- Email: [email protected]
Frontal lobe functions and personality in mentally abnormal offenders
Person. indicid. Dig
0191-8869 88 S3.00+0.00
Vol. 9. No. 2. pp. 339-344. 1988
Printed!n Great Britain
Pcrgamon Press
FRONTAL LOBE FUNCTIONS AND PERSONALITY MENTALLY ABNORMAL OFFENDERS
plc
IN
P. A. DEVONSHIRE,’ R. C. HOWARD’* and C. SELLARS’ ‘Broadmoor Hospital, Crowthome,
England and *Queen’s University, Belfast, Northern Ireland (Received
8 May 1987)
Summary-This study addresses the recent controversy regarding frontal lobe deficits in psychopaths (Gorenstein, 1982; Hare, 1984) and more generally the question of a relationship between psychopathy as variously attributed (by legal criteria, by clinical-behavioural criteria, and by psychometric criteria) and performance on a task used in the assessment of frontal lobe function, Nelson’s Modified Wisconsin Card Sorting Test (MWCST). Two samples of Special Hospital patients were tested as well as a small group of normal healthy volunteers. Patients classified legally as suffering from a ‘Psychopathic Disorder’ did not differ on MWCST measures from patients classified legally as ‘Mentally Ill’. There were no differences on performance measures comparing patients assessed as ‘high’ or ‘low’ on Hare’s Psychopathy Checklist. Comparison between psychometrically derived patient groups corresponding to Blackbum’s (1974) ‘primary’ and ‘secondary’ psychopathic types yielded statistically significant results: ‘secondary’ psychopaths showed significantly more total errors and achieved significantly fewer categories than did ‘primary’ psychopaths and controls. This suggests that the discrepancy between Gorenstein’s (1982) and Hare’s (1984) results can parsimoniously be explained by their use of different selection criteria to select their ‘psychopaths’. However, it is suggested that performance deficits on the MWCST such as were obtained in ‘secondary’ psychopaths are not a correlate of ‘psychopathy’ (however defined), but rather reflect an inability to maintain set resulting from an over-appraisal of threat on the part of the anxious, socially withdrawn individual.
INTRODUCTION
The idea that psychopaths may show a frontal lobe deficit has been current for a number of years. Elliott (1978) pointed out that considerable overlap exists between the constellation of behavioral patterns shown by psychopaths and that shown by patients with frontal lobe lesions (although, as he points out, there are some notable exceptions). Schalling (1978) suggested that psychopaths may show a reduced inhibitory control exerted by frontal cortex over autonomic and skeleto-muscular systems, consequent upon low cortical arousal. Damage to the orbital zones of the frontal cortex has been shown to produce a generalised disinhibition and gross changes in affective processes, characterised by a lack of self-control, violent emotional outbursts and gross changes in character (Luria, 1973; Valenstein, 1973). Insofar as impulsiveness may be said to be a defining characteristic of psychopathy (Craft, 1966; Blackbum, 1980), there are therefore good grounds for supposing that a frontal lobe dysfunction might be implicated in this disorder. It has been suggested (Howard, 1981; Fenwick, Howard and Fenton, 1983) that Gray’s Behavioural Inhibition System (Gray, 1982), comprising a Frontal-SeptalHippocampal system with its noradrenergic innervation, might be the substrate of impulsiveness and of dyscontrolled behaviour. A recent study has focussed on a related personality dimension which has been called ‘Approach-Withdrawal’ (Howard, Fenton and Fenwick, 1982; Howard, 1984). This dimension, defined by the interaction of the Impulsivity and Sociability dimensions (Blackbum, 1971), corresponds to the first MMPI factor, Emotionality (Kassebaum, Couch and Slater, 1959) (see Fig. 1). In studies of mentally abnormal offenders it has been found that individuals at the ‘withdrawal’ end of the Approach-Withdrawal dimension (so-called ‘withdrawers’) show a distinct pattern of electrophysiological changes: their resting electroencephalogram shows anomalous signs indicative of low cortical arousal (Howard, 1984); and the slow negative potential (Contingent Negative Variation or CNV) evoked during the foreperiod in a forewarned reaction time paradigm is of *Address for correspondence: Department of Psychological Medicine, University of OtagO, Dunedin. Qtago, New Zealand. 339
P. A. DEVONSHIRE er al.
340
IMPULSIVE HIGH
ANXIOUS
Withdmwol
SOCIA8LE
&
SHY
/ // I’ / Approach I
LOW ANXIOUS CONTR-OLLED
Fig. I. The ‘Approach-Withdrawal’ dimension, defined by the interaction of orthogonal Sociability dimensions, after Blackburn (1971).
