The changing face of face research Vicki Bruce School of Psychology Newcastle University
Bruce & Young (1986) EXPRESSION ANALYSIS STRUCTURAL ENCODING FACIAL SPEECH ANALYSIS FACE RECOGNITION UNITS DIRECTED VISUAL PROCESSING PERSON IDENTITY NODES COGNITIVE SYSTEM NAME GENERATION
(Selective) developments since 1986 • Simple ‘box and arrow’ outline replaced in 1990s by computer model – Interactive Activation with Competition • Much better ideas about the kinds of visual representations that form the core of the ‘FRUS’ or equivalent • Development of cognitive neuroscience models (Haxby and many others) • Emergence of ‘social cognition’ and central role played by gaze
Simple ‘box and arrow’ outline replaced in 1990s by computer model – Interactive Activation with Competition
Burton, Bruce and Johnston (1990) • IAC - Interactive activation with competition (cf early McClelland & Rumelhart) • Pools of units for features, FRUs, PINS, SIUs • Excitation between pools, inhibition within pools • Familiarity decisions when PIN reaches threshold
Provides good simulations of • Repetition priming - via strengthened connections (so long-lasting, but not cross domain) • Associative priming - via temporary activation (so short-lasting but crosses domains) • Covert recognition in prosopagnosia • Predicted face-name matching in patient ME
Name retrieval in IAC? • Burton and Bruce (1992) proposed names like other semantic information but with fewer connections.
Name retrieval in IAC? • This position, however, has not stood up to empirical test. • 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.
Much better ideas about the kinds of visual representations that form the core of the ‘FRUS’ or equivalent
Burton, Bruce & Hancock (1999)Cognitive Science • IAC model of person recognition (familiar) • FRUs driven by distributed reps - PCA • Look at how model behaves in recognition and priming now using real faces as input.
Data set • 50 young men • all captured in a neutral expression and 2 or 3 other expressions • In total • 50 neutral faces + 136 expressive faces
Results Face recognition Correct PIN identified
Distinctiveness Human subjects rated neutral versions of faces. (1=typical, 15=distinctive) Correlation between human rating and cycles-to-reach-PIN = - 0.31
Semantic priming Pairs defined as sharing 2 semantic units Mean cycles to threshold for test faces
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
How do we represent familiar faces? • Just the average of each distinct image we see of them? • 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 • Jenkins, R. & Burton, A.M. (2008), Science, 319, p.435.
What about Face Space? • Valentine (1991) and later • Adaptation studies (Rhodes et al..) • PCA dimensions can be thought of as forming the dimensions of ‘face space’ (though this is not the only possible model)
After Bruce & Young (1986) After Haxby et al, 2000 Diagram from Calder & Young (2005)
Are faces special? Or, is face recognition special? • Innateness (congenital prosopagnosia, congenital cataracts suggest sensitive period) • Localisation (FFA active even in congenital Ps) • Specificity (still debated...)
Exciting hot topics...Gaze • Information from dynamic patterns • Interactions between systems • Gaze and social cognition: certainly eyes are special.. • But why eyes?
-dynamics -interactions -gaze! Bruce & Young (1986) EXPRESSION ANALYSIS STRUCTURAL ENCODING FACIAL SPEECH ANALYSIS FACE RECOGNITION UNITS DIRECTED VISUAL PROCESSING PERSON IDENTITY NODES COGNITIVE SYSTEM NAME GENERATION
Eyes important for..Social reasons • We look at other people’s eyes for • Intimacy • Control • Regulating conversational turns etc
Cognitive reasons • We look at other people’s eyes to • Mind-read (Baron-Cohen) • Establish shared attention • Dogs do this too..(Miklosi et al, 2003) • Can’t ignore what another person gazes at • Gaze cuing • But sometimes we must look away (gaze aversion) • Different gaze patterns in different genetic learning disorders
So, why eyes? • We need to look at them/use them for other social and cognitive purposes • They tell us about gaze and also other expressions • They don’t change when other facial features do. • Probably explains why representations of familiar faces are weighted to the eyes.
School of Psychology Summing up • Bruce and Young (1986) mapped broad relationships between different processes of face perception. • In past 25 years we have begun to understand the mechanisms. • Social cognition is the new hot topic, and there’s plenty left to learn.