Internal and external control: a two-factor model of amplitude change of event-related potentials

The present paper critically examines the contributions of Event-Related Potential (ERP) measures in mental chronometry research. It is argued that amplitude variations in ERP components may provide valuable information regarding the intensity and timing of information processes, and that these amplitude changes are related to energetical rather than to computational processes. It is also suggested that amplitude variations of ERP components in visual discrimination and selective attention tasks are caused by two different processing modes, denoted as external and internal control that are associated with different neural structures. It is further assumed that these two control systems converge upon thalamic neurons that regulate the sensory input to cortex, and that the direction of sustained ERP amplitude changes reflects which system is dominant. Recent ERP studies have shown that the effects of task variables related to motor control are manifested in a surprisingly early phase of the ERP waveform, and that these effects overlap in time with the effects of task variables related to input control. These findings suggest that at least in visual discrimination and selective attention tasks external and internal modes of processing may be activated in parallel.     

The temporal selectivity of additive factor effects on the reaction process revealed in ERP component latencies

An experiment was conducted to relate individual components of the event-related brain potential to specific stages of information processing in a two-choice reaction time (RT) task in a group of undergraduate students. Specifically, the latency of the P300 component and the lateralized readiness potential (LRP) were studied as a function of variations in stimulus degradation and response complexity. It was hypothesized that degrading the stimulus would delay the P300 and LRP to the same extent as RT, and that increasing response complexity would affect RT but not P300 latency. The extant literature did not permit any hypothesis regarding the effect of response complexity on LRP latency. The two task variables were found to have additive effects on RT. As predicted, variations in stimulus degradation influenced the latencies of both components, whereas alterations in response complexity had no effect on P300 latency. A significant new finding was that the onset latency of the LRP remained unchanged across levels of response complexity. The overall pattern of results supports the notion of temporal selectivity of stage manipulations that is derived from discrete stage models of human information processing. Furthermore, these results refine the functional interpretation of the LRP by indicating that within the conceptual framework of a stage model the processes this component indexes succeed the start of response choice but precede the start of motor programming.     

How Experts Adapt Their Gaze Behavior When Modeling a Task to Novices

Domain experts regularly teach novice students how to perform a task. This often requires them to adjust their behavior to the less knowledgeable audience and, hence, to behave in a more didactic manner. Eye movement modeling examples (EMMEs) are a contemporary educational tool for displaying experts’ (natural or didactic) problem-solving behavior as well as their eye movements to learners. While research on expert-novice communication mainly focused on experts’ changes in explicit, verbal communication behavior, it is as yet unclear whether and how exactly experts adjust their nonverbal behavior. This study first investigated whether and how experts change their eye movements and mouse clicks (that are displayed in EMMEs) when they perform a task naturally versus teach a task didactically. Programming experts and novices initially debugged short computer codes in a natural manner. We first characterized experts’ natural problem-solving behavior by contrasting it with that of novices. Then, we explored the changes in experts’ behavior when being subsequently instructed to model their task solution didactically. Experts became more similar to novices on measures associated with experts’ automatized processes (i.e., shorter fixation durations, fewer transitions between code and output per click on the run button when behaving didactically). This adaptation might make it easier for novices to follow or imitate the expert behavior. In contrast, experts became less similar to novices for measures associated with more strategic behavior (i.e., code reading linearity, clicks on run button) when behaving didactically.     

A computational account of altered error processing in older age: Dopamine and the error-related negativity

When participants commit errors or receive feedback signaling that they have made an error, a negative brain potential is elicited. According to Holroyd and Coles’s (in press) neurocomputational model of error processing, this error-related negativity (ERN) is elicited when the brain first detects that the consequences of an action are worse than expected. To study age-related changes in error processing, we obtained performance and ERN measures of younger and high-functioning older adults. Experiment 1 demonstrated reduced ERN amplitudes in older adults in the context of otherwise intact brain potentials. This result could not be attributed to uncertainty about the required response in older adults. Experiment 2 revealed impaired performance and reduced response- and feedback-related ERNs of older adults in a probabilistic learning task. These age changes could be simulated by manipulation of a single parameter of the neurocomputational model, this manipulation corresponding to weakened phasic activity of the mesencephalic dopamine system.     

