Response conflict determines sequential effects in serial response time tasks with short response-stimulus intervals

In serial choice reaction time (RT) tasks, performance in each trial critically depends on the sequence of preceding events. In this study, the authors specifically examined the mechanism underlying RT sequence effects at short response-stimulus intervals (RSIs), in which performance is impaired in the current trial N if events alternate rather than repeat from trial N-2 to trial N-1. Different accounts of this RT pattern in terms of perceptual noise, response-selection monitoring, and response conflict were tested in 4 experiments. Second-order RT costs were caused by the response sequence rather than the stimulus sequence. Manipulation of stimulus contrast, stimulus classification difficulty, and set-level compatibility did not modulate the response-related second-order RT effect, whereas this effect increased when spatially incompatible responses were demanded. These findings support a response conflict account of higher order sequential effects in short-RSI situations.     

Ecosystems and society: Implications for sustainable development

Human systems are interacting with, and dependent on, the global ecosystem. These complex interconnected systems have to obey natural laws and system laws in order to remain viable in the long‐term. “Sustainable development” therefore has to adhere to certain principles and constraints which derive partially from physical conditions, partially from principles of (evolving) ecosystems, partially from principles applying to human systems with conscious actors and normative standards. Although “sustainable development” constrains the spectrum of permissible processes, it does not define a final steady state. The development process must be guided by reference to an ethical principle and to the balanced satisfaction of the basic orientors resulting from a system's interaction with its environment. The systems perspective required encompasses a wide range of scientific disciplines, for which a comprehensive bibliography is provided.     

Executive control in the Simon task: A dual-task examination of response priming and its suppression

Executive control processes are supposed to regulate behaviour and to resolve conflicts in information processing. Recently, Stürmer and colleagues (Stürmer et al., 2002; Stürmer & Leuthold, 2003) reported electrophysiological findings in a Simon task that indicated control over a location-based processing route that mediates response priming. Importantly, when a response conflict occurred on a given trial, a suppression of response priming on the immediately following trial was demonstrated. The present study examines boundary conditions of such control in the Simon paradigm by comparing single-task with dual-task performance. In four experiments a second task, alternating trial-by-trial with the Simon task, was systematically manipulated in its control demands. Whereas reaction time (RT) analysis of single-task conditions revealed the absence of location-based response priming in the Simon task, such priming reappeared when the second task required an overt response. In contrast, working memory load as such did not touch the Simon effect. Therefore, not the response conflict itself but capacity-limited response monitoring processes seem to be critical for executive control in the Simon task and the suppression of response priming.     

Hindsight bias in political elections

Two studies on political hindsight bias were conducted on the occasions of the German parliament election in 1998 and the Nordrhein-Westfalen state parliament election in 2000. In both studies, participants predicted the percentage of votes for several political parties and recalled these predictions after the election. The observed hindsight effects were stronger than those found in any prior study on political elections (using percentage of votes as the dependent variable). We argue that the length of the retention interval between original judgement and recollection is mainly responsible for this difference. In our second study, we investigated possible artifacts in political hindsight biases using a control-group design where half of the participants recalled their predictions shortly before or after the election. Hindsight bias was preserved, reinforcing the results of earlier studies with non-control-group designs. Finally, we discuss the possibility that the hindsight experience (in political judgement and in general) actually consists of three different, partly independent components.     

Differential effect of ill-being and chronic stress on cradling behavior of first and multi-time parents

A preference for cradling infants on the left side has been demonstrated in women, as has a relation of reduced left-cradling and stress/negative affect. This relation has not yet been investigated in male participants. Due to less left-cradling in non-fathers compared to fathers it was suggested that fatherhood might have an influence on cradling behavior. The present study investigated the cradling preference of first- and multi-time parents before and after birth, and its relation to ill-being and stress. Results revealed that cradling behavior of first-time fathers was not different before and after the birth of the infant. Thus, fatherhood does not seem to have an acute influence on cradling behavior. Furthermore, cradling behavior of first- and multi-time parents was differentially influenced by ill-being and stress.These results present new information about the course of cradling preference from pregnancy to postpartum and indicate that the relation of cradling and ill-being/stress is more complex for parents than for non-parents.     

Schema and deviation effects in remembering repeated unfamiliar stories

In today's globalized world, we frequently encounter unfamiliar events that we may have difficulty comprehending – and in turn remembering – due to a lack of appropriate schemata. This research investigated schema effects in a situation where participants established a complex new schema for an unfamiliar type of story through exposure to four variations. We found that immediate recall increased across subsequent stories and that distortions occurred less frequently – participants built on the emerging schema and gradually established representations of parts of the story that were initially transformed. In recall with delays increasing up to 1 month, quantitative measures indicated forgetting while distortions increased. The second focus of this research was on content and order deviation effects on recall. The content deviation, in contrast with previous repeated-event research, was not remembered well and was associated with lower recall; the order deviation had a similar (but expected) effect. We discuss discrepancies between results of this study and previous literature, which had focused on schemata for familiar events, in relation to stages of schema development: it seems that in unfamiliar repeated events, a complex new schema is in the early stages of formation, where the lack of attentional resources limits active processing of deviations.