Face Perception - An Overview Bozana Meinhardt-Injac Malte Persike Johannes Gutenberg University Mainz
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Interesting to mention Bahrik, Bahrik & Wittlinger,1977 The identification and matching of once familiar names and faces remain approximately 90% correct for at least 15 years even for members of very large classes! 3
Overview What we know about face perception and how we can study it in different experimental settings? Are faces special? My own theoretical and experimental approach in studying face perception. Discussion and Questions. 4
Motivating previous works There is a vast number of papers about face perception a recent search on the subject had over 10.000 entries! Are faces a special visual category? There is a strong inversion effect. There is prosopagnosia. There is the Face Fusiform Area and the N170. There is advantage for faces in Visual Working Memory. There is improvement with development. 5
Motivating previous works Inversion Effect (Yin, 1969; Diamond & Carey, 1986; Robbins & McKone, 2007) 6
Motivating previous works Inversion Effect (Yin, 1969; Diamond & Carey, 1986, Robbins & McKone, 2007) 7
Motivating previous works Inversion Effect (Malcolm, Leung & Barton, 2005) 8
Motivating previous works Inversion Effect (Thompson, 1980) Thatcher Illusion (here with J. Roberts) 9
Motivating previous works Prosopagnosia selective impairement of face recognition ability Acquired and Developmental Prosopagnosia Evidence for the hypothesis that recognition of faces and objects rely on distinct mechanisms 10
Motivating previous works Prosopagnosia (Duchaine & Nakayma, 2005) 11
Motivating previous works The Face Fusiform Area (Kanwisher, McDermott, & Chun, 1997) Pictures taken from: http://www.slicer.org/publications/gallery/index/19?selectedcollection=all&entriesperpage=50 12
Motivating previous works The ERP component N170 (Itier & Taylor, 2004) 13
Motivating previous works The Visual Working Memory advantage for faces (Curby & Gauthier, 2007) 14
Motivating previous works The Visual Working Memory advantage for faces (Curby & Gauthier, 2007) 15
Motivating previous works Improvement in face recognition with development (Carey & Diamond, 1977) Type 1 & 2: paraphernalia to fool Type 3: paraphernalia equal Type 4: paraphernalia to help 16
Own Research
Overview Open questions that we pursue in our work and a selection of the most crucial experimental findings: Facial features and facial familiarity Microgenesis of the visual percept Processing of configural and featural information in a face Working memory for faces and non-face visual objects Becoming a face expert about the development of face perception. Discussion and Questions. 18
Internal and External Facial Features Internal features External features 19
Internal and External Facial Features HOLISTIC face processing 20
Facial Features and Face Familiarity Variability in appearance of internal and external features in natural faces 21
Facial Features and Face Familiarity Target Test Faces Experiment 1: Whole faces Time 0.7 0.6 0.5 Experiment 2: External features Time error rate 0.4 0.3 0.2 0.1 0.0 unfamiliar f. familiar f. Experiment 3: Internal features Time 30/90/130/ 190 ms 1500ms self-paced / until response 22
Facial Features and Face Familiarity Recognition of familiar faces relies on spatial relations among features, particularly internal features. External features are more relevant for recognition of unfamiliar faces. But, whole faces are always better recognized than its parts holistic processing mode is dominant in face recognition! 23
Microgenesis of the Visual Percept How does the visual percept or holistic face percept - evolve in real time? (Bachmann & Vipper, 1983; Bachmann 1991; Sergent, 1986) Provides the opportunity to get a deeper understanding of the perceptual and cognitive processes involved in face and non-face object processing. Focus on early processing stages of faces and non-face visual objects. 24
Microgenesis of the Face Percept Contextual Modulation Paradigm Experimental approach to test holistic viewing: SPEEDED SAME - DIFFERENT MATCHING TASK 25
Microgenesis of the Face Percept Contextual Modulation Paradigm Definition of Same (or Task): Matching of external features / Matching of internal features Exposure Duration: D = {51, 119, 221, 340, 442, 629} ms 26
Contextual Modulation Paradigm 27
Contextual Modulation Paradigm IDE SISE identical/ different same internal/ external f. T1 T3 T2 T4 28
Contextual Modulation Paradigm Task 1 Matching of external features Task 2 Matching of internal features stimulus 1 stimulus 2 29
Contextual Modulation Paradigm Task 1 Matching of external features Task 2 Matching of internal features stimulus 1 stimulus 2 30
Contextual Modulation Paradigm Task 1 Matching of external features Task 2 Matching of internal features stimulus 1 stimulus 2 31
Contextual Modulation Paradigm Task 1 Matching of external features Task 2 Matching of internal features stimulus 1 stimulus 2 32
Contextual Modulation Paradigm Task 1 Matching of external features Task 2 Matching of internal features stimulus 1 stimulus 2 33
Contextual Modulation Paradigm Task 1 Matching of external features Task 2 Matching of internal features stimulus 1 stimulus 2 34
Microgenesis of the Holistic Face Percept - CC Congruent Context CC Match Internal Match External 35
Microgenesis of the Holistic Face Percept - IC Incongruent Context IC Match Internal Match External 36
Microgenesis of the Holistic Face Percept Context Effect Context Effect = CC - IC Measure of holistic processing!!! 37
Conclusions Internal and external facial features might involve different processing mechanisms fast processing for global aspects of faces, which might be used as a 'header' to prepare destination areas for receiving more detailed information. The whole is more than the sum of the parts internal and external features interact in representing holistic faces. Is holistic processing face-specific or can it be found for non-face stimuli of comparable complexity? 38
