Neuroaffective processing in criminal psychopaths: brain event-related potentials reveal task-specific anomalies

This study aimed to confirm neuroaffective processing deficits in psychopaths by measuring late brain event-related potential (ERP) components and behavior in groups of psychopathic and nonpsychopathic inmates of a Singaporean prison while they performed two tasks. In a Categorization task, affective stimuli were task-relevant and required focused attention, while in a Vigilance task, affective pictures were presented in the background while participants discriminated vertical from oblique lines. Psychopaths showed differences in late positive ERPs that were sensitive to affective stimulus properties (valence and arousal) in the Categorization, but not in the Vigilance task, suggesting that only under conditions of focused attention did psychopaths show a neuroaffective processing deficit. In the Categorization task, psychopaths also showed a significantly larger prefrontal negative ERP (N350) whose amplitude correlated positively with the behavioral facet of psychopathy. In the Vigilance task, psychopaths both missed more targets and showed significantly smaller target-evoked parietal ERPs when viewing arousing pictures, suggesting their attentional focus was disrupted by the affective background.     

Facial affect recognition in criminal psychopaths

Prior studies provide consistent evidence of deficits for psychopaths in processing verbal emotional material but are inconsistent regarding nonverbal emotional material. To examine whether psychopaths exhibit general versus specific deficits in nonverbal emotional processing, 34 psychopaths and 33 nonpsychopaths identified with Hare's (R. D. Hare, 1991) Psychopathy Checklist--Revised were asked to complete a facial affect recognition test. Slides of prototypic facial expressions were presented. Three hypotheses regarding hemispheric lateralization anomalies in psychopaths were also tested (right-hemisphere dysfunction, reduced lateralization, and reversed lateralization). Psychopaths were less accurate than nonpsychopaths at classifying facial affect under conditions promoting reliance on right-hemisphere resources and displayed a specific deficit in classifying disgust. These findings demonstrate that psychopaths exhibit specific deficits in nonverbal emotional processing.     

Treating criminal psychopaths in a therapeutic community program

A Therapeutic Community (TC) treatment program for adult male offenders is summarized and treatment outcome data are discussed. Psychopaths showed less clinical improvement, displayed lower levels of motivation and were discharged from the program earlier than non-psychopaths. There were significant positive treatment effects for the non-psychopaths and a mixed group. Psychopathy Checklist scores (Hare, 1985) consistently postdict and predict treatment outcome and attrition from the program.     

Aberrant neural processing of moral violations in criminal psychopaths

A defining characteristic of psychopathy is the willingness to intentionally commit moral transgressions against others without guilt or remorse. Despite this "moral insensitivity," the behavioral and neural correlates of moral decision-making in psychopathy have not been well studied. To address this issue, the authors used functional magnetic resonance imaging (fMRI) to record hemodynamic activity in 72 incarcerated male adults, stratified into psychopathic (n = 16) and nonpsychopathic (n = 16) groups based on scores from the Hare Psychopathy Checklist-Revised (R. D. Hare, 2003), while they made decisions regarding the severity of moral violations of pictures that did or did not depict moral situations. Consistent with hypotheses, an analysis of brain activity during the evaluation of pictures depicting moral violations in psychopaths versus nonpsychopaths showed atypical activity in several regions involved in moral decision-making. This included reduced moral/nonmoral picture distinctions in the ventromedial prefrontal cortex and anterior temporal cortex in psychopaths relative to nonpsychopaths. In a separate analysis, the association between severity of moral violation ratings and brain activity across participants was compared in psychopaths versus nonpsychopaths. Results revealed a positive association between amygdala activity and severity ratings that was greater in nonpsychopaths than psychopaths, and a negative association between posterior temporal activity and severity ratings that was greater in psychopaths than nonpsychopaths. These results reveal potential neural underpinnings of moral insensitivity in psychopathy and are discussed with reference to neurobiological models of morality and psychopathy.     

Performance of criminal psychopaths on selected neuropsychological tests

Screening batteries of standard neuropsychological tests were administered to 2 different samples (Ns = 90 and 167) of male prison inmates. Scores on the revised Psychopathy Checklist were used to divide inmates in each sample into high, moderate, and low psychopathy groups. There were no group differences in test performance in either of the samples, even when the effects of self-reported psychopathology and substance abuse were taken into account. The overall prevalence of both test-specific and global neuropsychological impairment was low and did not vary significantly across the 3 groups. The results provide no support for traditional brain-damage explanations of psychopathy.     

