*afecto y razonamiento coltheart 2010

7/28/2019 *Afecto y Razonamiento Coltheart 2010

1/27

This article was downloaded by: [Universidad de Chile]On: 25 June 2013, At: 06:46Publisher: RoutledgeInforma Ltd Registered in England and Wales RegisteredNumber: 1072954 Registered office: Mortimer House, 37-41

Mortimer Street, London W1T 3JH, UK

Cognitive

NeuropsychiatryPublication details, including

instructions for authors and

subscription information:http://www.tandfonline.com/loi/

pcnp20

The role of affect and

reasoning in a patient

with a delusion ofmisidentificationNora Breen , Diana Caine & Max

Coltheart

Published online: 09 Sep 2010.

To cite this article: Nora Breen , Diana Caine & Max Coltheart (2002):The role of affect and reasoning in a patient with a delusion of

misidentification, Cognitive Neuropsychiatry, 7:2, 113-137

To link to this article: http://dx.doi.org/10.1080/13546800143000203

PLEASE SCROLL DOWN FOR ARTICLE

Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions

This article may be used for research, teaching, and privatestudy purposes. Any substantial or systematic reproduction,
http://www.tandfonline.com/page/terms-and-conditionshttp://www.tandfonline.com/page/terms-and-conditionshttp://dx.doi.org/10.1080/13546800143000203http://www.tandfonline.com/loi/pcnp20http://www.tandfonline.com/loi/pcnp20http://www.tandfonline.com/page/terms-and-conditionshttp://www.tandfonline.com/page/terms-and-conditionshttp://dx.doi.org/10.1080/13546800143000203http://www.tandfonline.com/loi/pcnp20http://www.tandfonline.com/loi/pcnp20


2/27

redistribution, reselling, loan, sub-licensing, systematic supply,or distribution in any form to anyone is expressly forbidden.

The publisher does not give any warranty express or impliedor make any representation that the contents will be completeor accurate or up to date. The accuracy of any instructions,

formulae, and drug doses should be independently verifiedwith primary sources. The publisher shall not be liable forany loss, actions, claims, proceedings, demand, or costs ordamages whatsoever or howsoever caused arising directly orindirectly in connection with or arising out of the use of thismaterial.

Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


3/27

The role of affect and reasoning in a patient with a

delusion of misidentification

Nora Breen

Macquarie University and Royal Prince Alfred Hospital, NSW, Australia

Diana Caine

Royal Prince Alfred Hospital and University of Sydney, Australia

Max ColtheartMacquarie University, NSW, Australia

Introduction. This study investigated a patient with a delusion of misidentification(DM) resembling a Capgras delusion. Instead of the typical Capgras delusionthe

false belief that someone has been replaced by an almost identical impostorpatient MF misidentified his wife as his former business partner.

Method. Detailed investigation of MFs face processing, affective response andaffect perception, and ability to evaluate, and reject, implausible ideas was

undertaken.Results. MFs visual processing of identity, gender, and age of familiar and

unknown faces was intact but he was unable to identify the facial expressions ofanger, disgust, and fear, or to match faces across expressions. MF also showed a

reduced affective responsiveness to his environment, and impaired reasoningability.

Conclusions. We propose that MFs delusion of misidentification resulted from a

combination of affective deficits, including impairment of both affective responseand affect perception, in addition to an inability to evaluate, and reject, implausibleideas. These deficits, in combination with specific life events at the time of onset of

the delusion, may have contributed to the form and content of the delusion. Inaddition, the results raise the possibility that the processing of face identity and

facial expression are not as independent as previously proposed in models of faceprocessing.

Correspondenc e should be addressed to Nora Breen, Macquarie Centre for Cognitive Science

(MACCS), Division of Linguistics and Psychology, Macquarie University, Sydney, NSW 2109,

Australia. Email: [email protected] u

# 2002 Psychology Press Ltd

http://www.tandf.co.uk/journals/pp/13546805.html DOI:10.1080/13546800143000203

COGNITIVE NEUROPSYCHIATRY, 2002, 7 (2), 113137

Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


4/27

Delusions of misidentification (DM) are a group of fascinating disorders in

which there is a mistaken belief in the identity of oneself, other people, places,

or objects. Of all the different forms of DM, the Capgras delusionthe false

belief that someone, often a close relative, has been replaced by an almost

identical-looking impostorhas received both the most attention and the most

rigorous scientific investigation. Much of this work has attempted to delineate

the factors underlying the form and content of these delusions, with a particular

focus on face perception. The innovative testing of face processing in these

patients has further enabled a more sophisticated understanding of normal face

recognition (Breen, Caine, & Coltheart, 2000a; Ellis & Young, 1990).

Recent work on the Capgras delusion has revolved around Ellis and Youngs

(1990) proposal that the Capgras delusion might arise from a loss of the normal

affective (autonomic) response to familiar faces. In these circumstances, thepatient would have the conflicting experience of recognising a known face (such

as that of their spouse), but without any accompanying affective response,

leading them to conclude that the person was an impostor or double. In

confirmation of this hypothesis, two independent research groups (Ellis, Young,

Quayle, & de Pauw, 1997; Hirstein & Ramachandran, 1997) have now

documented reduced skin conductance response (SCR) to known faces in

patients with the Capgras delusion.

This absent affective accompaniment to seeing a known face was describedby Stone and Young (1997) as constituting anomalous perceptual experiences

created by a deficit to the persons perceptual system. (p. 327). Although the

concept of a perceptual anomaly successfully captured a salient aspect of the

patients experience, it also elided two potentially separable sources of distorted

or impoverished information: externally derived incoming sensory information

(visual, auditory, tactile), more usually described as perceptual, and internally

derived autonomic information with its cognitive correlates, more usually

described as affect or emotion.

We have previously reported two cases of mirrored-self misidentification

(Breen et al., 2000a, 2001), a delusion involving the false belief that your own

reflection is another real person. In these studies we clearly distinguished

between the terms perceptual and affective in order to explore the

possible contribution to the DM from both of these sources. Both cases (FE and

TH) had perceptual abnormalities that, we argued, to some extent determined

the form and content of the delusion, although the actual abnormality varieddramatically between the two casesFE had a dramatic impairment in the

perceptual processing of faces, whereas TH had an inability to interpret reflected

space, a mirror agnosia. These two cases thus also demonstrated that very

different perceptual abnormalities could give rise to very similar delusional

phenomena. In addition both FE and TH tended to judge unknown faces to be

personally familiar. As we have discussed in detail elsewhere (Breen et al.,

2001), a sense of familiarity occurs when viewing a personally known face as a

114 BREEN, CAINE, C OLTHEART

Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


5/27

result of activation of the corresponding face recognition unit (FRU) (Bruce &

Young, 1986), indicating that the face has been previously seen, and from

generation of the affective response corresponding to that particular person.

