The Experience in Personal Social Systems Questionnaire (EXIS.pers): Development and Psychometric Properties

This study presents the theoretical background, development, and psychometric properties of the German and English versions of the Experience in Personal Social Systems Questionnaire (EXIS.pers). It assesses how the members of a personal social system experience their situation within that system. It is designed as a research tool for interventions in which only one member of the system participates (e.g., Family Constellation Seminars). The EXIS.pers was created to measure change on the individual level relating to one's own important personal social system. In Study 1, we used exploratory factor analysis (EFA) for latent variable identification of the original German EXIS.pers (n = 179). In Studies 2 and 3, we used confirmatory factor analysis (CFA) to examine the dimensionality of the German (n = 634) and English (n = 310) EXIS.pers. Internal consistencies and cross‐cultural structural equivalence were assessed. EFA indicated that a four‐factor model provided best fit for the German EXIS.pers. For both the German and English EXIS.pers, CFA provided the best fit for a five‐factor bi‐level model that included a general factor (Experience In Personal Social Systems) and four dimensions (Belonging, Autonomy, Accord, Confidence). Good internal consistencies, external associations, and cross‐cultural structural equivalence were demonstrated. This study provides first evidence for the German and English EXIS.pers as an economical and reliable measure of an individual's experience within his or her personal social systems.     

A fast numerical algorithm for the estimation of diffusion model parameters

In this paper, we describe a new algorithmic approach for parameter estimation in Ratcliff's [(1978). A theory of memory retrieval. Psychological Review, 85 (2), 59-108] diffusion model. This problem, especially if inter-trial variabilities of parameters are included in the model, is computationally very expensive; the parameter estimation procedure often takes a long time even with today's high-speed computers. The algorithm described here makes the calculation of the cumulative distribution functions for predicted process durations computationally much less expensive. This improvement is achieved by solving the Kolmogorov backward equation numerically instead of employing the previously used closed form solution. Additionally, the algorithm can determine the optimum fit for one of the model parameters (the starting point z) directly, thereby reducing the dimension of the parameter search space by one. The resulting method is shown to be notably faster than the standard (closed-form solution) method for parameter estimation.     

Accurate forced-choice recognition without awareness of memory retrieval

Recognition confidence and the explicit awareness of memory retrieval commonly accompany accurate responding in recognition tests. Memory performance in recognition tests is widely assumed to measure explicit memory, but the generality of this assumption is questionable. Indeed, whether recognition in nonhumans is always supported by explicit memory is highly controversial. Here we identified circumstances wherein highly accurate recognition was unaccompanied by hallmark features of explicit memory. When memory for kaleidoscopes was tested using a two-alternative forced-choice recognition test with similar foils, recognition was enhanced by an attentional manipulation at encoding known to degrade explicit memory. Moreover, explicit recognition was most accurate when the awareness of retrieval was absent. These dissociations between accuracy and phenomenological features of explicit memory are consistent with the notion that correct responding resulted from experience-dependent enhancements of perceptual fluency with specific stimuli--the putative mechanism for perceptual priming effects in implicit memory tests. This mechanism may contribute to recognition performance in a variety of frequently-employed testing circumstances. Our results thus argue for a novel view of recognition, in that analyses of its neurocognitive foundations must take into account the potential for both (1) recognition mechanisms allied with implicit memory and (2) recognition mechanisms allied with explicit memory.     

How to make your own response boxes: A step-by-step guide for the construction of reliable and inexpensive parallel-port response pads from computer mice

Psychological research is based in large parts on response latencies, which are often registered by keypresses on a standard computer keyboard. Recording response latencies with a standard keyboard is problematic because keypresses are buffered within the keyboard hardware before they are signaled to the computer, adding error variance to the recorded latencies. This can be circumvented by using external response pads connected to the computer's parallel port. In this article, we describe how to build inexpensive, reliable, and easy-to-use response pads with six keys from two standard computer mice that can be connected to the PC's parallel port. We also address the problem of recording data from the parallel port with different software packages under Microsoft's Windows XP.     

