Heritability of startle reactivity and affect modified startle.

Startle reflex and affect-modified startle reflex are used as indicators of defensive reactivity and emotional processing, respectively. The present study investigated the heritability of both the startle blink reflex and affect modification of this reflex in a community sample of 772 twins ages 14-15years old. Subjects were shown affective picture slides falling in three valence categories: negative, positive and neutral; crossed with two arousal categories: high arousal and low arousal. Some of these slides were accompanied with a loud startling noise. Results suggested sex differences in mean levels of startle reflex as well as in proportions of variance explained by genetic and environmental factors. Females had higher mean startle blink amplitudes for each valence-arousal slide category, indicating greater baseline defensive reactivity compared to males. Startle blink reflex in males was significantly heritable (49%), whereas in females, variance was explained primarily by shared environmental factors (53%) and non-shared environmental factors (41%). Heritability of affect modified startle (AMS) was found to be negligible in both males and females. These results suggest sex differences in the etiology of startle reactivity, while questioning the utility of the startle paradigm for understanding the genetic basis of emotional processing.

Lapses in skin conductance responding across anatomical sites: Comparison of fingers, feet, forehead, and wrist.

The fingers are widely accepted as the gold standard for skin conductance (SC) recording, with the feet as a strong alternative. However, there are gaps in the current literature comparing these sites. There is also a great deal of interest in alternative recording sites to permit mobility, but data evaluating these are few and inconsistent. The present report compared multiple sites (fingers, abductor hallucis of the foot, arch of the foot, toes, forehead, and wrist) from 45 college student participants in a short-term sedentary laboratory setting and found large variation in both tonic and phasic SC responses, as well as crucial lapses in responding at nonpalmar sites. Across-site correlations between participants and within participants were also examined. The present data show that, in the laboratory setting employing commonly used recording techniques and stimuli, the nonpalmar sites are generally less responsive than the fingers, and the wrist in particular is the lowest in responding, whereas the toes are most similar to the fingers in responding. Within-participant correlations between the fingers and other sites were greatest for the plantar sites and least for the forehead.

Sensory Adapted Dental Environments to Enhance Oral Care for Children with Autism Spectrum Disorders: A Randomized Controlled Pilot Study.

This pilot and feasibility study examined the impact of a sensory adapted dental environment (SADE) to reduce distress, sensory discomfort, and perception of pain during oral prophylaxis for children with autism spectrum disorder (ASD). Participants were 44 children ages 6-12 (n = 22 typical, n = 22 ASD). In an experimental crossover design, each participant underwent two professional dental cleanings, one in a regular dental environment (RDE) and one in a SADE, administered in a randomized and counterbalanced order 3-4 months apart. Outcomes included measures of physiological anxiety, behavioral distress, pain intensity, and sensory discomfort. Both groups exhibited decreased physiological anxiety and reported lower pain and sensory discomfort in the SADE condition compared to RDE, indicating a beneficial effect of the SADE.

Feasibility of a sensory-adapted dental environment for children with autism.

OBJECTIVE: To provide an example of an occupational therapy feasibility study and evaluate the implementation of a randomized controlled pilot and feasibility trial examining the impact of a sensory-adapted dental environment (SADE) to enhance oral care for children with autism spectrum disorder (ASD). METHOD: Twenty-two children with ASD and 22 typically developing children, ages 6-12 yr, attended a dental clinic in an urban hospital. Participants completed two dental cleanings, 3-4 mo apart, one in a regular environment and one in a SADE. Feasibility outcome measures were recruitment, retention, accrual, dropout, and protocol adherence. Intervention outcome measures were physiological stress, behavioral distress, pain, and cost. RESULTS: We successfully recruited and retained participants. Parents expressed satisfaction with research study participation. Dentists stated that the intervention could be incorporated in normal practice. Intervention outcome measures favored the SADE condition. CONCLUSION: Preliminary positive benefit of SADE in children with ASD warrants moving forward with a large-scale clinical trial.

Physiological and behavioral stress and anxiety in children with autism spectrum disorders during routine oral care.