Whereas FEs false recognition may have resulted directly from his impaired

perceptual processing of facesdegradation in the structural encoding of faces

may have led to unfamiliar faces causing erroneous activation of the FRUs of

known peopleTHs structural encoding of faces was entirely intact. We

suggested that THs false recognition of unfamiliar faces resulted from an

inappropriately modulated affective response to all faces, and therefore an

erroneous sense of familiarity in response to a strangers face. Whereas Ellis and

Young have focused on the loss of the affective response, our work with TH

suggested that an excess of affective responsiveness equally might underlie the

formation of a misidentification delusion.When considering abnormal affective experience in patients with DM it is

important to consider two dissociable factorsones emotional response to the

environment and the ability to recognise emotional (face) expressions in others.

To distinguish between them, we propose to use the terms affect perception

and affective response. Using this terminology, affect perception refers to the

subjects ability to read emotional expressions on the faces of others. On the

other hand, the affective response refers to the subjects emotional

responsiveness to the environment.Although it has been argued that the affective response to known faces can be

relatively selectively impaired (Ellis et al., 1997), it is likely that patients with

brain damage causing a global flattening of responsiveness towards the

environment would concomitantly have a decreased autonomic response to

well-known faces. Support for this contention comes from work with patients

with bilateral ventromedial frontal lobe lesions demonstrating that in addition to

the more specific deficit in skin conductance response to familiar faces (Tranel,

Damasio, & Damasio, 1995), these patients also fail to produce the normal skin

conductance response to emotionally charged visual stimuli, such as pictures of

mutilation and social disaster (Damasio, Tranel, & Damasio, 1991). However, if

altered affective response is implicated in the formation of DM, this finding

raises the question of why the patients with ventromedial damage are not

delusional. One possibility is that the loss of affective response to familiar faces

is not crucial for the formation of the Capgras delusion. This seems unlikely in

that, although to date only six Capgras patients have been tested (Ellis et al.,1997; Hirstein & Ramachandran, 1997), the finding of reduced SCR to familiar

faces has been surprisingly consistent. Alternatively, patients with ventromedial

lesions may lack additional contributing factors necessary for the formation and

maintenance of a delusion, factors that have not yet been fully delineated.

One contributing factor to the phenomenology of a DM, in addition to

perceptual and affective abnormalities already described, is likely to be some

form of defective reasoning, although this idea has yet to be satisfactorily

A DELUSION OF MISIDENTIFICATION 115

Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


6/27

explored or explained (Breen et al., 2000b; Langdon & Coltheart, 2000; Young,

1998). Young et al. (1993) have argued that the failure of reasoning is generated

and maintained by a particular mood, but the question of whether reasoning as

such in these patients may be impaired has never been addressed. For instance,

although it is easy to imagine that an abnormal experience initially leads to a

false belief, it is difficult to imagine that one would not rapidly evaluate the

belief as false and subsequently reject it. There are many reports in the literature

of non-delusional patients with perceptual and/or affective deficits that are very

similar, if not identical, to those described in patients with DM. It would appear

that patients with DM lack insight regarding their perceptual and/or affective

deficits that might have helped them to override their false belief(s) arising from

their abnormal experience. For example, patients with prosopagnosia are unable

to recognise their own face in a mirror yet generally are not reported as havingthe delusion of mirrored-self misidentification, presumably because they are

aware that a neurological condition is preventing them from correct recognition

of faces. In contrast, it would appear that patients with DM are unable to reject a

belief on the grounds of its implausibility and inconsistency with everything else

that they know. This is highlighted by reports of patients with DM who

appreciate that others find their belief bizarre, yet strongly adhere to their

delusion and cannot be persuaded that their belief is false (Alexander, Stuss, &

Benson, 1979; Young, 1998).In our earlier work with patients with DM (Breen et al., 2000b, 2001), we

investigated the question of perceptual and affective abnormalities with respect

to face processing underlying the delusion of mirrored-self misidentification. In

the present study, we sought to investigate further the role of impaired

processing of affect, both in terms of affective response and affect perception,

and the nature of the inability to reject a belief once established, in the

production of a DM. The case study presented had a variant of the Capgras

delusion that had remained stable for 10 months prior to our investigations.

CASE STUDY

Background

At the time of testing, MF was a 68-year-old man, who had been married for

42 years, and had three adult children. He was a practising litigation attorney atthe time he suffered his head injury (four years prior to the current assessment)

and had up to that time enjoyed an extremely successful and high-profile

career, which included an 8-year partnership in a law firm with JY, a female

attorney. His only significant medical history prior to the head injury was a

short episode of left-sided weakness in 1996 that his general practitioner

attributed to a small stroke. In December 1997, MF sustained a severe head

injury when he fell an estimated 20 feet from a ladder, landing on a concrete


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


7/27

driveway. On arrival at hospital his Glascow Coma Score (GCS) was initially

11, but then deteriorated. An initial CT brain scan showed bifrontal and right

temporal lobe contusions, and MF was immediately ventilated, intubated, and

put into an induced coma. A repeat CT brain scan the following day showed

massive bifrontal contusions, and posterior displacement of the ventricles. A

left frontal lobectomy was performed to alleviate intracranial pressure due to

swelling and haemorrhaging. A further left frontal lobectomy was performed

three days after his admission due to continued mass effects from swelling. He

remained comatose and on ventilation for 2 months. He had a number of

medical problems during that time including hydrocephalus (and subsequent

ventricular-peritoneal shunt insertion), atrial fibrillation, intermittent elevations

in intracranial pressure, shunt infections, pancreatitis, and staphylococcal

infection. He had a feeding gastrostomy inserted due to swallowing difficultiesand had a urinary catheter for 18 months. He suffered bilateral hearing loss

secondary to the head injury, and now wears bilateral hearing aids. He had

several neurosurgical operations over the next 2 years including insertion of a

metal grate implanted over the left frontal surgical site, and subsequent

debridement of the infected skull plate. He suffered several post head injury

seizures. A CT brain scan 2 years post injury reported chronic encephaloma-

lacic changes in the frontal lobes bilaterally, a small calcified subdural

haematoma in the left frontal region, mild cerebellar atrophy, and a lacunarinfarct within the pons (see Figure 1).

MF remained in an acute care hospital for 2 months, followed by 8 months in

a rehabilitation hospital, and then nursing home care. A neuropsychological

assessment 6 months post head injury demonstrated that he was oriented, had a

mildmoderately impaired attention span, a mild memory impairment, and

severely impaired constructional skills. With regard to language, his naming was

entirely normal, but he showed mildly impaired comprehension and impaired

repetition. His ability to make common sense judgements was normal but he had

a mild reasoning deficit. He was discharged home 1 year post injury. He was

initially wheelchair-bound, and received physiotherapy, speech therapy, and

nursing care. He made a dramatic recovery at home, and 4 years after the

operation had achieved independent mobility and was independent in activities

of daily living.

Following his head injury, MF showed a number of behavioural changes

consistent with bilateral frontal lobe damage. He had a flattened affect, althoughhe retained an appropriate, and often witty, sense of humour. His family

described his emotional responsiveness post head injury as blunted, and said that

his emotional warmth and interaction with them was somewhat reduced. He

lacked initiative but was cooperative with activities that were arranged for him.

He occasionally made insensitive comments and appeared unaware that he had

hurt peoples feelings, even when he had reduced someone to tears after an

insulting remark.


