Robert F. Simons

Stress recovery during exposure to natural and urban environments

Different conceptual perspectives converge to predict that if individuals are stressed, an encounter with most unthreatening natural environments will have a stress reducing or restorative influence, whereas many urban environments will hamper recuperation. Hypotheses regarding emotional, attentional and physiological aspects of stress reducing influences of nature are derived from a psycho-evolutionary theory. To investigate these hypotheses, 120 subjects first viewed a stressful movie, and then were exposed to color/sound videotapes of one of six different natural and urban settings. Data concerning stress recovery during the environmental presentations were obtained from self-ratings of affective states and a battery of physiological measures: heart period, muscle tension, skin conductance and pulse transit time, a non-invasive measure that correlates with systolic blood pressure. Findings from the physiological and verbal measures converged to indicate that recovery was faster and more complete when subjects were exposed to natural rather than urban environments. The pattern of physiological findings raised the possibility that responses to nature had a salient parasympathetic nervous system component; however, there was no evidence of pronounced parasympathetic involvement in responses to the urban settings. There were directional differences in cardiac responses to the natural vs urban settings, suggesting that attention/intake was higher during the natural exposures. However, both the stressor film and the nature settings elicited high levels of involuntary or automatic attention, which contradicts the notion that restorative influences of nature stem from involuntary attention or fascination. Findings were consistent with the predictions of the psycho-evolutionary theory that restorative influences of nature involve a shift towards a more positively-toned emotional state, positive changes in physiological activity levels, and that these changes are accompanied by sustained attention/intake. Content differences in terms of natural vs human-made properties appeared decisive in accounting for the differences in recuperation and perceptual intake.

The feedback-related negativity reflects the binary evaluation of good versus bad outcomes

Electrophysiological studies have utilized event-related brain potentials to study neural processes related to the evaluation of environmental feedback. In particular, the feedback-related negativity (FRN) has been shown to reflect the evaluation of monetary losses and negative performance feedback. Two experiments were conducted to examine whether or not the FRN is sensitive to the magnitude of negative feedback. In both experiments, participants performed simple gambling tasks in which they could receive a range of potential outcomes on each trial. Relative to feedback indicating monetary gain, feedback indicating non-rewards was associated with a FRN in both experiments; however, the magnitude of the FRN did not demonstrate sensitivity to the magnitude of non-reward in either experiment. These data suggest that the FRN reflects the early appraisal of feedback based on a binary classification of good versus bad outcomes. These data are discussed in terms of contemporary theories of the FRN, as well as appraisal processes implicated in emotional processing.

To err is autonomic: Error‐related brain potentials, ANS activity, and post‐error compensatory behavior

A two-component event-related brain potential consisting of an error-related negativity (ERN/Ne) and positivity (Pe) has been associated with response monitoring and error detection. Both the ERN and Pe have been source-localized to the anterior cingulate cortex (ACC)--a frontal structure implicated in both cognitive and affective processing, as well as autonomic nervous system (ANS) modulation. The current study sought to examine the relationships among the ERN, the Pe, two autonomic measures, and behavior. Electroencephalogram (EEG), heart rate (HR), and skin conductance (SC) were recorded while subjects performed a two-choice reaction-time task. In addition to the characteristic ERN-Pe complex, errors were associated with larger SCRs and greater HR deceleration. The ERN correlated with the number of errors, but was unrelated to ANS activity and compensatory behavior. Pe, on the other hand, was correlated significantly with SCR, and both SCR and Pe were significantly correlated with post-error slowing.

Anxiety and error-related brain activity

Error-related negativity (ERN/Ne) is a component of the event-related brain potential (ERP) associated with monitoring action and detecting errors. It is a sharp negative deflection that generally occurs from 50 to 150 ms following response execution and has been associated with anterior cingulate cortex (ACC) activity. An enhanced ERN has been observed in patients with obsessive-compulsive disorder (OCD)--reflecting abnormal ACC activity hypothesized as part of the pathophysiology of OCD. We recently reported that the ERN is also enhanced in a group of college students with OC characteristics. The present study extended these findings by measuring the ERN in college undergraduates who scored high on either the Penn State Worry Questionnaire (PSWQ) or a combined version of the Snake (SNAQ) and Spider (SPQ) Questionnaires. Results indicate that, like OC subjects, subjects who score high on a measure of general anxiety and worry have enhanced error-related brain activity relative to both phobic and non-anxious control subjects. The enhanced ERN was found to generalize beyond OCD within the anxiety spectrum disorders but also shows some specificity within these disorders.

Observational, Physiological, and Self-Report Measures of Children's Anger: Relations to Reactive versus Proactive Aggression.