Impulsivity
and
reduced amplitude (Howard et al., 1982). It has been speculated (Howard, 1981) that these ‘withdrawers’ (a class which would include both ‘secondary’ psychopaths, and withdrawn schizophrenics) might show a lateralised (left-sided) fronto-temporal dysfunction resulting in an over-active right hemisphere. Until recently there has been a lack of empirical studies addressing the issue of frontal lobe involvement in ‘psychopaths’. Gorenstein (1982) reported that psychopaths showed deficits in performance on the Wisconsin Card Sorting Test, the Sequential Matching Memory Test and the Necker Cube. Hare (1984) failed to replicate these findings and criticised Gorenstein’s study on several grounds, the most important being the criteria used to select the ‘psychopaths*. This issue of selection criteria is indeed critical to the question of frontal lobe involvement in psychopaths. Gorenstein relied chiefly on low scores on Gough’s Socialisation (So) Scale (Gough. 1969) to select his pychopaths, while Hare used his own Research Scale for the Assessment of Psychopathy (RSAP: Hare, 1980), which is based on Cleckley’s criteria for psychopathy (Cleckley, 1982). Hare points out that according to his reckoning, Gorenstein’s psychopaths were by no means ‘psychopathic’ by his (Hare’s) and Cleckley’s criteria. Equally however, it must be said that Hare’s ‘high psychopathy’ and ‘low psychopathy’ groups both scored poorly on Gough’s So: thus according to this criterion of psychopathy, Hare’s groups were equally ‘psychopathic’. Moreover, although Hare criticises Gorenstein’s misuse of a normal control group comprising healthy college students, it would have been helpful if Hare’s study had included data from a group of healthy, non-criminal individuals scoring within the normal range on Gough’s So. It is difficult to know whether his ‘high Psychopathy’ and ‘low Psychopathy’ groups, while not differing from each other in their performance on tests related to frontal lobe function, might each have differed from such a ‘normal’ control group. Both the above mentioned studies ignore the critical distinction drawn by Blackburn (1980) between 2 species of the genus ‘psychopath’. One type, characterised by low to average scores on trait anxiety measured psychometrically and high scores on sociability, Blackbum labels ‘primary psychopaths’; while the other type, characterised by high scores on trait anxiety and social withdrawal, he labels ‘secondary psychopaths’. Blackbum (1980) found ‘secondary psychopaths’ to be considerably less well socialised according to Gough’s ‘So’ scale than ‘primary psychopaths’, and we have confirmed this in an unpublished study of 42 consecutive admissions to a Special Hospital: ‘So’ correlated significantly both with another MMPI derived scale Impulsivity (-0.60) and with Welsh’s Anxiety (-0.34). Gorenstein’s psychopaths could therefore be of the ‘secondary’ type, since they were selected on the basis of low scores on Gough’s ‘So’. Hare’s psychopaths could have been either ‘primary’ or ‘secondary’, since it has been found that Hare’s scale is blind to this dichotomy (Howard, Bailey and Newman, 1984). It seems reasonable to hypothesize, therefore, that the frontal lobe deficit revealed by the tests used in both Hare’s and Gorenstein’s studies might apply to ‘secondary psychopaths’ rather than to ‘primary psychopaths’. The present study addressed this possibility and, more generally, the question of a possible relationship between ‘psychopathy’ as variously established (i.e. legal versus clinical-behavioural versus self-report questionnaire assessment) and frontal lobe function.
Frontal
lobe
functions
341
METHODS Two samples of mentally abnormal offenders were investigated: a sample of Special Hospital male residents (N = 49) and a sample of consecutive male admissions (N = 37) undergoing routine psychological assessment on admission. The resident sample was divided fairly equally between patients admitted under the 1959 Mental Health Act legal classifications of Mental Illness (MI: N = 27) and Psychopathic Disorder (PD: N = 22) while the admission sample was predominantly Mentally 111(29 MI versus 8 PD). In addition a normal control group comprising 10 healthy volunteers was included. Each subject was administered Nelson’s modification of the Wisconsin Card Sorting Test, which has been shown to be as sensitive to frontal lobe lesions, particularly in respect of perseverative errors, as the longer original version (Nelson, 1976). Instructions given to the patients were “Here we have 4 key cards, I want you to sort these cards (indicating the pack of 48 response cards) under the key cards according to certain rules. The whole point of the test is that I shall not tell you what the rule is. I want you to find out by trying out different rules; each time I shall tell you whether it’s right or wrong. Now go ahead and find out the rule”. The rule changed every time the patient obtained 6 consecutive correct responses and the patient was informed of the rule change. When the patient had successfully completed 3 categories (colour, shape, number, in any order) he had to repeat the categories in the original order. The test was completed when the patient had sorted all 48 cards. The following measures were obtained following Nelson (1976). 1. Total errors, including both perseverative and random errors. 2. Total number of categories achieved, out of maximum possible eight categories. 3. Total ‘PM’ Perseverative Errors: where the patient repeated the immediately preceding correct category; this is the measure of perseverative errors originally used by Milner (1964). 4. Total ‘PN’ Perseverative Errors: where the patient perseverated with the previous incorrect response. This is a measure of perseverative errors introduced by Nelson (1976). All patients were administered the MMPI on admission as part of their routine assessment procedure. The ‘Psychopathy’ (P) score derived from the abbreviated (15 item) version of Hare’s RSAP (Hare, 1980) was obtained for each patient. Each of the 15 RSAP items was rated on the basis of a semi-structured interview and reading of case-notes and scored 0 (“definitely not applicable”), 1 (“insufficient or conflicting information”) or 2 (“definitely applicable”), yielding a total maximum score of 30 (see Howard et al., 1984). RESULTS Legal (1959 MHA) criteria for psychopathy
The resident sample was dichotomised as ‘mentally ill’ (MI) [N = 271 or ‘psychopathically disordered’ (PD) [N = 221 under the terms of the 1959 Mental Health Act. Modified WCST performance scores for each group are shown in Table 1. MI and PD patients did not differ from each other on any of the performance measures, using Mann-Whitney U Tests to compare group means. Psychometric criteria: ‘primary’ versus ‘secondary’ psychopathy. In order to make a more direct comparison between performance of ‘primary’ and ‘secondary’ psychopaths on the MWCST a sub-group (N = 8) of Special Hospital residents was selected who not only met the criteria for belonging to a larger group of ‘Approachers’ (that is, they scored 3 or less on Welsh’s (1956)
Table
I.
under
the MHA
Modified
WCST (1959)
categories
performance ‘Mental
Illness’
in the special
scores and
hospital
Total eIT0l-S
Menkd
illness
Mean SD
Psychopathic
Mean
disorder
SD
Cats
for
patients
‘Psychopathic
resident
admitted Disorder’