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


8/27

Figure 1. CT brain scans for patient MF, 9 months post head injury. Scans show severe trauma to

the frontal lobes bilaterally, with the left side affected to a greater degree than the right. Lacunar

infarcts are present within the pons on the right side of the midline and also in the right thalamus. The

ventricular-peritonea l shunt is present within the body of the right lateral ventricle.

118

Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


9/27

The delusion

In June 1999, 18 months post head injury, MF underwent an operation to remove

his gastrostomy feeding tube, an operation that involved a general anaesthetic.

When MF woke from the anaesthetic after the operation his wife was sitting next

to his bed. He exchanged some pleasantries with her and then asked her if shehad seen his wife! From that point on, and for the next 10 months, MF believed

that his wife was JY, his former partner in the law firm. This was the only

misidentification that MF displayed. He correctly identified all of his other

relatives including his three children, his grandchildren, his mother-in-law, and

sister-in-law, and had no difficulty identifying friends and acquaintances.

Interestingly, his wifes name was Joan and his former business partners name

was Joanne. His wife is 13 years older than JY, but the two women are of similarcolouring and build. His wife has reddish-blonde, short, wavy hair whereas JYs

red hair was longer and straight. MF and his wife have three children, as do JY

and her husband. MF said that although he respected JYs ability as an attorney,

he intensely disliked her on a personal level. In the eight years that MF and JY

were law partners, they had only one social meal together.

MF did not protest about leaving the hospital with the woman he thought was

his former business partner and was reasonably happy for her to look after him

as long as she was not too affectionate towards him. Not long after thegastrostomy operation, he and his wife were in the small elevator in their multi-

storey home. His wife was unclear at this stage whether MFs delusion was

constant or intermittent and, as she felt they were getting along very well at that

moment, she leaned towards him, put her hand on his arm, and attempted to kiss

him. MF reacted angrily, backed away from her waving his cane in a menacing

way, and threatened to strike her. The following day, MF told his doctor about

the incident stating that she was all over me. When the doctor light-heartedly

responded that most men would be thrilled if their wives wanted to kiss them,

MF replied, I would be happy too if it was my wife, but it wasnt my wife, it

was JY. If my wife knew about this she would not have appreciated it! His

wife was forced to move out of their bedroom as MF refused to sleep in the same

room with her. MFs wife and children constantly tried to reason with him but

were unable to convince him that the woman living with him was his wife and

not JY. Ownership of their home was transferred to his wifes name at this time,

and MF was angry for several weeks, as he believed that JY now had control ofthe house that he and his wife owned.

Occasionally, MF asked his wife (whom he thought was JY) where his wife

was, but he never made an attempt to find her. When he was asked where his

wife was, he said that she was in the other house, a house that he described as

having exactly the same address, including street number, street, and suburb, as

the house in which he currently lived. He described the two houses as identical

except that the house he currently lived in had two storeys, whereas the house


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


10/27

his wife lived in had three storeys. He identified all of the mens clothing in his

bedroom as being his own and said that all of the womens clothing was JYs

and did not belong to his wife. He said that all of his wifes clothing and her

belongings were at the other house. When MF was told by the examiner that

she found his storythat JY had taken him home from hospital and taken care

of him since the head injury, and that his wife now lived in another house that

had the same address as the one he currently lived inbizarre and extremely

hard to believe, MF agreed that it was strange, but nevertheless insisted that it

was true.

MFs indifference to constant questioning about his delusion was striking. He

was unperturbed when evidence contradicting his delusion was pointed out to

him, and when the examiner repeatedly emphasised the improbability of the

delusion. MF understood that the research the examiner was conductinginvolved investigating delusions, and he understood that the particular delusion

being investigated was his belief that the woman living with him was not his

wife. However, he repeatedly told the researchers that he did not have a

delusion, and that they should investigate the real delusionthe delusion held

by his former business partner, JY, who believed that she was his wife!

Neuropsychological testing

Neuropsychological testing was undertaken to evaluate MFs performance in a

range of cognitive domains (see Table 1). Based on his education and

employment history, MF was estimated to have a high averagesuperior intellect

prior to his head injury. Testing revealed that his current intellect was in the

average range, as assessed by measures of verbal (NART) and non-verbal

(Ravens Coloured Progressive Matrices; Raven, 1947) ability.

Attention and Intellectual Function. MFs verbal attention span was limited

and below the average range, but his visual attention span was in the average

range (WAIS-R; Wechsler, 1981). His manual speed was very slow as

demonstrated on a timed copying test (WAIS-R Digit-Symbol subtest).

MF performed in the average range on tests of language. In contrast, his

performance on a test of mental arithmetic was very impaired, and well below

the expected average range. MFs basic visuo-perceptual skills were intact as

evidenced by his intact clock drawing and copying of various pictures (includinga bicycle and 3-dimensional cube) and he was able to identify missing

components in line drawings (Picture Completion, WAIS-R). His constructional

skills were somewhat less robust (Block Design, WAIS-R).

Memory. MF demonstrated a dissociation between his verbal and non-

verbal memory function. His verbal memory for stories and word associations

was intact in the high average to superior range (WMS-R; Wechsler, 1987), as


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


11/27

TABLE 1

Results of tests of cognitive ability for patient MF

Tests Patient MF

IQ NART (Estimated Full Scale IQ) 107 (Average)

Language Test of Reception of Grammar (TROG) 73/80 (91%)

WAIS-R MOANS ASS

Vocabulary 8

Mental Arithmetic 4

Similarities 9

Non-verbal skills Ravens Coloured Progressive Matrices 75%tile

Clock drawing 10/10

Copying of shapes, designs and bicycle intactCopy of 3-dimensional cube intact

REY Complex Figure TestCopy 29.5*

WAIS-R MOANS ASS

Picture Completion 13

Picture Arrangemen t 10

Block Design 8

Digit Symbol 4

Attention/ WMS-R MOANS ASS

Concentration Digit Span 5 (5 forward, 3 backward )

Visual Span 9 (7 forward, 6 backward )

Memory WMS-R MOANS ASS

Logical Memory I 14

Logical Memory II 14

Verbal Paired Associates I 12

Verbal Paired Associates II 13

Visual Reproduction I 12Visual Reproduction II 9

(Visual Reproduction II, with prompt) (12)

Rey Complex Figuredelaye d recall 8.5*

Autobiographica l Memory Interview Personal Sem Autobiograp h

Childhood 15 borderline 7 Acceptable

Early Adult Life 17 Acceptable 9 Acceptable

Recent Life 21 Acceptable 6 Acceptable

Total 53 Acceptable 22 Acceptable

Warrington Recognition Memory Test Raw Score ASS

Words 49 15

Faces 41 9

(Continued overleaf)


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


12/27

was his recognition memory for words (WRMT; Warrington, 1984). In contrast,

he demonstrated a deterioration of newly acquired visual information over time.

