Biomedical subjects

Robert F Simons

Publications and source records attributed to Robert F Simons.

13 recordsLinked to original sources

PubMed2006

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.

Adult↗

PubMed2006

Intentional modulation of emotional responding to unpleasant pictures: an ERP study.

Intentionally altering responses to unpleasant stimuli affects physiological and hemodynamic activity associated with emotional and cognitive processing. In the present experiment, we measured the late-positive potential (LPP) of the visually evoked event-related brain potential to examine the effects of intentional emotion modulation on electrophysiological correlates of emotional and cognitive processing. Seventeen participants received instructions to view, suppress, and enhance emotional responses to unpleasant stimuli. Results revealed significantly decreased electrophysiological activity during suppression of emotional responses beginning around 250 ms poststimulus and lasting several hundred milliseconds. These data suggest that ERPs are sensitive to emotion modulation/regulation processes.

Adult↗

PubMed2005

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.

Affect↗

PubMed2005

Error-preceding brain activity: robustness, temporal dynamics, and boundary conditions.

A recent study reported a positive modulation of the response-locked event-related brain potential (ERP) on trials preceding errors (i.e., error-1 trials). It was proposed that this error-preceding positivity (EPP) reflects the disengagement of the response monitoring system prior to errors. In three studies, we sought to replicate the EPP, and to delineate the conditions under which it can be observed. Study 1 replicated the finding of a positive modulation of the ERP on error-preceding compared to RT-matched correct-preceding trials. This enhanced positivity was not due to differences in stimulus-related processing, and a similar modulation was not observed on error-2 or error+1 trials. Studies 2 and 3 indicated that similar EPP-like phenomena could be observed across a variety of tasks, and using much longer inter-trial intervals. The onset and duration of the modulation, however, did vary between studies. These results are discussed in terms of response-locked ERPs and action monitoring.

Adolescent↗

PubMed2005

On the ERN and the significance of errors.

The error-related negativity (ERN) is an event-related brain potential observed when subjects commit errors. To examine whether the ERN is sensitive to the value of errors, the motivational significance of errors was manipulated in two experiments. In Experiment 1, low and high monetary value errors were compared to evaluate the effect of trial value on the ERN. In Experiment 2, subjects performed a flanker task both while their performance was being evaluated and during a control condition. Consistent with the notion that the error-detection system is sensitive to the significance of errors, the ERN was significantly larger on high-value trials in Experiment 1 and during evaluation in Experiment 2. There were no corresponding effects on the correct response negativity, and no behavioral differences between conditions were evident in either experiment. These results are discussed in terms of the functional role of the ERN in response monitoring.

Adult↗

PubMed2005

Brain potentials associated with expected and unexpected good and bad outcomes.

The error-related negativity (ERN) is an event-related brain potential observed when subjects receive feedback indicating errors or monetary losses. Evidence suggests that the ERN is larger for unexpected negative feedback. The P300 has also been shown to be enhanced for unexpected feedback, but does not appear to be sensitive to feedback valence. The present study evaluated the role of expectations on the ERN and P300 in two experiments that manipulated the probability of negative feedback (25%, 50%, or 75%) on a trial-by-trial basis in experiment 1, and by varying the frequency of positive and negative feedback across blocks of trials in experiment 2. In both experiments, P300 amplitude was larger for unexpected feedback; however, the ERN was equally large for expected and unexpected negative feedback. These results are discussed in terms of the potential role of expectations in processing errors and negative feedback.

Adult↗

PubMed2005

The effects of fear on performance monitoring and attentional allocation.

Evidence from event-related potential (ERP) studies indicates abnormal error processing and attentional allocation in "trait"-anxious individuals. However, few studies have been conducted that evaluate relevant ERP components during the induction of an anxious state (i.e., fear). In the present study, ERPs were measured in 16 undergraduates during control and fear induction conditions to examine the effects of fear on error processing and attentional allocation. Despite comparable performance in both experimental conditions, the ERP data indicated reductions in attentional allocation and error salience during fear induction. Fear did not appear to directly alter early error processing, as indicated by the error-related negativity, however. The implication of these results for understanding how trait and state anxiety may affect error processing and attentional allocation are discussed.

Adult↗

PubMed2004

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.

Adult↗

PubMed2004

Psychometric properties of the OCI-R in a college sample.

Two studies examined the psychometric properties of the Obsessive-Compulsive Inventory-Revised (OCI-R; Psychol. Assessment 14 (2002) 485) in a nonclinical student sample. In Study 1, we investigated the factor structure and internal consistency of the OCI-R using a sample of 395 undergraduate students. At a second testing session 1 month later, 178 students completed the OCI-R. Test-retest reliability was examined using data from 94 students who completed the OCI-R in both sessions. Convergent validity was also assessed with the Maudsley Obsessive-Compulsive Inventory (MOCI). In Study 2, we further investigated the convergent and divergent validity of the OCI-R using a new sample of 221 students who completed a battery of measures of obsessive-compulsive symptoms, worry, and depression. There was a significant order effect for both the OCI-R and the MOCI: means of each measure were significantly lower when presented second. Despite the order effect, statistical analyses indicated that the OCI-R has adequate test-retest reliability for the full scale and subscale scores, solid factor structure, and high internal consistency. Convergent validity with other measures of obsessive-compulsive symptoms was moderate to excellent, and divergent validity was good. The results indicate that the OCI-R is a short, psychometrically sound self-report measure of obsessive-compulsive symptoms.

Adult↗

PubMed2003

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.

Anxiety↗

PubMed2003

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.

Adult↗

PubMed2002

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.

Adolescent↗

PubMedDate not supplied

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 children's 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 children's 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.

Aggression↗