D-cycloserine facilitates context-specific fear extinction learning

D-cycloserine (DCS) may facilitate fear extinction learning, but the behavioral consequences and mechanisms behind this effect are not well understood at present. In this paper, we re-analyze data from previously reported null result experiments and find that rats showing above-median extinction learning during DCS treatment benefited from the drug, whereas rats showing below-median (and in this case little) extinction learning did not. Two additional experiments found that DCS facilitated extinction learning when specifically combined with a moderate, but not a small, number of extinction trials. DCS thus facilitates extinction learning only if the behavioral procedure first engages the extinction learning process. The benefits of the drug, however, were specific to the context in which extinction was learned--i.e., DCS did not prevent or influence the renewal of fear observed when the extinguished cue was tested in the original conditioning context.     

Intra-amygdala anxiogenic drug infusion prior to retrieval biases rats towards the use of habit memory

In a dual-solution plus-maze task that can be acquired using either hippocampus-dependent "cognitive/place" learning or dorsal striatal-dependent "habit/response" learning, pre-acquisition peripheral or intra-basolateral amygdala (BLA) injections of anxiogenic drugs result in the predominant use of response learning. The present experiments examined the effect of anxiogenic drug treatment on the relative use of multiple memory systems when administered prior to memory retrieval. Adult male Long-Evans rats were trained for two days (6 trials/day, 30s ITI) in a dual-solution plus-maze task to swim from the same start point (south) to an escape platform that was located in a consistent goal arm (west). On day three, prior to a memory retrieval probe trial from a novel start point (north), rats received a peripheral (0.03, 0.1 or 0.3 mg/kg), or intra-BLA (0.1 microg/0.5 microl) injection of the anxiogenic alpha(2)-adrenoreceptor antagonist RS 79948-197, or saline. Relative to saline controls, rats receiving either peripheral or intra-BLA infusions of RS 79948-197 predominantly displayed response learning on the probe trial. In an additional experiment peripheral (0.1 mg/kg) or intra-BLA (0.1 microg) drug injections administered prior to both acquisition and retrieval also resulted in the predominant use of response learning. The findings indicate that (1) similar to acquisition, peripheral injection of an anxiogenic drug prior to memory retrieval biases rats towards the use of habit/response memory, (2) intra-BLA infusions of an anxiogenic drug is sufficient to produce this modulatory effect of emotional state on memory retrieval, and (3) state-dependency does not appear to play a role in the effects of anxiogenic drug treatment on multiple memory system use. The findings may have implications for understanding the interaction between brain function, emotion, and the relative use of multiple memory systems in human psychopathology.     

Gender swapping and socializing in cyberspace: an exploratory study.

Massively multiplayer online role-playing games (MMORPGs) are one of the most interesting innovations in the area of online computer gaming. Given the relative lack of research in the area, the main aims of the study were to examine (a) the impact of online gaming (e.g., typical playing behavior) in the lives of online gamers, (b) the effect of online socializing in the lives of gamers, and (c) why people engage in gender swapping. A self-selecting sample of 119 online gamers ranging from 18 to 69 years of age (M = 28.5 years) completed a questionnaire. The results showed that just over one in five gamers (21%) said they preferred socializing online to offline. Significantly more male gamers than female gamers said that they found it easier to converse online than offline. It was also found that 57% of gamers had engaged in gender swapping, and it is suggested that the online female persona has a number of positive social attributes in a male-oriented environment.     

Children's subjective identification with social groups: a self-stereotyping approach

We contend that previous work on children's identification with social groups has looked at the mere categorization of the self in group terms and not subjective identification properly conceived. Drawing upon self-categorization theory, the present research operationalizes identification as self-stereotyping (i.e. the ability to conceive of the self in group-relevant terms). Children's self-stereotyping was explored in two studies using gender as the relevant ingroup. Study 1 required 5-, 7- and 10-year-old children, on two separate occasions, to rate their similarity to, and difference from, same-sex peers. Relative to the control condition, when gender had been made salient, children perceived significantly greater similarity, and smaller difference, between themselves and same-sex peers, thus providing evidence of a capacity for self-stereotyping and, hence, for subjective identification with a social category. Similarly, Study 2 sought trait ratings of the self both when gender had been made salient and when it had not. Boys of all ages (though not girls) rated ingroup-stereotypical traits (such as bravery and strength) to be more characteristic of the self when gender was salient than when it was not. Together, these findings suggest that the capacity for subjective identification with social groups is present at least by the age of 5 years. Moreover, they demonstrate that children's self-conceptions are contextually variable.     

