Emotion in the criminal psychopath: Fear image processing.

We tested the hypothesis that the response mobilization that normally accompanies imagery of emotional situations is deficient in psychopaths. Cardiac, electrodermal, and facial muscle responses of 54 prisoners, assigned to low- and high-psychopathy groups using R. D. Hare's (1991) Psychopathy Checklist—Revised, were recorded while subjects imagined fearful and neutral scenes in a cued sentence-processing task. Groups did not differ on self-ratings of fearfulness, imagery ability, or imagery experience. Low-psychopathy subjects showed larger physiological reactions during fearful imagery than high-psychopathy subjects. Extreme scores on the antisocial behavior factor of psychopathy predicted imagery response deficits. Results are consistent with the idea that semantic and emotional processes are dissociated in psychopaths. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion processing in the criminal psychopath: The role of attention in emotion-facilitated memory.

The response modulation hypothesis specifies that low-anxious psychopathic individuals have difficulty processing information outside their primary attentional focus. To evaluate the applicability of this model to affective processing, the authors had 239 offenders, classified with the Psychopathy Checklist--Revised (R. D. Hare, 2003) and the Welsh Anxiety Scale (G. Welsh, 1956), perform 1 of 3 emotion memory tasks that examined the effects of emotion on memory for primary and contextual information. Regardless of anxiety level, psychopathic and control offenders demonstrated a significant and comparable memory bias for emotional over neutral words in the primary conditions. However, psychopathic individuals showed significantly less memory bias than did controls in the contextual conditions. Results indicate that the impact of emotion on memory is moderated by attentional factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The psychopath as observer: Emotion and attention in picture processing.

This study extended prior work showing abnormal affect–startle modulation in psychopaths. Male prisoners viewed specific categories of pleasant (erotic or thrilling) and unpleasant (victim or direct threat) slide pictures, along with neutral pictures. Acoustic startle probes were presented early (300 and 800 ms) and late (1,800, 3,000, and 4,500 ms) in the viewing interval. At later times, nonpsychopaths showed moderate and strong reflex potentiation for victim and threat scenes, respectively. For psychopaths, startle was inhibited during victim scenes and only weakly potentiated during threat. Psychopaths also showed more reliable blink inhibition across pleasant contents than nonpsychopaths and greater heart rate orienting to affective pictures overall. These results indicate a heightened aversion threshold in psychopaths. In addition, deficient reflex modulation at early times suggested a weakness in initial stimulus evaluation among psychopaths. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Startle Modulation During Conscious Emotion Regulation Is Arousal-Dependent.

Conscious regulation of negative emotion has been shown to affect human eyeblink startle responses, but whether these results depend on modulation of arousal- or valence-based processes is unknown. The authors presented participants with negative, neutral, and positive pictures and directed them to enhance, maintain, and suppress emotional responses. On emotional picture trials, startle responses decreased as a function of cue in the following order: enhance > maintain > suppress. Analysis of negative and positive picture trials separately revealed similar patterns of startle modulation by emotion regulation. There were no effects of emotion regulation on neutral trials. Results indicate that arousal, not valence, may be critical to startle modulation via conscious emotion regulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pursuing the psychopath: Capturing the fledgling psychopath in a nomological net.

The present article reports on an attempt to import the concept of psychopathy at the childhood level. Childhood psychopathy was assessed in 430 boys ages 12 and 13 years by using caretaker reports on a translation of an adult psychopathy assessment instrument. A systematic construct validation approach revealed that childhood psychopathy fits into the nomological network surrounding adult psychopathy. Children with psychopathic personalities, like their adult counterparts, were serious and stable offenders, impulsive, and more prone to externalizing than internalizing disorders. Childhood psychopathy also provided incremental validity in predicting serious stable antisocial behavior in adolescence over and above other known predictors and one other classification approach. These results suggest that psychopathy has a childhood manifestation that can be measured reliably. Implications and future directions are outlined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Startle reflex inhibition in the rat: Its persistence after extended repetition of the inhibitory stimulus.

Startle reflexes to intense sound bursts are inhibited by weak stimuli that briefly precede their elicitation. In 3 experiments, with 36 Long-Evans hooded rats, the startle stimulus (a 110-db tone burst) was presented 100 msec after the final link in a train of stimuli, the length of the train varying from 1 to 1,000, its repetition rate varying from 1 to 10 per sec, and its constituents being 40 db or 50 db white noise bursts of 25 msec duration. Inhibition was invariant across train length and repetition rate. In Exp IV, the startle stimulus was presented a variable interval after the final link, from 40 to 1,280 msec with 1 or 100 noise bursts (50 db) in the train. Inhibition developed more rapidly following the last member of the 100-stimulus train, suggesting a "priming" or sensitization effect of stimulus repetition, but its overall strength and subsequent rate of decay were not different in the 2 conditions. The general persistence of inhibition following these extended series of stimuli reveals that reflex inhibition must be the outcome of a fixed and obligatory process associated with sensory input. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion, novelty, and the startle reflex: Habituation in humans.