His immediate recall of the WMS-R line drawings was in the high average

range, however his recall dropped to a low averageaverage level after a short

delay. Similarly, his delayed recall of the Rey Complex Figure was very

impoverished. In contrast to his very good recognition of words (ASS 15) on the

WRMT, he only achieved an ASS 9 on recognition memory for faces. His

autobiographical memory for childhood, early adult life, and recent life was

entirely intact (AMI). His personal semantic memory was in the borderline

range for his childhood, but was entirely intact regarding both his early adult and

recent life.

Executive function. MFs most striking deficits occurred on tests of

executive function. He was accurate, although slow, on Trails A, but made many

errors, became hopelessly confused, and eventually abandoned Trails B after

almost 5 minutes. His phonemic and category fluency were very impoverished.

He achieved the required two categories on the simple CFST, but did not

achieve a single category on the Wisconsin Card Sorting Test, a performance

TABLE 1

Continued

Tests Patient MF

Executive Function Trails A (ASS) 7

Trails B incomplete

Controlled Oral Word Association Test

Total in 3 minutes (phonemic cue) 13 ASS 3 1st percentile

Animal FluencyTotal in 1 minute 9 < 10th percentile

Colour Form Sorting Ttest 2/2 categories

Wisconsin Card Sorting Test

Numbe r of categorie s complete d 0

Errors 96 1st percentilePerseverative Errors 94 < 1st percentile

The scores reported for MF on the Wechsler Adult Intelligence ScaleRevised (WAIS-R),

Wechsler Memory ScaleRevised (WMS-R) are age-scaled scores (ASS) as reported in the Mayo

Older American Normative Studies (Malec et al., 1992; Ivnik et al., 1992a, 1996).

*within 1 sd of mean. (AMIPersonal Sem for Personal Semantic, Autobiograph Autobio-

graphical).

The scores reported for MF on Trail Making Test (TMT) and Controlled Oral Word Association

Test (COWAT) are age-scaled scores (ASS) as reported in the Mayo Older American NormativeStudies (Malec et al., 1992; Ivnik et al., 1992a; Ivnik et al., 1992b; Ivnik et al., 1996). *within 1 sd of

mean.


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


13/27

that was dominated by perseverative errors. His performance on the Wisconsin

Card Sorting Test is discussed in more detailed later in the section on

Investigation of reasoning ability.

INVESTIGATION OF FACE PROCESSING

MFs face processing abilities were thoroughly investigated using a combination

of standardised and experimental tests. MFs performance on these tests was

compared to his wifes performance when appropriate (for example, recognition

of personally familiar faces) or compared to a normative sample of five males,

matched for age and educational attainment (see Appendix 1 for the normative

sample demographics). The results of MFs face processing tests are presented

in Table 2.

Experiment 1: Face matching

Face matching was assessed with the Benton Facial Recognition Test (Benton,

Hamsher, Varney, & Spreen, 1983), a difficult test where cues are limited

(matching is conducted on the basis of facial features only, as hairstyles have

been removed), the lighting is varied (often resulting in significant portions of

the faces being covered by dark shadow), and the faces are often in very

different orientations.

Results. MF performed in the normal range on this test.

Experiment 2: Identification of age of unfamiliarfaces

Ten black and white photographs of unfamiliar faces (with no other identifying

cues) were presented in a random order and the subject was asked to give anapproximate age for each of the faces.

Results. The age approximations on this test are subjective. MFs age

identifications for eight of the faces were within the range of ages reported by

the five control subjects. His age approximations for the other two faces were

very close to the age range provided by the controls (4 years and 9 years outside

the range). As eight of MFs age approximations were inside the range provided

by the control subjects, and as this measure is subjective and the control group

small, we have concluded that MFs age identification of faces is within the

normal range.

Experiment 3: Famous face identification

Identification of famous faces was assessed with an experimental test consisting

of photographs of the faces of 22 famous people and 22 matched unknown


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


14/27

people. The unknown faces were matched according to gender, age, and

physical similarity. An additional 37 unknown faces, not matched to the famous

faces, were also included in the test, making a total of 59 strangers faces. Each

photograph was modified to produce black and white pictures of the face with no

other identifying cues (e.g., body parts, contextual cues). The faces were

TABLE 2

Results for the face-processing tests

MF Controls

Face Matching Facial Recognitio n Test (Benton) 47 Range 4154

Age Identification (Unfamiliar faces) Age (years) Range (years)

1 15

1 13

18 1320

12 38

35 2045

25 2535

35 4455

45 4560

70 5575

70 7084

Face Recognitio n Personally familiar (family members ) MFs wife

Identified as familiar 12/12 12/12

Named 12/12 12/12

Famous

Identified as familiar 19/22 19/22

Name/Specific semantic identification 17/22 18/22

Unfamiliar (strangers faces)

Identified as unfamiliar 56/59 56/59

Facial Affect Ekman & Friesen Facial Affect Photos (/10) Controls (n = 5)

Perception Happy 10 9.8 (sd 0.45)

Sadness 8 8.2 (sd 1.64)

Surprise 10 9.2 (sd 1.09)

Anger 7 8.2 (sd 1.30)

Disgust 7*** 9.3 (sd 0.55)

Fear 5** 8.2 (sd 1.30)

Controls (n = 5)

X sd

Matching Faces Neutral Expression 33* 38.0 (2.45)

Across Expressions Same Expressions 25*** 38.8 (1.79)

Different Expressions 23*** 37.2 (3.35)

*significant at p < .025, **significant at p < .01, ***significant at p < .0001.

The Calder et al. (1996) subset of Ekman and Friesen Pictures of Facial Affect was used.


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


15/27

presented in a random order, one at a time, in the centre of a PC laptop screen.

The examiner controlled the rate of the stimuli presentation and each face

remained on the screen until the subject identified whether it was familiar or not.

If the face was identified as familiar, the subject was asked to provide a name

and/or identifying semantic information. MFs wife acted as the control subject

on this test.

Results. MF identified 19/22 of the famous faces as familiar and provided

the correct name or identifying semantic information for 17/22, a performance

no different from that of his wife. MF correctly identified 35/37 strangers faces

as unfamiliar, which was also consistent with his wifes performance on this test.

MF and his wife each incorrectly identified two strangers faces as familiar,

saying that the faces looked familiar but they did not know who they were.

Experiment 4a: Identification of personally knownfaces

MFs ability to identify personally familiar faces was examined with an

individually tailored test. Photographs of his immediate family members,

relatives, close friends, and JY, were modified to produce black and white

photographs of faces without any other cues (e.g., body parts, contextual cues),and 12 appropriate photographs were thus obtained. Each known face was

matched with an unfamiliar face of the same sex, approximate age, and physical

likeness. An additional 12 unknown faces were also included in the test, making

a total of 22 strangers faces. The faces were presented one at a time, in a

random order, on a PC laptop screen. The subject was initially asked whether

each face was familiar or not, and then to provide as much information as

possible, including the name, about the individuals whose faces they classed as

familiar. This test was administered to MFs wife who acted as the control

subject.

Results. MF correctly identified all 12/12 personally familiar faces as

familiar and provided the correct name for each, including his wife and JY. His

wife was also 100% correct on this test. MF correctly identified 21/22 strangers

faces as unfamiliar, a performance no different from that of his wife.

