Fundamentals
of .Sfrill
vt,
A. T. WELFORD M.4., Sc.D. Professor of Psychology in the University of Adelaide Formerly Fellow of St lohn's College, Cambridge and University Lecturer in Experimental Psychology
METHUEN & CO LTD rr
New Fetter Lane London EC+
First published 1968 by Methuen and Co
e
1968
A. T, Welfurd
Printed in Ctreat Britain by
& Tanner Ltd Frome and London
Butler
SBN
416 o3ooo 9
Distributed in the USA by Barutes €* Noble fnc.
Ltd
Contents
Preface
I
9
II
Introdustion Sensory-motor shill and tlu cyberrutic apfroach Signal dctection, vigilartrn afid dccision Mental skill and conceptuctl frameworks The present research position
II
27
Simple Decisions lYebef s Law, threslwlds and, disdmirrution
Tlw dccision-tlrcory approach The tirne required
III
for discrimination
Identification and Choice
60
Hick' s inforuation-theory law Conceptual modcls
Factors affecting thc extent to sthich reaction-time rises ssith number of alternatioes Separating idmtifuation from choice studies of prceptual selcction
Fwtlw
Mingle-Channel Operation
ro5
The effect of a signal during the reaction-timc to a praious
signal
Tfu effect of a signal
[email protected] tlrc movement made in to a preuious signal Sorne arnmalous resuhs Altematizte tlwories The speed of continuous prformance
Meast ing'mefltal load' ,l
5
response
Cmtutts
6
V
Movement
r37
Smsory control Time required for feedback to be effectioe Relationships between speed and accurecy
VI
Economy of Decision
r6r
Economy in prception Recoding and translation
Higher units of perfotmance
VII
Short-Term Retention
r97
Basic facts of immediate memory Sources of lhnitation Measuring thc capacity of thc store Locating the store Short-tqm retmtion as a factor in complex performance
VIII