Previous research with both animal and human Ss has shown that startle reflex magnitude is potentiated in an aversive stimulus context, relative to responses elicited in a neutral or appetitive context. In the present experiment, the same pleasant, unpleasant, and neutral picture stimuli were repeatedly presented to human Ss. Startle reflex habituation was assessed in each stimulus context and was compared with the habituation patterns of heart rate, electrodermal, and facial corrugator muscle responses. All systems showed initial differentiation among affective picture contents and general habituation over trials. The startle reflex alone, however, continued to differentiate among pleasant, neutral, and unpleasant pictures throughout the presentation series. These results suggest that (1) the startle probe reflex is relatively uninfluenced by stimulus novelty, (2) the startle modulatory circuit (identified with amygdala-reticular connections in animals) varies systematically with affective valence, and (3) the modulatory influence is less subject to habituation than is the obligatory startle pathway or responses in other somatic and autonomic systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotion, attention, and the startle reflex.

This theoretical model of emotion is based on research using the startle-probe methodology. It explains inconsistencies in probe studies of attention and fear conditioning and provides a new approach to emotional perception, imagery, and memory. Emotions are organized biphasically, as appetitive or aversive (defensive). Reflexes with the same valence as an ongoing emotional state are augmented; mismatched reflexes are inhibited. Thus, the startle response (an aversive reflex) is enhanced during a fear state and is diminished in a pleasant emotional context. This affect–startle effect is not determined by general arousal, simple attention, or probe modality. The effect is found when affects are prompted by pictures or memory images, changes appropriately with aversive conditioning, and may be dependent on right-hemisphere processing. Implications for clinical, neurophysiological and basic research in emotion are outlined. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention and schizophrenia: Impaired modulation of the startle reflex.

The startle reflex (SR) elicited by abrupt stimuli can be modified by attention to nonstartling stimuli that shortly precede the startle-eliciting stimulus. The present study of 15 recent-onset, relatively asymptomatic schizophrenic outpatients and 14 demographically matched normal control Ss demonstrated that attentional modulation of SR is impaired in schizophrenic patients. Specifically, the control group exhibited greater startle eye-blink modification following to-be-attended prestimuli than following to-be-ignored prestimuli, whereas the patients failed to show the attentional modulation effect. These results suggest traitlike attentional deficits in schizophrenia because the patients were relatively asymptomatic. The measurement of attentional modulation of SR may provide a nonverbal, reflexive, state-independent marker of the vulnerability to schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Affective individual differences and startle reflex modulation.

Potentiation of startle has been demonstrated in experimentally produced aversive emotional states, and clinical reports suggest that potentiated startle may be associated with fear or anxiety. To test the generalizability of startle potentiation across a variety of emotional states as well as its sensitivity to individual differences in fearfulness, the acoustic startle response of 17 high- and 15 low-fear adult Ss was assessed during fear, anger, joy, sadness, pleasant relaxation, and neutral imagery. Startle responses were larger in all aversive affective states than during pleasant imagery. This effect was enhanced among high fear Ss, although follow-up testing indicated that other affective individual differences (depression and anger) may also be related to increased potentiation of startle in negative affect. Startle latency was reduced during high- rather than low-arousal imagery but was unaffected by emotional valence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Startle responses measured in muscles innervated by facial and trigeminal nerves show common modulation.

Electromyographic (EMG) potentials of several head muscles were recorded simultaneously in freely moving rats with chronically implanted electrodes. The startle responses of m. temporalis, m. levator auris, and m. levator labii superior were compared. All muscles showed a parallel decrease in latency and an increase in response elicitability and amplitude with an increase in stimulus intensity. A significant latency difference of about 1 msec existed between m. levator auris and m. temporalis. The shortest latency of the EMG response in m. levator auris was 5.5 msec (110 dB SPL). A common fluctuation in response amplitude and latency was found in simultaneous recordings of muscles innervated by the facial and trigeminal nerve, respectively. This shows a common modulatory input to the startle pathway to the cranial motor nuclei. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Startle potentiation: shock sensitization, aversive learning, and affective picture modulation

This study investigated the size of, and relationship between, different modulatory effects of aversive stimulation on the acoustic startle reflex. This reflex is potentiated by shock exposure and associative shock conditioning (in animals and human volunteers) and unpleasant pictures (in human volunteers). In this study, dramatic sensitization of the probe-startle response was observed after shock exposure but not after a control task. Magnitude of sensitization was significantly larger than associative shock conditioning and picture modulation effects (also significant). Sensitization and conditioning scores showed modest, significant correlations with one another but not with picture modulation scores, consistent with animal data showing that partially overlapping brain mechanisms (i.e., amygdaloid-reticular projections) mediate these effects. The present results also indicate that sensitization of startle in human volunteers is a relatively more robust defensive response to aversive stimulation.     

Spectral frequency and the modulation of the acoustic startle reflex by background noise.

