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.     

Sequelae of Aggression in Acutely Suicidal Adolescents

The consequences of aggression on problem course and suicide risk were examined in 270 acutely suicidal adolescents (ages 12-17 years; 184 girls). Participants were assessed during psychiatric hospitalization (T1), 6-months post-hospitalization (T2), and 15 or more months post-hospitalization (T3). Study variables included self- and parent-reported aggression; self-reported internalizing symptoms, suicidal ideation, suicide attempt, and adverse events; and clinician-rated suicidal behavior. Aggression was not directly related to suicide attempt concurrently or prospectively. However, among more aggressive youth, internalizing symptoms were more predictive of T3 suicide attempt than among less aggressive youth. T1 aggression predicted aggressive incidents and the likelihood of incarceration prior to T3. Two-level hierarchical linear modeling indicated that self-reported aggression and internalizing problems were linked in terms of severity and rates of decline over time. Overall, parent-reported aggression was negatively associated with suicidal ideation. Findings highlight (a) the continuity and consequences of aggression, (b) a possible role of aggression in worsening suicide risk factors and potentiating suicide attempt, and (c) the importance of ongoing research on subtypes of suicidal adolescents.     

Genetic studies of stuttering in a founder population

Genome-wide linkage and association analyses were conducted to identify genetic determinants of stuttering in a founder population in which 48 individuals affected with stuttering are connected in a single 232-person genealogy. A novel approach was devised to account for all necessary relationships to enable multipoint linkage analysis. Regions with nominal evidence for linkage were found on chromosomes 3 (P=0.013, 208.8 centiMorgans (cM)), 13 (P=0.012, 52.6 cM), and 15 (P=0.02, 100 cM). Regions with nominal evidence for association with stuttering that overlapped with a linkage signal are located on chromosomes 3 (P=0.0047, 195 cM), 9 (P=0.0067, 46.5 cM), and 13 (P=0.0055, 52.6 cM). We also conducted the first meta-analysis for stuttering using results from linkage studies in the Hutterites and The Illinois International Genetics of Stuttering Project and identified regions with nominal evidence for linkage on chromosomes 2 (P=0.013, 180-195 cM) and 5 (P=0.0051, 105-120 cM; P=0.015, 120-135 cM). None of the linkage signals detected in the Hutterite sample alone, or in the meta-analysis, meet genome-wide criteria for significance, although some of the stronger signals overlap linkage mapping signals previously reported for other speech and language disorders. EDUCATIONAL OBJECTIVES: After reading this article, the reader will be able to: (1) summarize information about the background of common disorders and methodology of genetic studies; (2) evaluate the role of genetics in stuttering; (3) discuss the value of using founder populations in genetic studies; (4) articulate the importance of combining several studies in a meta-analysis; (5) discuss the overlap of genetic signals identified in stuttering with other speech and language disorders.     

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.     

Social interaction patterns of geriatric home and community residents

Thirty elderly nursing home residents and ten community residing older adults were observed in group settings. Their behavior was assessed for dependent personal maintenance, independent personal maintenance, and appropriate and inappropriate behaviors. Responses by staff and peers to these behaviors were classified as positive, negative, or ignore. The frequency of occurrence of these behaviors as well as the relationship of resident to peer or staff behaviors were analyzed. Results indicate that community-residing elders' behaviors differ from nursing home residents' in quantity rather than quality of interactions. There was a lower frequency of behaviors in the nursing home residents. Though older adults respond differentially to various behaviors of other nursing home residents, staff responses were consistent regardless of residents' behavior. These results suggest that geriatric home residents' behavior can be characterized as withdrawn rather than dependent.     

Case study: Controlling self-injurious escape behaviors

The present study investigated the effects of a treatment program on the self-injurious behaviors of a 12-year-old autistic male. Initial observations indicated that these behaviors functioned primarily as escape responses to terminate performance demands. For 1 year the subject received general compliance training with the frequency of demands being systematically increased through consecutive treatment weeks. The subject's self-injurious behaviors were no longer reinforced by his escaping from demands nor did they receive social attention. Compliance to demands and appropriate behaviors in general were positively reinforced. The treatment produced substantial reductions in the rates of self-injurious behaviors and increased compliance. Additionally, the intensity of the subject's self-injurious behaviors decreased over the course of treatment. The present study suggests that the treatment approach is a reliable means of not only reducing self-injurious behaviors but also expanding performance repertoires.