The influence of visual search efficiency on the time-course of identity-based SR-compatibility

Three experiments were conducted to investigate the impact of stimulus-driven control on the time-course of stimulus-response (SR) compatibility. Participants responded to the presence or absence of a singleton arrow that was presented among multiple nontargets. When the singleton arrow was present, observers pressed a button with their right index finger, when it was absent they pressed with their left-index finger. SR-compatibility depended on the relation between the identity of the target and the present response: Even though the identity of the target singleton arrow (whether it was pointing to the right or left) was irrelevant to the task, the direction could be corresponding (right arrow) or noncorresponding (left arrow) with a target present response (the right hand). To examine the time-course of performance target-distractor similarity was varied to increase or decrease visual search efficiency and accordingly response latency. There were three main findings. First, the results of Experiment 1 showed that observers were no faster to respond 'present' when the singleton arrow pointed to the right (corresponding to the right hand) than when it pointed left (noncorresponding to the right hand) in a simple present-absent detection task. Second, only when observers were encouraged to process the identity of the arrow singleton, an effect of an SR-compatibility effect was found which developed over time. Third, the time-course of SR-compatibility was not influenced by visual search efficiency. The results of the present work suggest that visual selection and response selection occur in different stages.     

Keeping People In or Out?

Abstract : In this article I argue that the Lutheran doctrine of two kingdoms provides a good basis for the legitimate participation of all citizens in political discourse and decisions, no matter what faith they hold. The argument is backed by selected insights from philosopher Jürgen Habermas and sociologists Linda Woodhead and Paul Heelas. Against this backdrop, I suggest some challenges for a theology that addresses issues related to religion and society.     

Dividing attention lowers children's but increases adults' false memories

The present study examined the impact of divided attention on children's and adults' neutral and negative true and false memories in a standard Deese/Roediger-McDermott paradigm. Children (7- and 11-year-olds; n = 126) and adults (n = 52) received 5 neutral and 5 negative Deese/Roediger-McDermott word lists; half of each group also received a divided attention task. The results showed that divided attention affected children's and adults' false memory levels differently but did not alter true memory differently. Our results revealed a developmental shift in that divided attention lowered children's false memory rates but increased adults' false memory rates, regardless of the nature of the material (i.e., neutral or negative). Our study indicates that manipulations that target conscious processing (e.g., divided attention) result in marked qualitative and quantitative differences between children's and adults' false memories but not true memories.     

System consolidation of memory during sleep

Over the past two decades, research has accumulated compelling evidence that sleep supports the formation of long-term memory. The standard two-stage memory model that has been originally elaborated for declarative memory assumes that new memories are transiently encoded into a temporary store (represented by the hippocampus in the declarative memory system) before they are gradually transferred into a long-term store (mainly represented by the neocortex), or are forgotten. Based on this model, we propose that sleep, as an offline mode of brain processing, serves the ‘active system consolidation’ of memory, i.e. the process in which newly encoded memory representations become redistributed to other neuron networks serving as long-term store. System consolidation takes place during slow-wave sleep (SWS) rather than rapid eye movement (REM) sleep. The concept of active system consolidation during sleep implicates that (a) memories are reactivated during sleep to be consolidated, (b) the consolidation process during sleep is selective inasmuch as it does not enhance every memory, and (c) memories, when transferred to the long-term store undergo qualitative changes. Experimental evidence for these three central implications is provided: It has been shown that reactivation of memories during SWS plays a causal role for consolidation, that sleep and specifically SWS consolidates preferentially memories with relevance for future plans, and that sleep produces qualitative changes in memory representations such that the extraction of explicit and conscious knowledge from implicitly learned materials is facilitated.     