sample PM
PN
CmOTS
CfTOI3
13.6
4.6
5.6
3.7
8.8
1.8
5.0
4.5
16.3
3.8
5.1
3.4
8.6
1.9
4.2
3.0
P. A. DEVONSHIRE et al.
342 Table
2. Modified WCST performance scores for ‘Primary’ ‘Secondary’ psychopaths and for healthy control subjects
Primary psychopaths (N = 8) Secondary psychopaths (N=9) Normal controls (N = IO)
Total errors
cats
PM e*rOrS
PN errors
Mean SD
9.6 4.9
4.9 0.8
4.1 2.8
2.4 3.0
Mean SD
20.6 5.2
3.0 1.7
6.8 4.0
4.9 3.4
Mean SD
4.0 2.2
7.0 0.8
1.3 l.S
0.3 0.5
and
Anxiety scale), but in addition showed the classic ‘4-9’ MMPI profile characteristic of ‘primary’ psychopaths (Blackburn, 1974) and whose legal classification under the 1959 MHA was Psychopathic Disorder. A further sub-group (N = 9) of Special Hospital residents was selected who not only met the criteria for belonging to a larger group of ‘withdrawers’ (that is, they scored at least 18 on Welsh’s (1956) Anxiety), but who in addition showed the MMPI profile characteristic of Blackburn’s (1974) ‘paranoid-aggressive’ type and whose 1959 MHA classification was Psychopathic Disorder. In short, this sub-group met the criteria for ‘secondary’ psychopathy according to Blackburn (1974). It may be seen from Table 2 that the ‘secondary’ psychopaths performed worse than the ‘primary’ psychopaths on all measures, achieving significantly fewer categories (U = 12, P < 0.05) and making significantly more total errors (U = 6, P < 0.02). A 2 x 2 contingency table dichotomising patients (‘primary’ versus ‘secondary’ and total categories achieved (> = 4 versus ~4) revealed a significant effect using Fisher’s Exact Probability Test (P = 0.025). The ‘normal’ control group performed significantly better than the ‘primary’ psychopaths on all modified WCST measures: for total errors, U = 8.5, P < 0.02; for categories achieved, U = 3, P < 0.002; for PM errors, U = 12.5. P < 0.02; for PN errors, U = 16, P -=z0.05. Clinical behavioural criteria for psychopathy Hare’s Research Scale for the Assessment of Psychopathy (RSAP). Patients in the admission sample were assigned to one of two groups (‘High P’:N = 19, and ‘Low P’: N = 18) by dividing at the mean score for the sample on Hare’s RSAP (18.3). No significant correlations between Hare’s P and any of the modified WCST scores was found: all correlations approximated to zero. Mean scores on the modified WCST measures for ‘High P’ and ‘Low P’ groups are shown in Table 3. There were no significant between-group differences on any of the measures. DISCUSSION
Our results suggest that the mentally abnormal offender population as a whole shows performance deficits in a test (Nelson’s MWCST) said to tap frontal lobe function, regardless of whether patients are admitted under the 1959 MHA category of ‘Mental Illness’ or ‘Psychopathic Disorder’. However, there does appear to be some variability in the population, with ‘secondary’ psychopaths performing particularly poorly and ‘primary’ psychopaths performing less poorly. So far as the issue of a possible frontal lobe dysfunction in psychopaths is concerned, the present results clarify the apparent contradiction between Gorenstein’s (1982) and Hare’s (1984) results.
Table 3. Modified WCST performance scores for patients in the admission sample scoring high (‘High P’) and low (‘Low P’) on the abbreviated version of Hare’s RSAP
‘High P (N==l9) ‘LOW P (N = 18)
Mean SD Mean SD
Total errors
Cats
PM errors
PN errors
RSAP range
13.6 7.6 11.9 8.05
4.5 1.6 5.3 1.8
5.9 5.0 5.0 5.3
2.6 4.1 2.0 3.7
19-27 6-18
Frontal lobe functions
343
It appears that this could be explained by their use of different selection criteria to select their psychopaths. Our results suggest that if Hare’s Psychopathy Checklist is used to define psychopathic and non-psychopathic groups, no differences between groups in performance tests related to frontal lobe function will be found, confirming Hare’s (1984) findings. If, however, psychopaths are selected on the basis of low scores on Gough’s Socialisation measure, they would tend to be ‘secondary’ psychopaths and would therefore be expected to differ from high So scorers in test performance. However, while our own and Gorenstein’s (1982) results might be taken as evidence in favour of the idea that frontal lobe dysfunction is implicated in psychopathy qua personality disorder (as opposed to psychopathy in the North American sense of chronic antisocial behaviour from an early age), there are good reasons for nor drawing this conclusion from the present study. Firstly, it is highly probable that the poor performance found in ‘secondary’ psychopaths reflects their high social withdrawal, rather than their belligerence/impulsiveness. This is because in another sample of 40 legally-defined Broadmoor psychopaths, a highly significant correlation was found between total errors on the MWCST (the measure best found to discriminate ‘secondary’ psychopaths from others in the present study) and Blackbum’s MMPI-derived Sociability measure: r = - 0.47, P < 0.001). That is, socially withdrawn individuals showed a high number of total errors. They also achieved significantly fewer categories. Secondly, in another recent study (Howard and Johnston, unpublished) Blackbum’s Belligerence measure, which correlates with other psychometric measures of impulsiveness (Barbour-McMullan, Coid and Howard, 1988) and taps the personality disorder concept of psychopathy (Blackbum, 1987), was found to correlate significantly with verbal recognition memory, a measure of temporal lobe function, but not with measures of frontal lobe function. The possibility must be considered that poor performance on tasks such as the WCST may not reflect frontal lobe function in any simple or straightforward way. Firstly, Milner’s data on WCST performance in frontal lobe patients (Milner, 1964) clearly indicated an effect of side of lesion, with fefr frontal patients performing particularly poorly. Moreover, while Milner’s results implicated dorsoluteral aspects of the frontal lobe in WCST performance, the types of error which our ‘secondary ’ psychopaths show are more akin to those indicative of poor set maintenance reported by Stuss, Benson, Kaplan, Weir, Naeser, Lieberman and Ferrill (1983) to occur in patients with orbitofrontal lesions. Secondly, poor performance on the MWCST of the type noted in this study (a high number of total errors and few categories achieved) may be a direct reflection of reduced cortical efficiency, which in turn may reflect an over-perception of threat (faulty ‘primary appraisal’: Folkman, Schaefer and Lazarus, 1979) in the face of a task which demands effortful, active coping. This interpretation is supported by the finding reported by Howard (1984) that highly anxious, socially withdrawn patients showed EEG signs of a reduction in cortical tone. A decrease in cortical tone was reported by Luria (1973) to result from medial frontal lesions. It has been found that highly anxious individuals perceive situations which demand effortful active coping as particularly stressful (Howard, Lumsden, Fenton and Armstrong, 1984). In short, therefore, rather than simply reflecting a frontal lobe dysfunction, the poor performance on the modified WCST obtained here in ‘secondary’ psychopaths may reflect a disturbance in the interaction between the anxious, socially withdrawn individual and his environment, including his cognitive appraisal of that environment, resulting in a failure to maintain attentional set in the task. Finally, it seems unlikely that the performance deficits which we find in highly anxious, socially withdrawn individuals simply reflect a generalised cognitive impairment, since in another (unpublished) study, we have found that MWCST performance correlates significantly only with particular subtests of the Wechsler Adult Intelligence Scale (WAIS), namely Digit Symbol, Block Design and Arithmetic. The deficits in WCST performance reported by Stuss et al. (1983) were similarly reported to be independent of genera1 IQ measures.
