The effect of stress on the suppression of erroneous competing responses

Abstract

Evidence exists that the intention to perform certain cognitive tasks activates, unintentionally, competing responses and computations that intrude on the performance of the intended tasks. For the intended task to be performed effectively, such intrusions must be controlled. Two experiments were carried out to test the hypothesis that stress heightens the difficulty of exercising effective control over erroneous competing responses, a possible explanation of decrements in the performance of cognitive tasks under stress. Participants performed four tasks, which contained features that could potentially prime or activate erroneous responses. The results demonstrated that the interference of these features with performance was more pronounced among stressed than among less-stressed participants. The need for a more comprehensive theory of the effects of stress on information processing is discussed.     

The effect of knowledge of mathematics on gambling behaviours and erroneous perceptions

This study evaluates the effect of knowledge of mathematics as a protective factor against excessive gambling behaviours and erroneous beliefs. Two groups with different levels of knowledge of mathematics were compared as to their perceptions and behaviours before and during a gambling session. A total of 60 participants (30 men, 30 women) completed a questionnaire evaluating how they perceive the notion of chance and participated in two experimental tasks: the production of a random sequence of heads/tails, and a gambling session on a video lottery terminal. The results show that participants with knowledge of mathematics held more erroneous perceptions of gambling before the experiment whereas both groups showed an equal number of erroneous perceptions and behaviours during gambling. The importance of knowledge of mathematics as a protective factor against excessive gambling is questionable. The theoretical and practical implications of these results are discussed with regard to the prevention of excessive gambling.     

The effect of superstitious thinking on psychosocial stress responses and perceived task performance

Previous research on superstitious belief, a subset of paranormal belief (Irwin, 1993 ), has suggested that people tend to invoke luck‐related superstitions in stressful situations as an attempt to gain an illusion of control over outcomes. Based on this, the current study examined whether luck‐related superstition, in the form of a “lucky” pen, could influence the psychological response to a psychosocial stressor. Participants (N = 114), aged between 17 and 59 years (M = 22.98, SD = 4.57) from James Cook University Singapore, were randomly assigned to one of four conditions: (a) no‐stress with no lucky pen; (b) no‐stress with a lucky pen; (c) stress with no lucky pen or; (d) stress with a lucky pen. The results revealed that participants provided with a lucky pen experienced lower state anxiety when exposed to the stressor. Further, participants provided with a lucky pen perceived their performance to be better than those without it. However, superstitious belief did not significantly change following exposure to stress. Taken together, the present findings add some support to the suggestion that belief in transferable luck may facilitate coping with a stressor. However, further research is needed to fully understand the mechanisms behind the potential benefits of superstitious belief.     

Reconsideration of the role of competing responses in demonstrations of the interference effect (learned helplessness)

In Experiment 1a, rats trained to escape shock by performing a 2-s inactive response were less impaired on a subsequent 2-way shuttle response than their yoked counterparts that received inescapable shock. In contrast, in Experiment 1b, rats trained to escape shock by performing a longer duration inactive response were more impaired on the subsequent escape task than their inescapably shocked counterparts. In Experiment 2, the results of Experiments 1a and 1b were replicated, and the inactive responses performed during pretreatment by both the escapable and inescapable shock groups were assessed and correlated with test stage 2-way shuttle escape performance. These activity data indicate that inactivity during pretreatment shock in both escapable and inescapable shock groups was a highly reliable predictor of subsequent 2-way shuttle performance, irrespective of the pretreatment shock contingency to which these Ss were exposed.     

The effect of contrast on the completeness of binocular rivalry suppression

Binocular rivalry between orthogonal sine wave gratings was studied by asking subjects to indicate when they saw just one or the other grating, as opposed to a composite. Using this measure, it was found that the completeness of rivalry (1) usually increased with grating contrast; (2) increased as a trial progressed, up to about 40 sec; and (3) depended on spatial frequency, with the optimal spatial frequency being lower than that at which contrast sensitivity was maximal. These findings supplement what has been learned about rivalry by other methods.     