The rat's (Long-Evans) acoustic startle reflex to a high-frequency tone burst (10.5 kHz) was depressed by intense high-frequency band-pass noise (8–26 kHz) but enhanced by low frequency noise (1–2 kHz). However, contrary to the hypothesis that the depression of startle in intense background noise is produced by sensory masking, the reflex to a low-freqency tone burst (at 1 kHz) was depressed by both high- and low-frequency band-pass noise. Two additional hypotheses are offered to supplement sensory masking in order to explain the asymmetry in these data. The first is that the intratympanic reflex, which acts as a high pass filter on acoustic input, is elicited in intense backgrounds. The second is that acoustic startle reflexes elicited by intense low-frequency tones are in part elicited by their high-frequency distortion products and that these distortion products are then masked by high-frequency background noise. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anomalous perceptual asymmetries for negative emotional stimuli in the psychopath.

This study tested the hypothesis that when processing negative emotional material, psychopaths, compared with nonpsychopaths, would rely less on connotative-emotional processes based in the right hemisphere and more on denotative-linguistic processes based in the left hemisphere. Psychopathic and nonpsychopathic inmate groups, defined by their scores on the Psychopathy Checklist—Revised (R. D. Hare 1985), completed 2 analogous tachistoscopic tasks (words and faces). Accuracy and reaction times of inmates' responses in identifying which of 2 bilaterally presented stimuli (1 neutral and 1 emotional) was the emotional stimulus were measured. Significant lateral processing differences between the 2 groups emerged on the word task but not on the face task, providing partial support for the experimental hypothesis. Psychopaths also showed lower generalized emotional responsivity than nonpsychopaths on the Affect Intensity Measure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Early identification of the fledgling psychopath: Locating the psychopathic child in the current nomenclature.

This research attempted to test D. R. Lynam's (1996) hypothesis regarding the developmental relation between adult psychopathy and children with symptoms of hyperactivity. impulsivity, and attention problems (HIA) and concurrent conduct problems (CP). In a large sample of adolescent boys, 4 groups (non-HIA–CP, HIA only, CP only, and HIA–CP) were compared on measures found to discriminate between psychopathic and nonpsychopathic offenders. In line with predictions, the HIA–CP boys most closely resembled psychopathic adults. HIA–CP boys scored higher than HIA-only and non-HIA–CP boys on a measure of psychopathic personality. As with their adult counterparts, HIA–CP boys were the most antisocial, were the most disinhibited, and tended to be the most neuropsychologically impaired of all the groups. Implications for treatment, research, and the study of comorbidity are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychopathic, not psychopath: Taxometric evidence for the dimensional structure of psychopathy.

Although psychopathy is frequently regarded as qualitatively distinct from other conditions, relatively little research has examined whether psychopaths represent a distinct class of individuals. Using a sample of 876 prison inmates and court-ordered substance abuse patients who were administered the Psychopathy Checklist-Revised (R. D. Hare, 2003), the authors examined the latent structure of psychopathy using several taxometric procedures developed by Meehl and colleagues (P. E. Meehl & L. J. Yonce, 1994; N. G. Waller & P. E. Meehl, 1998). The results across these procedures offer no compelling support for the contention that psychopathy is a taxonic construct and contradict previous reports that psychopathy is underpinned by a latent taxon. The authors discuss the theoretical, public policy, and practice-level implications of these findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High Illumination Levels Potentiate the Acoustic Startle Response in Preweanling Rats.

Fear potentiation of the acoustic startle response (FPS) by aversive conditioned stimuli does not emerge in rats until Postnatal Day (P)23 (see P. S. Hunt & B. A. Campbell, 1997). However, the present study found that when presented with an unconditioned fear-eliciting stimulus, rats younger than P23 display FPS. Specifically, high illumination levels were found to enhance startle amplitudes in rats aged 18 and 25 days, but not 14 days. Furthermore, the light-enhanced startle observed in P18 rats was prevented by a systemic injection of the noradrenergic beta-receptor antagonist propranolol. These data suggest that conditioned and unconditioned FPS have different ontogenetic trajectories, and thereby provide support for the idea that learned and unlearned fear are subserved by dissociable neural systems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of The psychopath: Theory, research and practice.

Reviews the book, The psychopath: Theory, research and practice edited by Hugues Hervé and John C. Yuille (see record 2006-11788-000). This book begins with an historical overview of the construct of psychopathy and then works its way through a variety of important issues, including measurement, etiology, behavioural manifestations of the disorder, typologies, and practice considerations. A few notable exceptions notwithstanding, this text is a fine primer on psychopathy: It includes a number of outstanding chapters and other important issues in the area of psychopathy receive solid treatment. Although there is occasionally some drop-off in quality, I suspect that even the less outstanding chapters in this book would prove informative for students, lay consumer groups, and clinicians who do not routinely work with psychopaths. (PsycINFO Database Record (c) 2010 APA, all rights reserved)