P3 event-related potentials and childhood maltreatment in successful and unsuccessful psychopaths

Although P3 event-related potential abnormalities have been found in psychopathic individuals, it is unknown whether successful (uncaught) psychopaths and unsuccessful (caught) psychopaths show similar deficits. In this study, P3 amplitude and latency were assessed from a community sample of 121 male adults using an auditory three-stimulus oddball task. Psychopathy was assessed using the Psychopathy Checklist-Revised (Hare, 2003) while childhood physical maltreatment was assessed using the Conflict Tactic Scale (Straus, 1979). Results revealed that compared to normal controls, unsuccessful psychopaths showed reduced parietal P3 amplitudes to target stimuli and reported experienced more physical abuse in childhood. In contrast, successful psychopaths exhibited larger parietal P3 amplitude and shorter frontal P3 latency to irrelevant nontarget stimuli than unsuccessful psychopaths. This is the first report of electrophysiological processing differences between successful and unsuccessful psychopaths, possibly indicating neurocognitive and psychosocial distinctions between these two subtypes of psychopathy.     

Autonomic stress reactivity and executive functions in successful and unsuccessful criminal psychopaths from the community

A significant gap in the psychopathy literature is the lack of studies comparing "successful," nonconvicted psychopaths with "unsuccessful," convicted psychopaths. This study tested the hypothesis that successful psychopaths show increased autonomic stress reactivity and better neuropsychological function compared with unsuccessful psychopaths. A total of 26 controls, 16 unsuccessful psychopaths, and 13 successful psychopaths were assessed on psychophysiological measures recorded during an emotional manipulation, the Wisconsin Card Sorting Test (WCST), Wechsler Memory Scale--Revised subtests, and childhood stressors. Compared with controls, unsuccessful psychopaths showed reduced cardiovascular stress reactivity. In contrast, successful psychopaths showed heightened reactivity, better WCST performance, and more parental absence than unsuccessful psychopaths and controls. The implications of these findings and the generalizability of existing psychopathy research are discussed.     

Neuropsychology and temporal lobe epilepsy

The purpose of this article is to review aspects of the neuropsychology of temporal lobe epilepsy. Evidence will be presented to demonstrate that the cognitive consequences of this focal seizure disorder can be more generalized in nature than expected. Consistent with the extratemporal neurocognitive findings, careful quantitative magnetic resonance imaging volumetrics have shown that structural brain changes may be detected outside the temporal lobes. Many factors can potentially affect cognition and brain structure. We focus on the potential neurodevelopmental impact of early-onset temporal lobe epilepsy on brain structure and cognition positing that this disorder can have both immediate and lifespan implications for cognition and psychosocial status.     

Interictal discourse production in temporal lobe epilepsy

Discourse production was investigated in 16 patients with left-temporal-lobe epilepsy (LTLE) and 17 neurologically normal relatives. Narrative was elicited with the Joanette and Goulet (1989) eight frame "Cowboy" cartoon on three immediately consecutive occasions. Variables of interest were fluency (words/s), speaking time, and word count. While controls produced increasingly concise forms of the story over repetitions, the TLE group became more verbose. Fluency did not not differentiate the groups. These findings suggest that LTLE is associated with macrolinguistic disturbances. The role of capacity limitations and motivational factors in TLE discourse production is discussed.     

Near-death experiences and the temporal lobe

Abstract— Many studies in humans suggest that altered temporal lobe functioning, especially functioning in the right temporal lobe, is involved in mystical and religious experiences. We investigated temporal lobe functioning in individuals who reported having transcendental "near-death experiences" during life-threatening events. These individuals were found to have more temporal lobe epileptiform electroencephalographic activity than control subjects and also reported significantly more temporal lobe epileptic symptoms. Contrary to predictions, epileptiform activity was nearly completely lateralized to the left hemisphere. The near-death experience was not associated with dysfunctional stress reactions such as dissociation, posttraumatic stress disorder, and substance abuse, but rather was associated with positive coping styles. Additional analyses revealed that near-death experiencers had altered sleep patterns, specifically, a shorter duration of sleep and delayed REM sleep relative to the control group. These results suggest that altered temporal lobe functioning may be involved in the near-death experience and that individuals who have had such experiences are physiologically distinct from the general population.     