The effect of stress on inflammation

Stress can either enhance or suppress aspects of the immune response, depending on the nature, duration, timing and intensity of the stressor. This paper focuses on the effects on inflammation of two behavioural stress paradigms: learned helplessness (La) and the open-field test (OF), and of the immunological stressor lipopolysaccharide (LPS). We have observed that the onset and severity of inflammation in adjuvant-induced arthritis (AA) in the rat can be altered by experience of the LH paradigm, or by priming with LPS, but not by OF.In the LH test, some rats escape (LH(-)) and others do not (LH(+)). Despite the LH(-) group demonstrating a greater corticosterone response to the LH stressor compared to the LH(+)rats, they exhibited earlier onset and greater seventy of AA. In contrast, intraperitoneal injection of LPS several weeks prior to induction of AA protected against inflammation. These results provide further evidence that environmental factors influence the etiology of at least one type of inflammation. The modulation of inflammation by a defined stressor suggests that understanding of the underlying mechanisms may provide a potential for novel therapies.     

基于干扰物特征的统计规则对注意抑制效应的影响

采用经典的额外单例范式的变式, 通过操纵基于干扰物颜色的统计规则, 考察其对注意抑制效应的影响。结果发现：(1)当迫使被试采取特征探测策略时, 与无颜色独子的条件相比, 被试在所有呈现独子的条件中反应都显著较快; (2)与呈现低概率颜色独子条件相比, 呈现高概率颜色独子条件下被试的反应显著较快。研究表明, 统计规则对注意的影响不局限于刺激位置, 基于干扰物特征的统计规则也会影响注意抑制效应的大小。     

Unilateral neglect: the effect of competing stimuli on estimated line length

Normal subjects and patients with right hemisphere lesions with or without signs of left unilateral neglect judged the length of a horizontal line presented on the left or on the right side of space. In half of the trials, the line was presented with a centrally located square or diamond, and subjects had to identify the central stimulus before performing the judgment of length. The presence of the central stimulus improved accuracy of performance in controls and in patients without neglect; neglect patients, however, produced more overestimations of left-sided lines when these was presented with a central stimulus than when the lines occurred in isolation. This finding underlines the importance of attentional factors in length estimates performed by neglect patients in their neglected space.     

The role of neuroticism on psychological and physiological stress responses

This study examined the influence of personality on stressor appraisals and emotional, physiological, and behavioral responses to psychosocial stress. Appraisals were used to classify participants as threatened (they believed their coping resources were inadequate relative to stressor demands) or challenged (they believed their coping resources were commensurate with stressor demands). Neuroticism predicted threat appraisals, and both were related to negative emotional experience and poor task performance. The influence of neuroticism on negative emotions and poor performance was mediated by threat appraisals. High neuroticism confers stress vulnerability, but only when conditions are construed as threatening.     

Echo suppression and discrimination suppression aspects of the precedence effect

The precedence effect is a phenomenon that may occur when a sound from one direction (the lead) is followed within a few milliseconds by the same or a similar sound from another direction (the lag, or the echo). Typically, the lag sound is not heard as a separate event, and changes in the lag sound’s direction cannot be discriminated. The hypothesis is proposed in this study that these two aspects of precedence (echo suppression and discrimination suppression) are at least partially independent phenomena. Two experiments were conducted in which pairs of noise bursts were presented to subjects from two loudspeakers in the horizontal plane to simulate a lead sound and a lag sound (the echo). Echo suppression threshold was measured as the minimum echo delay at which subjects reported hearing two sounds rather than one sound; discrimination suppression threshold was measured as the minimum echo delay at which subjects could reliably discriminate between two positions of the echo. In Experiment 1, it was found that echo suppression threshold was the same as discrimination suppression threshold when measured with a single burst pair (average 5.4 msec). However, when measured after presentation of a train of burst pairs (a condition that may produce “buildup of suppression”), discrimination suppression threshold increased to 10.4 msec, while echo suppression threshold increased to 26.4 msec. The greater buildup of echo suppression than of discrimination suppression indicates that the two phenomena are distinct under buildup conditions and may be the reflection of different underlying mechanisms. Experiment 2 investigated the effect of the directional properties of the lead and lag sounds on discrimination suppression and echo suppression. There was no consistent effect of the spatial separation between lead and lag sources on discrimination suppression or echo suppression, nor was there any consistent difference between the two types of thresholds (overall average threshold was 5.9 msec). The negative result in Experiment 2 may have been due to the measurements being obtained only for single-stimulus conditions and not for buildup conditions that may involve more central processing by the auditory system.     