Experiment 4b: Identification of persons implicatedin the DM from photographs

MF was further tested on his ability to identify his wife and JY in photographs.

Colour photographs, which had been taken by MFs family members, were

presented in which his wife and JY appeared either individually in different

photographs or together in the same photograph. When MF was shown a


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


16/27

photograph that included MF, his wife, and JY, he was asked to identify which

person in the photograph was sitting beside him during the testing (his wife).

Results. MF correctly identified his wife and JY in several photographs in

which they appeared individually. He made these identifications rapidly and

confidently. When shown a photograph of himself, his wife and JY together, hecorrectly named each person. When he was asked to point to the person in the

photograph who was the same person as the one sitting next to him during the

testing (his wife), he pointed to JY. The examiner asked MF several times

whether he was sure that the person he had indicated in the photograph (JY)

looked exactly the same as the woman beside him (his wife), and MF remained

adamant that they were the same person. The examiner pointed out to MF that,

in her opinion, the photograph of JY did not look like the woman sitting next to

him, but rather the photograph of his wife looked identical to the woman whowas sitting next to him. MF said that he did not agree. His reaction was

unperturbed, and he did not get agitated when confronted in this way.

Experiment 5: Identification of facial expressions(affect perception)

MFs ability to identify facial expressions was tested with Ekman and Friesens

(1976) black and white photographs of unfamiliar people expressing emotion.We used the Calder et al. (1996) subset of 60 of the Ekman and Friesen faces,

which included pictures of 10 models faces (5 women, 5 men). For each face,

there were poses corresponding to each of six emotions (happiness, sadness,

disgust, fear, anger, and surprise). The names of the six emotions were printed

on a card and this was placed in front of the subject throughout the test. The

subject was shown each of the photographs one at a time, in a random order, and

asked to decide which of the six emotion names best described the facial

expression shown. There were 60 trials (one for each of the six emotions for

each of the 10 models), leading to an accuracy score out of a possible maximum

of 10 for each of the six emotions.

Results. MFs ability to identify the facial expressions happiness, sadness,

and surprise did not differ from the controls. In contrast, MFs ability to identify

anger was only borderline and he was significantly worse than controls in his

ability to identify the facial expressions disgust and fear (see Figure 2).

Experiment 6: MFs understanding of the emotionshe was impaired at identifying

MFs difficulty in recognising some facial expressions did not appear to reflect

failure to comprehend emotional terms: he gave examples of occasions when he

would feel angry, disgusted, and afraid, and could describe circumstances in

which other people would experience the same emotions.


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


17/27

Experiment 7: Matching faces across expressions

This test consisted of pairs of faces (black and white photographs from the

Ekman and Friesen series), presented side by side, so that for each trial two face

images were presented simultaneously until MF made a response. This test had

three different conditions:

1. Neutral Expression; two pictures either of the same person or of two

different people (same gender), with the same neutral expression.

2. Same Expression; two pictures either of the same person or two different

people (same gender) with the same facial expression (happy, sad, disgust, fear,

anger, or surprise).

3. Different Expression; two pictures either of the same person or two

different people (same gender) each having a different expression (happy, sad,

disgust, fear, anger, or surprise).

In each condition the subject was asked to decide if the two faces had the

same identity (that is, whether or not they were pictures of the same person)

regardless of the facial expression. The items were presented in a random order,

and the subject gave a verbal response.

Results. In contrast to his good performance on other tests of face

recognition, MF demonstrated a significant interference effect of facial

expression when making judgements about face identity. When the two faces

were expressionless (neutral expressions) he was 83% accurate in discriminating

whether the face identity was the same or different. In striking contrast, he was

almost at chance (60%) at discriminating facial identity when the faces had an

expression (see Figure 3). The interference effect was cumulative: he was 83%

Figure 2. Face expression recognition.


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


18/27

correct when both faces had a neutral expression; 63% correct when the two

faces had the same expression; and only 58% (almost chance) if the two faces

had different expressions.

As MF performed in the normal range on the more difficult Benton Face

Recognition Test (indicating intact face matching on the basis of limited cues,

varied lighting, and different orientation), it was somewhat surprising that his

ability to match faces in the Neutral Expression condition of this test was not

equal to that of the controls. It should be noted that had MF achieved one more

correct match on this Neutral Expression subtest of the Matching Faces Across

Expressions test, his performance would not have been significantly different

from that of the controls. Nevertheless, his below average performance on this

subtest remains puzzling. The only difference between the two tests was in the

administration, in that the easier neutral Matching Faces Across Expressions testwas intermixed with matching of faces with various expressions. As we will

discuss later, MF was impaired at identifying facial expressions and very

impaired at discriminating between faces when the face identities were

discrepant with the facial expressions (e.g., same identities, different expres-

sions). It may be that the presentation of the neutral expression face stimuli

among faces with expressions in the experimental Matching Faces Across

Expressions test interfered with MFs ability to perform the neutral face-

matching test to the best of his ability.

INVESTIGATION OF REASONING ABILITY

MF demonstrated average level verbal reasoning and averagehigh average

level reasoning about visually presented material on standardised subtests of the

WAIS-R. This included tests of visual reasoning (Picture Completion, ASS 13),

logical sequencing of events, which included anticipating the consequence of

Figure 3. Face constancy: Matching faces across expressions.


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


19/27

actions and distinguishing essential from irrelevant details (Picture Arrange-

ment, ASS 10), and conceptual reasoning (ASS 9).

Experiment 8: Affect-neutral reasoning test

The Wisconsin Card Sorting Test was administered to assess MFs reasoningability on an affect-neutral task.

Results. MF was grossly impaired on this test. He perseverated to an

incorrect category for the entire test, 128 consecutive trials. His performance

indicated impaired error monitoring and set shifting, and inability to adapt his

own performance according to external feedback.

Experiment 9: Plausible/implausible reasoning test

An experimental test of reasoning ability was devised to assess MFs ability to

evaluate information (provided in story format) that could be interpreted in two

ways, to make either a plausible or implausible conclusion. One of the stories

was specifically tailored to MFs delusion in order to investigate whether his

delusional belief (that his wife had been replaced by someone else) was a

circumscribed belief, or whether the belief was more generalised (i.e., whether

he believed that other people could have relatives replaced by impostors). Thefour stories that made up this test are presented in Appendix 2. The subjects had

unlimited time to read the story and select their response (by circling).

Results. The results are presented in Table 3. All five of the controls chose

the plausible conclusion for Story 1, and 4/5 chose the plausible conclusion for

both Story 3 and Story 4. One control subject for both Story 3 and Story 4 chose

the cant tell option, indicating that he did not feel he had enough

information to reach a conclusion. It is important to note that none of the control

subjects chose the implausible conclusion for any of the four stories. In contrast,

MF selected the cant tell option for Stories 1, 2, and 4. In addition, he chose

the implausible conclusion for the scenario that was tailored towards his own

TABLE 3

MFs performance on the experimental plausible/implausible reasoning test

MF Controls (n = 5)

Subject 1 Subject 2 Subject 3 Subject 4 Subject 5

Story 1 Cant tell No No No No No

Story 2 Cant tell No No No No No

Story 3 No Yes Yes Yes Cant tell Yes

Story 4 Cant tell No No Cant tell No No


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


20/27

delusional belief, indicating that he believed that identical-looking impostors

could replace other peoples wives.