REFERENCES Barbour-McMullan J., Coid J. and Howard R. (1988) The psychometric identification of psychopathy in mentally abnormal offenders. Person. individ. Diff. In press.
344
P. A. DEVONSHIRE er al.
Blackbum R. (1971) MMPI dimensions of sociability and impulse control. J. consult. clin. Psych. 37, 166. Blackburn R. (1974) Personality and The CIPssi/ication of Psychopathic Disorders. Special Hospital Research Report, No. IO, Special Hospitals Research Unit, London. Blackburn R. (1979) Cortical and autonomic arousal in primary and secondary psychopaths. PsvchophJsiology 16, 14F150. Blackbum R. (1980) Personality and the criminal psychopath: a logical analysis and some empirical data. In Lo Psicopatico Deliquenu. Facolta di Giurisprudenza, Universita di Messina, Giuffre, Milan. Blackburn R. (1987) Two scales for the assessment of personality disorder in antisocial populations. Person. Indicid. 018 8. 81-93. Cleckley H. (1982) The Mask of Saniry. Mosby, St Louis. Craft M. (1966) The meaning of the term psychopath. In Psychopathic Disorders and Their Assessmew (Edited by Craft M.). Pergamon Press, Oxford. Elliott F. A-(1978) Neurological aspects of antisocial behavior. In The Psychopath: A comprehensive stud.?, of Anfisocial Disorders and Behauiours (Edited by Reid W. H.). Chapter 8, pp. 146-189. BrunnerMazel, New York. Fenwick P. B. C., Howard R. and Fenton G. W. (1983) Review of cortical excitability, neurohumoral transmission and the dyscontrol syndrome. In Aduances in epileptology: XIMh Epilepsy International S.vmposium (Edited by Parsonage M.). Raven Press, New York. Folkman S., Schaefer C. and Lazarus R. S. (1979) Cognitive processes as mediators of stress and coping. In Human Stress and Cognifion: An Information Processing Approach (Edited by Hamilton V. and Warburton D. M.). J. Wiley and Sons. New York. Gorenstein E. E. (1982) Frontal lobe functions in psychopaths. J. abnorm. Pswhol. 93, 133-140. Gough H. G. (1969) Manual for the California Psychological Inventory. Consulting Psychologists Press. Palo Alto, CA. of Anxiety: an Enquiry into the Functions of the Gray J. A. (1982) Precis of Gray’s “The Neuropsychology Septo-Hippocampal System”. Behau. Brain Sci. 5, 469-534. Hare R. D. (1980) A research scale for the assessment of psychopathy in criminal populations. Person. indiuid. Difl 1. 111-119. Hare R. D. (1984) Performance of psychopaths on cognitive tasks related to frontal lobe function. J. abnorm. Psycho/. 93. 133-140. Howard R. C. (1981) Slow Cerebral Event-Related polenrials, Conditioning and Personality. Unpublished doctoral dissertation. Queen’s University of Belfast. Howard R. C. (1984) The clinical EEG and personality in mentally abnormal offenders. Psychol. Med. 14, 569-580. Howard R. C. (1986) Psychopathy: A psychobiological perspective. Person. indirid. 01% 7, 795-806 Howard R. C., Fenton G. W. and Fenwick P. B. C. (1982) Event Relafed Brain Potentials in Personalify and Psychopathology: A Pavlovian Approach. Letchworth: Research Studies Press. John Wiley and Sons, New York. Scale for the Assessment of Howard R. C., Bailey R. and Newman A. (1984) A preliminary study of Hare’s “Research Psychopathy” in mentally abnormal offenders. Person. indiuid. 018 5, 389-396. Howard R. C.. Lumsden J., Fenton G. W. and Armstrong A. (1984) Psychophysiological correlates of ‘helplessness’ in Man. Biol. Psychol. 18, 4. Kassebaum G. S., Couch A. R. and Slater P. E. (1959) The factorial dimensions of the MMPI. J. Consult. Clin. Psychol. 23, 226236. Luria A. R. (1973) The Working Bruin. Chap. 7, pp. 187-225. The Penguin Press, London. Mimer 8. (1964) Some effects of frontal lobectomv in Man. In The fronral Granular Cortex and Behaior (Edited by Warren J. M. and Akert K.), pp. 313-334. McGraw:Hill, New York. Nelson H. A. (1976) A modified card sorting task sensitive to frontal lobe defects. Cor1e.y 12, 313-324. Schalling D. (1978) Psychopathy related personality variables and the psychophysiology of socialisation. In Psychoparhic Behauiour: Approaches ro Research (Edited by Hare R. D. and Schalling D.), Chapt. 6. J. Wiley & Sons, New York. Stuss D. T., Benson D. F., Kaplan E. F., Weirs W. S., Naeser M. A., Lieberman I. and Ferrill D. (1983) The involvement of orbitofrontal cerebrum in cognitive tasks. Neuropsychologia, 21, 235-248. Valenstein E. S. (1973) Brain Conwol: A Critical Examination of Brain Stimulation and Psychosurgery. J. Wiley & Sons. New York. Welsh G. S. (1956) Factor dimensions A and R. In Basic Reading on rhe MMPI in Psychology and ,Wedicine. University of Minnesota Press, Minneapolis.
