The N2 in go/no-go tasks reflects conflict monitoring not response inhibition

The functional significance of the N2 in go/no-go tasks was investigated by comparing electrophysiological data obtained from two tasks: a go/no-go task involving both response inhibition as well as response conflict monitoring, and a go/GO task associated with conflict monitoring only. No response was required to no-go stimuli, and a response with maximal force to GO stimuli. The relative frequency of the go stimuli (80% vs. 50%) was varied. The N2 peaked on both no-go and GO trials, with larger amplitudes for both signals when presented in a context of frequent (80%) go signals. These results support the idea that the N2 reflects conflict monitoring not response inhibition.     

The duration of response inhibition in the stop-signal paradigm varies with response force

In a previous study, we have found that the speed of stopping a response is delayed when response readiness is reduced by cuing the probability of no-go trials [Acta Psychol. 111 (2002) 155]. Other investigators observed that responses are more forceful when the probability to respond is low than when it is high (e.g. [Quart. J. Exp. Psychol. A 50 (1997) 405]). In this study, the hypothesis was tested that low probability responses are more forceful than high probability responses and that these responses are more difficult to stop. Subjects performed on a choice reaction task and on three tasks with respectively 100%, 80%, and 50% response probabilities. Stop signals were presented on 30% of the trials, instructing subjects to withhold their response. Response force on non-signal (go) trials and the duration of response inhibition on signal (stop) trials increased as response probability decreased. This pattern of findings was interpreted to support the hypothesis predicting that stopping is more difficult when response readiness is low than when it is high.     

The paradoxical effects of suppressing anxious thoughts during imminent threat

In line with the ironic processing theory of Wegner (Psychol. Rev. 101 (1994) 34), it is often argued that the suppression of anxiety-related thoughts results in a paradoxical increase of anxiety and thought intrusions, both after and during the thought suppression. In a sample of undergraduate students (14 men, 18 women), we investigated the effects of suppressing anxious thoughts about an imminent painful electrocutaneous stimulus. During thought suppression, self-reported anxiety and frequency of anxious thoughts did not increase, and duration of anxious thoughts decreased. After thought suppression, participants experienced an increase in self-reported anxiety and the frequency of anxious thoughts. There was no effect upon thought duration. The results support the idea that suppression of anxiety-related thoughts may result in a paradoxical increase in anxiety, and may cause and/or maintain anxiety problems.     

Shoot or don't shoot? Why police officers are more inclined to shoot when they are anxious

We investigated the effect of anxiety on police officers' shooting decisions. Thirty-six police officers participated and executed a low- and high-anxiety video-based test that required them to shoot or not shoot at rapidly appearing suspects that either had a gun and "shot," or had no gun and "surrendered." Anxiety was manipulated by turning on (high anxiety) or turning off (low anxiety) a so-called "shootback canon" that could fire small plastic bullets at the participants. When performing under anxiety, police officers showed a response bias toward shooting, implying that they accidentally shot more often at suspects that surrendered. Furthermore, shot accuracy was lower under anxiety and officers responded faster when suspects had a gun. Finally, because gaze behavior appeared to be unaffected by anxiety, it is concluded that when they were anxious, officers were more inclined to respond on the basis of threat-related inferences and expectations rather than objective, task-relevant visual information.     

Lying and executive control: an experimental investigation using ego depletion and goal neglect

This study investigated whether lying requires executive control using a reaction-time based lie test. We hypothesized that (1) goal neglect induced by a long response-stimulus interval (RSI; 5-8s) would make lying harder relative to a short RSI (.2 s) that promoted attentional focus, and (2) participants whose executive control resources were depleted by an initial executive control task would experience more difficulty to lie than control participants who performed a task that required little executive control. Across two experiments, the ego depletion manipulation did not reliably affect lying. Both experiments revealed that the cognitive cost associated with lying was larger for the long compared to the short RSI. This finding supports the idea that lying requires more executive control than truth telling. The manipulation of RSI may provide a simple, yet effective means to improve lie detection accuracy.     

Associations between the developmental trajectories of visual scanning and disengagement of attention in infants

The relation between the developmental trajectories of visual scanning and disengagement of attention and gaze were examined throughout early infancy. A sample of 10 infants carried out a scanning and a disengagement task with the same visual stimuli six times between 6 and 26 weeks of age. Frequency and latency measures were analyzed using multivariate multilevel models and Monte Carlo analyses. The results suggest that the ability to scan a face or an abstract stimulus evolves slightly earlier than the ability to shift gaze to a newly appeared target in the periphery. This is consistent with the account that the parvocellular stream becomes functional slightly before the magnocellular stream. The study revealed no indications of a positive association between the development of scanning and disengagement on the level of the individual infant. Scanning and disengagement change scores contrasted more with one another than could be expected on the basis of chance. This implies that the magnocellular and the parvocellular stream develop rather independently up to the age of 26 weeks.     

The Moral Judgment of Juvenile Delinquents: A Meta-Analysis

A meta-analysis of 50 studies was conducted to investigate whether juvenile delinquents use lower levels of moral judgment than their nondelinquent age-mates and, if so, what factors may influence or moderate the developmental delay. The results show a lower stage of moral judgment for juvenile delinquents (d=.76). Effect sizes were large for comparisons involving male offenders, late adolescents, delinquents with low intelligence, and incarcerated delinquents. The largest effect sizes were found for period of incarceration and comparisons involving juvenile delinquents with psychopathic disorder. Production instead of recognition measures, dilemma-free assessment methods, and non-blind scoring procedures yielded relatively large effect sizes, whereas effect sizes were medium for comparisons involving delinquents with average intelligence, non-incarcerated delinquents, female offenders, as well as early and middle adolescents. Psychopathic disorder and institutionalization were identified as unique moderators of the link between moral judgment and juvenile delinquency. It is concluded that developmentally delayed moral judgment is strongly associated with juvenile delinquency, even after controlling for socioeconomic status, gender, age and intelligence.This article stems from a paper presented at the meeting of the Association for Moral Education, July 2006, Fribourg, Switzerland.     

The automatic orienting of attention to goal-relevant stimuli

It is often assumed that attention is automatically allocated to stimuli relevant to one’s actual goals. However, the existing evidence for this idea is limited in several ways. We investigated whether words relevant to a person’s current goal influence the orienting of attention even when an intention to attend to the goal-relevant stimuli is not present. In two experiments, participants performed a modified spatial cueing paradigm combined with a second task that induced a goal. The results of the experiments showed that the induced goal led to the orientation of attention to goal-relevant words in the spatial cueing task. This effect was not found for words semantically related to the goal-relevant words. The results provide evidence for motivational accounts of attention, which state that the automatic allocation of attention is guided by the current goals of a person.