BACKGROUND: Children with autism spectrum disorders (ASD) commonly exhibit uncooperative behaviors which impede oral care. Previous studies have utilized dentist-report measures of uncooperative behaviors in children with ASD but none have utilized an objective measure of children's behavior or a physiological measure of distress. This study investigated behavioral and physiological distress in children with ASD during routine oral care and examined factors associated with this distress. METHODS: Participants were 44 children (n=22 typical, n=22 ASD) aged 6-12 receiving routine dental cleanings. Behavioral and physiological measures of stress and anxiety were collected during dental cleanings. RESULTS: Children with ASD exhibited greater distress, compared to the typical group, on dentist-report and researcher-coded measures of overt distress behaviors and on physiological measures. Correlations between physiological and behavioral measures of distress were found in the ASD but not in the typical group. Behavioral distress was correlated with age in the typical group and with expressive communication ability and sensory processing difficulties in the ASD group; physiological distress was correlated with parent-report of anxiety in the typical group and sensory processing difficulties in the ASD group. CONCLUSIONS: Novel strategies may be required to decrease behavioral and physiological distress in children with ASD in the dental clinic.

Can you give me a hand? A comparison of hands and feet as optimal anatomical sites for skin conductance recording.

The fingers and feet have long been accepted as optimal anatomical recording sites for electrodermal activity. The available literature suggests that the feet are more responsive than the fingers. The present report compared skin conductance level (SCL) and responses (SCRs) from the left foot and the distal phalanges of the fingers on the nondominant hand among 19 participants. The principal results were (a) SCRs recorded from the fingers were significantly larger and more frequent with shorter latencies than SCRs from the foot, (b) SCL from the fingers was significantly higher than from the foot, (c) the fingers exhibited significantly greater discrimination conditioning than the foot, and (d) skin conductance measures recorded from the fingers and foot were significantly positively correlated. Specifically, our results demonstrate that the distal phalanges of the fingers are electrodermally more responsive than the abductor hallucis area of the foot.

Virtual reality Stroop task for assessment of supervisory attentional processing.

The current project is a preliminary attempt at assessing the potential of a three-dimensional virtual reality Stroop task (VRST) for investigation of supervisory attentional processing. The VRST was compared with paper-and-pencil and computer automated (two-dimensional) versions of the Stroop. Psychophysiological measures were also used to assess varying levels of user arousal. The three versions of the Stroop task were conducted with a sample of 50 healthy university students, between the ages of 18 and 28 years, which included equivalent distributions of men and women from ethnically diverse populations. No significant differences were found for age, gender, or education. Results indicated that the typical Stroop effect pattern found in the Delis-Kaplan Executive Function System (D-KEFS) and Automated Neuropsychological Assessment Metrics (ANAM) occurs in the VRST; the complexity condition of the VRST offers potential for assessment of exogenous and endogenous attentional processing; the two single-item presentation formats of the Stroop are comparable; there is a psychophysiological difference in arousal between low- and high-threat zones; and while there is a learning effect present in the VRST across conditions, it is limited by the arousal conditions in the high-threat zones. Additionally, no negative side effects were associated with use of the virtual environment. We conclude that the VRST has the potential to offer a novel approach to assessment of supervisory attentional processing within an ecologically relevant environment.

Can human autonomic classical conditioning occur without contingency awareness? The critical importance of the trial sequence.

Most evidence suggests that awareness of the CS-US contingency is necessary for human autonomic conditioning. However, Schultz and Helmstetter (2010) reported unaware skin conductance conditioning using difficult-to-discriminate visual CSs. We sought to replicate these findings with procedures nearly identical to Schultz and Helmstetter among 66 participants. Results replicated the findings of significantly greater autonomic responding to CS+ than CS-; however, participants also demonstrated greater expectancy of shock to CS+ than CS- despite being classified as unaware. The differential expectancy and conditioning occurred only on trials that followed a CS+/CS- alternating sequence. On non-alternating trials, there was significantly higher expectancy and skin conductance responding to CS- compared to CS+. These results indicate that what initially appeared to be unaware differential conditioning was likely due to differential expectancy arising from a predictable trial sequence. These results underscore the critical importance of controlling for trial sequence effects in the study of learning.

The interaction of electrodermal activity and expressed emotion in predicting symptoms in recent-onset schizophrenia.

In the present study, expressed emotion (EE) was assessed among immediate family members of 94 recent-onset schizophrenia patients at initial study entry point, and patients' electrodermal activity (EDA) was measured without the presence of family members at a baseline outpatient stabilization assessment. Psychiatric symptoms were also rated, both at the baseline outpatient test and at 1-year follow-up. Electrodermal activity × expressed emotion interactions were observed at both test points. In each case, the highest levels of negative symptoms were observed among those who exhibited greater EDA and lived in a high-EE environment. These results support the view that the combination of high family EE and sympathetic nervous system arousal confer especially high risk for poor negative symptom outcomes.

Publication recommendations for electrodermal measurements.

