Claims of amnesia for criminal offenses: psychopathology, substance abuse, and malingering

The forensic psychiatric examiner often encounters defendants who deny memory for their offense. Past research proposes a variety of factors to account for offense amnesia. To date there have been few systematic studies of offense amnesia in relation to psychiatric diagnosis, either alone or in combination with other known factors such as substance use and malingering. We studied 53 pretrial felony defendants who had been referred for psychiatric examination; 40% claimed amnesia for their offense. Examinees with psychotic disorders in general, and schizophrenia in particular, were relatively less likely to claim amnesia than were examinees with other diagnoses. Substance use at the time of the offense and associated substance use disorder diagnoses were positively associated with offense amnesia. Malingering diagnosed by general clinical criteria was a poor predictor of amnesia claims. These data suggests that two prominent reasons for referral for forensic psychiatric evaluation include the presence of psychotic symptoms and claims of amnesia for the offense.     

A study of amnesia in homicide cases and forensic psychiatric experts' examination of such claims

About one third of defendants in homicide cases claim amnesia during the time of their alleged act. Examining the authenticity of claimed amnesia is a special challenge for forensic experts. Because the experts' conclusions have legal implications, it is useful to study the characteristics of defendants who claim amnesia regarding a homicidal act and how forensic experts assess these defendants' claims. The forensic psychiatric reports from 2001 to 2007 on 102 Norwegian defendants charged with homicide were assessed quantitatively with a structured rating form. Due to multiple comparisons p of .003 was chosen. Twenty-six defendants claimed partial and 17 claimed total amnesia. No significant differences in the characteristics of the defendants were found between the partial, total, and no amnesia claiming groups. Claims of partial or total amnesia did not change the procedures and content of the forensic experts' examination. A memory test was applied in only one case. Despite the seriousness of the crime and the difficulty of assessing amnesia, the experts did not apply psychological testing of memory function or appropriate tests of possible malingering. Guidelines or standardized procedures for evaluation of defendants who claim amnesia should be developed. This could eventually contribute to more reliable and valid evaluations by forensic experts and increase the probability of just court outcomes.     

Symptom Validity Testing for the detection of simulated amnesia: Not robust to coaching

Abstract

Symptom Validity Testing (SVT) has been proposed as a method to assess the veracity of claims of amnesia. Performance below chance levels on a forced choice task is indicative of malingering. Previous research has shown that the Symptom Validity Test is a promising challenge test: at levels of high specificity, it may detect approximately half of those who malinger. The present study investigated the effect of coaching on the sensitivity of the Symptom Validity Test. Participants were instructed to feign complete amnesia and tested about their identity using the Symptom Validity Test. Half of the participants were coached not to perform below chance levels. Results were straightforward: 58% of 19 naive malingerers were detected, but none of 19 coached malingerers were detected. The results show that the Symptom Validity Test is not resistant to coaching.     

The association of alcohol-induced blackouts and grayouts to blood alcohol concentrations

The primary aim of this study was to investigate the association between measured blood alcohol concentration (BAC) and the presence and degree of amnesia (no amnesia, grayout, or blackout) in actively drinking subjects. A secondary aim was to determine potential factors other than BAC that contribute to the alcohol-induced memory loss. An interview questionnaire was administered to subjects regarding a recent alcohol associated arrest with a documented BAC greater than 0.08 g/dL for either public intoxication, driving under the influence, or under age drinking was administered. Demographic variables collected included drinking history, family history of alcoholism, presence of previous alcohol-related memory loss during a drinking episode, and drinking behavior during the episode. Memory of the drinking episode was evaluated to determine if either an alcohol-induced grayout (partial anterograde amnesia) or blackout (complete anterograde amnesia) occurred. Differences in (1) mean total number of drinks ingested before arrest, (2) gulping of drinks, and (3) BAC at arrest were found for those having blackouts compared with no amnesia; while differences in drinking more than planned were found between the no amnesia and grayout groups. A strong linear relationship between BAC and predicted probability of memory loss, particularly for blackouts was obvious. This finding clinically concludes that subjects with BAC of 310 g/dL or greater have a 0.50 or greater probability of having an alcoholic blackout.     

