Rainer H. Kluwe

Cognitive Knowledge and Executive Control: Metacognition

The domain of psychological research with regard to metacognition is discussed on the basis of a distinction between declarative and procedural knowledge in information processing systems. According to these types of knowledge, one can distinguish between a person’s cognitive knowledge and executive processes. Cognitive knowledge refers to a person’s stored information about human thinking, especially about the features of his own thinking. Executive processes refer to cognitive activity directed at the monitoring of the application and the effects of solution strategies and at the regulation of the course of one’s own thinking. The subject of psychological research of metacognition is considered to be the control of activity in information processing systems.

Preparatory Processes in the Task-Switching Paradigm: Evidence From the Use of Probability Cues

The purpose of the investigations was to dissociate processes of task preparation from task execution in the task-switching paradigm. The basic assumption was that task repetitions have 2 advantages over task shifts: an activation advantage as a result of the execution of the same task type in the pretrial, and an expectation advantage, because participants, in general, implicitly expect a repetition. In Experiments 1-3, the authors explicitly manipulated expectancies by presenting cues that announced a shift and/or a repetition with probabilities of 1.00, .75, .50, or .25. Increasing latencies with decreasing probability for shifts and repetitions show that the expectation advantage can be equalized by preparation. However, the activation advantage represented by constant shift costs between tasks of the same probability is not penetrable by preparation. In Experiments 4 and 5, the authors found evidence that preparation involves activation of the expected task and inhibition of distracting tasks.

Sequential modulations of interference evoked by processing task-irrelevant stimulus features

Compatibility level repetition benefits in interference paradigms have been taken to reflect enhanced processing selectivity in response to cognitive conflict elicited by a task-irrelevant stimulus feature. The authors demonstrate such sequential effects in the Simon task which (a) occur independent of previous behavioral conflict effects and (b) cannot be accounted for by selectivity enhancement. Furthermore, when presenting more than one type of irrelevant stimulus features, compatibility level repetition effects occurred in a type-specific manner. The results do not support the notion that cognitive conflict results in enhanced processing selectivity and favor a feature integration account.

Disentangling Sequential Effects of Stimulus- and Response-related Conflict and Stimulus-Response Repetition using Brain Potentials

Conflict monitoring theory holds that detection of conflicts in information processing by the anterior cingulate cortex (ACC) results in processing adaptation that minimizes subsequent conflict. Applying an Eriksen f lanker task with four stimuli mapped onto two responses, we investigated whether such modulation occurs only after response-related or also after stimulus-related conflict, focusing on the N2 component of the event-related potential. Contrasting with previous findings, both stimulus- and response-related conflict elicited enhancement of the N2, suggesting that the ACC is sensitive to conflict at both the stimulus and the response level. However, neither type of conflict resulted in reduced conflict effects on the following trial when stimulus-response (S-R) sequence effects were controlled by excluding identical S-R repetition trials. Identical S-R repetitions were associated with facilitated processing, thus demonstrating that inclusion of these trials in the analysis may mimic results predicted by the conflict adaptation hypothesis.

Backward Inhibition as a Means of Sequential Task-Set Control: Evidence for Reduction of Task Competition

Endogenously initiated transitions between tasks are associated with inhibition of the attentional set for the task preceding the transition, as demonstrated by slowed reactions to a task most recently switched away from (U. Mayr & S. W. Keele, 2000). Using an altered methodological approach, the authors found that this backward inhibition counteracts perseverative tendencies when switching to a new task in that it selectively reduces interference exerted by the preceding task set. The reduction of interference was dependent on endogenous preparation for the new task and did not occur for unpredictable task switches or for task switches that were precued without information about the identity of the new task.

Location-specific versus hemisphere-specific adaptation of processing selectivity

Current theories of cognitive control assume that processing selectivity is adjusted according to the utility of processing task-irrelevant stimulus features. Consistently, interference evoked by flanker stimuli is reduced when the proportion of incompatible trials—in which flankers are associated with an incorrect response—is increased. Consistent with the idea that the cerebral hemispheres select processing strategies independently of each other, Corballis and Gratton (2003) demonstrated that flanker interference for stimuli presented in either the left or right visual hemifield is affected by the ratio of compatible and incompatible target-flanker pairings presented in the same—but not in the other—hemifield. Presenting stimuli at four different locations, we demonstrated independent effects of the ratio of compatible and incompatible trials for stimulus locations in different hemifields as well as for stimulus locations within the same hemifield. Independent selectivity adjustment regarding the left and right visual hemifields thus appears to be a special case of a larger class of location-specific adaptation effects and might not be informative regarding hemisphere-specific processing.

