Richard W. Backs

A Comparison of Younger and Older Adults' Self-Assessment Manikin Ratings of Affective Pictures

ABSTRACT Self-Assessment Manikin (SAM) ratings were used to examine whether groups of 21 younger (M age = 20.02 years, SD = 2.28) and 21 older (M age = 66.26 years, SD = 5.64) adults had similar affective experiences to pictures from the International Affective Picture System (Lang, Bradley, & Cuthbert, 1997). The psychometrics of the SAM valence and arousal scales were also compared across age groups. Internal consistency reliability (Cronbachs alpha) was similar for younger and older adults, where both groups made less consistent valence ratings than arousal ratings. Both groups differed from the norms for valence for pleasant pictures, but were no more different from each other than they were from the norms. Age group differences were most evident in the pleasant region of the bivariate valence by arousal affective space, where younger adults found pleasant-aroused pictures to be more pleasant and arousing than older adults did. We suggest that this age group difference could be explained by greater affect intensity and surgency for the younger group and greater emotional control and leveling of positive affect for the older group.

Emotion Regulation via the Autonomic Nervous System in Children with Attention-Deficit/Hyperactivity Disorder (ADHD)

Despite growing interest in conceptualizing ADHD as involving disrupted emotion regulation, few studies have examined the physiological mechanisms related to emotion regulation in children with this disorder. This study examined parasympathetic and sympathetic nervous system reactivity via measures of respiratory sinus arrhythmia (RSA) and cardiac pre-ejection period (PEP) in children with ADHD (n = 32) and typically developing controls (n = 34), using a novel emotion task with four conditions: negative induction, negative suppression, positive induction, and positive suppression of affect. Both groups showed strong task-response effects in RSA. However, typically developing children showed systematic variation in parasympathetic activity (RSA) depending on both emotion valence (more activation for negative emotion, reduced activation for positive emotion) and task demand (more activation for suppression than induction). In contrast, children with ADHD displayed a stable pattern of elevated parasympathetic activity (RSA) across all task conditions compared to baseline. No group differences in sympathetic activity (PEP) were observed. It is concluded ADHD in childhood is associated with abnormal parasympathetic mechanisms involved in emotion regulation.

Cardiac measures of driver workload during simulated driving with and without visual occlusion.

Cardiac (heart rate, pre-ejection period, and respiratory sinus arrhythmia), performance, and visual demand measures of driver workload were obtained from 15 male university students who drove a simulated course multiple times at a fixed speed of 72.4 km/h. The course contained curves of 3 different radii (582, 291, and 194 m) and was driven with and without visual occlusion of the road scene to manipulate driver workload. Visual occlusion of the road scene significantly reduced driving performance but did not affect the cardiac measures. Driving performance significantly deteriorated and visual demand significantly increased as curve radius decreased. The cardiac measures were differentially affected by curve radius, indicating different modes of autonomic control for the 291-m curve as compared with the 582- and 194-m curves. The patterns of dissociation across the cardiac, performance, and visual demand measures were interpreted as being capable of isolating the perceptual demands of driving from the central and motor processing demands. A potential application of this research is that the combination of psychophysiological and visual occlusion methodologies are a powerful research tool to assess performance and processing resource cost trade-offs associated with using advanced in-vehicle technologies.

Psychophysiological Measures of Workload during Continuous Manual Performance

Twelve subjects (six female) participated in an experiment designed to separate the effects of perceptual/central and physical demands on psychophysiological measures of peripheral nervous system activity. The difficulty of a single-axis continuous manual tracking task was varied in two ways: order of control was manipulated to vary perceptual/central processing demand, and disturbance amplitude was manipulated to vary physical demand. Physiological measures were sensitive to the imposition of a task and were more sensitive to physical than to perceptual/central demands. A principal components analysis identified five factors (three of them physiological) that accounted for 83.1% of the observed variance. Perceptual/central processing demands specifically affected the component identified with sympathetic cardiovascular control, whereas physical demands were reflected in the component identified with parasympathetic cardiovascular control. This finding suggests that dissociations observed among cardiovascular measures in manual performance tasks are attributable to differential activation of the autonomic control systems.

Cardiac Autonomic Control During Simulated Driving With a Concurrent Verbal Working Memory Task

Objective: The objective of the study was to illustrate sensitivity and diagnosticity differences between cardiac measures and lane-keeping measures of driving performance. Background: Previous research suggests that physiological measures can be sensitive to the effects of driving and side task performance and diagnostic of the source of the attentional demands. We hypothesized that increases in side task difficulty would elicit physiological change without reduction of driving task performance and that the side task demands would elicit patterns of autonomic activity that map to specific attentional processing resources. Method: Separately and concurrently, thirty-two participants performed a simulated driving task and verbal working memory task (with two levels of difficulty, 0 back and 3 back) separately and concurrently. Attentional demands were assessed through physiological and performance measures. Results: Cardiac measures reflected changes in attentional demand from single- to dual-task driving with an n-back task, whereas lane-keeping measures did not. Furthermore, patterns of autonomic activity elicited by driving, n-back task, and dual-task driving with a 3-back task were consistent with our predictions about autonomic activity. Conclusion: Changes in cardiac measures without changes in lane-keeping measures provide evidence that cardiac measures can be sensitive to hidden costs in attention that do not manifest in coarse measures of driving performance. Furthermore, correct predictions regarding the patterns of autonomic activity elicited suggests that cardiac measures can serve as diagnostic tools for attention assessment. Application: Because of the demonstrated differences in sensitivity and diagnosticity, researchers should consider the use of cardiac measures in addition to driving performance measures when studying attention in a driving simulator environment.

