Psychological Model for Presymptomatic Test Interviews: Lessons Learned from Huntington Disease

This paper reflects on experience gained from presymptomatic testing for Huntington disease. An approach is presented which considers the role of the clinician and aims of the interview. Irrespective of the disease being tested for, it is suggested that the psychological aim of presymptomatic testing is to foster emotional insight and understanding that will help clients in their decision-making process about testing and their subsequent adjustment to the result. Based on these aims the process of presymptomatic testing, counseling is considered in terms of clarification, consideration, education, and reflection, followed by decision making. Practical approaches are discussed and illustrated with clinical examples.     

PC operating system for measuring discrete biological responses during classical conditioning

A software package, written in C source code for MS-DOS 5.0 or higher IBM-compatible computers, was developed for the classical conditioning of discrete biological responses. The program’s primary functions include collecting and storing conditioning parameters, controlling presentation of stimuli, transforming discrete analog responses into dependent measures (e.g., CR frequencies and various measures of response topography), and generating data sets for use with commercial PC statistical packages. These functions were implemented in a windows-based user interface to increase the experimenter’s ease of use and to maximize efficiency in performing experimental procedures. Scrollable windows provide detailed visual displays that permit monitoring responses during conditioning and a review of each trial after the session is over. Additional software tools aid the visual inspection of response topographies, data manipulation, and calibration of the experimental apparatus. An overview of the system, its design objectives, and the user interface is presented.     

The Minnesota interactive statistical system

The Minnesota Interactive Statistical System (MISS) is reviewed as a successful application of on-line minicomputing in an instructional and research context. The MISS system is described with regard to (1) the instructional and research needs which prompted its development, (2) its programming design, (3) its operating system, (4) its computer hardware requirements, and (5) the continued innovative minicomputing development that it has inspired.     

Data archiving in animal experimentation: merits, challenges, and a case study.

Electronic data archives may supplement the traditional peer-reviewed journal article. The merits of data archiving include public service, a more complete research project, overcoming barriers to limited-access research resources, and increasing the impact of a scientific project. A case study of chimpanzee timing performance in space is derived from the NASA Life Sciences Data Archive (http://lsdajsc. nasagov). An analysis of the archived data suggests that the scalar property (a form of Weber's law) applies to timed performance of a chimpanzee in orbit of the earth. Challenges associated with data archives are discussed. Although significant challenges are associated with archiving electronic data, these difficulties are outweighed by its merits.     

Is Obstructive Sleep Apnoea Related to Neuropsychological Function in Healthy Older Adults? A Systematic Review and Meta-Analysis

Previous systematic reviews and meta-analyses have identified cognitive deficits in adults with obstructive sleep apnoea (OSA). However, quantitative analysis of the association between OSA and neuropsychological performance has not been conducted specifically in older adults, for whom there is a greater risk of cognitive decline. We searched Medline, Embase and PsycINFO through August 2016 for studies describing associations between OSA and neuropsychological outcomes in people aged>50 years. Meta-analyses were performed on these studies for overall cognition and within cognitive domains. Subgroup analyses were performed taking into account risk of bias and moderating differences in study design. 13 studies met eligibility criteria for analysis. A small negative association was found between OSA and all neuropsychological outcomes combined, g=0.18(95% CI 0.04–0.32), and in memory and processing speed domains. Small case-control studies from sleep clinic populations observed the greatest associations, while larger cohort studies from community samples illustrated no association. Analysis accounting for publication bias resulted in a null overall association, g=0.02 (95%CI -0.12 to 0.16). Associations between OSA and cognition in later life are highly variable and the findings differ based on the type and setting of study. It appears some older adults may be at risk of cognitive impairments attributable to OSA; however, the risk of bias renders the evidence inconclusive. High quality research is warranted in clinically diagnosed OSA patients as well as those already experiencing neuropsychological impairment and who may be regarded at higher risk of further cognitive decline.     

A test of the reward-value hypothesis

Rats retain source memory (memory for the origin of information) over a retention interval of at least 1 week, whereas their spatial working memory (radial maze locations) decays within approximately 1 day. We have argued that different forgetting functions dissociate memory systems. However, the two tasks, in our previous work, used different reward values. The source memory task used multiple pellets of a preferred food flavor (chocolate), whereas the spatial working memory task provided access to a single pellet of standard chow-flavored food at each location. Thus, according to the reward-value hypothesis, enhanced performance in the source memory task stems from enhanced encoding/memory of a preferred reward. We tested the reward-value hypothesis by using a standard 8-arm radial maze task to compare spatial working memory accuracy of rats rewarded with either multiple chocolate or chow pellets at each location using a between-subjects design. The reward-value hypothesis predicts superior accuracy for high-valued rewards. We documented equivalent spatial memory accuracy for high- and low-value rewards. Importantly, a 24-h retention interval produced equivalent spatial working memory accuracy for both flavors. These data are inconsistent with the reward-value hypothesis and suggest that reward value does not explain our earlier findings that source memory survives unusually long retention intervals.     

Rats’ acquisition of the ephemeral reward task

The ephemeral reward task provides a subject with a choice between two alternatives A and B. If it chooses alternative A, reinforcement follows and the trial is over. If it chooses alternative B, reinforcement follows but the subject can also respond to alternative A which is followed by a second reinforcement. Thus, it would be optimal to choose alternative B. Surprisingly, Salwiczek et al. (PLoS One 7:e49068, 2012. doi: 10.1371/journal.pone.00490682012) reported that adult fish (cleaner wrasse) mastered this task within 100 trials, whereas monkeys and apes had great difficulty with it. The authors attributed the species differences to ecological differences in the species foraging experiences. However, Pepperberg and Hartsfield (J Comp Psychol 128:298–306, 2014) found that parrots too learned this task easily. We have found that with a similar task pigeons are not able to learn to choose optimally within 400 trials (Zentall et al. in J Comp Psychol 130:138–144, 2016). In Experiment 1 of the present study, we found that rats did not learn to choose optimally in 840 trials; however, in Experiment 2 we added a prior commitment to the initial choice by increasing delay to reinforcement for the choice response from a single lever press to the first lever press after 20 s (FI20 s). In a comparable amount of training to Experiment 1, the rats learned to choose optimally. Although the use of a prior commitment increases the delay to reinforcement, it appears to reduce impulsive responding which in turn leads to optimal choice.     

Default “Gunel and Dickey” Bayes factors for contingency tables

The analysis of R×C contingency tables usually features a test for independence between row and column counts. Throughout the social sciences, the adequacy of the independence hypothesis is generally evaluated by the outcome of a classical p-value null-hypothesis significance test. Unfortunately, however, the classical p-value comes with a number of well-documented drawbacks. Here we outline an alternative, Bayes factor method to quantify the evidence for and against the hypothesis of independence in R×C contingency tables. First we describe different sampling models for contingency tables and provide the corresponding default Bayes factors as originally developed by Gunel and Dickey (Biometrika, 61(3):545–557 (1974)). We then illustrate the properties and advantages of a Bayes factor analysis of contingency tables through simulations and practical examples. Computer code is available online and has been incorporated in the “BayesFactor” R package and the JASP program (jasp-stats.org).