The anatomical basis of face recognition: evidence from studies of intact individuals:

1. The anatomical basis of face recognition: evidence from studies of intact individuals:

2. What is the anatomical basis of face recognition in humans?: Right hemisphere seems particularly important for face-recognition. Farah (1990): 65% of 81 prosopagnosics had bilateral damage, 29% RH only, 6% LH only. RH important for configural processing, LH for featural?

3. Which hemisphere is most important for face recognition? Divided-field studies with normal people (Bourne, Vladeanu and Hole, 2008): Stimuli in extreme left visual field go first to right hemisphere, and vice versa. Both hemispheres can recognise faces. LH: featural processing. RH: configural processing.

4. RH faster than LH with complete faces. Blurring affects LH more than RH. Features-only affects RH more than LH. Mean RT (+ 1 SE) to normal and blurred faces as a function of visual field of presentation. Mean RT (+ 1 SE) to complete faces and the eyes only as a function of visual field of presentation.

5. Bourne and Hole (2003): hemispheric differences in processing incomplete faces: Complete Eyes missing Nose missing Mouth missing

6. Bourne and Hole (2003): hemispheric differences in processing incomplete faces: Bars represent the difference between the complete face condition and each experimental condition. The greater the difference the more detrimental the effect of the manipulation. LH (featural) copes worse with missing features than RH (configural).

7. Tong, Nakayama, Moskowitz, Weinrib and Kanwisher (2000): fMRI study of fusiform responses to face-like stimuli, eyes, houses and non-face objects. FFA response similar for cat, cartoon and human faces (with/without eyes); weaker for schematic faces and eyes alone; equal for front and profile views, but declining as face rotated away from view; weakest for non-face objects and houses. Conclusion: fusiform gyrus responds best to facial configurations plus features - involved in "face" perception/detection.

8. Schiltz, Dricot, Goebel and Rossion (2010): fMRI adaptation study of neural responses to composite faces. Right middle fusiform ("FFA") sensitive to composites - treats them as "new" faces. Right FFA involved in "holistic" processing.

9. Lee, Anaki, Grady and Moscovitch (2012): fMRI study of responses to face halves separated in time or space. Behavioural data: ISI 0 and ISI 200 similar; ISI 800 and Misaligned similar to each other, and worse than ISI 0 and ISI 200. ISI 800: activated face processing regions (more bilaterally) plus areas involved in attention and working memory (strategic processing?) ISI 0 and ISI 200: better identification correlated with increased activity in “configural processing” network (R fusiform, middle occipital, bilateral superior temporal, inferior/middle cingulate and frontal cortex). ISI 800 and Misaligned: better identification correlated with less activity in these regions. Suggest configural and analytic processing regions oppose each other.

10. Gorno-Tempini and Price (2001) PET/MRI study: Four visual tasks: (a) Famous face matching. (b) Non-famous face matching. (c) Famous building matching. (d) Non-famous building matching. Category-specific perceptual processing: Faces (famous and non-famous) activate fusiform gyrus. Buildings (famous and non-famous) activate parahippocampal gyrus. Shared analysis of semantic processing: Fame (faces or buildings) activates left anterior middle temporal gyrus.

11. Event-related potential (ERP) studies: (a) P1: (100 ms after presentation of a visual stimulus) occipital response to low-level stimulus characteristics (e.g. luminance and contrast). (b) N170) occipito-temporal response, larger for faces than other objects: structural encoding or detection of a face-like pattern ALSO VPP (vertex positive potential, a fronto-central positive counterpart to N170) (c) P2 (200 ms after presentation) more fine-grained analysis of featural distances or facial distinctiveness (d) N250: related to processing of facial identity – more negative for repetitions of familiar faces compared to non-repeated familiar faces (N250r effect) – facilitated access to representations of familiar faces. N250r also increases during face learning. (e) LPC (“late positive component”, 400-700 ms at central-parietal sites: related to retrieval from episodic memory (old/new effect)