This committee was appointed by the SPR Board to provide recommendations for publishing data on electrodermal activity (EDA). They are intended to be a stand-alone source for newcomers and experienced users. A short outline of principles for electrodermal measurement is given, and recommendations from an earlier report (Fowles et al., ) are incorporated. Three fundamental techniques of EDA recording are described: (1) endosomatic recording without the application of an external current, (2) exosomatic recording with direct current (the most widely applied methodology), and (3) exosomatic recording with alternating current-to date infrequently used but a promising future methodology. In addition to EDA recording in laboratories, ambulatory recording has become an emerging technique. Specific problems that come with this recording of EDA in the field are discussed, as are those emerging from recording EDA within a magnetic field (e.g., fMRI). Recommendations for the details that should be mentioned in publications of EDA methods and results are provided.

Age-related affective modulation of the startle eyeblink response: older adults startle most when viewing positive pictures.

Previous studies reveal age by valence interactions in attention and memory, such that older adults focus relatively more on positive and relatively less on negative stimuli than younger adults. In the current study, eyeblink startle response was used to measure differences in emotional reactivity to images that were equally arousing to both age groups. Viewing positive and negative pictures from the International Affective Picture System had opposite effects on startle modulation for older and younger adults. Younger adults showed the typical startle blink pattern, with potentiated startle when viewing negative pictures compared to positive pictures. Older adults, on the other hand, showed the opposite pattern, with potentiated startle when viewing positive pictures compared to viewing negative and neutral pictures. Potential underlying mechanisms for this interaction are evaluated. This pattern suggests that, compared with younger adults, older adults are more likely to spontaneously suppress responses to negative stimuli and process positive stimuli more deeply.

Psychophysiological prodromal signs of schizophrenic relapse: a pilot study.

Do physiological changes occur shortly prior to psychotic relapse in schizophrenia outpatients? We addressed this question in a group of schizophrenia outpatients by measuring changes in symptoms and changes in activation of the sympathetic nervous system, as indexed by changes in skin conductance level (SCL), on a biweekly basis for between one and two years. All six outpatients exhibited heightened SCL within two weeks prior to relapse or exacerbation, compared to SCL proceeding continued remission. These results shed light on the psychotic relapse process and are consistent with neural diathesis-stress models of schizophrenia.

Better than the real thing: eliciting fear with moving and static computer-generated stimuli.

As the popularity of virtual reality as an exposure therapy increases, it is important to validate the use of computer-generated stimuli in comparison to standardized images of "real" phobic objects, such as those of the International Affective Picture System (IAPS). The present study examined physiological and subjective measures of negative affect when viewing static IAPS images, static computer-generated images and moving videos of computer-generated images of feared stimuli and other negative stimuli which were not specifically feared. For example, a picture of a spider would be a "feared" stimulus for a spider fearful participant, whereas a picture of a snake would be categorized as a "negative" stimulus for that participant. Eighteen participants scoring high (high fear (HF) cohort) on questionnaires assessing specific fears of spiders or snakes and 20 participants scoring low (low fear (LF) cohort) on the questionnaires viewed the stimuli. The computer-generated videos elicited greater physiological (skin conductance and startle eyeblink potentiation) and self-report arousal responses than the IAPS images and the computer-generated static images. Computer-generated stills and IAPS images did not differ in eliciting emotional responses. Additionally, HF participants showed greater heart rate acceleration and larger skin conductance responses to their feared stimulus than to the negative stimulus, especially when viewing computer-generated moving videos. The results demonstrate the importance of motion in eliciting fear and the usefulness of computer-generated stimuli in the study of emotion.

The development of skin conductance fear conditioning in children from ages 3 to 8 years.

Although fear conditioning is an important psychological construct implicated in behavioral and emotional problems, little is known about how it develops in early childhood. Using a differential, partial reinforcement conditioning paradigm, this longitudinal study assessed skin conductance conditioned responses in 200 children at ages 3, 4, 5, 6, and 8 years. Results demonstrated that in both boys and girls: (1) fear conditioning increased across age, particularly from ages 5 to 6 years, (2) the three components of skin conductance fear conditioning that reflect different degrees of automatic and controlled cognitive processes exhibited different developmental profiles, and (3) individual differences in arousal, orienting, and the unconditioned response were associated with individual differences in conditioning, with the influence of orienting increasing at later ages. This first longitudinal study of the development of skin conductance fear conditioning in children both demonstrates that children as young as age 3 years evidence fear conditioning in a difficult acquisition paradigm, and that different sub-components of skin conductance conditioning have different developmental trajectories.

