Directed Movement: BBS Call for Commentators

Below is the abstract of a forthcoming target article on: SPEED/ACCURACY TRADEOFFS IN TARGET DIRECTED MOVEMENTS By Rejean Plamondon & Adel M. Alimi This article has been accepted for publication in Behavioral and Brain Sciences (BBS), an international, interdisciplinary journal providing Open Peer Commentary on important and controversial current research in the biobehavioral and cognitive sciences. Commentators must be current BBS Associates or nominated by a current BBS Associate. To be considered as a commentator for this article, to suggest other appropriate commentators, or for information about how to become a BBS Associate, please send email to: bbs(a)soton.ac.uk or write to: Behavioral and Brain Sciences Department of Psychology University of Southampton Highfield, Southampton SO17 1BJ UNITED KINGDOM http://www.princeton.edu/~harnad/bbs.html gopher://gopher.princeton.edu:70/11/.libraries/.pujournals ftp://ftp.princeton.edu/pub/harnad/BBS To help us put together a balanced list of commentators, please give some indication of the aspects of the topic on which you would bring your areas of expertise to bear if you were selected as a commentator. An electronic draft of the full text is available for inspection by anonymous ftp (or gopher or world-wide-web) according to the instructions that follow after the abstract. ____________________________________________________________________ SPEED/ACCURACY TRADEOFFS IN TARGET DIRECTED MOVEMENTS Rejean Plamondon & Adel M. Alimi Ecole Polytechnique de Montreal Laboratoire Scribens Departement de genie Electrique et de genie informatique C.P. 6079, Succ. "Centre-Ville" Montreal PQ H3C 3A7 ha03(a)music.mus.polymtl.ca KEYWORDS: Speed/accuracy tradeoffs, Fitts' law, central limit theorem, velocity profile, delta-lognormal law, quadratic law, power law. ABSTRACT: This paper presents a critical survey of the scientific literature dealing with the speed/accuracy tradeoffs of rapid-aimed movements. It highlights the numerous mathematical and theoretical interpretations that have been proposed over recent decades from the different studies that have been conducted on this topic. Although the variety of points of view reflects the richness of the field as well as the high degree of interest that such basic phenomena represent in the understanding of human movements, it questions the validity of many models with respect to their capacity to explain all the basic observations consistently reported in the field. In this perspective, this paper summarizes the kinematic theory of rapid human movements, proposed recently by the first author, and analyzes its predictions in the context of speed/accuracy tradeoffs. Numerous data available from the scientific literature are reanalyzed and reinterpreted in the context of this new theory. It is shown that the various aspects of the speed/accuracy tradeoffs can be taken into account by considering the asymptotic behavior of a large number of coupled linear systems, from which a delta-lognormal law can be derived, to describe the velocity profile of an end-effector driven by a neuromuscular synergy. This law not only describes velocity profiles almost perfectly, but it also predicts the kinematic properties of simple rapid movements and provides a consistent framework for the analysis of different types of rapid movements using a quadratic (or power) law that emerges from the model. -------------------------------------------------------------- To help you decide whether you would be an appropriate commentator for this article, an electronic draft is retrievable by anonymous ftp from ftp.princeton.edu according to the instructions below (the filename is bbs.glenberg). Please do not prepare a commentary on this draft. Just let us know, after having inspected it, what relevant expertise you feel you would bring to bear on what aspect of the article. ------------------------------------------------------------- These files are also on the World Wide Web and the easiest way to retrieve them is with Netscape, Mosaic, gopher, archie, veronica, etc. Here are some of the URLs you can use to get to the BBS Archive: http://www.princeton.edu/~harnad/bbs.html http://cogsci.soton.ac.uk/~harnad/bbs.html gopher://gopher.princeton.edu:70/11/.libraries/.pujournals ftp://ftp.princeton.edu/pub/harnad/BBS/bbs.glenberg ftp://cogsci.soton.ac.uk/pub/harnad/BBS/bbs.glenberg To retrieve a file by ftp from an Internet site, type either: ftp ftp.princeton.edu or ftp 128.112.128.1 When you are asked for your login, type: anonymous Enter password as queried (your password is your actual userid: yourlogin(a)yourhost.whatever.whatever - be sure to include the "@") cd /pub/harnad/BBS To show the available files, type: ls Next, retrieve the file you want with (for example): get bbs.glenberg When you have the file(s) you want, type: quit ---------- Where the above procedure is not available there are two fileservers: ftpmail(a)decwrl.dec.com and bitftp(a)pucc.bitnet that will do the transfer for you. To one or the other of them, send the following one line message: help for instructions (which will be similar to the above, but will be in the form of a series of lines in an email message that ftpmail or bitftp will then execute for you). -------------------------------------------------------------