Relative judgments affect assessments of stimulus duration

Humans were trained on two independent temporal discriminations, with correct choice dependent on the initial stimulus duration. In Experiment 1, the durations were 1.0 and 4.0 sec, with one set of choice stimuli, and 2.0 and 8.0 sec, with a different set of choice stimuli. The 2.0- and 4.0-sec values were selected to be the geometric mean of the two values in the other discrimination. In Experiment 2, the durations were 2.0 and 5.0 sec for one discrimination and 3.5 and 6.5 sec for the other. The 3.5- and 5.0-sec values were selected to be the arithmetic mean of the two values in the other discrimination. In both experiments, participants showed evidence for relational coding of the duration pairs. That is, the test durations were selected to be at the presumed bisection point (i.e., they should have produced indifferent choice), but instead the shorter test duration from the longer duration pair produced a “short” bias (in both experiments), whereas the longer duration from the shorter duration pair produced a “long” bias (in the second experiment). Results were similar to those from Zentall, Weaver, and Clement (2004) with pigeons.     

Prospective and retrospective duration judgments: A meta-analytic review

A meta-analytic review compared prospective and retrospective judgments of duration, or duration judgment paradigm. Some theorists have concluded that the two paradigms involve similar cognitive processes, whereas others have found that they involve different processes. A review of 20 experiments revealed that prospective judgments are longer and less variable than are retrospective judgments. Several theoretically important variables moderate these effects, especially those concerned with information processing activities. Therefore, somewhat different cognitive processes subserve experienced and remembered duration. Attentional models are needed to explain prospective judgments, and memory-based models are needed to explain retrospective judgments. These findings clarify models of human duration judgment and suggest directions for future research. Evidence on duration judgments may also influence models of attention and memory.     

Effects of event structure on retrospective duration judgments

Two experiments examined whether varying degrees of event coherence influence the remembering of an event’s actual duration. Relying on musical compositions (Experiment 1) or filmed narratives (Experiment 2) as experimental stimuli, the underlying hierarchy of information within events (i.e., melodic intervals or story elements) was either attentionally highlighted or obscured by placing a varying number of accents (i.e., prolonged notes or commercial breaks) at locations that either coincided or conflicted with grammatical phrase boundaries. When subjects were unexpectedly asked to judge the actual duration of events, through a reproduction (Experiment 1) or verbal estimation (Experiment 2) task, duration estimates became more accurate and less variable when the pattern of accentuation increasingly outlined the events’ nested relationships. Conversely, when the events’ organization was increasingly obscured through accentuation, time judgments not only became less accurate and more variable, but were consistently overestimated. These findings support a theoretical framework emphasizing the effects of event structure on attending and remembering activities.     

Time perception and attention: The effects of prospective versus retrospective paradigms and task demands on perceived duration

This research was designed to compare time judgments obtained under prospective conditions (in which subjects are instructed to attend to time) and retrospective conditions (in which subjects are unaware that they will be required to judge time). In Experiment 1, subjects prospectively or retrospectively judged the duration of intervals spent performing a perceptual-motor task at different levels of difficulty. The results showed that subjects tested under both research paradigms tended to give increasingly shorter and/or more inaccurate time judgments with increases in nontemporal task demands. Experiment 2 was designed to test the effects of attentional deployment on perceived time by comparing prospective and retrospective judgments under control, selective attention, and divided attention conditions. Both types of time judgments became increasingly inaccurate as attention was more broadly deployed. The results of these experiments are consistent with an attentional allocation model, and they suggest that nontemporal task demands disrupt or interfere with timing in both prospective and retrospective situations.     