Sub-centimeter language organization in the human temporal lobe

The human temporal lobe is well known to be critical for language comprehension. Previous physiological research has focused mainly on non-invasive neuroimaging and electrophysiological techniques with each approach requiring averaging across many trials and subjects. The results of these studies have implicated extended anatomical regions in peri-sylvian cortex in speech perception. These non-invasive studies typically report a spatially homogenous functional pattern of activity across several centimeters of cortex. We examined the spatiotemporal dynamics of word processing using electrophysiological signals acquired from high-density electrode arrays (4 mm spacing) placed directly on the human temporal lobe. Electrocorticographic (ECoG) activity revealed a rich mosaic of language activity, which was functionally distinct at four mm separation. Cortical sites responding specifically to word and not phoneme stimuli were surrounded by sites that responded to both words and phonemes. Other sub-regions of the temporal lobe responded robustly to self-produced speech and minimally to external stimuli while surrounding sites at 4 mm distance exhibited an inverse pattern of activation. These data provide evidence for temporal lobe specificity to words as well as self-produced speech. Furthermore, the results provide evidence that cortical processing in the temporal lobe is not spatially homogenous over centimeters of cortex. Rather, language processing is supported by independent and spatially distinct functional sub-regions of cortex at a resolution of at least 4 mm.     

Attentional control in patients with temporal lobe epilepsy

Across different studies, patients with temporal lobe epilepsy (TLE) demonstrate impairments on numerous measures of attentional control that are classically associated with frontal lobe functioning. One aspect of attentional control that has not been examined in TLE is the ability to execute two modality‐specific tasks concurrently. We sought to examine the status of dual‐task coordination in TLE. We further examined the cohorts' performance on a range of traditional measures of attentional control. Eighteen TLE patients and 22 healthy controls participated in the study. Dual‐task performance involved comparing the capacity to execute a tracking and a digit recall task simultaneously with the capacity to execute the tasks separately. We also administered measures of: set shifting (odd‐man‐out test), sustained attention (elevator counting), selective attention (elevator counting with distraction), and divided attention (trail making test). We found that the proportional decrement in dual‐task performance relative to single‐task performance did not vary between the groups (TLE = 92.48%; controls = 93.70%), nor was there a significant difference in sustained attention (p > .10). Patients with TLE did demonstrate marked deficits in selective attention (p < .0001), divided attention (p < .01), and set shifting (p < .01). These findings add to the knowledge about cognitive dysfunction in TLE, indicating that impairments in attentional control in TLE tend to be selective. The greatest deficits appear to be on tasks that invoke a high level of processing resources. In contrast, sustained attention is less compromised and the capacity to allocate cognitive resources appears to be normal in patients with TLE.     

Psychopathology and criminal personality changes in patients with frontal lobe injuries

Proceeding from H. Cosack (1937), and in view of the fact that since then no further casuistic contributions relating to the crimogenic aspect of the psychopathological frontal brain syndrome or to the forensic psychiatry of persons with frontal brain damage have appeared, we take up the discussion with five of our own cases. Since modern procedures have made it possible to localise exactly the consequences of brain damage, a new round of investigations might be expected to resolve the problems still left open.     

Content-specific source encoding in the human medial temporal lobe

Although the medial temporal lobe (MTL) is known to be essential for episodic encoding, the contributions of individual MTL subregions remain unclear. Data from recognition memory studies have provided evidence that the hippocampus supports relational encoding important for later episodic recollection, whereas the perirhinal cortex has been linked with encoding that supports later item familiarity. However, extant data also strongly implicate the perirhinal cortex in object processing and encoding, suggesting that perirhinal processes may contribute to later episodic recollection of object source details. To investigate this possibility, encoding activation in MTL subregions was analyzed on the basis of subsequent memory outcome while participants processed novel scenes paired with 1 of 6 repeating objects. Specifically, encoding activation correlating with later successful scene recognition memory was evaluated against that of source recollection for the object paired with the scene during encoding. In contrast to studies reporting a link between perirhinal cortex and item familiarity, it was found that encoding activation in the right perirhinal cortex correlates with successful recollection of the paired object. Furthermore, other MTL subregions also exhibited content-specific source encoding patterns of activation, suggesting that MTL subsequent memory effects are sensitive to stimulus category.