0191-8869 88 S3.00+0.00
Vol. 9. No. 2. pp. 339-344. 1988
Printed!n Great Britain
Pcrgamon Press
FRONTAL LOBE FUNCTIONS AND PERSONALITY MENTALLY ABNORMAL OFFENDERS
plc
IN
P. A. DEVONSHIRE,’ R. C. HOWARD’* and C. SELLARS’ ‘Broadmoor Hospital, Crowthome,
England and *Queen’s University, Belfast, Northern Ireland (Received
8 May 1987)
Summary-This study addresses the recent controversy regarding frontal lobe deficits in psychopaths (Gorenstein, 1982; Hare, 1984) and more generally the question of a relationship between psychopathy as variously attributed (by legal criteria, by clinical-behavioural criteria, and by psychometric criteria) and performance on a task used in the assessment of frontal lobe function, Nelson’s Modified Wisconsin Card Sorting Test (MWCST). Two samples of Special Hospital patients were tested as well as a small group of normal healthy volunteers. Patients classified legally as suffering from a ‘Psychopathic Disorder’ did not differ on MWCST measures from patients classified legally as ‘Mentally Ill’. There were no differences on performance measures comparing patients assessed as ‘high’ or ‘low’ on Hare’s Psychopathy Checklist. Comparison between psychometrically derived patient groups corresponding to Blackbum’s (1974) ‘primary’ and ‘secondary’ psychopathic types yielded statistically significant results: ‘secondary’ psychopaths showed significantly more total errors and achieved significantly fewer categories than did ‘primary’ psychopaths and controls. This suggests that the discrepancy between Gorenstein’s (1982) and Hare’s (1984) results can parsimoniously be explained by their use of different selection criteria to select their ‘psychopaths’. However, it is suggested that performance deficits on the MWCST such as were obtained in ‘secondary’ psychopaths are not a correlate of ‘psychopathy’ (however defined), but rather reflect an inability to maintain set resulting from an over-appraisal of threat on the part of the anxious, socially withdrawn individual.
INTRODUCTION
The idea that psychopaths may show a frontal lobe deficit has been current for a number of years. Elliott (1978) pointed out that considerable overlap exists between the constellation of behavioral patterns shown by psychopaths and that shown by patients with frontal lobe lesions (although, as he points out, there are some notable exceptions). Schalling (1978) suggested that psychopaths may show a reduced inhibitory control exerted by frontal cortex over autonomic and skeleto-muscular systems, consequent upon low cortical arousal. Damage to the orbital zones of the frontal cortex has been shown to produce a generalised disinhibition and gross changes in affective processes, characterised by a lack of self-control, violent emotional outbursts and gross changes in character (Luria, 1973; Valenstein, 1973). Insofar as impulsiveness may be said to be a defining characteristic of psychopathy (Craft, 1966; Blackbum, 1980), there are therefore good grounds for supposing that a frontal lobe dysfunction might be implicated in this disorder. It has been suggested (Howard, 1981; Fenwick, Howard and Fenton, 1983) that Gray’s Behavioural Inhibition System (Gray, 1982), comprising a Frontal-SeptalHippocampal system with its noradrenergic innervation, might be the substrate of impulsiveness and of dyscontrolled behaviour. A recent study has focussed on a related personality dimension which has been called ‘Approach-Withdrawal’ (Howard, Fenton and Fenwick, 1982; Howard, 1984). This dimension, defined by the interaction of the Impulsivity and Sociability dimensions (Blackbum, 1971), corresponds to the first MMPI factor, Emotionality (Kassebaum, Couch and Slater, 1959) (see Fig. 1). In studies of mentally abnormal offenders it has been found that individuals at the ‘withdrawal’ end of the Approach-Withdrawal dimension (so-called ‘withdrawers’) show a distinct pattern of electrophysiological changes: their resting electroencephalogram shows anomalous signs indicative of low cortical arousal (Howard, 1984); and the slow negative potential (Contingent Negative Variation or CNV) evoked during the foreperiod in a forewarned reaction time paradigm is of *Address for correspondence: Department of Psychological Medicine, University of OtagO, Dunedin. Qtago, New Zealand. 339
P. A. DEVONSHIRE er al.
340
IMPULSIVE HIGH
ANXIOUS
Withdmwol
SOCIA8LE
&
SHY
/ // I’ / Approach I
LOW ANXIOUS CONTR-OLLED
Fig. I. The ‘Approach-Withdrawal’ dimension, defined by the interaction of orthogonal Sociability dimensions, after Blackburn (1971).