When seeing what's wrong makes you right: The effect of erroneous examples on 3D diagram learning

Comprehending 3D diagrams is critical for success in scientific practice and research demonstrates that understanding of 3D geology diagrams can be improved by making predictive sketches. In mathematics, explaining erroneous examples can support learning. This study combined these approaches to better understand how to effectively support 3D geologic diagram understanding. Participants generated sketches, explained erroneous example sketches, or copied and explained correct sketches. It was hypothesized that generating sketches or explaining erroneous cases would improve understanding, but an open question was whether these conditions would differ from each other. Explaining erroneous examples and sketching improved understanding whereas explaining correct sketches did not. Further, explaining erroneous examples was a more efficient strategy than sketching. These results indicate that erroneous examples can be effective for supporting 3D diagram comprehension and may be a practical substitute for some traditional sketching activities in the context of real classrooms where class time is limited.     

Medial prefrontal cortex lesions abolish contextual control of competing responses

There is much debate as to the extent and nature of functional specialization within the different subregions of the prefrontal cortex. The current study was undertaken to investigate the effect of damage to medial prefrontal cortex subregions in the rat. Rats were trained on two biconditional discrimination tasks, one auditory and one visual, in two different contexts. At test, they received presentations of audiovisual compounds of these training stimuli in extinction. These compounds had dictated either the same (congruent trials) or different (incongruent trials) responses during training. In sham-operated controls, contextual cues came to control responding to conflicting information provided by incongruent stimulus compounds. Experiment 1 demonstrated that this contextual control of responding was not evident in individual rats with large amounts of damage that included the prelimbic and cingulate subregions of the prefrontal cortex. Experiment 2 further dissociated the result of Experiment 1, demonstrating that lesions specific to the anterior cingulate cortex were sufficient to produce a deficit early on during presentation of an incongruent stimulus compound but that performance was unimpaired as presentation progressed. This early deficit suggests a role for the anterior cingulate cortex in the detection of response conflict, and for the medial prefrontal cortex in the contextual control of competing responses, providing evidence for functional specialization within the rat prefrontal cortex.     

Effects of increased response effort on self-injury and object manipulation as competing responses

We evaluated the effects of a response-effort intervention on the occurrence of self-injurious hand mouthing and a competing response (object manipulation) with 4 individuals who had profound developmental disabilities. During Phase 1, results of functional analyses showed that all participants engaged in high levels of hand mouthing in the absence of social contingencies, suggesting that the behavior was maintained by automatic reinforcement. In Phase 2, preferred leisure items were identified for participants during assessments in which duration of leisure item manipulation was used as the index of preference. In Phase 3, participants were observed to engage in high levels of hand mouthing and in varying levels of object manipulation when they had free access to their most preferred leisure items during baseline. The effects of increased response effort on hand mouthing and object manipulation were then evaluated in mixed multiple baseline and reversal designs. The response-effort condition was identical to baseline, except that participants wore soft, flexible sleeves that increased resistance for elbow flexion but still enabled participants to engage in hand mouthing. Results showed consistent decreases in SIB and increases in object manipulation during the response-effort condition for all participants. These results suggested that a less preferred reinforcer (produced by object manipulation) may substitute for a more highly preferred reinforcer (produced by hand mouthing) when response effort for hand mouthing was increased. DESCRIPTORS: self-injurious behavior, automatic reinforcement, reinforcer substitutability, response effort