Response Selection Difficulty and Asymmetrical Costs of Switching Between Tasks and Stimuli: No Evidence for an Exogenous Component of Task-Set Reconfiguration.

Four task-switching experiments examined the notion of an exogenous component of task-set reconfiguration (i.e., a process needed to shift task set that is not initiated in the absence of a task-associated figuration stimulus). The authors varied the complexity and familiarity of stimulus-response (SR) mapping rules to produce differentially time-consuming reconfiguration demands. Tasks with more complex or less familiar rules did not display increased switch costs, given that stimulus repetitions were excluded from the analysis. These results do not support the idea of exogenous reconfiguration. Moreover, stimulus repetitions inflated task-switch costs and did so disproportionately for tasks with increased response selection difficulty, thereby demonstrating that insufficient control of the sequence of stimuli may yield results that mimic those predicted by exogenous reconfiguration accounts.

Task Switching and Backward Inhibition in Obsessive-Compulsive Disorder

The presumed involvement of the prefrontal cortex in the pathogenesis of obsessive-compulsive disorder (OCD) has fueled growing interest in cognitive paradigms with a putative sensitivity to this brain region. Measures of inhibition and executive functioning are thought to be promising in this regard. To our knowledge, this is the first study that has investigated task switching in OCD captures an important aspect of a paradigm that executive control, namely the preparation for an upcoming task. It was speculated that task switching costs would be enhanced in OCD patients, reflecting a fundamental deficit to quickly control the stream of thoughts. In addition, the paradigm allowed the measurement of backward inhibition, that is the time costs afforded for the re-engagement of a previously irrelevant task. A sample of 40 OCD patients, 20 psychiatric controls with anxiety disorders other than OCD as well as 20 healthy controls was investigated. Contrary to expectation, task switching costs were not elevated in OCD patients. Although anxiety control patients failed to display robust backward inhibition, group comparisons did not reach significance. Implications for future research are discussed.

Intentionale Steuerung kognitiver Prozesse

ZusammenfassungGegenstand des Beitrags sind neuere Forschungsansätze zu Mechanismen der intentionalen Kontrolle und Steuerung kognitiver Aktivität. Gängige Modelle zur Abbildung von Steuerungsvorgängen legen in der Regel eine zentrale Steuerungsinstanz zugrunde (zentrale Exekutive), die als einheitlich, kapazitätsbegrenzt und autonom gilt. Diese Annahmen werden durch neuere experimentelle Ergebnisse kognitionspsychologischer Forschung nicht unterstützt. Gleiches gilt für Befunde aus (PET)-Studien sowie aus neuropsychologischen Untersuchungen an Patienten mit Läsionen des präfrontalen Cortex. Derzeit lassen sich spezifische Funktionen für die Steuerung kognitiver Aktivität noch nicht ausreichend mit anatomischen Strukturen verbinden. Aus empirischen Untersuchungen resultiert jedoch eine Befundlage, die eine Beteiligung anatomisch separierbarer Netzwerke wahrscheinlich machen. Diskutiert wird unter anderem, daß sich dorsolaterale Areale des präfrontalen Cortex in Verbindung mit dem Cingulum anterior hinsichtlich spezifischer Steuerungsfunktionen von ventralen Arealen unterscheiden lassen.SummaryThe article is concerned with recent empirical approaches in the domain of control of mental processes. Models for intentional control of cognitive activity usually postulate a central, unitary subsystem, central executive, with limited capacity. Recent data resulting from experimental research in cognitive psychology do not support these assumptions. Also from PET-studies, and from neuropsychological studies of patients with lesions of prefrontal cortical areas no clear cut picture with regard to the control problem can be derived. Though it is not yet possible to attribute specific control functions to different cortical structures, there is empirical evidence supporting the notion of anatomically separate networks. Among others, a distinction is discussed referring to different control functions of the dorsolateral prefrontal areas together with the anterior cingulate compared to the ventral areas.

Understanding and Problem-Solving

In this chapter, results from empirical studies will be reported that refer to two domains of cognitive developmental research: (1) problem-solving performance and (2) understanding the general principles of a problem situation in terms of verbalizable knowledge. The first study is concerned with problem-solving performance, and examines children’s ability to tune their own problem-solving behavior flexibly given different situational demands. The second study is directed at children’s understanding of the cognitive demands associated with specific situational characteristics.