On the scaling of size judgements by orientational cues

Abstract

Observers carried out multiple, concurrent size discriminations with a range of size standards. The task was to classify each stimulus as larger or smaller than the appropriate standard size for the set to which it belonged. The set to which each stimulus belonged was indicated by its orientation, or in different experiments, by its spatial location. Observers were able to maintain appropriate discrimination, both when there were four concurrent standards and when there were eight. Both angle and position functioned as effective cues. The size of the orientational cue appeared to make little difference to the efficiency of discrimination. However, when the relationship between standard size and orientation was random, rather than regular, performance got worse. The analogy between such discrimination and size constancy is pointed out, and the results are discussed in relation to Andrews, D. P.'s [(1964)

Optimal Encoding of Interval Timing in Expert Percussionists

“…This is the basis of the psychophysical technique known as the method of single stimuli (Woodworth, 1938), where subjects report whether an individual trial is of higher or lower magnitude than the average of all seen to date. Subjects can keep at least four separate averages simultaneously (Morgan, 1992), and the noise associated with the average seems to be less than that of the sensory judgments (Morgan et al, 2000). That subjects are so good at this task is consistent with the notionthatcontinuousestimatesaremadeofthemean,andperhapsthe variance, of past sensory events.…”

“…Much evidence (Woodworth, 1938;Morgan, 1992;Morgan et al, 2000) shows that humans can easily maintain a running average of a variety of sensory attributes, including size, color, shape, and numerosity. This is the basis of the psychophysical technique known as the method of single stimuli (Woodworth, 1938), where subjects report whether an individual trial is of higher or lower magnitude than the average of all seen to date.…”

Estimating averages from distributions of tone durations

“…In a visual averaging task, Morgan et al (2000) found that when asked to do so, participants could make a judgment about the average of a specific sample of stimuli, ignoring other stimuli. This confirmed previous results by Morgan (1992), " Morgan's [1992] results indicate that the observer can select the stimuli that are relevant to a particular judgement, and ignore the others," (Morgan et al, 2000(Morgan et al, , p. 2345. Further, Chong and Treisman (2005) found that when blue circles and green circles were randomly intermixed in the same display, participants were able to successfully estimate the average size of circles for each color separately.…”

The Mechanisms of Size Constancy

“…Although the size of the retinal image decreases, we do not perceive the object as smaller but farther away. This perceptual re scaling of size is known as size constancy (Andrews, 1964;Gregory, 1998;Morgan, 1992).…”