The goal of this study was to examine the relations of reactive versus proactive aggression to childrens anger, as assessed using observational, physiological, and self-report measures. Anger was hypothesized to be related to reactive aggression, but not to proactive aggression. Children (N = 272 second-grade boys and girls) participated in a procedure in which they lost a board game and prize to a confederate who cheated. Skin conductance reactivity and heart rate reactivity were measured throughout the procedure. Following the interaction, children viewed a videotape of the game and self-reported on their level of anger after each turn of the game. Observational coding of childrens angry facial expressions and angry nonverbal behaviors was conducted. Reactive aggression, but not proactive aggression, was positively related to skin conductance reactivity and angry nonverbal behaviors, both at an aggregated level and in terms of rate of increase over the time span of the game.

Error-related psychophysiology and negative affect ☆

The error-related negativity (ERN/Ne) and error positivity (Pe) have been associated with error detection and response monitoring. More recently, heart rate (HR) and skin conductance (SC) have also been shown to be sensitive to the internal detection of errors. An enhanced ERN has consistently been observed in anxious subjects and there is some suggestion that the ERN is related to general negative affective experience (NA). The ERN has been source localized to the anterior cingulate cortex-a structure implicated in the regulation of affective, response selection, and autonomic resources. Thus, the findings that autonomic measures and affective distress are related to response monitoring are consistent with anterior cingulate cortex function. In the present experiment, we sought to evaluate more comprehensively the relationship between self-reported negative affect and error-related physiology in a between-groups design. Results indicate that high NA was associated with significantly greater ERN and error-related SCR, and smaller Pe. These results are discussed in terms of anterior cingulate cortex function, psychopathology, and response monitoring.

Error-related brain activity in obsessive–compulsive undergraduates

Error-related negativity (ERN/Ne) is a component of the event-related brain potential (ERP) associated with monitoring action and detecting errors. It is a sharp negative deflection that generally occurs from 50 to 150 ms following response execution and has been associated with activity involving the anterior cingulate cortex (ACC). An enhanced ERN has recently been observed in patients with obsessive-compulsive disorder (OCD). We extended these findings by measuring the ERN in college undergraduates with OC characteristics as measured by the Obsessive-Compulsive Inventory (OCI). Eighteen high-OC subjects and 17 low-OC subjects performed a modified Stroop task with equal emphasis placed on speed and accuracy. Response-locked ERPs revealed a frontally maximal negativity associated with erroneous responses that was significantly larger in the high-OCI group. There were no performance differences between the two groups. Our results support the view that the characteristics associated with OCD are related to hyper-functioning error and action-monitoring processes.

Attending to affect: appraisal strategies modulate the electrocortical response to arousing pictures.

Arousing (unpleasant and pleasant) pictures elicit increased neurophysiological measures of perceptual processing. In particular, the electrocortical late positive potential (LPP) is enhanced for arousing, compared with neutral, pictures. To determine whether the magnitude of the LPP is sensitive to the way stimuli are appraised, 16 participants viewed both pleasant and unpleasant pictures and categorized them along an affective or nonaffective dimension. Results indicate that the LPP was reduced for both pleasant and unpleasant pictures when participants made nonaffective, compared with affective, judgments. These results are consistent with previous studies that have used functional neuroimaging to investigate the role of appraisal on emotional processing. The results are further discussed in terms of the utility of using the LPP to study emotion regulation.

N400 to semantically anomalous pictures and words

The N400 component of the human event-related brain potential appears to be related to violations of semantic expectancy during language comprehension. The present experiment investigated whether the N400 is related specifically to activity in a language system or is an index of a conceptual system that is accessed by both pictures and words. Sentences were visually presented one word at a time with the last word being replaced in one condition by a line drawing representing the same concept (eg, the word socks was replaced by a picture of socks). The N400 recorded in the Pictures Condition was found to be identical to the N400 generated by words in terms of amplitude, scalp distribution, and latency. These results suggest that the N400 is an index of activity in a conceptual memory that is accessed by both pictures and words.

Roll ‘em!: The effects of picture motion on emotional responses

An experiment investigated the effects of picture motion on individuals’ emotional reactions to images. Participants in the study viewed moving and still versions of 27 different images extracted from a variety of film and television programs. Subjective measures (self‐reports) and physiological data (skin conductance and heart rate) were obtained to provide convergent data on affective responses. Results indicate that picture motion significantly increased arousal, particularly when the image was already arousing. Both skin conductance and self‐report data supported this finding. Picture motion also tended to prompt more heart‐rate deceleration, most likely reflecting a greater allocation of attention to the more arousing images. In this study, the influence of picture motion on affective valence was evident only in the self‐report measures; positive images were experienced as more positive and negative images as more negative when the image contained motion.