Multimodal Measures of Mental Workload during Dual-Task Performance: Energetic Demands of Cognitive Processes

Fifteen male volunteers participated in a dual-task study in which the central processing load of visual memory and tracking tasks and the physical load of the tracking task were orthogonally manipulated to produce varying levels of task difficulty. Multiple modes of assessment were used to measure mental workload (MWL) across difficulty levels, including: performance, subjective, cardiovascular, and metabolic. To our knowledge, this study is the first to demonstrate metabolic change with manipulations of cognitive task difficulty; others have found only baseline-to-task changes. The relation of the metabolic demands of the task to central processing resource utilization provided support for a structural energetic model of attention that may help to explain measure dissociations. The results of the present study indicated that heart period was only sensitive to central manipulations of task difficulty that affected energetic resources. Performance and subjective MWL were sensitive to all cognitive components of the tasks. We suggest that cardiovascular measures will associate with other measures only when the manipulations of task difficulty require energetic adjustment, and would expect these measures to dissociate when energetic adjustment is not required.

Effects of obstructive sleep apnea on autonomic cardiac control during sleep

IntroductionThe present study investigated whether autonomic control of the heart for persons with low and high levels of sleep apnea/hypopnea differed between sleep stages and across the sleep period.DiscussionElectrocardiography and impedance cardiography of 24 patients referred to polysomnography were recorded through the night. A mixed repeated-measures and between-subjects, quasi-experimental design was utilized. Heart period, high frequency heart rate variability, and pre-ejection period were computed, respectively, as measure of heart rate and estimates of parasympathetic and sympathetic control. The cardiac and autonomic measures for participants with low apnea–hypopnea indices were compared to those of patients with high rates of apnea–hypopnea across the sleep period and sleep stages. Cardiac rates of the two groups decreased incrementally through the sleep period. Cardiovascular measures during sleep from the group with high rates of apnea–hypopnea indicated larger parasympathetic activation in relation to wake baseline for epochs without arousals than from the group with low apnea–hypopnea rates. Parasympathetic activation during nonrapid-eye movement (non-REM) sleep (sleep stage 2) was significantly greater than during REM sleep. Higher levels of apnea–hypopnea seem to be associated with increased parasympathetic control, especially during lighter, non-REM sleep. A possible explanation for this phenomenon is a compensatory response to oxygen desaturation caused by disturbed breathing.

Behavioral and cardiovascular responses to frustration during simulated driving tasks in young adults with and without attention disorder symptoms.

Objective: The present study examined the role of negative emotions on driving performance in relation to ADHD, by comparing young adults scoring high on measures of ADHD (n = 20) with a control group (n = 22). Method: The authors used cardiorespiratory physiological measures, simulated driving behavior, and self-report to examine how participants with high and low ADHD symptoms responded to frustration and to determine how frustration affected simulated driving performance. Results: Groups did not differ in operational driving skills, but participants with high ADHD symptoms reported more frustration and exhibited more impairment at the tactical level of driving performance than the controls. There was significant suppression of respiratory sinus arrhythmia from resting baseline during tasks, but it did not differ between groups during driving. Conclusion: This article proposes that remedial driver training for ADHD populations should focus more on the control of negative emotions rather than on attention or fundamental driving skills. (J. of Att. Dis. 2012; 16(6) 478-490)

Cardiovascular Measures of Attention to Illusory and Nonillusory Visual Stimuli

This study was an extension of the Berntson, Cacioppo, and Fieldstone (1996) study that found that attending to visual illusions presented with text (usually a question directing attention to the illusory property) lengthened heart period via uncoupled vagal activation. Eighty participants were assigned to one of four groups that received either the original Berntson et al. illusions or a modification formed by the factorial combination of whether the illusion and its related text were present or absent. Participants also performed the same serial-subtraction mental-arithmetic task from Berntson et al. During the mental-arithmetic task heart period (HP) shortened, respiratory sinus arrhythmia (RSA) was reduced, and preejection period (PEP) shortened, which indicated a reciprocally coupled sympathetic activation and parasympathetic inhibition mode of cardiac control. Although idiographic analyses found this to be the most common control mode, all other modes were also obtained – especially the nonreciproca...

Enhancing assessment of in-vehicle technology attention demands with cardiac measures

In this paper, the differences between driving performance and cardiac measures in attention assessment research are discussed, particularly with regard to evaluating in-vehicle technology design. A number of ways to enhance a set of measures for the purposes of attention assessment are discussed. Finally, the benefits of including cardiac measures as part of a set of IVT attention assessment tools are discussed.