Impulsivity
and
reduced amplitude (Howard et al., 1982). It has been speculated (Howard, 1981) that these ‘withdrawers’ (a class which would include both ‘secondary’ psychopaths, and withdrawn schizophrenics) might show a lateralised (left-sided) fronto-temporal dysfunction resulting in an over-active right hemisphere. Until recently there has been a lack of empirical studies addressing the issue of frontal lobe involvement in ‘psychopaths’. Gorenstein (1982) reported that psychopaths showed deficits in performance on the Wisconsin Card Sorting Test, the Sequential Matching Memory Test and the Necker Cube. Hare (1984) failed to replicate these findings and criticised Gorenstein’s study on several grounds, the most important being the criteria used to select the ‘psychopaths*. This issue of selection criteria is indeed critical to the question of frontal lobe involvement in psychopaths. Gorenstein relied chiefly on low scores on Gough’s Socialisation (So) Scale (Gough. 1969) to select his pychopaths, while Hare used his own Research Scale for the Assessment of Psychopathy (RSAP: Hare, 1980), which is based on Cleckley’s criteria for psychopathy (Cleckley, 1982). Hare points out that according to his reckoning, Gorenstein’s psychopaths were by no means ‘psychopathic’ by his (Hare’s) and Cleckley’s criteria. Equally however, it must be said that Hare’s ‘high psychopathy’ and ‘low psychopathy’ groups both scored poorly on Gough’s So: thus according to this criterion of psychopathy, Hare’s groups were equally ‘psychopathic’. Moreover, although Hare criticises Gorenstein’s misuse of a normal control group comprising healthy college students, it would have been helpful if Hare’s study had included data from a group of healthy, non-criminal individuals scoring within the normal range on Gough’s So. It is difficult to know whether his ‘high Psychopathy’ and ‘low Psychopathy’ groups, while not differing from each other in their performance on tests related to frontal lobe function, might each have differed from such a ‘normal’ control group. Both the above mentioned studies ignore the critical distinction drawn by Blackburn (1980) between 2 species of the genus ‘psychopath’. One type, characterised by low to average scores on trait anxiety measured psychometrically and high scores on sociability, Blackbum labels ‘primary psychopaths’; while the other type, characterised by high scores on trait anxiety and social withdrawal, he labels ‘secondary psychopaths’. Blackbum (1980) found ‘secondary psychopaths’ to be considerably less well socialised according to Gough’s ‘So’ scale than ‘primary psychopaths’, and we have confirmed this in an unpublished study of 42 consecutive admissions to a Special Hospital: ‘So’ correlated significantly both with another MMPI derived scale Impulsivity (-0.60) and with Welsh’s Anxiety (-0.34). Gorenstein’s psychopaths could therefore be of the ‘secondary’ type, since they were selected on the basis of low scores on Gough’s ‘So’. Hare’s psychopaths could have been either ‘primary’ or ‘secondary’, since it has been found that Hare’s scale is blind to this dichotomy (Howard, Bailey and Newman, 1984). It seems reasonable to hypothesize, therefore, that the frontal lobe deficit revealed by the tests used in both Hare’s and Gorenstein’s studies might apply to ‘secondary psychopaths’ rather than to ‘primary psychopaths’. The present study addressed this possibility and, more generally, the question of a possible relationship between ‘psychopathy’ as variously established (i.e. legal versus clinical-behavioural versus self-report questionnaire assessment) and frontal lobe function.
Frontal
lobe
functions
341
METHODS Two samples of mentally abnormal offenders were investigated: a sample of Special Hospital male residents (N = 49) and a sample of consecutive male admissions (N = 37) undergoing routine psychological assessment on admission. The resident sample was divided fairly equally between patients admitted under the 1959 Mental Health Act legal classifications of Mental Illness (MI: N = 27) and Psychopathic Disorder (PD: N = 22) while the admission sample was predominantly Mentally 111(29 MI versus 8 PD). In addition a normal control group comprising 10 healthy volunteers was included. Each subject was administered Nelson’s modification of the Wisconsin Card Sorting Test, which has been shown to be as sensitive to frontal lobe lesions, particularly in respect of perseverative errors, as the longer original version (Nelson, 1976). Instructions given to the patients were “Here we have 4 key cards, I want you to sort these cards (indicating the pack of 48 response cards) under the key cards according to certain rules. The whole point of the test is that I shall not tell you what the rule is. I want you to find out by trying out different rules; each time I shall tell you whether it’s right or wrong. Now go ahead and find out the rule”. The rule changed every time the patient obtained 6 consecutive correct responses and the patient was informed of the rule change. When the patient had successfully completed 3 categories (colour, shape, number, in any order) he had to repeat the categories in the original order. The test was completed when the patient had sorted all 48 cards. The following measures were obtained following Nelson (1976). 1. Total errors, including both perseverative and random errors. 2. Total number of categories achieved, out of maximum possible eight categories. 3. Total ‘PM’ Perseverative Errors: where the patient repeated the immediately preceding correct category; this is the measure of perseverative errors originally used by Milner (1964). 4. Total ‘PN’ Perseverative Errors: where the patient perseverated with the previous incorrect response. This is a measure of perseverative errors introduced by Nelson (1976). All patients were administered the MMPI on admission as part of their routine assessment procedure. The ‘Psychopathy’ (P) score derived from the abbreviated (15 item) version of Hare’s RSAP (Hare, 1980) was obtained for each patient. Each of the 15 RSAP items was rated on the basis of a semi-structured interview and reading of case-notes and scored 0 (“definitely not applicable”), 1 (“insufficient or conflicting information”) or 2 (“definitely applicable”), yielding a total maximum score of 30 (see Howard et al., 1984). RESULTS Legal (1959 MHA) criteria for psychopathy
The resident sample was dichotomised as ‘mentally ill’ (MI) [N = 271 or ‘psychopathically disordered’ (PD) [N = 221 under the terms of the 1959 Mental Health Act. Modified WCST performance scores for each group are shown in Table 1. MI and PD patients did not differ from each other on any of the performance measures, using Mann-Whitney U Tests to compare group means. Psychometric criteria: ‘primary’ versus ‘secondary’ psychopathy. In order to make a more direct comparison between performance of ‘primary’ and ‘secondary’ psychopaths on the MWCST a sub-group (N = 8) of Special Hospital residents was selected who not only met the criteria for belonging to a larger group of ‘Approachers’ (that is, they scored 3 or less on Welsh’s (1956)
Table
I.
under
the MHA
Modified
WCST (1959)
categories
performance ‘Mental
Illness’
in the special
scores and
hospital
Total eIT0l-S
Menkd
illness
Mean SD
Psychopathic
Mean
disorder
SD
Cats
for
patients
‘Psychopathic
resident
admitted Disorder’