DISCUSSION

Following the work of Ellis and Young (1990) on face processing deficits in

Capgras patients, and our own positive findings in two cases of mirrored-self

misidentification, we examined in detail MFs ability to discriminate and

recognise faces. MF was able to identify both personally familiar and famous

faces, to discriminate between familiar and unfamiliar faces, and to identify the

approximate age of unfamiliar faces. Although his ability to match unfamiliar

faces was inconsistent, he was able to match unfamiliar faces with neutral

expressions on the most difficult face matching test (Facial Recognition Test,Benton 1983).

As visual face processing per se seemed to be intact, we proceeded to

investigate the possible contribution of altered affect in MF. We did this in three

ways. We interviewed his family about his affective responsiveness towards

them; we interviewed MF with respect to his understanding of emotion; and we

looked at his ability to recognise facial affect (affect perception). Although he

appeared to understand the difference between emotions, in that he was able

appropriately to describe occasions when he or others would feel differentemotions, his family reported that there was generalised blunting of emotions,

with little emotional expression, dulled responses in emotional situations, and

reduced emotional warmth towards his children and other close relatives.

As previously discussed, it is likely that MFs global dampening of affective

responsiveness to the environment encompasses a reduction in affective

response (SCR) to familiar faces, as has been documented in other patients

with ventromedial frontal lobe damage (Tranel et al., 1995). To that extent he

can be thought of as being like more typical Capgras patients. It is further

possible that MFs delusional belief that he was not living in his own home was

directly related to this reduced responsiveness to the environment. MF may have

resolved the discrepancy of living in a house that looked like his own house with

the same address as his house, but that didnt feel like his home, by

generating the belief that he was living in a house that was somehow like his real

home, but that his real home (where his wife lived) was somewhere else.

In addition to reduced affective responsiveness, MFs ability to identify facialexpressions was selectively impaired: while his identification of the facial

expressions of happiness, sadness, and surprise were normal, his ability to

recognise anger was only borderline, and he was frankly impaired at

discriminating disgust and fear. His difficulty in recognising facial expression

was not simply an exaggeration of the normal pattern: while control subjects in

this study, and in studies by Calder et al. (1996) and Ekman and Friesen (1976),

found anger and fear relatively more difficult to identify, they were easily able


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


21/27

to identify the expression of disgust, which was second only to happiness (see

Appendix 3 for control data for Calder et al., 1996, Ekman & Friesen, 1976, and

our controls for this study).

We investigated whether MFs difficulty in discriminating among some facial

expressions might affect his otherwise intact face matching ability. This was

indeed the case: MFs impaired expression analysis interfered with his ability to

match faces and the interference effect was incremental. MF was best at

matching faces with neutral expressions, more impaired if both faces had the

same expression, and most impaired if the two faces had different expressions.

Thus, MFs deficit in interpreting facial expression led him to mistake

differences in expression for differences in identity, notwithstanding that he

was able to make appropriate allowances for the effects of changes in orientation

and lighting when matching faces with neutral expressions.We speculate that MFs impaired identification of some facial expressions,

and his very impaired ability to discriminate face identity when the face showed

an expression, are likely to be contributing to his misidentification of his wife as

his former business partner. Interestingly, MFs wife provided some support for

this when she was given feedback about his face processing deficits. MF had

told his wife that she could not be his wife because his wife smiled a great deal

whereas she never smiled. MFs wife reported that the observation was true in

that since his head injury she was not the happy person she used to be: she hadbeen forced to take on the role of head of the household, which included

controlling their finances and making all the decisions. This was a role that she

had never previously assumed or desired during their 42 years of marriage, and

having to do so now caused her a great deal of stress and worry.

However, other patients have been reported with either widespread problems

in the recognition of facial expressions (Etcoff, 1984) or more specific deficits in

the recognition of fear (Adolphs, Tranel, Damasio, & Damasio, 1994, 1995;

Broks et al., 1998; Calder et al., 1996), disgust (Gray et al., 1997;

Sprengelmeyer et al., 1997), or both (Sprengelmeyer et al., 1996, 1997), and

are not delusional, although matching of identity across expressions has only

rarely been tested. One non-delusional patient, DR, has been reported to have

both a specific deficit in the recognition of fear and an impaired ability to match

faces across identities, a profile very similar to that of MF (Young, Hellawell,

van de Wal, & Johnson, 1996). The degree of deficit was different, however.

While both MF and DR had significant deficits in the perception of facialexpressions, DR was only mildly impaired in her ability to match face identities

across different expressions, whereas MF was severely impaired on this task.

Why did MF believe his wife was JY, and not a stranger who looked similar

to his wife, or some other person that he knew? In addition to the physical

similarity between the two women, and their similar names (Joan and Joanne),

the nature of MFs attachment to JY may have contributed to her role in his

delusional belief. MF and his family described him as having a strong, albeit


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


22/27

negatively charged, emotional relationship with JY. During the 8 years that MF

and JY ran their law firm, MF reported that he and JY had many confrontations

due to personality clashes and conflicting ethical values. Although MF respected

JY on a professional level, he said that he disliked her intensely on a personal

level. In the same way that Capgras patients typically misidentify the person to

whom they have the strongest positive or negative emotional attachment

(Young, 1998), it is probably significant that MF misidentified his wife, to

whom he had a very close positive emotional attachment, as a woman with

whom he had an intensely negative emotional relationship. Such similarities

between actual and delusional characteristics have been reported previously.

Burgess, Baxter, Rose, and Alderman (1996) reported a man (PD) who,

following a severe head injury, had the delusional belief that a fellow patient

(Jake) was a male nurse (Jamie) who had previously cared for him (in a differentinstitution), and that he was having an affair with PDs wife. Further, the wife of

one of the nurses who had cared for PD had the same name as PDs own wife

(Jane).

It is further conceivable that the content of MFs delusion, and possibly other

delusions of misidentification, may depend on specific life events occurring at

the time of the onset of the delusion. Although prior to the head injury MF had

not had contact with JY for 8 years, she regularly visited him following the head

injury and while he was in PTA. She spent a substantial amount of time with himshowing him photographs and mementos to assist his recall. MF does not have

much conscious recollection of her visits during this time. He may have stored

interlinked memories of his wife and JY during his period of PTA, memories

that were most likely patchy and somewhat confused. Following the head injury

and his recovery from PTA, MF was not delusional, and he correctly identified

both his wife and JY. It was only 18 months after the head injury that the

delusion arose, immediately following a surgical procedure that involved a

general anaesthetic. The mild disorientation and confusion due to the effects of

the general anaesthesia may have caused displacement of patchy recall of

episodes from the period of PTA, and hence contributed to the misidentification

of his wife as JY. A number of other cases have also been reported to have

developed delusions while either still in, or immediately following, a period of

PTA following a head injury (Box, Laing, & Kopelman, 1999; Burgess et al.,

1996).