The Accuracy of Public Beliefs about Crime Further Evidence

Criminologists largely agree that public beliefs about crime are inaccurate, and some seem willing to abandon crime reduction as a policy goal in favor of strategies which directly affect public perceptions of crime. Yet direct tests of the accuracy of public beliefs about crime are rare. In a sample survey of Tucson adults, respondents were asked to estimate the percentage of Tucson juveniles who had committed each of fifteen offenses (i.e., the categorical rates of the offenses) and the offender sex ratio for each offense. Responses were compared with self-reported data from students in three Tucson high schools. Among the fifteen offenses there is remarkable agreement between the perceived categorical rates, sex ratios, and the self-reported figures. Taken in conjunction with earlier studies, these findings suggest that strategies designed to reduce the social consequences of crime by altering public beliefs about crime are unlikely to succeed unless they are accompanied by true reductions in the crime rate.     

Minimizing culpability increases commission errors in a mock crime paradigm

Purpose. Empirical studies have demonstrated that feigning amnesia undermines memory for a mock crime. Not much is known about the effects of other culpability‐reducing strategies on memory. The present study investigated what strategies participants use when they are instructed to minimize culpability and if these strategies undermine memory to a similar extent as claiming amnesia. Methods. Participants performed a mock crime. Next, they were either instructed to minimize culpability for this mock crime in a simulated interrogation or asked to respond honestly. One week later, memory for the mock crime was tested. Results. None of the participants claimed amnesia when trying to minimize culpability. Conversely, all participants fabricated an alternative account of their role in the crime. Compared with responding honestly on both tests, fabricating an alternative story on the first test undermined memory for the mock crime in terms of commission errors. Correct recall was unaffected. It appeared that this effect was related to story length: the longer the fabricated story, the more the commission errors when telling the truth 1 week later. Conclusions. Fabricating an alternative story (i.e. lying) did not compromise correct recall, but induced more commission errors. The findings are discussed in terms of possible underlying mechanisms.     

计算机动态姿势图识别伪装平衡功能障碍

目的 建立本实验室用动态姿势图识别非器质性或伪装平衡功能障碍的客观方法.方法 对104例正常受试者行动态姿势图检查后指导其伪装平衡功能障碍再进行动态姿势图检查,将伪装前后的平衡分进行配对t检验;应用以往研究提示伪装的7条标准对本实验的50例伪装前后的姿势图表现(包括原始曲线)进行判别,按照90％的敏感性选取并建立本实验...     

Symptom validity testing of feigned dissociative amnesia: A simulation study

Abstract

It has been argued that Symptom Validity Testing (SVT) has limited sensitivity in correctly identifying feigned autobiographical memory loss (e.g., dissociative amnesia) because malingerers would easily understand that below change performance on the SVT implies feigned memory loss. The current study tested this assumption in a sample of undergraduate students (N = 20) who committed a mock crime and then were instructed to feign complete amnesia for this event. Next, they had to answer 15 forced-choice questions that always contained the correct answer and an equally plausible alternative. Results show that a nontrivial minority of participants (40%) performed below chance. As well, understanding the SVT rationale appeared not to be related to random behaviour. Taken together, the results indicate that SVT procedures might be helpful in identifying feigned dissociative amnesia.     

Clinical presentation of malingerers diagnosed by experienced forensic psychologists

Little is known about the incidence of malingering or the diagnostic criteria for malingering employed by forensic clinical psychologists conducting pretrial evaluations for the criminal justice system. The clinical presentations of 39 criminal defendants diagnosed as malingering psychotic symptoms were contrasted with 25 defendants diagnosed as genuinely psychotic. The incidence of diagnosed malingering was 8% in a series of 314 consecutive evaluations. Malingerers differed from psychotics on 14 of 24 clinical presentation variables, including measures of general presentation, affect, hallucinations, delusions, and formal thought disorder. Results indicate consistent clinical features associated with the diagnosis of malingered psychosis.A summary of this study was presented at the 1988 Annual Convention of the American Psychological Association in Atlanta, Georgia. We very much appreciate the contribution made by the six forensic clinical psychologists at the Michigan Center for Forensic Psychiatry who volunteered to participate in this study.     

The effects of unfair procedure on negative affect and protest

The present study extends earlier research on procedural unfairness by assessing subjects' reactions to a procedural change before they learn about the outcome of the changed procedure. Subjects performed a series of four tests. After three tests, the procedure to calculate the test scores was changed into a procedure that was very inaccurate or slightly inaccurate compared to what subjects had experienced until then. The very inaccurate procedure was judged as more unfair as the slightly inaccurate procedure. As predicted, the unfair procedure raised negative affect and motivated subjects to protest. Implications of the results for procedural justice theory are discussed.     