sample PM
PN
CmOTS
CfTOI3
13.6
4.6
5.6
3.7
8.8
1.8
5.0
4.5
16.3
3.8
5.1
3.4
8.6
1.9
4.2
3.0
P. A. DEVONSHIRE et al.
342 Table
2. Modified WCST performance scores for ‘Primary’ ‘Secondary’ psychopaths and for healthy control subjects
Primary psychopaths (N = 8) Secondary psychopaths (N=9) Normal controls (N = IO)
Total errors
cats
PM e*rOrS
PN errors
Mean SD
9.6 4.9
4.9 0.8
4.1 2.8
2.4 3.0
Mean SD
20.6 5.2
3.0 1.7
6.8 4.0
4.9 3.4
Mean SD
4.0 2.2
7.0 0.8
1.3 l.S
0.3 0.5
and
Anxiety scale), but in addition showed the classic ‘4-9’ MMPI profile characteristic of ‘primary’ psychopaths (Blackburn, 1974) and whose legal classification under the 1959 MHA was Psychopathic Disorder. A further sub-group (N = 9) of Special Hospital residents was selected who not only met the criteria for belonging to a larger group of ‘withdrawers’ (that is, they scored at least 18 on Welsh’s (1956) Anxiety), but who in addition showed the MMPI profile characteristic of Blackburn’s (1974) ‘paranoid-aggressive’ type and whose 1959 MHA classification was Psychopathic Disorder. In short, this sub-group met the criteria for ‘secondary’ psychopathy according to Blackburn (1974). It may be seen from Table 2 that the ‘secondary’ psychopaths performed worse than the ‘primary’ psychopaths on all measures, achieving significantly fewer categories (U = 12, P < 0.05) and making significantly more total errors (U = 6, P < 0.02). A 2 x 2 contingency table dichotomising patients (‘primary’ versus ‘secondary’ and total categories achieved (> = 4 versus ~4) revealed a significant effect using Fisher’s Exact Probability Test (P = 0.025). The ‘normal’ control group performed significantly better than the ‘primary’ psychopaths on all modified WCST measures: for total errors, U = 8.5, P < 0.02; for categories achieved, U = 3, P < 0.002; for PM errors, U = 12.5. P < 0.02; for PN errors, U = 16, P -=z0.05. Clinical behavioural criteria for psychopathy Hare’s Research Scale for the Assessment of Psychopathy (RSAP). Patients in the admission sample were assigned to one of two groups (‘High P’:N = 19, and ‘Low P’: N = 18) by dividing at the mean score for the sample on Hare’s RSAP (18.3). No significant correlations between Hare’s P and any of the modified WCST scores was found: all correlations approximated to zero. Mean scores on the modified WCST measures for ‘High P’ and ‘Low P’ groups are shown in Table 3. There were no significant between-group differences on any of the measures. DISCUSSION
Our results suggest that the mentally abnormal offender population as a whole shows performance deficits in a test (Nelson’s MWCST) said to tap frontal lobe function, regardless of whether patients are admitted under the 1959 MHA category of ‘Mental Illness’ or ‘Psychopathic Disorder’. However, there does appear to be some variability in the population, with ‘secondary’ psychopaths performing particularly poorly and ‘primary’ psychopaths performing less poorly. So far as the issue of a possible frontal lobe dysfunction in psychopaths is concerned, the present results clarify the apparent contradiction between Gorenstein’s (1982) and Hare’s (1984) results.
Table 3. Modified WCST performance scores for patients in the admission sample scoring high (‘High P’) and low (‘Low P’) on the abbreviated version of Hare’s RSAP
‘High P (N==l9) ‘LOW P (N = 18)
Mean SD Mean SD
Total errors
Cats
PM errors
PN errors
RSAP range
13.6 7.6 11.9 8.05
4.5 1.6 5.3 1.8
5.9 5.0 5.0 5.3
2.6 4.1 2.0 3.7
19-27 6-18
Frontal lobe functions
343
It appears that this could be explained by their use of different selection criteria to select their psychopaths. Our results suggest that if Hare’s Psychopathy Checklist is used to define psychopathic and non-psychopathic groups, no differences between groups in performance tests related to frontal lobe function will be found, confirming Hare’s (1984) findings. If, however, psychopaths are selected on the basis of low scores on Gough’s Socialisation measure, they would tend to be ‘secondary’ psychopaths and would therefore be expected to differ from high So scorers in test performance. However, while our own and Gorenstein’s (1982) results might be taken as evidence in favour of the idea that frontal lobe dysfunction is implicated in psychopathy qua personality disorder (as opposed to psychopathy in the North American sense of chronic antisocial behaviour from an early age), there are good reasons for nor drawing this conclusion from the present study. Firstly, it is highly probable that the poor performance found in ‘secondary’ psychopaths reflects their high social withdrawal, rather than their belligerence/impulsiveness. This is because in another sample of 40 legally-defined Broadmoor psychopaths, a highly significant correlation was found between total errors on the MWCST (the measure best found to discriminate ‘secondary’ psychopaths from others in the present study) and Blackbum’s MMPI-derived Sociability measure: r = - 0.47, P < 0.001). That is, socially withdrawn individuals showed a high number of total errors. They also achieved significantly fewer categories. Secondly, in another recent study (Howard and Johnston, unpublished) Blackbum’s Belligerence measure, which correlates with other psychometric measures of impulsiveness (Barbour-McMullan, Coid and Howard, 1988) and taps the personality disorder concept of psychopathy (Blackbum, 1987), was found to correlate significantly with verbal recognition memory, a measure of temporal lobe function, but not with measures of frontal lobe function. The possibility must be considered that poor performance on tasks such as the WCST may not reflect frontal lobe function in any simple or straightforward way. Firstly, Milner’s data on WCST performance in frontal lobe patients (Milner, 1964) clearly indicated an effect of side of lesion, with fefr frontal patients performing particularly poorly. Moreover, while Milner’s results implicated dorsoluteral aspects of the frontal lobe in WCST performance, the types of error which our ‘secondary ’ psychopaths show are more akin to those indicative of poor set maintenance reported by Stuss, Benson, Kaplan, Weir, Naeser, Lieberman and Ferrill (1983) to occur in patients with orbitofrontal lesions. Secondly, poor performance on the MWCST of the type noted in this study (a high number of total errors and few categories achieved) may be a direct reflection of reduced cortical efficiency, which in turn may reflect an over-perception of threat (faulty ‘primary appraisal’: Folkman, Schaefer and Lazarus, 1979) in the face of a task which demands effortful, active coping. This interpretation is supported by the finding reported by Howard (1984) that highly anxious, socially withdrawn patients showed EEG signs of a reduction in cortical tone. A decrease in cortical tone was reported by Luria (1973) to result from medial frontal lesions. It has been found that highly anxious individuals perceive situations which demand effortful active coping as particularly stressful (Howard, Lumsden, Fenton and Armstrong, 1984). In short, therefore, rather than simply reflecting a frontal lobe dysfunction, the poor performance on the modified WCST obtained here in ‘secondary’ psychopaths may reflect a disturbance in the interaction between the anxious, socially withdrawn individual and his environment, including his cognitive appraisal of that environment, resulting in a failure to maintain attentional set in the task. Finally, it seems unlikely that the performance deficits which we find in highly anxious, socially withdrawn individuals simply reflect a generalised cognitive impairment, since in another (unpublished) study, we have found that MWCST performance correlates significantly only with particular subtests of the Wechsler Adult Intelligence Scale (WAIS), namely Digit Symbol, Block Design and Arithmetic. The deficits in WCST performance reported by Stuss et al. (1983) were similarly reported to be independent of genera1 IQ measures.
