Microcomputer-based estimation of psychophysical thresholds: The Best PEST

A new, maximally efficient technique for measuring psychophysical thresholds (Pentland, 1980) has been implemented on the microcomputer. This PEST (parameter estimation by sequential testing) technique is the most efficient sequential parameter estimation technique possible, given that the form of the psychometric function is known. The technique is similar to but faster and more accurate than other staircase procedures and may be applied whenever staircase techniques are applicable. The “Best PEST” is easily implemented on the micro-computer; a BASIC program for the Apple II which does so is presented. The Best PEST is compared with other staircase procedures, including one recently implemented on a micro-computer (Corwin, Kintz, & Beaty, 1979).     

Mapping Word to World in ASL: Evidence from a Human Simulation Paradigm

Across languages, children map words to meaning with great efficiency, despite a seemingly unconstrained space of potential mappings. The literature on how children do this is primarily limited to spoken language. This leaves a gap in our understanding of sign language acquisition, because several of the hypothesized mechanisms that children use are visual (e.g., visual attention to the referent), and sign languages are perceived in the visual modality. Here, we used the Human Simulation Paradigm in American Sign Language (ASL) to determine potential cues to word learning. Sign-naïve adult participants viewed video clips of parent–child interactions in ASL, and at a designated point, had to guess what ASL sign the parent produced. Across two studies, we demonstrate that referential clarity in ASL interactions is characterized by access to information about word class and referent presence (for verbs), similarly to spoken language. Unlike spoken language, iconicity is a cue to word meaning in ASL, although this is not always a fruitful cue. We also present evidence that verbs are highlighted well in the input, relative to spoken English. The results shed light on both similarities and differences in the information that learners may have access to in acquiring signed versus spoken languages.     

The effects of labelling,expert testimony,and information processing mode on juror decisions in SVP civil commitment trials

Expert witnesses offering testimony in sexually violent predator civil commitment trials may use diagnostic labels that are either familiar (e.g. ‘psychopath’) or unfamiliar (e.g. ‘paraphilia’) to jurors. Using predictions based on cognitive experiential self-theory, we explored the influence of testimony type (clinical versus actuarial) and diagnostic label (psychopath versus paraphilia) on jurors motivated to adopt either an experiential processing mode (PM; in which heuristic cues may be strongly relied upon) or an analytic rational PM. Consistent with previous research, our results indicated that when given a psychopathic diagnostic label, mock jurors motivated to process information experientially were more influenced by clinical testimony, whereas mock jurors induced into a rational mode were more influenced by actuarial testimony. However, experientially oriented jurors given a paraphilia diagnostic label did not show the expected influence of clinical expert testimony, and instead were more persuaded by actuarial testimony. These findings are discussed from a judgement and heuristics cues framework. The implications of several procedural suggestions are examined. Copyright © 2009 John Wiley & Sons, Ltd.