Effects of stop-signal probability in the stop-signal paradigm: the N2/P3 complex further validated

The aim of this study was to examine the effects of frequency of occurrence of stop signals in the stop-signal paradigm. Presenting stop signals less frequently resulted in faster reaction times to the go stimulus and a lower probability of inhibition. Also, go stimuli elicited larger and somewhat earlier P3 responses when stop signals occurred less frequently. Since the amplitude effect was more pronounced on trials when go signals were followed by fast than slow reactions, it probably reflected a stronger set to produce fast responses. N2 and P3 components to stop signals were observed to be larger and of longer latency when stop signals occurred less frequently. The amplitude enhancement of these N2 and P3 components were more pronounced for unsuccessful than for successful stop-signal trials. Moreover, the successfully inhibited stop trials elicited a frontocentral P3 whereas unsuccessfully inhibited stop trials elicited a more posterior P3 that resembled the classical P3b. P3 amplitude in the unsuccessfully inhibited condition also differed between waveforms synchronized with the stop signal and waveforms synchronized with response onset whereas N2 amplitude did not. Taken together these findings suggest that N2 reflected a greater significance of failed inhibitions after low probability stop signals while P3 reflected continued processing of the erroneous response after response execution.     

Effects of mixed versus blocked design on stimulus evaluation: combining underadditive effects

According to the asynchronous discrete coding model of Miller, two manipulations should display underadditive effects on reaction time if they slow down noncontingent stages associated with the processing of two separable dimensions of a stimulus. Underadditive effects are also predicted by a dual route model when a task variable is factorially varied with design type (mixed vs blocked). Interpretations of both underadditive effects and their combination were evaluated. Intact and degraded stimuli were presented to 18 young adults either in a single block (mixed) or in separate blocks (blocked). Spatial stimulus-response (S-R) compatibility was manipulated in all conditions. Stimulus degradation and S-R compatibility interacted underadditively, but only in blocked presentations. Both interpretations of underadditive effects were supported. Eye-movement registrations provided additional support for the alternative routes model.     

Maternal attachment representations after very preterm birth and the effect of early intervention

Objective

For very preterm infants the mother-infant relationship may be compromised. Maternal attachment representations 18 (corrected) months after very preterm birth and the effect of the post-discharge Infant Behavioral Assessment and Intervention Program (IBAIP) were studied. The IBAIP is designed to assist parents to support and enhance their infant's regulatory competence and development. The intervention consisted of 6-8 home visits during the first 8 months after birth.

Method

Seventy-eight mothers of very preterm infants (<32 weeks and/or <1500 g) were interviewed, who participated in a randomized controlled trial: 41 from the intervention group and 37 from the control group. Maternal attachment representations were assessed with the Working Model of the Child Interview (WMCI). The interviews resulted in a classification of the attachment representations into balanced or non-balanced.

Results

30% of the mothers had non-balanced attachment representations. Qualitative content analysis of the answers showed that negative feelings when first seeing their baby and negative or ambivalent feelings in the first weeks at home with their baby are related to non-balanced attachment representations. The WMCI revealed no differences between the intervention and control group.

Conclusion

Early support for mothers of very preterm born infants to develop a healthy mother-infant relationship is recommended especially for mothers who report negative first experiences.     

Effectiveness of Specific Techniques in Behavioral Teacher Training for Childhood ADHD Behaviors: Secondary Analyses of a Randomized Controlled Microtrial

Research on Child and Adolescent Psychopathology - Behavioral teacher training is an effective intervention for children with attention-deficit/hyperactivity disorder (ADHD). Intervention...     

Condom use in steady and casual sexual relationships: Planning, preparation and willingness to take risks among adolescents

Condom use within steady and casual sexual relationships was examined among 14-16 year old Dutch adolescents from secondary school (N?=?140). It was hypothesised that among adolescents sex and subsequently condom use with casual sex partners is less likely to be considered in advance, more context-dependent and less habitual; whereas the opposite is true for steady relationships. Therefore, preparatory behaviours (buying and carrying condoms and communicating about condom use) were expected to mediate the intention-behaviour relation in the context of steady relationships, but not in the context of casual sex. Results confirmed that condom use with steady sex partners was explained by preparatory behaviours, habits, and to some extent, behavioural willingness, and that preparatory behaviours mediated the intention-behaviour relationship. Condom use with casual sex partners was predicted by risk willingness and intentions, without any mediation by preparatory behaviours. The results indicate that it is essential to increase awareness among adolescents that unexpected sexual situations may occur and to train them to take preparatory actions.