Association of poor childhood fear conditioning and adult crime.

OBJECTIVE: Amygdala dysfunction is theorized to give rise to poor fear conditioning, which in turn predisposes to crime, but it is not known whether poor conditioning precedes criminal offending. This study prospectively assessed whether poor fear conditioning early in life predisposes to adult crime in a large cohort. METHOD: Electrodermal fear conditioning was assessed in a cohort of 1,795 children at age 3, and registration for criminal offending was ascertained at age 23. In a case-control design, 137 cohort members with a criminal record were matched on gender, ethnicity, and social adversity with 274 noncriminal comparison members. Statistical analyses compared childhood fear conditioning for the two groups. RESULTS: Criminal offenders showed significantly reduced electrodermal fear conditioning at age 3 compared to matched comparison subjects. CONCLUSIONS: Poor fear conditioning at age 3 predisposes to crime at age 23. Poor fear conditioning early in life implicates amygdala and ventral prefrontal cortex dysfunction and a lack of fear of socializing punishments in children who grow up to become criminals. These findings are consistent with a neurodevelopmental contribution to crime causation.

Reduced electrodermal fear conditioning from ages 3 to 8 years is associated with aggressive behavior at age 8 years.

BACKGROUND: Poor fear conditioning characterizes adult psychopathy and criminality, but it is not known whether it is related to aggressive/antisocial behavior in early childhood. METHODS: Using a differential, partial reinforcement conditioning paradigm, electrodermal activity was recorded from 200 male and female children at ages 3, 4, 5, 6, and 8 years. Antisocial/aggressive and hyperactive-inattentive measures were collected at age 8. RESULTS: Poor electrodermal fear conditioning from ages 3 to 8 years was associated with aggressive behavior at age 8 in both males and females. CONCLUSIONS: Results indicate that the relationship between poor fear conditioning and aggression occurs early in childhood. Enhanced electrodermal fear conditioning may protect children against future aggressive/violent behavior. Abnormal amygdala functioning, as indirectly assessed by fear conditioning, may be one of the factors influencing the development of childhood aggression.

Quality-control analytical methods: pharmacopeial bacterial endotoxins test chapters.

This article summarizes and explains the essential provisions of the harmonized Bacterial Endotoxins Test chapter. The bacterial endotoxins test is an important requirement of United States Pharmacopeia Chapter 797, Pharmaceutical Compounding-Sterile Preparations, which requires endotoxin testing of high-risk compounded sterile preparations. This article includes recommendations on endotoxin testing.

Arousal, working memory, and conscious awareness in contingency learning.

There are wide individual differences in the ability to detect a stimulus contingency embedded in a complex paradigm. The present study used a cognitive masking paradigm to better understand individual differences related to contingency learning. Participants were assessed on measures of electrodermal arousal and on working memory capacity before engaging in the contingency learning task. Contingency awareness was assessed both by trial-by-trial verbal reports obtained during the task and by a short post-task recognition questionnaire. Participants who became aware had fewer non-specific skin conductance responses and tended to score higher on a digit span assessment. Skin conductance level was not significantly lower in the aware group than in the unaware group. These findings are consistent with studies showing that lower arousal and greater cognitive processing capacity facilitate conscious perception of a greater breadth of information within a scene or a task.

Probing attentional dysfunctions in schizophrenia: Startle modification during a continuous performance test.

Startle eyeblink modification was measured in 20 relatively asymptomatic medicated schizophrenia outpatients and 18 matched controls in order to test for deficits in early and later stages of attentional processing during a memory-load version of the Continuous Performance Test. Participants viewed a series of digits and pressed a button after the digit 7 of each 3-7 sequence. On some trials, a startling noise burst was presented either 120 or 1200 ms following cues that a response might be needed soon (the digit 3) and also following noncues. Controls showed greater startle inhibition at 120 ms following cue than noncue prepulses, whereas patients showed equal inhibition to both, suggesting a deficiency in allocation of controlled attentional resources in early stages of processing. The patients, however, did show large startle inhibition at 120 ms when a distracting stimulus accompanied the task-relevant cue, unlike the controls, who ignored the distracting stimulus. In contrast, both groups showed equal startle inhibition 1200 ms following cue and noncue prepulses, indicating that later modality-specific attention processes are not impaired in patients during this paradigm. Both groups also showed equal inhibition at 120 ms during passively attended prepulses, suggesting that automatic attentional processes were not impaired in these patients.