Elsevier

Consciousness and Cognition

Volume 18, Issue 3, September 2009, Pages 628-638
Consciousness and Cognition

In what sense ‘familiar’? Examining experiential differences within pathologies of facial recognition

https://doi.org/10.1016/j.concog.2009.06.006Get rights and content

Abstract

Explanations of Capgras delusion and prosopagnosia typically incorporate a dual-route approach to facial recognition in which a deficit in overt or covert processing in one condition is mirror-reversed in the other. Despite this double dissociation, experiences of either patient-group are often reported in the same way – as lacking a sense of familiarity toward familiar faces. In this paper, deficits in the facial processing of these patients are compared to other facial recognition pathologies, and their experiential characteristics mapped onto the dual-route model in order to provide a less ambiguous link between facial processing and experiential content. The paper concludes that the experiential states of Capgras delusion, prosopagnosia, and related facial pathologies are quite distinct, and that this descriptive distinctiveness finds explanatory equivalence at the level of anatomical and functional disruption within the face recognition system. The role of skin conductance response (SCR) as a measure of ‘familiarity’ is also clarified.

Introduction

Since its inception in 1990, Ellis and Young’s ‘dual-route’ model of overt and covert facial recognition has formed the basis for a number of explanations of prosopagnosia and the Capgras delusion1 (see Bayne and Pacherie, 2005, Bortolotti, 2005, Coltheart, 2007, Davies and Coltheart, 2000, Gilleen and David, 2005, Klee, 2004, Stone and Young, 1997, Young and de Pauw, 2002, Young, 2008a). The function of the overt route matches closely Bruce and Young’s (1986) original sequential system in which facial characteristics are first encoded and then processed by the Face Recognition Unit (FRU), before activating Person Identity Nodes (PINs) (in the case of familiar faces).2 Activation of a particular PIN enables contextual semantic and biographical information relating to that face (person) to be accessed, including as a final step the person’s name.3 Ellis and Young contribution to this process was to include a second, covert and parallel pathway which subserves our affective response to familiar faces. In more recent versions, however (see Breen et al., 2000, Ellis and Lewis, 2001), the covert route forms part of a dual system of processing post FRU.4 In other words, faces are processed along a single route until they reach the FRU. After that, familiar faces which are matched to a stored representation by the FRU not only activate PINs but also produce heightened autonomic arousal, an indices of which is increased skin conductance response (SCR).5

The connection between SCR and the facial recognition pathologies of prosopagnosia and the Capgras delusion6 has been much discussed. It is well documented, for example, that prosopagnosic patients typically show an increase in SCR when presented with images of familiar faces despite a failure to identify the face as belonging to someone they know (Bauer, 1984, Tranel and Damasio, 1985). Similarly, research has shown that Capgras patients do not show heightened SCR when presented with a familiar face (Ellis et al., 1997, Hirstein and Ramachandran, 1997, Brighetti et al., 2007). What is less extensively discussed, however, is the relationship between SCR and the experiences of these patient-groups. Ellis and Young claim that SCR is a measure of covert recognition – present in prosopagnosia and absent in the Capgras delusion. But what is less clear – and certainly less coherently described – is the manner in which this presence or absence of covert recognition manifests itself within the patient’s experiential content.

The aim of this paper is to examine the relationship between SCR and experience more closely; not only by comparing similarities and differences in the experiential, anatomical and functional states and processes of prosopagnosic and Capgras patients, but also by presenting other case study examples of facial recognition pathologies, as well as research findings from work within the recognition without identification (RWI) paradigm. Together, these comparisons will help us understand, with a greater degree of clarity and coherence, what these experiences entail and how they can best be explained with reference to functional deficits within the most recent dual-route model (that of Ellis & Lewis, 2001). The paper also aims to disambiguate what it is that the SCR is a measure of in cases of prosopagnosia and the Capgras delusion.

Before discussing these issues further, however, some preliminary groundwork must be done. In the next section, I will map the anatomical and functional structure of the dual-route model, and introduce the double dissociation characteristic of Ellis and Young’s original mirror-image account of prosopagnosia and the Capgras delusion (which is maintained by Ellis & Lewis). The material presented in this section is well documented and much discussed; but as it forms the basis for the arguments to follow, it is important to present of overview – however rudimentary – of our understanding to date. In addition, as the focus of this paper is on patient experience, particularly phenomenal content, it is important to clarify how the terms ‘experience’ and, ‘phenomenal experience’ are being used. Put simply, experience should be understood as synonymous with consciousness. When a person experiences x, he/she is conscious of x. Phenomenal experience concerns the what-it-is-likeness (Nagel, 1974) of experiencing x – in other words, the manner in which x pervades consciousness, the nature of its salience.

Section snippets

The anatomical and functional basis for a double dissociation

Put simply, the prosopagnosic patient’s inability to consciously recognise (as in, identify) familiar faces7 is believed to stem from damage to the ventral route of the visual system subserving conscious visual recognition. Yet when presented

What is it to have a sense of familiarity without identification?

Experientially, there is clearly a difference between being in a room full of people I am acquainted with and the sense of familiarity identified by Cleary and Specker (2007) as tartling13 – to sense that a face is familiar without being able to retrieve associated information, such as the person’s name or other relevant semantic or biographical details.