Confidently Wrong: Police Endorsement of Psycho-Legal Misconceptions

Public beliefs about psychological issues relevant to the legal system have been demonstrated to often be misconceived, but the endorsement of such beliefs in law enforcement samples is largely unknown. This study was the first to compare psycho-legal beliefs between law enforcement officers and the general public in the UK. Participants were presented a 50-item questionnaire measuring five psycho-legal topics; police procedures, courts, tough on crime, mental illness, and memory and cognition. Despite direct involvement and relevant experience, law enforcement officers endorsed just as many empirically contradictory beliefs as those who were not law enforcement officers. Further, law enforcement officers were more confident in their responses. This research has implications for identifying areas of limited knowledge within police samples that can be targeted by police education.     

Simulating amnesia and memories of a mock crime

Abstract

Defendants often feign (i.e. simulate) dissociative amnesia for their crimes. The Symptom Validity Test (SVT) may be used to detect such feigning. Some studies have shown that feigning amnesia for a mock crime has memory-undermining effects. In this study, we wanted to replicate the memory-undermining effects of simulated amnesia. We also examined whether such effects would occur when participants’ memories were evaluated with a SVT. Thirty participants committed a mock crime and then simulated amnesia for it. During a follow-up test, participants were instructed to perform as well as they could on a free recall test and a SVT. Their memory performance was compared with that of a control group (n=30). Although only a minority of simulating participants (7%) was detected by our SVT, the memory-undermining effect of simulating amnesia appeared to be a robust phenomenon. That is, ex-simulators displayed poorer free recall, more commission errors, and lower SVT scores relative to memory performance of honestly responding controls. However, at follow-up testing the poor memory of ex-simulators did not take the form of a real amnesia (i.e. random performance on SVT).     

Effects of prior knowledge and expert statement on belief in recovered memories: an international perspective

We tested the hypothesis that beliefs in the purported attributes of recovered memories of child sexual abuse (CSA) are associated with knowledge of the "recovered/false memory debate", and that such beliefs will be related to assessments of the credibility of statements made by participants in a vignette about CSA. Participants from five countries (the United States, Canada, New Zealand, the United Kingdom and Israel) responded to a questionnaire regarding beliefs about recovered memory as well as self-reported exposure to and knowledge of the debate. In addition, they assessed the credibility of statements made by a daughter (reporting recovery of memories of sexual abuse by her father), her father (denying the allegation and accusing the daughter's therapist of implanting in her false "memories" of abuse), and two experts (each supporting one of the two protagonists). We found that prior knowledge of the debate across countries was linked to beliefs in specific attributes of recovered memories and to a subset of the credibility assessments of statements made by the protagonists and their experts. For individuals, however, credibility assessments were unrelated to knowledge of the debate, but they were related to beliefs about memory recovery. Finally, credibility of the protagonists' statements was differentially associated with those made by the daughter's and the father's experts. The results suggest that whereas familiarity with the debate does not affect the credibility of the statements made by the complainant and the accused, expert testimony does, as has been found in prior research. The psycholegal implications of this conclusion are discussed.     

Memory for murder. A psychological perspective on dissociative amnesia in legal contexts

There is currently a complex and inconsistent state in the law relating to dissociation and dissociative amnesia (McSherry, 1998). Although dissociative amnesia in defendants is relevant to both competency to stand trial and criminal responsibility in principle, courts have typically assumed a skeptical stance toward such claims in practice. However, there is considerable evidence from both nonoffender and offender populations to support the validity of dissociative amnesia in defendants. Further, there is information available to aid in the evaluation of amnesia, such as the quality of the report itself and characteristics of the person reporting the amnesia (e.g., psychopathy). When consideration is given to the legal response to reports of dissociative amnesia by complainants, the situation becomes even more complex. While some courts have rejected recovered memory evidence, others have convicted defendants of historical offenses based on such evidence. In some cases, judges have argued that jurors should be left to decide on the validity of recovered memories based on their common sense and experience. The uncritical acceptance of the validity of repressed memories in complainants by many courts stands in stark contrast to the response to claims of amnesia from defendants. It seems apparent that the courts need better guidelines around the issue of dissociative amnesia in both populations. We think that the increasing scientific understanding of memory in the past decade (see Schacter, 1999) can meaningfully contribute to the development of such guidelines. Responsible, nonpartisan expert testimony from mental health professionals would be one step in the direction of rectifying the current state of law in regards to dissociation.     