Feedback and driver situation awareness (SA): A comparison of SA measures and contexts

The dominant technological trajectory in vehicle design brings with it similarly dominant driver performance issues in regard to vehicle feedback and driver situational awareness (SA). Three experiments are reported in this paper that describe not only the effects on driver SA of manipulations of vehicle feedback but also illuminate issues concerned with SA measurement methods and contexts. The findings suggest that current trends in vehicle design may contribute little towards a driver’s SA and, in fact, may actually show a generalized trend towards decreasing it. The efficacy of verbal protocol and probe recall SA measurement techniques is noted in terms of observing this effect. On the other hand, a concerning dissociation occurred with findings from a self-report measure of SA. Drivers appear to show a concerning lack of self-awareness of their SA and, indeed, any shortfall in it.     

Ontological issues in distance perception: cue use under full cue conditions cannot be inferred from use under controlled conditions

Phosphorescent square tiles (arranged to yield a single image size) were viewed in the dark by 56 monocular observers who utilized a chinrest. The targets were placed at one of three horizontal distances and at one of three eye heights, allowing us to study the relative effect of height in the visual field (HVF) and sagittal distance on observers' verbal reports of the horizontal distance at which the object lay (near, middle, or far). In Experiment 1, we found that reports covaried primarily with HVF and, as predicted, they exhibited a weak paradoxical inverse relation with horizontal distance. In a second and third experiment, a visible surface was placed under the targets at the three eye heights in both dark and fully lighted conditions. In this situation, the inverse distance relation disappeared, and HVF no longer influenced the judgments of most observers. The results show that information projected from relevant support surfaces is essential for veridical information about object distance. These results raise fundamental issues for perceptual researchers regarding how to decide when a cue has been properly delineated, given the assumption that the relation between a cue and what it specifies is probabilistic.     

Stimulus frequency influences spontaneous perceptual reversals in ambiguous apparent motion

The temporal integration of continuous sensory information into a temporally extended percept becomes evident in spontaneous reversals of ambiguous apparent motion. To study the temporal relation of spontaneous percept reversals and temporal stimulus properties, we systematically varied presentation frequency in an ambiguous-apparent-motion paradigm. Moreover, we triggered percept reversals in a manner that was not consciously perceived by manipulating the duration of single frames. We found that the reversal rate depended on the stimulus frequency (with higher frequencies resulting in faster percept reversals) and that we could externally trigger perceptual reversals. Our findings support the idea that spontaneous reversals of ambiguous apparent motion are influenced by bottom-up effects at early processing levels. The paradigm allows for specific contrasts of spontaneous and externally triggered (but otherwise identical) perceptual reversals and, by this means, for further study of the underlying mechanisms.     

Microswitch-based programs for persons with multiple disabilities: an overview of some recent developments

Persons with multiple disabilities are often unable to interact with their environment due to their limited response repertoire. Microswitch programs are designed to help them control environmental events, generally preferred stimulation, through simple (feasible) responses. To make microswitch programs a more widely usable and relevant resource for intervention with these persons, a number of new developments were pursued in recent years. This paper examines three of those developments as specifically addressed in our research activity, namely, (a) assessment of new, nontypical responses and matching microswitches, (b) fostering of multiple responses and exercise of choice, and (c) targeting of habilitative and clinical (therapeutic) objectives. The encouraging outcomes of these developments are reviewed in relation to their potentially wide implications for daily practice and the need of additional developments in the area.     

The ontology of meanings

In part 4 of Meaning, Expression, and Thought, Davis rejects what he calls Fregean ideational theories, according to which the meaning of an expression is an idea; and then presents his own account, which states that, e.g., the meaning of ‘Primzahl’ in German is the property of meaning prime number. Before casting doubt on the latter ontology of meanings, I come to Frege’s defence by pointing out that he was not an advocate of the position Davis named after him because Fregean senses are not lexical meanings and Fregean thoughts are not types of mental events.