Feelings of familiarity in related pathologies

In the RWI task, Morris et al.’s participants were not, of course, prosopagnosic; yet, because of speed of presentation (30 ms), they were not always successful at identifying the item. In terms of individual items, familiarity did not correspond to successful identity, but latency. One might speculate, then, that the allocation of resources (of which the longer-latency SCR is said to be a measure) was triggered by some feature of the item: a feature that was able to initiate the allocation of

Mapping the discussion points onto a model of facial recognition

The evidence and argument presented thus far, although compatible with the more recent model of facial recognition proposed by Ellis and Lewis (2001) nevertheless directs us towards minor but not insignificant refinements that need to be made. The cases of misidentification reported by Rapcsak et al. (1994), for example, inform us of a functional divide in face encoding that is subserved by areas of the right and left hemispheres, respectively. The structural encoding of the face prior to FRU

Examining the phenomenology of the Capgras delusion

In the case of the Capgras delusion, the patient is able to encode the face in terms of global and local features; the FRU is activated and specific person-identity information is easily accessed. Of course, the Capgras patient denies that this person is who they claim to be. Nevertheless, in terms of the face recognition model, PINs are able to access relevant contextual semantic/biographical information – including a name – based on physical identity alone. If the putative impostor did not

Conclusion

To conclude, in the first part of this paper I outlined what I claimed was something of a puzzle within the reported experiences of prosopagnosic and Capgras patients. Each is described as lacking a sense familiarity toward familiar faces (persons); yet this (apparent) uniform absence occurs in conjunction with an anatomical and functional dissociation in which disruption to the ventral-limbic structure (covert route) of the Capgras patient remains unaffected in cases of prosopagnosia. Thus one

Garry Young is currently a senior lecturer in the Division of Psychology, Nottingham Trent University. His research interests include concepts and experiences of self in cyberspace, pre-conscious embodied interaction, the relationship between consciousness and knowledge, and delusional misidentification (particularly the Capgras delusion).

References (72)

  • S.Z. Rapcsak et al.

    False recognition of unfamiliar faces following right hemisphere damage: Neuropsychological and anatomical observations

    Cortex

    (1996)
  • B. Renault et al.

    Brain potentials reveal covert facial recognition in prosopagnosia

    Neuropsychologia

    (1989)
  • S.R. Schweinberger et al.

    Covert recognition and the neural system for face processing

    Cortex

    (2003)
  • A. Stone et al.

    Perspectives on prosopagnosia and models of face recognition

    Cortex

    (2003)
  • P. Verstichel

    False recognition of faces associated with fronto-temporal dementia with prosopagnosia

    Revue Neurologique

    (2005)
  • G. Young

    Capgras delusion: An interactionist model

    Consciousness and Cognition

    (2008)
  • G. Yovel et al.

    The neural basis of the butcher-on-the-bus phenomenon: When a face seems familiar but is not remembered

    NeuroImage

    (2004)
  • T. Bayne et al.

    Bottom-up or top-down? Campbell’s account of monothematic delusions

    Philosophy, Psychiatry, and Psychology

    (2004)
  • T. Bayne et al.

    In defence of the doxastic conception of delusions

    Mind and Language

    (2005)
  • L. Bortolotti

    Delusions and the background of rationality

    Mind and Language

    (2005)
  • S. Brédart et al.

    Self-recognition in everyday life

    Cognitive Neuropsychiatry

    (2004)
  • N. Breen et al.

    Models of face recognition and delusional misidentification: A critical review

    Cognitive Neuropsychology

    (2000)
  • G. Brighetti et al.

    Far from the heart far from the eye: Evidence from the Capgras delusion

    Cognitive Neuropsychiatry

    (2007)
  • V. Bruce et al.

    Understanding face recognition

    British Journal of Psychology

    (1986)
  • J. Campbell

    Rationality, meaning and the analysis of delusion

    Philosophy, Psychiatry, and Psychology

    (2001)
  • J. Capgras et al.

    L’illusion des ‘soises’ dans un délire systématisé chronique. Bulletin de la Société Clinique de Médicine Mentale

  • A.M. Cleary et al.

    Recognition without identification

    Journal of Experimental Psychology: Learning, Memory and Cognition

    (2000)
  • A.M. Cleary et al.

    Recognition without face identification

    Memory and Cognition

    (2007)
  • M. Coltheart

    The 33rd Sir Fredrick Bartlett lecture. Cognitive neuropsychiatry and delusional belief

    The Quarterly Journal of Experimental Psychology

    (2007)
  • P. Dalgalarrondo et al.

    Capgras syndrome and blindness: Against the prosopagnosia hypothesis

    The Canadian Journal of Psychiatry

    (2002)
  • M. Davies et al.

    Introduction: Pathologies of belief

    Mind and Language

    (2000)
  • E.H.F. de Haan et al.

    Behavioral and physiological evidence for covert recognition in a prosopagnosic patient

    Cortex

    (1992)
  • Denburg, N.L., Jones, R.D., & Tranel, D. (2009). Recognition without awareness in a patient with simultanagnosia....
  • H.D. Ellis et al.

    Accounting for delusional misidentification

    British Journal of Psychiatry

    (1990)
  • H.D. Ellis et al.

    Reduced autonomic responses to faces in Capgras delusion

    Proceedings of the Royal Society: Biological Science

    (1997)
  • C. Fine et al.

    Damned if you do; damned if you don’t: The impasse in cognitive accounts of Capgras delusion

    Philosophy, Psychiatry, and Psychology

    (2005)
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    Garry Young is currently a senior lecturer in the Division of Psychology, Nottingham Trent University. His research interests include concepts and experiences of self in cyberspace, pre-conscious embodied interaction, the relationship between consciousness and knowledge, and delusional misidentification (particularly the Capgras delusion).

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