Sequence learning and sequential effects

In a serial reaction time (RT) task with a probabilistic stimulus sequence, the length of the response-to-stimulus interval (RSI) and the sequence complexity was manipulated to investigate the relationship between sequence learning and sequential effects in serial RT tasks. Sequential effects refer to the influence of previous stimulus presentations on the RT to the current stimulus. Sequence learning is stimulus-transition specific and is demonstrated as the difference between practiced and unpracticed sequences within an interpolated random block of trials. There is a clear parallel between sequence learning and specific changes in sequential effect in the short RSI conditions, suggesting that a common mechanism may lie at the basis of sequence learning and automatic facilitation, which is responsible for sequential effects at short RSI. Importantly, the changes in sequential effects accompanying sequence learning are the same as those observed with practice in random serial RT tasks, indicating that the learning process underlying sequence learning is the same as in random tasks.     

The influence of irrelevant stimulus changes on stimulus and response repetition effects

In this study the influence of irrelevant stimulus changes from one trial to another in a serial reaction time task was investigated. Two experiments were performed in which subjects were required to respond to stimulus colour. Four colours were mapped on two response keys, so that colour and response repetition effects could be dissociated. In Experiment 1, the irrelevant stimulus dimension was location and in Experiment 2 it was shape. Both experiments were performed with a short and a long response-stimulus interval (RSI)-condition. In both experiments, the irrelevant dimension influenced the response repetition effect but not the colour repetition effect. In the reaction times, a response alternation effect was observed only when the irrelevant location of the stimulus changed in the long RSI-condition. The error rates showed a response alternation benefit for both irrelevant dimensions, in the short and the long RSI-condition. The benefit for response alternations is explained in terms of a response bias towards change that is triggered by a changing stimulus feature. We assume that the response bias is stronger for location than for colour and that accuracy is more sensitive to this bias than response latencies.     

Sequential analysis of a Simon task--evidence for an attention-shift account

 We investigated the attention-shift hypothesis of the Simon effect by analysing the effect of repeating relevant colour or irrelevant location of the stimulus in four serial reaction time tasks. In Experiment 1 with short response-stimulus intervals (RSI), we assume that there is no time to engage attention at the fixation cross before the onset of a new stimulus. In agreement with the hypothesis, Experiment 1 reveals no Simon effect when the stimulus location is repeated. In Experiment 2 with long RSI, we observe a Simon effect for location repetitions and alternations. In Experiment 3 with long RSI, we hinder the disengagement of attention by displaying the stimulus after response execution. As expected, the Simon effect is reduced for location repetitions. In Experiment 4 with stimuli additionally presented at the fixation cross, responses are faster if the attention shift towards the centrally presented stimulus corresponds with the location of the required response. Additionally, we argue that binding of the stimulus features into an object or event file better explains the so-called blocking of the automatic response-priming route after a noncorresponding trial. Received: 2 February 2000 / Accepted: 10 November 2000     

Shared spatial representations for numbers and space: the reversal of the SNARC and the Simon effects

In 4 experiments, the authors investigated the reversal of spatial congruency effects when participants concurrently practiced incompatible mapping rules (J. G. Marble & R. W. Proctor, 2000). The authors observed an effect of an explicit spatially incompatible mapping rule on the way numerical information was associated with spatial responses. The authors also observed an effect of an incompatible numerical mapping rule (if smaller than 5, press right; if larger than 5, press left) on the Simon effect. This effect was observed only when both tasks used the same effectors. The results point to a shared spatial representation for explicit spatial information (locations) and implicit spatial information (numbers).     

Parent–adolescent conflict,treatment adherence and glycemic control in Type 1 diabetes: The importance of adolescent externalising symptoms

Parent–adolescent conflict has been demonstrated to relate to treatment adherence and glycemic control in adolescents with Type 1 diabetes. The present longitudinal study investigated how these variables were interrelated over time, and examined whether externalising and internalising symptoms function as mediating variables. A total of 109 adolescents with diabetes participated at four annual time points and completed measures on conflict with parents, internalising and externalising symptoms. Information on treatment non-adherence and glycemic control was obtained from treating physicians. Cross-lagged analyses from a structural equation modelling approach indicated that father–adolescent but not mother–adolescent conflict positively influenced treatment non-adherence over time, which, in turn, was associated with higher glycosylated haemoglobin-values. Further, externalising but not internalising symptoms were found to mediate the pathway from father–adolescent conflict to treatment adherence over time. Finally, mother–adolescent conflict was found to relate indirectly to treatment non-adherence through its relationship with externalising symptoms. Hence, the present longitudinal study provides evidence that externalising symptoms represent an important mechanism through which earlier experiences of parent–adolescent conflict may influence later treatment non-adherence and poorer glycemic control. Implications and suggestions for future research are outlined.     

