEM STRUCTURAL ENCODING FACE RECOGNITION UNITS PERSON IDENTITY NODES NAME GENERATION (Selective) developments since 1986 вЂў вЂў вЂў вЂў Simple вЂ�box and arrowвЂ™ outline replaced in 1990s by computer model вЂ“ Interactive Activation with Competition Much better ideas about the kinds of visual representations that form the core of the вЂ�FRUSвЂ™ or equivalent Development of cognitive neuroscience models (Haxby and many others) Emergence of вЂ�social cognitionвЂ™ and central role played by gaze Simple вЂ�box and arrowвЂ™ outline replaced in 1990s by computer model вЂ“ Interactive Activation with Competition Burton, Bruce and Johnston (1990) вЂў IAC - Interactive activation with competition (cf early McClelland & Rumelhart) вЂў Pools of units for features, FRUs, PINS, SIUs вЂў Excitation between pools, inhibition within pools вЂў Familiarity decisions when PIN reaches threshold Provides good simulations of вЂў Repetition priming - via strengthened connections (so long-lasting, but not cross domain) вЂў Associative priming - via temporary activation (so short-lasting but crosses domains) вЂў Covert recognition in prosopagnosia вЂў Predicted face-name matching in patient ME Name retrieval in IAC? вЂў Burton and Bruce (1992) proposed names like other semantic information but with fewer connections. Name retrieval in IAC? вЂў This position, however, has not stood up to empirical test. вЂў E.g. Bredart et al (1995) showed that you were not slower (actually faster) to name people about whom you knew a lot rather than a little information. After Bredart et al (1995) QJEP Much better ideas about the kinds of visual representations that form the core of the вЂ�FRUSвЂ™ or equivalent Burton, Bruce & Hancock (1999) Cognitive Science вЂў IAC model of person recognition (familiar) вЂў FRUs driven by distributed reps PCA вЂў Look at how model behaves in recognition and priming now using real faces as input. Data set вЂў 50 young men вЂў all captured in a neutral expression and 2 or 3 other expressions In total вЂў 50 neutral faces + 136 expressive faces Results Face recognition Correct PIN identified E xpressing N eutral faces (/50) faces (/136) Shape-free (50-bit) 50 129 (95% ) R aw im age (50 bit) 50 113 (83% ) Shape-free plus shape (70 bit) 50 131 (96% ) Distinctiveness Human subjects rated neutral versions of faces. (1=typical, 15=distinctive) Correlation between human rating and cycles-toreach-PIN = - 0.31 Semantic priming Pairs defined as sharing 2 semantic units Mean cycles to threshold for test faces U n related p rim e R elated p rim e Face p rim e 65 38 N am e p rim e 63 41 Repetition priming Procedure: 1. Present prime face 2. Cycle model & Hebb update 3. ISI - present lots more faces (c. 100) 4. Present test face (same or different view) Mean cycles to threshold for test faces U n p rim ed 7 8 .6 P rim ed w ith sam e im age 6 0 .1 P rim ed w ith d ifferen t im a ge 6 4 .8 Burton, Bruce & Hancock, 1999 How do we represent familiar faces? вЂў Just the average of each distinct image we see of them? вЂў See Burton, A.M., Jenkins, R., Hancock, P.J.B. & White, D. (2005) Robust representations for face recognition: The power of averages. Cognitive Psychology, 51 (3), 256-284 вЂў Jenkins, R. & Burton, A.M. (2008), Science, 319, p.435. Face Recognition Units? What about Face Space? вЂў Valentine (1991) and later вЂў Adaptation studies (Rhodes et al..) вЂў PCA dimensions can be thought of as forming the dimensions of вЂ�face spaceвЂ™ (though this is not the only possible model) Development of cognitive neuroscience models (Haxby) After Bruce & Young (1986) After Haxby et al, 2000 Diagram from Calder & Young (2005) Are faces special? Or, is face recognition special? вЂў Innateness (congenital prosopagnosia, congenital cataracts suggest sensitive period) вЂў Localisation (FFA active even in congenital Ps) вЂў Specificity (still debated...) Exciting hot topics...Gaze вЂў Information from dynamic patterns вЂў Interactions between systems вЂў Gaze and social cognition: certainly eyes are special.. вЂў But why eyes? Bruce & Young (1986) EXPRESSION ANALYSIS -dynamics -interactions -gaze! FACIAL SPEECH ANALYSIS DIRECTED VISUAL PROCESSING COGNITIVE SYSTEM STRUCTURAL ENCODING FACE RECOGNITION UNITS PERSON IDENTITY NODES NAME GENERATION Eyes important for.. Social reasons вЂў вЂў вЂў вЂў We look at other peopleвЂ™s eyes for Intimacy Control Regulating conversational turns etc Cognitive reasons вЂў We look at other peopleвЂ™s eyes to вЂ“ Mind-read (Baron-Cohen) вЂ“ Establish shared attention вЂ“ Dogs do this too..(Miklosi et al, 2003) вЂў CanвЂ™t ignore what another person gazes at вЂ“ Gaze cuing вЂ“ But sometimes we must look away (gaze aversion) вЂў Different gaze patterns in different genetic learning disorders From D. Riby & Hancock (2008) Neuropsychologia So, why eyes? вЂў We need to look at them/use them for other social and cognitive purposes вЂў They tell us about gaze and also other expressions вЂў They donвЂ™t change when other facial features do. вЂў Probably explains why representations of familiar faces are weighted to the eyes. And if you donвЂ™t want to be recognised? School of Psychology Summing up вЂў Bruce and Young (1986) mapped broad relationships between different processes of face perception. вЂў In past 25 years we have begun to understand the mechanisms. вЂў Social cognition is the new hot topic, and thereвЂ™s plenty left to learn.