Microgenesis of the Visual Percept of Non-Face Objects Visual Search Task was used to estimate perceptual complexity of the four object categories (see also Alvarez & Cavanagh, 2004; Eng et al., 2005) Yes/No target (1000 ms) mask (350 ms) search array (until space bar is pressed - RT) Was target present in search array? If yes, which number was behind the target? (until response) 39
Microgenesis of the Visual Percept of Non-Face Objects Target present: Colors: 29 ms/item Shoes: 77 ms/item Watches: 82 ms/item Faces: 99 ms/item Target absent: Colors: 52 ms/item Shoes: 222 ms/item Watches: 258 ms/item Faces: 266 ms/item 40
Whole faces vs. facial features IDE SISE T1 identical/different same internal/external f. T3 T2 T4 41
Microgenesis of the Visual Percept of Non-Face Objects - CC Congruent Context CC Match Internal Match External Inverted Upright 42
Microgenesis of the Visual Percept of Non-Face Objects - IC Incongruent Context IC Match Internal Match External Inverted Upright 43
Microgenesis of the Holistic Face Percept Context Effect Context Effect = CC - IC 44
Microgenesis of the Visual Percept of Non-Face Objects No context effect for non-face objects holistic processing seems to be exclusive for faces. Faster and more accurate processing of faces than non-face objects only in optimal condition (i.e., upright whole faces) expertise with upright faces speeds its processing when compared with objects of non-expertise (Curby & Gauthier, 2009; Tanaka, 2001). Inverse internal-external features asymmetry as compared to faces (?) 45
Composite Effect Paradigm for Faces and Non-Faces Composite Effect (Young, Hellawell, & Hay, 1987) aligned misaligned 46
Composite Effect Paradigm for Faces and Non-Faces Composite Effect 47
Composite Effect Paradigm for Faces and Non-Faces Composite Effect 48
Composite Effect Paradigm for Faces and Non-Faces 49
Composite Effect Paradigm for Faces and Non-Faces 50
Composite Effect Paradigm for Faces and Non-Faces Composite Effect 51
Composite Effect Paradigm for Faces and Non-Faces No composite effect for non-face objects. Best performance (at the ceiling level) with congruent face stimuli faster and more accurate processing than non-face stimuli. The findings of the previous study are confirmed!!! 52
Face Expertise Hypothese Maybe the functional and anatomical specialization of face perception mechanisms in adults ADULTS arise because of substantial experience in individual-level discrimination (i.e., Mary versus Jane), whereas other objects are usually indentified at the basic level of categorization (i.e., chair vs. table) See: Diamond & Carey, 1986; Gauthier & Tarr, 1997; Mondloch, Leis, & Maurer, 2006. 53
Becoming a face expert Studies of preschool and school-aged children suggest that face processing undergoes rapid and dramatic changes particularly during the first decade of life. The question under debate is whether performance differences reflect different degrees of maturation in the substrate of face perception, or just differences in general cognitive development? 54
Becoming a face expert Face-specific perceptual development theory: Increase in the capabilities of holistic viewing Specific and prolonged development of face-selective areas in the human visual cortex. 55
Becoming a face expert General cognitive development theory: Face perception itself is mature in early childhood All development of task performance reflects improvements in general cognitive mechanisms such as concentration, visual attention, and explicit memory ability. 56
Becoming a face expert Contextual modulation paradigm offers new aspects for comparing child and adult face vision: Internal/external features asymmetry studied in natural and intact face stimuli same stimuli used in both tasks. Control for non-perceptual factors performance in CC in both tasks as a baseline. Time-course of the visual processes 57
Becoming a face expert Context modulation paradigm 58
Becoming a face expert Up to now we have tested: 8-10 11-12 14-15 years old and adults (19-37 years old) + old age 70 and > 59
Becoming a face expert External vs. internal features- CC: 60
Becoming a face expert External vs. internal features- IC: 61
Becoming a face expert External vs. internal features summary: Asymmetry in face matching performance with internal and external features: Face matching by attending external features is well developed and robust against variable facial contexts. Face matching by attending internal features is generally poor and strongly affected by interleaved congruent and incongruent contextual information. 62
Becoming a face expert Context Effect at different ages: 63
Becoming a face expert Context Effect x Time x Age: 64
Becoming a face expert Context Effect at different ages - summary: 8-10 years old: the context effect increases with increasing viewing time from part-based to holistic viewing? 11-15 years old: the context effect remains about constant at all exposure durations. Adults: the context effect decreases with time = control over incongruent contexts and feature selective focus from holistic to part-based viewing? 65
Becoming a face expert Time Course of Face Processing No developmental changes in the time course of face processing! 66
Becoming a face expert Still open question: Does face processing change with development? External-internal features asymmetry The strength of the context effect depends on the stage of processing. But: no differences in the time course of face processing. We need a comparison with non-face stimuli experiments are running at the moment. We need a new experimental approach where the speed of processing and interference could be tested separately. 67
Interesting Preview - Old Age - Congruent Context- CC Incongruent Context- IC 68
Face Perception through the Lifespan How does face perception change through the lifespan? What are the mechanisms that account for life-long changes? What is the relationship between general cognitive factors and holistic face processing? Speed of information processing Inhibition 69
Thanks for Listening Any Questions? Bozana Meinhardt-Injac Malte Persike Johannes Gutenberg University Mainz