Background music as a quasi clock in retrospective duration judgments

The segmentation-change model of time perception proposes that individuals engaged in cognitive tasks during a given interval of time retrospectively estimate duration by recalling events that occurred during the interval and inferring each event's duration. Previous research suggests that individuals can recall the number of songs heard during an interval and infer the length of each song, exactly the conditions that foster estimates of duration based on the segmentation-change model. The results of a laboratory experiment indicated that subjects who solved word-search puzzles for 20 min. estimated the duration of the interval to be longer when 8 short songs (<3 min.) as opposed to 4 long songs (6+ min.) were played in the background, regardless of whether the musical format was Contemporary Dance or New Age. Assuming each song represented a distinct segment in memory, these results are consistent with the segmentation-change model. These results suggest that background music may not always reduce estimates of duration by drawing attention away from the passage of time. Instead, background music may actually expand the subjective length of an interval by creating accessible traces in memory, which are retrospectively used to infer duration.     

Relative - not absolute - judgments of credibility affect susceptibility to misinformation conveyed during discussion

People remember different details about the same events, and when they discuss events they exchange new – and misleading – information. Discussion can change memory, especially when the source of new information is highly credible. But we do not know whether the effects of credibility are based on absolute judgments – judging a source's credibility independently from our own credibility – or relative judgments – judging a source's credibility only in relation to our own credibility. We addressed this question by manipulating subjects' expectations, leading them to believe that they either had the same, higher or lower “visual acuity” than their partner while they watched a movie together. To create ample opportunities for the pairs to mention misleading details to one another, each member unknowingly saw a different version of the movie. The pairs then discussed some of the critical differences, but not others. Later, everyone took an independent recognition test. Subjects' susceptibility to misinformation depended on their own credibility relative to their partner's, supporting the idea that susceptibility to misinformation depends on relative differences in credibility.     

Temporal concepts and predicted duration judgments

The present research investigated whether certain conceptualizations of time influence the planning fallacy or the tendency to underestimate predicted task durations. In Experiment 1, participants were presented with one of three types of primes (video, linguistic, video + linguistic) that reflected either an ego or time motion perspective (i.e. an individual moving through time vs. time moving toward an individual). Afterwards, all participants predicted the amount of time required to sort and shelve a stack of journals before actually completing the task. The results showed that across all priming conditions, subjects in the ego motion condition underestimated to a greater extent than those in the time motion condition. Experiment 2 replicated this effect and also found that underestimations are reduced when the implied duration of the experimental session is short vs. long. As a set, these findings have relevant theoretical implications and suggest some potential de-biasing techniques.     

Session duration and the VI response function: Within-session prospective and retrospective effects

Two experiments examined the effects of session duration on responding during simple variable-interval schedules. In Experiment 1, rats were exposed to a series of simple variable-interval schedules differing in both session duration (10 min or 30 min) and scheduled reinforcement rate (7.5 s, 15 s, 30 s, and 480 s). The functions relating response rate to reinforcement rate were predominantly monotonic for the short (10-min) sessions but were predominantly bitonic for the long (30-min) sessions, when data from the entire session were considered. Examination of responding within sessions suggested that differences in the whole-session data were produced by a combination of prospective processes (i.e., processes based on events scheduled to occur later in the session) and retrospective processes (i.e., processes based on events that had already occurred in the session). In Experiment 2, rats were exposed to a modified discrimination procedure in which pellet flavor (standard or banana) predicted session duration (10 min or 30 min). All rats came to respond faster during the short (10-min) sessions than during the first 10 min of the long sessions. As in Experiment 1, the results seemed to reflect the simultaneous operation of both prospective and retrospective processes. The results shed light on the recent controversy over the form of the variable-interval response function by identifying one variable (session duration) and two types of processes (prospective and retrospective) that influence responding on these schedules.     