12. RH LH Anatomical location of processes involved in face recognition (Schweinberger and Burton (2003): Fusiform gyrus Lingual gyrus Parahippocampal gyrus Structural encoding N170 (superior temporal sulcus) Face recognition (Fusiform gyrus) N250R Name (Left temporal lobe) PIN N400 (Anterior temporal lobe) Arousal to familiar face (Amygdala) Skin conductance response Semantic information (Anterior medial temporal lobe) Integrative device Attribution processes

13. Event-related Potential (ERP) studies of face processing (Schweinberger 2003): N170: Generated from posterior lateral occipitotemporal cortex (superior temporal sulcus). Larger for faces than most other visual stimuli. Not human face-specific: also produced by car "faces", ape faces, schematic faces and inverted faces. Unaffected by face familiarity or face priming. i.e., not related to face recognition. Correlate of structural encoding, identification of face-like configurations?

14. N250R: Strongly right hemisphere. Affected by familiarity of faces, and larger for personally-familiar faces than famous faces. Activity modulated in response to repeated faces (even if diffferent views each time, though strongest with identical images). Probably generated from fusiform gyrus. Most response from human faces; then ape faces; no response to inverted faces or car "faces". Correlate of "face recognition units"? N400: Anterior medial temporal cortex. Correlate of "person identity nodes" (post-perceptual response to individuals)?

15. ERP and experience: Wiese, Wolff, Steffens and Schweinberger (2013): Effects of experience on own-age bias. Young experts (geriatric nurses) and novices. Recognition task with old and young faces. OAB in novices but not experts. Larger N170 and P2 for young than old faces in both groups (i.e. similar for early perceptual processing). Novices: N250 more anterior repetition effects for own- than other-age faces. Experts: no differences. Novices : larger LPC for old than young faces. Experts: no differences. Conclusion: experience with other-age faces does not affect early perceptual processing; affects later stages related to memory retrieval.

16. ERP and experience: Balas and Saville (2015): Undergraduates from small (500-1000) or large (30,000-100,000) towns. CFMT. Classifcation task: respond “chair” or “face” to upright or inverted stimuli. Small-town: poorer face memory and an N170 that was less specific to faces (a smaller difference between face and chair N170s for small-town subjects). Conclusion: the number of faces encountered during early experience affects adult face processing/brain structure.

17. ERP and experience: Dundas, Plaut and Behrmann (2014): Adults: larger LH N170 for words, RH N170 for faces. 7-12 year olds: adult pattern for words, but not faces: similar-sized N170s over both hemispheres. Hypothesis: Hemispheric development of face and word recognition ae interdependent: both compete for fine-grain visual analysis. Word lateralisation precedes and drives later face lateralisation. (As reading ability increases, decreased LH/increased RH FG actviation to faces). Dundas,Plaut and Behrmann (2013): DVF study in children, adolescents and adults. Reading scores predict face selectivity (hemifield superiority for matching faces or words in the two visual fields).

18. Barbeau, Taylor, Regis, Marquis, Chauvel and Liegeois-Chauvel (2008): Intra-cranial ERP study of time-course of famous face recognition. Massively distributed processing from 110 -600 msec post-stimulus - at least seven structures involved. Processing is not "one-way" - frontal areas influence "earlier" stages. FG - invariant aspects of faces; STS - changeable aspects. Perirhinal cortex -signals "familarity". Temporal structures - recognition. (Dark blue = periods when recognition effects were found).

19. Jonas et al. (2012): Intra-cranial electrode stimulation study in epileptic woman, K.V. Epilepsy due to right inferior occipital cortical dysplasia: normal face recognition. Stimulation of right inferior occipital gyrus (Occipital face Area) produced transient prosopagnosia (no naming or semantic information). ‘‘the facial elements were in disarray’’ Face-sensitive intra-cranial N170 from OFA (contacts 07 and 09) . Right OFA is necessary for normal face perception: possibly has critical role in configural processing.

20. Outstanding questions: How do the hemispheres cooperate during normal face processing? Are the RH and LH really specialised for configural and featural processing, or are these merely reflections of generalised differences in processing modes? (RH – global, LH – local). In particular, is featural processing really a mode of face processing, or merely a strategy to cope with odd-looking faces in psychology experiments?