Family Climate of Adolescents with and Without Type 1 Diabetes: Longitudinal Associations with Psychosocial Adaptation

Family climate is theorized to influence psychosocial functioning of adolescents both with and without type 1 diabetes. Family system theory considers adolescent behavior as a function of the dynamic interactions between family members. In the present multi-informant longitudinal study, we used two-step cluster analysis to empirically derive family climates based on four family dimensions (i.e., cohesion, conflict, organization, and control) at baseline and we related these climates to longitudinal assessments of adolescent psychosocial functioning. Analyses were conducted on a total of 220 adolescents (102 with diabetes, 118 healthy controls), 217 mothers, and 168 fathers. Cluster analysis on the four FES subscales revealed the following four family climates: a cohesive (moderately high on cohesion and moderately low to low on the other dimensions), balanced (high on cohesion and organization, low on conflict), conflictual (high on conflict, low on organization and cohesion), and controlling (high on control, moderately high on conflict and organization, moderately low on cohesion) climate. Adolescents with diabetes were somewhat overrepresented in the balanced climate, and underrepresented in the cohesive and conflictual climate as compared to their healthy peers. Consistent with hypotheses, we found that adolescents raised in cohesive or balanced climates fared better in terms of internalizing symptoms, externalizing symptoms, and self-concept as compared to adolescents raised in conflictual or controlling climates. Additionally, family climate was not associated with differential changes in outcome variables over time. These finding were consistent across informants and across time. Finally, these associations were not moderated by having type 1 diabetes. Suggestions for future research and practical implications are discussed.     

Error adaptation in mental arithmetic

Until now, error and conflict adaptation have been studied extensively using simple laboratory tasks. A common finding is that responses slow down after errors. According to the conflict monitoring theory, performance should also improve after an error. However, this is usually not observed. In this study, we investigated whether the characteristics of the experimental paradigms normally used could explain this absence. More precisely, these paradigms have in common that behavioural adaptation has little room to be expressed. We therefore studied error and conflict adaptation effects in a task that encounters the richness of everyday life's behavioural adaptation--namely, mental arithmetic, where multiple solution strategies are available. In accordance with our hypothesis, we observed that post-error accuracy increases after errors in mental arithmetic. No support for conflict adaptation in mental arithmetic was found. Implications for current theories of conflict and error monitoring are discussed.     

Signals of threat do not capture, but prioritize, attention: a conditioning approach

Research suggests that threatening information captures attention more rapidly than neutral information. However, in most studies threat stimuli differ perceptually from neutral stimuli and are instrumental to perform the task, leaving the question unanswered whether threat is sufficient to capture attention. In experiment 1, we designed a visual search task with stimuli of equal salience (colored circles) that have the potential to lead to efficient search (10 ms/item). In experiment 2, one of the colors (conditioned stimulus, CS+) was made threatening by means of fear conditioning. Participants responded to a target presented in one of the circles. Overall, the search was faster on congruent trials (where the target was presented in the CS+) than on baseline trials (where the CS + was absent). Furthermore, the search was slower on incongruent trials (where the target was presented in another color than the CS+) than on baseline trials. The search on congruent trials was affected by set size (90 ms/item), but to a lesser extent than on baseline trials (105 ms/item). We conclude that threat prioritizes, but does not capture attention.     

Conflict and error adaptation in the Simon task

We present recent empirical and theoretical advances in conflict and error monitoring in the Simon task. On the basis of the adaptation by binding account for conflict adaptation and the orienting account for post-error slowing, we predict a dissociation between conflict and error monitoring. This prediction is tested and confirmed as conflict adaptation is task-specific while post-error slowing is not.     

Post-error slowing: An orienting account

It is generally assumed that slowing after errors is a cognitive control effect reflecting more careful response strategies after errors. However, clinical data are not compatible with this explanation. We therefore consider two alternative explanations, one referring to the possibility of a persisting underlying problem and one on the basis of the low frequency of errors (orienting account). This latter hypothesis argues that infrequent events orient attention away from the task. Support for the orienting account was obtained in two experiments. Using a new experimental procedure, Experiment 1 demonstrated post-error slowing after infrequent errors and post-correct slowing after infrequent correct trials. In Experiment 2, slowing was observed following infrequent irrelevant tones replacing the feedback signals.