The discriminability of remembered magnitudes

Abstract

Psychometric functions and the associated indices of discriminative performance (i.e., the point of subjective equality [PSEl, just noticeable difference, and Weber fraction) were obtained with the method of constant stimuli using perceptual and remembered line-length standards. Three important results were obtained. First, comparisons with a perceptual or a remembered standard were sensitive to variations of absolute stimulus differences with a common ratio; that is, Weber's law was violated. Second, relative to discriminative performance with the longest and shortest remembered standards, comparisons involving mid-range remembered standards displayed increased variability in the PSE and inflated Weber fractions, characteristic of a reduction in the quality of the memorial representation. Finally, large and negative time-order errors (TOE) were observed for successive line judgments but not for those involving remembered standards. The implications of these findings for research concerned with the relationships between perception and memory, as well as the TOE phenomenon, are discussed. Woodworth (1938), in the first chapter of his classic text, .. Experimental Psychology," concludes:The experimental results are in good agreement on the negative conclusion: No absolute difference exists between an image and a percept, and there is 110 sure criterion by which one can be distinguished from the other. (p. 45) Following the recent resurgence of interest in the relationships between perception and memory, Woodworth's (1938) negative conclusion can be viewed more positively. Several findings, based on the application of traditional psychophysical methods to remembered stimuli, have revealed important commonalities between perception and memory, and these commonalities permit a characterization of their shared processes and properties (see Finke, 1980Finke, , 1985Finke & Shepard, 1985;Kosslyn, 1980; Shepard, 1984, for reviews). Shepard and Chipman (1970) originally provided the elegant demonstration of a ••second-order isomorphism" between perception and memory, derived from a multidimensional scaling analysis of perceived and remembered representations of the shapes of the U.S. states. Similarly, several experiments using magnitude estimates (Stevens, 1957) of perceived and remembered stimuli have demonstrated an important psychophysical relationship on various continua (e.g., Bjorkman, Lundberg, & Tarnblom, 1960;Bradley & Vido, 1985;Chew & Richardson, 1980;Kerst & Howard, 1978;Moyer, Bradley, Sorensen, Whiting, & Mansfield, 1978). In each case, the perceived and remembered magnitude estimates were power functions This research was supported by a grant from the Natural Sciences and Engineering Research Council (NSERC) of Canada to W.M.P. We thank Robert Proctor and three anonymous reviewers for their helpful comments. Correspondence can be addressed to either author at the Department of Psychology, Carleton University, Colonel By Drive, Ottawa, ON, Canada KIS 586. of the physical magnitudes with related expon...

Realism of confidence in sensory discrimination

“…Specifically, in the near-far task, accuracy was higher when the farther distance was on the left; with lines, accuracy was higher when the longer line was on the right. Under the assumption that subjects acquire the stimuli in a left-to-right fashion (Masin & Agostini, 1991), the increased accuracy in the short, long presentation order in the present study is consistent with the typically observed negative time order error (TOE) for lines (Baranski & Petrusic, 1992), whereby accuracy is higher when the longer of two lines is presented second (cf. Dawes, 1980, Experiment 5, for a view of the effects on calibration of the TOE in a duration discrimination task).…”

“…In fact, in all of our experiments employing the near-far task, we have been acutely aware that subjects might use the edge strategy, especially with the far pairs (see Petrusic, 1992;Petrusic & Baranski, 1989a, 1989b, 1997. Indeed, precisely in order to preclude the use of the edge of the screen, All subjectsweretold that becausethe fixationpoint varied from trial to trial (sometimes to the left of center, sometimes to the right), the edge of the screen did not provide a reliable cue for the nearer-farther judgment.…”

Distinctiveness and serial position effects in tonal sequences

“…Although there has been a great deal of research on the relationship between perceptual and memory effects, most of it has concentrated on the psychophysical aspects of perception and memory (e.g., Baranski & Petrusic, 1992;Bradley & Vido, 1985) or on the relationship between imagery and perception (Finke, 1980(Finke, , 1985Shepard, 1984). Few studies have examined serial position effects and their relationship to discrimination (but see Cacace et al, 1992;.…”

A clínica da psicofísica

“…Besides the extent of that value, we can extract important information that will help us to have more complete clinical features of early stages of perceptual and mental function conscious. Measures of variability sensory perception of linear behavior with the physical dimensions manipulated (Houstoun & Shearer, 1930;Stevens, 1957), functional capacity discriminating in comparison tasks (Baranski &Petrusic, 1992, Hanna, von Gierke, andGreen, 1986;Hecht, 1924;Mallery, Olomu, Uchanski, Militchin, & Hullar, 2010;Ross, 1997), perceptual measures of values for groups and populations (Deco & Rolls, 2006;Dzhafarov & Colonius, 2007;Sturzel & Spillmann, 2004, Warren, 2006 are just some examples of how information is psychophysical assessment and will be enriched as the clinical knowledge of diseases that affect mental processes, with the addition of a clinical psychology.…”