Recalled peritraumatic reactions, self-reported PTSD, and the impact of malingering and fantasy proneness in victims of interpersonal violence who have applied for state compensation

The present study explores the associations between three types of peritraumatic reactions (dissociation, distress, and tonic immobility) and posttraumatic stress disorder (PTSD) symptoms in a sample of 125 victims of interpersonal violence who had applied for compensation with the Dutch Victim Compensation Fund (DCVF). In addition, the confounding roles of malingering and fantasy proneness are examined. Results indicate that tonic immobility did not predict PTSD symptom levels when adjusting for other forms of peritraumatic reactions, whereas peritraumatic dissociation and distress did. However, after the effects of malingering and fantasy proneness had been controlled for, malingering is the only factor associated with increased PTSD symptomatology. Implications for policy practice as well as study strengths and limitations are discussed.     

Co-witness Information Can Have Immediate Effects on Eyewitness Memory Reports

When questioning a reluctant witness, investigators sometimes encourage the witness by providing information about what other witnesses have said. Three experiments were conducted to test the combined effects of such co-witness information and suggestive questioning on the accuracy of eyewitness memory reports. Experiment 1 was analogous to the experience of a witness who receives information from an interviewer or questioner about what other witnesses have already said, whereas Experiments 2 and 3 simulated the situation in which a witness receives information directly from a co-witness. In all three experiments, when participants received incorrect information about a co-witness's response, they were significantly more likely to give that incorrect response than if they received no co-witness information. This effect persevered in a delayed memory test 48 h after the initial questioning session in Experiment 3. Accuracy rates were lowest of all when incorrect co-witness information was paired with questioning that suggested an incorrect response. These results have implications not only for the immediate effects on the accuracy of witnesses' memory reports, but also for the impact that even one such inaccurate report can have on the manner in which a case is investigated by the police or other authorities.     

A comparison of memory for homicide, non-homicidal violence, and positive life experiences

Defendants commonly claim amnesia for their criminal actions especially in cases involving extreme violence. While some claims are malingered or result from physiological factors, other cases may represent genuine partial or complete amnesia resulting from the psychological distress and/or extreme emotion associated with the perpetration of the crime. Fifty Canadian homicide offenders described their memories of their homicide, a non-homicide violent offense, and their most positive adulthood life experience. Self-reported and objective measures of memories for these events revealed that homicides were recalled with the greatest level of detail and sensory information. Although dissociative tendencies were associated with a self-reported memory loss, objective measures of memory quality did not reflect this perceived impairment, suggesting a failure of meta-memory. Recollections of positive life events were superior to those of non-homicidal violence, possibly due to greater impact and meaning attached to such experiences. Findings suggest that memory for homicide typically is enhanced by the powerful emotion associated with its perpetration.     

Judgments about the right to property from preschool to adulthood

Legal theorists argue that the constitutional right to property is defined, in part, by the property beliefs of the community, and how they change; yet little is known about these beliefs. In each of the three present studies, subjects aged 4 to 15 years, and adults, rated story characters who refused to return objects to their previous owners. Subjects under 10 did not clearly differentiate loss or destruction of one's own from another's property (study I), or the rights of persons who acquired possession by theft, loan, finding, or gift (study II). Creative labor was considered a more legitimate basis for possession by 15-year-olds than by 10-year-olds or adults (study III). These results support the idea that children understand “own” in the same way as adults understand “on loan”.     

Potential for Bias in MMPI-2 Assessments Using the Fake Bad Scale (FBS)

The Fake Bad Scale (FBS), developed to identify malingering of emotional distress among claimants seeking compensation for personal injuries, was recently added to the MMPI-2 scoring materials, resulting in its widespread dissemination across the various clinical settings that use the MMPI-2 in psychological evaluations. We examine: (1) questions of item bias in the FBS; (2) how malingering and nonmalingering groups are identified in FBS studies, including whether the research has been broadly inclusive and fully represents the populations assessed by the MMPI-2; (3) the reliability and validity of the FBS; (4) the highly variable recommendations for raw score cut-offs and how they relate to T scores; (5) two inpatient groups [men in a tertiary care Veterans Affairs Healthcare System (VA) unit and women in an eating disorders program] who may be inappropriately labeled as malingering by the FBS; (6) the publisher’s statement on use of the FBS; and (7) a Frye hearing in Florida where the FBS was excluded from expert testimony, one of three so far. We raise questions about its potential bias against people with disabilities and physical illnesses, women, individuals exposed to highly traumatic situations, and those motivated to present themselves in a favorable light. Psychologists using the FBS for making decisions about clients’ motivations need to be aware of the serious problems with the scale’s use and the cases of its inadmissibility in court.