Fast-dm: A free program for efficient diffusion model analysis

In the present article, a flexible and fast computer program, called fast-dm, for diffusion model data analysis is introduced. Fast-dm is free software that can be downloaded from the authors' websites. The program allows estimating all parameters of Ratcliff's (1978) diffusion model from the empirical response time distributions of any binary classification task. Fast-dm is easy to use: it reads input data from simple text files, while program settings are specified by commands in a control file. With fast-dm, complex models can be fitted, where some parameters may vary between experimental conditions, while other parameters are constrained to be equal across conditions. Detailed directions for use of fast-dm are presented, as well as results from three short simulation studies exemplifying the utility of fast-dm.     

The aftermath of 9/11: effect of intensity and recency of trauma on outcome

Does trauma exposure have a long-term impact on the brain and behavior of healthy individuals? The authors used functional magnetic resonance imaging to assess the impact of proximity to the disaster of September 11, 2001, on amygdala function in 22 healthy adults. More than three years after the terrorist attacks, bilateral amygdala activity in response to viewing fearful faces compared to calm ones was higher in people who were within 1.5 miles of the World Trade Center on 9/11, relative to those who were living more than 200 miles away (all were living in the New York metropolitan area at time of scan). This activity mediated the relationship between group status and current symptoms of posttraumatic stress disorder. In turn, the effect of group status on both amygdala activation (fearful vs. calm faces) and current symptoms was statistically explained by time since worst trauma in lifetime and intensity of worst trauma, as indicated by reported symptoms at time of the trauma. These data are consistent with a model of heightened amygdala reactivity following high-intensity trauma exposure, with relatively slow recovery.     

Discrimination Reversal Conditioning of an Eyeblink Response is Impaired by NMDA Receptor Blockade

In the present study we examined the effects of the specific NMDA receptor antagonist CPP on discrimination reversal learning in rabbits. We report two primary findings. First, the institution of NMDA receptor blockade had no effect on a learned discrimination. Second, after stimulus reversal, CPP treatment impaired acquisition of the discrimination reversal. This impairment manifested itself early in training as a retardation in acquisition of a CR to the new CS+ and late in training as an inability to suppress responsiveness to the new CS-. Given the comparability of the present results with previously published results for phenytoin-treated rabbits, we suggest that the effects of phenytoin on learning in this paradigm is at least in part mediated by its effects on NMDA receptors. We further suggest that these findings emphasize the need to better define the role of NMDA receptor activation and hippocampally-mediated circuits in a variety of associative learning paradigms.     

A digital ultrasound recorder

A system that continuously monitors and records rodent ultrasonic vocalizations over the frequency range 10–90 kHz is described. The system records vocal frequency, sound pressure, time, and duration of call. Data are stored digitally. The system was validated by a pilot study in which distress calls of rat pups were selectively activated while they were subjected to a cold environment.     

Effects of implicit fear of failure on cognitive processing: A diffusion model analysis

Whereas previous studies suggest that individuals with high implicit fear of failure (FF) perform worse on various indicators of general performance, the underlying mechanisms of this effect have not yet been understood. In our experimental study, 280 participants worked on a binary color discrimination task. Half of the participants were frustrated by means of negative performance feedback, while the control group received mainly positive feedback. We employed a diffusion model analysis (Ratcliff in Psychol Rev 85(2):59–108, 1978) to disentangle the different components involved in the execution of the task. Results revealed that participants in the frustration condition adopted more conservative decision settings (threshold separation parameter of the diffusion model). Besides, high implicit FF was related to slow information accumulation (drift), and this relation was stronger in the frustration condition. Participants with higher FF further showed reduced learning rates during the task. Task related intrusive thoughts are discussed as mechanism for reduced performance of high FF individuals. We conclude that diffusion model analyses can contribute to a better understanding of the mechanisms underlying the effects of psychological motives.     

A mind to go out of: reflections on primary and secondary consciousness

Dreaming and waking are two brain-mind states, which are characterized by shared and differentiated properties at the levels of brain and consciousness. As part of our effort to capitalize on a comparison of these two states we have applied Edelman's distinction between primary and secondary consciousness, which we link to dreaming and waking respectively. In this paper we examine the implications of this contrastive analysis for theories of mental illness. We conclude that while dreaming is an almost perfect model of organic psychosis, it is less so for schizophrenia and major affective disorder where it must serve a primarily heuristic role helping us to model hallucinations and delusions but not the diseases themselves.