We have argued here that perceptual and/or affective deficits, as well,possibly, as specific life events occurring at the time of onset of the delusion,

can contribute to the form and content of the DM, yet they cannot be the entire

explanation, as all of these occur in patients who do not develop delusional

states. Patients with a DM must also have an additional deficit in reasoning that

prevents them from evaluating, and rejecting, implausible beliefs. In this study,

we had the opportunity to examine the reasoning of our patient with a DM on an

affect-neutral taskthe Wisconsin Card Sorting Test. On this task DM


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


23/27

perseverated to the incorrect category he first generated for the entire test (128

consecutive trials) despite feedback after every trial that his response was

incorrect. His reasoning was defective precisely in the sense that once he had

formed a belief (in the case of the Wisconsin Card Sorting Test, that a particular

category was the required one), he could not subsequently evaluate or change it.

This behaviour also characterised his DM: he clung tenaciously to the DM for 10

months, and no amount of evidence to the contrary could persuade him

otherwise during that time.

MFs reasoning was further tested with the experimental reasoning test. For

the story that was closest in content to his own delusional belief MF chose the

implausible conclusion; that is, he believed that an impostor had replaced the

mans wife in the vignette. MFs (implausible) response for this story was in

contrast to his cant tell response for the three other stories, suggesting thatMF may have identified with the fictitious man in Story 2, and responded to the

story scenario in the same way that he reacted to his own situation. For the three

stories that were not directly related to his own delusional belief, MF, in contrast

to controls, was not able to discard the implausible aspects of the story to come

to the more plausible conclusion. These data together indicate a more pervasive

reasoning deficit than has previously been suggested (see for example Young et

al., 1993; Stone & Young, 1997).

As demonstrated by Ellis and Young (1990) and by Breen et al. (2000a), thestudy of DM has both profited from and made a contribution to models of

normal face processing. Until recently, the dominant cognitive model of face

processing (Bruce & Young, 1986) only incorporated a role for affect in relation

to facial expression analysis. It proposed that expression analysis was

independent from, and not important to, either the recognition of familiar faces

or the processing of unfamiliar faces, both of which utilised separate, and

independent, cognitive pathways (Young et al., 1993). More recently, following

the work of Ellis and Young, and based on the findings of a double dissociation

between prosopagnosi c patients who demonstrated no overt face recognition yet

intact autonomic responses (SCR) to familiar faces, and Capgras patients, who

demonstrated intact overt face recognition but reduced or absent autonomic

responses to familiar faces, we proposed a modification to the Bruce and Young

(1986) model of face processing that included an intrinsic role for the processing

of affect in face recognition.

Although we have not yet tested whether MFs impaired facial expressionanalysis also interferes with his ability to identify famous or personally familiar

faces, a task he has no difficulty with when the faces had neutral expressions, the

data on MF raise further questions about the possible role of affect perception in

face processing. The finding that although he could efficiently discriminate

unfamiliar faces with neutral expressions, he was unable to match faces showing

expressions, suggests that facial expression analysis may not be as independent

of other aspects of face processing as previously thought.


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


24/27

CONCLUSION

In conclusion, we have proposed that MF has a delusion of misidentification

resulting from a combination of affective deficits, including impairment of both

affective response and affect perception, in addition to an inability to evaluate,

and reject, implausible ideas. The nature of his underlying deficits, incombination with specific life events at the time of onset of the delusion, were

likely to have contributed to the form and content of MFs delusion of

misidentification. In addition, our work with MF raises the possibility that the

processing of face identity and facial expression are not as independent as

previously proposed in cognitive models of face processing.

Manuscript received 12 February 2001

Revised manuscript received 7 September 2001

REFERENCES

Adolphs, R., Tranel, D., Damasio, H., & Damasio, A. (1994). Impaired recognition of emotion in

facial expressions following bilateral damage to the human amygdala. Nature, 372, 669672.

Adolphs, R., Tranel, D., Damasio, H., & Damasio, A.R. (1995). Fear and the human amygdala.

Journal of Neuroscienc e, 15, 58795891.

Alexander, M.P., Stuss, D.T., & Benson, D.F. (1979). Capgras syndrome: A reduplicativephenomenon. Neurology , 29, 334339.

Benton, A.L., Hamsher, K. de S., Varney, N.R., & Spreen, O. (1983). Facial recognition: Stimulus

and multiple choice pictures. New York; Oxford University Press.

Box, O., Laing, H., & Kopelman, M. (1999). The evolution of spontaneous confabulation, delusional

misidentification and a related delusion in a case of severe head injury. Neurocase , 5, 251262.

Breen, N., Caine, D., & Coltheart, M. (2001). Mirrored-self misidentification: Two cases of focal

onset dementia. Neurocase, 7, 239254.

Breen, N., Caine, D., & Coltheart, M. (2000a). Models of face recognition and delusional

misidentification: A critical review. Cognitive Neuropsycholog y, 17(1/2/3), 5571.Breen, N., Caine, D., Coltheart, M., Hendy, J., & Roberts, C. (2000b). Towards an understanding of

delusions of misidentification: Four case studies. Mind and Language, 15(1), 74110.

Broks, P., Young, A.W., Maratos, E.J., Coffey, P.J., Calder, A.J., Isaac, C.L., Mayes, A.R., Hodges,

J.R., Montaldi, D., Ceayirli, E., Roberts, N., & Hadley, D. (1998). Face processing impairments

after encephalitis: Amygdala damage and the recognition of fear. Neuropsychologia, 36(1),

5970.

Bruce, V., & Young, A.W. (1986). Understanding face recognition. British Journal of Psychology,

77, 305327.

Burgess, P.W., Baxter, D., Rose, M., & Alderman, N. (1996). Delusional paramnesic misidentifica-tion. In P.W. Halligan & J.C. Marshall (Eds), Method in madness: Case studies in cognitive

neuropsychiatry. Hove, UK: Psychology Press.

Calder, A.J., Young, A.W., Rowland, D., Perrett, D.I., Hodges, J.R., & Etcoff, N.L. (1996). Facial

emotion recognition after bilateral amygdala damage: Differentially severe impairment of fear.

Cognitive Neuropsycholog y, 13, 699745.

Damasio, A.R., Tranel, D., & Damasio, H. (1991). Somatic markers and the guidance of behavior:

Theory and preliminary testing. In H.S. Levin, H.M. Eisenberg, & A.L Benton (Eds.), Frontal

lobe function and dysfunction (pp. 217229). New York: Oxford University Press.


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


25/27

Ekman, P., & Friesen, W.V. (1976). Pictures of facial affect. Palo Alto, CA: Consulting

Psychologists Press.

Ellis, H.D., & Young, A. (1990). Accounting for delusional misidentifications. British Journal of

Psychiatry, 157, 239248.

Ellis, H.D., Young, A.W., Quayle, A.H., & de Pauw, K.W. (1997). Reduced autonomic responses to

faces in Capgras delusion. Proceedings of the Royal Society, London (B), 264, 10851092.