Gaze behaviour during space perception and spatial decision making

A series of four experiments investigating gaze behavior and decision making in the context of wayfinding is reported. Participants were presented with screenshots of choice points taken in large virtual environments. Each screenshot depicted alternative path options. In Experiment 1, participants had to decide between them to find an object hidden in the environment. In Experiment 2, participants were first informed about which path option to take as if following a guided route. Subsequently, they were presented with the same images in random order and had to indicate which path option they chose during initial exposure. In Experiment 1, we demonstrate (1) that participants have a tendency to choose the path option that featured the longer line of sight, and (2) a robust gaze bias towards the eventually chosen path option. In Experiment 2, systematic differences in gaze behavior towards the alternative path options between encoding and decoding were observed. Based on data from Experiments 1 and 2 and two control experiments ensuring that fixation patterns were specific to the spatial tasks, we develop a tentative model of gaze behavior during wayfinding decision making suggesting that particular attention was paid to image areas depicting changes in the local geometry of the environments such as corners, openings, and occlusions. Together, the results suggest that gaze during a wayfinding tasks is directed toward, and can be predicted by, a subset of environmental features and that gaze bias effects are a general phenomenon of visual decision making.     

Perceptual simulation in developing language comprehension

We tested an embodied account of language proposing that comprehenders create perceptual simulations of the events they hear and read about. In Experiment 1, children (ages 7–13 years) performed a picture verification task. Each picture was preceded by a prerecorded spoken sentence describing an entity whose shape or orientation matched or mismatched the depicted object. Responses were faster for matching pictures, suggesting that participants had formed perceptual-like situation models of the sentences. The advantage for matching pictures did not increase with age. Experiment 2 extended these findings to the domain of written language. Participants (ages 7–10 years) of high and low word reading ability verified pictures after reading sentences aloud. The results suggest that even when reading is effortful, children construct a perceptual simulation of the described events. We propose that perceptual simulation plays a more central role in developing language comprehension than was previously thought.     

Modulation of afterhyperpolarization evoked by doublets and increasing number of stimuli in rat motoneurons

The authors studied the influence of variable stimulation patterns on parameters of afterhyperpolarization (AHP) in rat spinal motoneurons using intracellular recording of antidromic action potentials. The action potentials analyzed were evoked by either (a) a single stimulus or pair of stimuli with gradually increasing interpulse intervals (IPI) of 5-20 ms or (b) an increasing number of stimulus pulses, from 1 to 4, at a constant IPI. It was demonstrated that modulations of AHP parameters after 2 pulses depended on the IPI, whereas the most significant changes in these parameters were found after the application of 2 or 3 stimuli in a series. The authors propose that changes in the AHP parameters have functional significance for motoneuronal firing pattern and therefore for motor unit force development during tetanic contractions.     

Factor Analysis via Components Analysis

When the factor analysis model holds, component loadings are linear combinations of factor loadings, and vice versa. This interrelation permits us to define new optimization criteria and estimation methods for exploratory factor analysis. Although this article is primarily conceptual in nature, an illustrative example and a small simulation show the methodology to be promising.     

Facilitated attentional disengagement from negative information in relation to self-reported depressive symptoms of Dutch female undergraduate students

Prior research has shown that depressive symptoms are associated with an enhanced attention toward negative stimuli and difficulty of disengaging attention from negative stimuli. The current study was an extension of a 2005 study by Koster and colleagues. A different stimulus presentation time and word set were used. The whole range of depressive symptoms was included in this sample instead of creating dichotomized groups. The Exogenous Cueing Task with negative, positive, and neutral cues was administered to 85 female undergraduate university students. Participants completed the Beck's Depression Inventory-II-NL questionnaire to measure self-reported depression. Contrary to previous findings, depressive symptoms were related to a facilitated rather than impaired attentional disengagement from negative stimuli. An explanation for the discrepancy with findings from Koster, et al. may be the different stimulus presentation time (1000 msec. instead of 500 or 1500 msec.).     

Immunizing Strategies and Epistemic Defense Mechanisms

An immunizing strategy is an argument brought forward in support of a belief system, though independent from that belief system, which makes it more or less invulnerable to rational argumentation and/or empirical evidence. By contrast, an epistemic defense mechanism is defined as a structural feature of a belief system which has the same effect of deflecting arguments and evidence. We discuss the remarkable recurrence of certain patterns of immunizing strategies and defense mechanisms in pseudoscience and other belief systems. Five different types will be distinguished and analyzed, with examples drawn from widely different domains. The difference between immunizing strategies and defense mechanisms is analyzed, and their epistemological status is discussed. Our classification sheds new light on the various ways in which belief systems may achieve invulnerability against empirical evidence and rational criticism, and we propose our analysis as part of an explanation of these belief systems’ enduring appeal and tenacity.