REFERENCES Barbour-McMullan J., Coid J. and Howard R. (1988) The psychometric identification of psychopathy in mentally abnormal offenders. Person. individ. Diff. In press.
344
P. A. DEVONSHIRE er al.
Blackbum R. (1971) MMPI dimensions of sociability and impulse control. J. consult. clin. Psych. 37, 166. Blackburn R. (1974) Personality and The CIPssi/ication of Psychopathic Disorders. Special Hospital Research Report, No. IO, Special Hospitals Research Unit, London. Blackburn R. (1979) Cortical and autonomic arousal in primary and secondary psychopaths. PsvchophJsiology 16, 14F150. Blackbum R. (1980) Personality and the criminal psychopath: a logical analysis and some empirical data. In Lo Psicopatico Deliquenu. Facolta di Giurisprudenza, Universita di Messina, Giuffre, Milan. Blackburn R. (1987) Two scales for the assessment of personality disorder in antisocial populations. Person. Indicid. 018 8. 81-93. Cleckley H. (1982) The Mask of Saniry. Mosby, St Louis. Craft M. (1966) The meaning of the term psychopath. In Psychopathic Disorders and Their Assessmew (Edited by Craft M.). Pergamon Press, Oxford. Elliott F. A-(1978) Neurological aspects of antisocial behavior. In The Psychopath: A comprehensive stud.?, of Anfisocial Disorders and Behauiours (Edited by Reid W. H.). Chapter 8, pp. 146-189. BrunnerMazel, New York. Fenwick P. B. C., Howard R. and Fenton G. W. (1983) Review of cortical excitability, neurohumoral transmission and the dyscontrol syndrome. In Aduances in epileptology: XIMh Epilepsy International S.vmposium (Edited by Parsonage M.). Raven Press, New York. Folkman S., Schaefer C. and Lazarus R. S. (1979) Cognitive processes as mediators of stress and coping. In Human Stress and Cognifion: An Information Processing Approach (Edited by Hamilton V. and Warburton D. M.). J. Wiley and Sons. New York. Gorenstein E. E. (1982) Frontal lobe functions in psychopaths. J. abnorm. Pswhol. 93, 133-140. Gough H. G. (1969) Manual for the California Psychological Inventory. Consulting Psychologists Press. Palo Alto, CA. of Anxiety: an Enquiry into the Functions of the Gray J. A. (1982) Precis of Gray’s “The Neuropsychology Septo-Hippocampal System”. Behau. Brain Sci. 5, 469-534. Hare R. D. (1980) A research scale for the assessment of psychopathy in criminal populations. Person. indiuid. Difl 1. 111-119. Hare R. D. (1984) Performance of psychopaths on cognitive tasks related to frontal lobe function. J. abnorm. Psycho/. 93. 133-140. Howard R. C. (1981) Slow Cerebral Event-Related polenrials, Conditioning and Personality. Unpublished doctoral dissertation. Queen’s University of Belfast. Howard R. C. (1984) The clinical EEG and personality in mentally abnormal offenders. Psychol. Med. 14, 569-580. Howard R. C. (1986) Psychopathy: A psychobiological perspective. Person. indirid. 01% 7, 795-806 Howard R. C., Fenton G. W. and Fenwick P. B. C. (1982) Event Relafed Brain Potentials in Personalify and Psychopathology: A Pavlovian Approach. Letchworth: Research Studies Press. John Wiley and Sons, New York. Scale for the Assessment of Howard R. C., Bailey R. and Newman A. (1984) A preliminary study of Hare’s “Research Psychopathy” in mentally abnormal offenders. Person. indiuid. 018 5, 389-396. Howard R. C.. Lumsden J., Fenton G. W. and Armstrong A. (1984) Psychophysiological correlates of ‘helplessness’ in Man. Biol. Psychol. 18, 4. Kassebaum G. S., Couch A. R. and Slater P. E. (1959) The factorial dimensions of the MMPI. J. Consult. Clin. Psychol. 23, 226236. Luria A. R. (1973) The Working Bruin. Chap. 7, pp. 187-225. The Penguin Press, London. Mimer 8. (1964) Some effects of frontal lobectomv in Man. In The fronral Granular Cortex and Behaior (Edited by Warren J. M. and Akert K.), pp. 313-334. McGraw:Hill, New York. Nelson H. A. (1976) A modified card sorting task sensitive to frontal lobe defects. Cor1e.y 12, 313-324. Schalling D. (1978) Psychopathy related personality variables and the psychophysiology of socialisation. In Psychoparhic Behauiour: Approaches ro Research (Edited by Hare R. D. and Schalling D.), Chapt. 6. J. Wiley & Sons, New York. Stuss D. T., Benson D. F., Kaplan E. F., Weirs W. S., Naeser M. A., Lieberman I. and Ferrill D. (1983) The involvement of orbitofrontal cerebrum in cognitive tasks. Neuropsychologia, 21, 235-248. Valenstein E. S. (1973) Brain Conwol: A Critical Examination of Brain Stimulation and Psychosurgery. J. Wiley & Sons. New York. Welsh G. S. (1956) Factor dimensions A and R. In Basic Reading on rhe MMPI in Psychology and ,Wedicine. University of Minnesota Press, Minneapolis.