Dependence on Visual Feedback During Motor Skill Learning in Alzheimer's Disease

Three experiments examined the role of visual feedback on the performance of a fine motor task, namely the rotary pursuit, in patients with Alzheimer's disease (AD) and healthy older adults. After extensive practice tracking a fully visible target, participants in Experiments 1 and 2 were tested under restricted vision (RV) conditions. In both experiments, the two groups showed a drop in performance when vision was restricted, with AD patients showing a significantly larger decline. Tracking improved significantly in normal controls, but not AD patients across the RV trials after the initial drop. When difficulty of the rotary pursuit task was manipulated in Experiment 3 without restricting vision, AD patients and normal controls showed identical patterns of performance. Consequently, it could be concluded that AD patients in the first two experiments were relying more heavily on visual information for accurate performance of the tracking task than their healthy peers.     

Structural analysis of the intension and extension of semantic concepts

The present studies examined the nature of visuo-spatial working memory development using conventional visual span and spatial span measures. Children aged between 6 and 13 years and adults aged 18-38 years were employed as participants. In Study 1, visual span, spatial span, articulation rate, and verbal fluency competencies were measured. In Study 2, visual span and spatial span maintenance was subject to five interference formats: nil, speech articulation, verbal fluency, visual masking, and spatial tapping. Distinct developmental rates were found for the two span tasks, which in the older children were correlated with the verbal fluency measure. Study 2 provided experimental evidence of the contribution of executive and spatial processes to spatial and to visual span maintenance. The results are interpreted as indicating that these memory span procedures make complex demands upon the visuo-spatial working memory architecture and consequently a precise identification of the process that actually develop is compromised. It is suggested that a componential approach where tasks are constructed to tap specific working memory components would afford a more accurate understanding of the development of these processes.     

The Effects of a Racist Act and Public Counter-Demonstrations on Race-Related Behavioral Intentions: A Natural Experiment

This study reports on a natural experiment that yielded information about the effects of a racist act and public counter-demonstrations on behavioral intentions. The conditions for this natural experiment arose when an act of racial hostility occurred at a small liberal-arts college in the northeastern United States. This event occurred approximately midway through data collection for a study comparing public and private behavioral intentions to donate money to African American interest groups. This coincidence afforded the opportunity to examine the effects of such events on members of the affected community. The results of this natural experiment show that both public and private expression of support for African American interest groups increased after the incident and ensuing demonstrations.     

Why and how to use virtual reality to study human social interaction: The challenges of exploring a new research landscape

As virtual reality (VR) technology and systems become more commercially available and accessible, more and more psychologists are starting to integrate VR as part of their methods. This approach offers major advantages in experimental control, reproducibility, and ecological validity, but also has limitations and hidden pitfalls which may distract the novice user. This study aimed to guide the psychologist into the novel world of VR, reviewing available instrumentation and mapping the landscape of possible systems. We use examples of state-of-the-art research to describe challenges which research is now solving, including embodiment, uncanny valley, simulation sickness, presence, ethics, and experimental design. Finally, we propose that the biggest challenge for the field would be to build a fully interactive virtual human who can pass a VR Turing test – and that this could only be achieved if psychologists, VR technologists, and AI researchers work together.     

Judicial gatekeeping on scientific validity with risk assessment tools

Risk assessment tools driven by algorithms offer promising advantages in predicting the recidivism risk of defendants. Jurisdictions are increasingly relying upon risk tool outcomes to help judges at sentencing with their decisions on whether to incarcerate or whether to use community-based sanctions. Yet as sentencing has significant consequences for public safety and individual rights, care must be taken that the tools relied upon are appropriate for the task. Judges are encouraged to act as gatekeepers to evaluate whether the forensic risk assessment tool offered has a sufficient level of validity in that it is fit for the purposes of sentencing, provides an acceptable level of accuracy in its predictions, and achieves an adequate standard of reliability with regard to its outcomes.     

Active selection of items to be remembered: The role of timing

A series of experiments was carried out in which Ss were required to extract critical stimuli from a stream of nine spoken inputs, presented at various rates, and report on these after the presentation of each list. The critical items were normally digits at positions 2, 4, 6, and 8 in the input sequence. Subjects were required to employ either an “active” extraction strategy, aimed at achieving temporary storage only of items to be remembered, or a “passive” strategy, involving storage of all inputs with subsequent extraction of critical items. The initial experiment showed that the active strategy markedly improved performance efficiency as the presentation rate decreased; passive performance remained relatively stable. Experiments 2 and 3 indicated that the level of active performance was higher when critical items were categorically different from unwanted items. There were indications that this effect was independent of the effect of changes in the presentation rate.The final experiments in the series showed that when Ss were denied the opportunity of predicting the time of arrival of critical items active performance hardly benefitted from a reduction in rate.A “controlled activation” process is proposed as a basis for S's ability to modulate his state of alertness, so as to maximize receptivity for critical stimuli arriving at well-defined points in time.