Etcoff, N.L. (1984). Selective attention to facial identity and facial emotion. Neuropsychologia, 22,

281295.

Gray, J.M., Young, A.W., Barker, W.A., Curtis, A., & Gibson, D. (1997). Impaired recognition of

disgust in Huntingtons disease carriers. Brain, 120, 20292038.

Hirstein, W., & Ramachandran, V.S. (1997). Capgras syndrome: A novel probe for understanding the

neural representation of the identity and familiarity of persons. Proceedings of the Royal Society

London, Series B, 264, 437444.

Ivnik, R.J., Malec, J.F., Smith, G.E., Tangalos, E.G., & Kurland, L.T. (1992a). Mayos Older

Americans Normative Studies: WAIS-R norms for ages 56 to 97. The Clinical Neuropsychol -

ogist, 6 (supplement), 130.Ivnik, R.J., Malec, J.F., Smith, G.E., Tangalos, E.G., & Peterson, R.C. (1996). Neuropsychologica l

test norms above age 55: COWAT, BNT, MAE Token, WRAT-R Reading, AMNART,

STROOP, TMT and JLO. The Clinical Neuropsychologist, 10(3), 262278.

Ivnik, R.J., Malec, J.F., Smith, G.E., Tangalos, E.G., Peterson, R.C., Kokmen, E., & Kurland, L.T.

(1992b). Mayos Older Americans Normative Studies: WMS-R norms for ages 56 to 94. The

Clinical Neuropsychologis t, 6 (supplement) , 4982.

Langdon, R., & Coltheart, M. (2000). The cognitive neuropsycholog y of delusions. Mind and

Language , 15(1), 183216.

Malec, J.F., Ivnik, R.J., Smith, G.E., Tangalos, E.G., Peterson, R.C., Kokmen, E., & Kurland, L.T.(1992). Mayos Older Americans Normative Studies: Utility of corrections for age and education

for the WAIS-R. The Clinical Neuropsychologist, 6 (supplement), 3147.

Raven, J.C. (1947). Coloured progressive matrices sets A, Ab, B. London: H.K. Lewis.

Sprengelmeyer, R., Young, A.W., Calder, A.J., Karnat, A., Lang, H.W., Homberg, V., Perrett, D.I.,

& Rowland, D. (1996). Loss of disgust: Perception of faces and emotions in Huntington s

disease. Brain, 119, 16471665.

Sprengelmeyer, R., Young, A.W., Sprengelmeyer , A., Calder, A.J., Rowland, D., Perrett, D.,

Homberg, V., & Lange, H. (1997). Recognition of facial expressions: Selective impairment of

specific emotions in Huntingtons disease. Cognitive Neuropsycholog y, 14, 839879.Stone, T., & Young, A.W. (1997). Delusions and brain injury: The philosophy and psychology of

belief. Mind and Language, 12(3/4), 327364.

Tranel, D., Damasio, H., & Damasio, A.R. (1995). Double dissociation between overt and covert face

recognition. Journal of Cognitive Neuroscience, 7(4), 425432.

Warrington, E.K. (1984). Recognition Memory Test. Windsor, UK: NFER-Nelson.

Wechsler, D. (1981). Wechsler Adult Intelligence ScaleRevised. San Antonio: Psychological

Corporation.

Wechsler, D. (1987). Wechsler Memory ScaleRevised. San Antonio: Psychological Corporation.

Young, A.W. (1998). Face and mind. New York: Oxford University Press.Young, A.W., Hellawell, D.J., van de Wal, C., & Johnson, M. (1996). Facial expression processing

after amygdalotomy . Neuropsychologia, 34, 3139.

Young, A.W., Newcombe, F., De Haan, E.H.F., Small, M., & Hay, D.C. (1993). Face perception

after brain injury: selective impairments affecting identity and expression. Brain, 116, 941959.


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


26/27

APPENDIX 2

The four stories from the experimental Plausible/implausible reasoning test are listed below. The

stories were presented one at a time and the subject was given as much time as he or she needed to

read the story and answer the question for each story. They were required to circle the response they

thought was correct.

Story 1Fred lay still all the time.

His wife and daughter tried to talk to him.

Fred did not respond.

Fred said that he was dead.

Do you think Fred is dead? (Please Circle)

YES NO CANT TELL

Story 2Margaret thought that people were always following her around.

She thought that the people following her around were people that she knew but that they were in

disguise.

It did not matter what time of day or night she left the house, the people would always follow her.

She said that sometimes the disguises were so good that a young woman could be disguised as a very

old stooped man with wrinkles and a bald head.

Nobody ever saw these people, even when they were with Margaret.

Margaret had contacted the police but after a long investigation they were unable to find any

evidence of people in disguise following Margaret.

Do you think people are following Margaret around? (Please Circle)

YES NO CANT TELL

Story 3

Peter and his wife had been married for 30 years and had two children.

One day Peter confronted the woman next to him in his bed and said that she was not his wife.

Peter said the woman was an impostor.

APPENDIX 1

Demographic details for control subjects and patient MF

Control subject Age Yrs education

RW 69 yrs, 2 months 16HR 67 yrs, 7 months 16

RT 70 yrs, 4 months 15

FB 69 yrs, 2 months 16

FC 69 yrs, 9 months 13

Mean 69 yrs, 1 month 15.2 years

Patient MF 68 yrs, 5 months 17 years


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013


27/27

His children disagreed, and said that the woman in their home was his wife and their mother.

His relatives also disagreed with him, and said that the woman was his wife.

Peter agreed that his wife and this impostor looked very similar.

He had no explanation as to where his wife was or where this impostor had come from.

He continued to live with this woman in his house.

Do you think the woman living with Peter is his wife? (Please Circle)

YES NO CANT TELL

Story 4

Jack went to town to do some shopping.

He paid for his groceries and then looked out of the shop window.

Across the street he saw his wife Mary kissing another man.

Jack rushed out onto the street but the couple were gone.

He immediately phoned Mary at home.

Mary answered the phone and denied leaving their home that day.Mary has a twin sister.

Did Jack see his wife Mary kissing another man? (Please Circle)

YES NO CANT TELL

APPENDIX 3

Face expression recognition: Control data

Ekman & Friesen

Percentage recognition

rates

Calder et al. n = 10

Mean identification

rates

Our controls n = 5

Mean identificatio n

rates

Happiness 99.10 sd 2.51 9.90 sd 0.32 9.8 sd 0.45

Disgust 93.10 sd 5.20 9.00 sd 1.25 9.3 sd 0.55

Surprise 90.70 sd 7.78 8.50 sd 1.58 9.2 sd 1.09

Fear 89.50 sd 5.91 8.60 sd 1.17 8.2 sd 1.30Sadness 89.70 sd 7.87 8.70 sd 1.34 8.2 sd 1.64

Anger 89.50 sd 11.39 7.70 sd 1.42 8.2 sd 1.30


Down

loa

de

dby

[Un

ivers

ida

ddeC

hile

]a

t06:4

625June

2013

*afecto y razonamiento coltheart 2010

Documents