Stimulus motion and retrospective time judgments

The effect of stimulus motion on retrospective time judgments was investigated in four experiments. Subjects reproduced the duration of a 32-s interval which was filled by either a stationary or moving visual element presented on a computer monitor. In Experiments 1 and 4, the element moved horizontally back and forth, and in Experiments 2 and 3 it traced a circular pathway. In Experiments 1 and 2, the element moved at speeds of either 5 or 20 cm/s. In Experiment 3, it moved at a constant speed, alternating direction between clockwise and anti-clockwise rotation once every 1, 4, 8 or 16 s. In Experiment 4 the element moved at linear speeds of 1, 2, 4, 8 or 16 cm/s back and forth along a 16 cm horizontal path thereby alternating between left- and rightward motion-directions once every 16, 8, 4, 2 and 1 s, respectively. Temporal reproductions were not systematically influenced by stimulus speed. Rather, the pattern of results indicated a nonmonotonic relationship between remembered duration and the frequency of motion-direction changes; whereas remembered duration was unaffected by either infrequent or very frequent rates of changes, moderate rates of motion-changes lengthens remembered duration. These findings are discussed in relation to the change models of retrospective timing, and the claim that stimulus speed, as distinct from changes in the direction of stimulus motion, is not an important determinant of retrospective timing.     

Relative distance judgments of familiar and unfamiliar objects viewed under representatively natural conditions

Carlson and Tassone (1971) reported that an object of familiar size viewed at an appreciable distance is perceived to be more distant than an unfamiliar object. Six experiments were designed to examine this effect. The results indicated that the effect is not dependent on Carlson and Tassone's method for assessing perceived relative distance; it occurs at some minimum viewing distance; it is unlikely to be caused by stimulus attributes confounded with the familiar versus unfamiliar size dichotomy; appears to be specific to judgments of the familiar object itself; and it does not occur if the familiar and unfamiliar objects have a common reference target. These findings are discussed with respect to the issue of whether familiar size influences perceived distance as distinct from influencing judgments of distance.     

Sequential effects in absolute judgments of loudness

The effects of preceding stimuli on the judgments of current stimuli were examined in a study using absolute judgments of loudness with feedback. It was found that the response on a given trial was dependent on the stimuli in the preceding sequence of at least five trials. Both assimilation and contrast effects were observed. The form of the dependency of a response on a prior stimulus was a function of the ordinal position of the stimulus in the preceding sequence of trials. The stimulus on the immediately preceding trial had an assimilative effect on the response and preceding stimuli two to five trials removed all showed a contrast effect on a given response. The extent to which these preceding stimuli contributed to the contrast effect was an increasing function of their recency. The reversal of the dependency of the response, from assimilation to the stimulus one trial back, to contrast with the stimuli two and more trials back, indicates a unique function of the immediately preceding stimulus in this task. Since there was a reduction in the variance of responses to those stimuli similar in value to the immediately preceding stimulus, it is proposed that the stimulus and feedback on the last trial were remembered and used asa standardin judging the presented stimulus. A model is presented in which it is assumed that the memory of the magnitude of the immediately preceding stimulus is contaminated in specified ways by prior stimuli in the series. The empirical findings of assimilation and contrastare expected consequences of the proposed memorial processes.     

Use of absolute and comparative performance feedback in absolute and comparative judgments and decisions

Which matters more—beliefs about absolute ability or ability relative to others? This study set out to compare the effects of such beliefs on satisfaction with performance, self-evaluations, and bets on future performance. In Experiment 1, undergraduate participants were told they had answered 20% correct, 80% correct, or were not given their scores on a practice test. Orthogonal to this manipulation, participants learned that their performance placed them in the 23rd percentile or 77th percentile, or they did not receive comparative feedback. Participants were then given a chance to place bets on two games—one in which they needed to get more than 50% right to double their money (absolute bet), and one in which they needed to beat more than 50% of other test-takers (comparative bet). Absolute feedback influenced comparative betting, particularly when no comparative feedback was available. Comparative feedback exerted weaker and inconsistent effects on absolute bets. Absolute feedback also had stronger (and more consistent) effects on satisfaction with performance and state self-esteem. Experiment 2 replicated these effects in a different university sample, and demonstrated that the effects emerge even when bets are placed after participants rate their satisfaction with their performance (although these ratings do not mediate the effect of feedback on bets). These findings suggest that information about one’s absolute standing on a dimension may be more influential than information about comparative standing, partially supporting a key tenet of Festinger’s [Festinger, L. (1954). A theory of social comparison processes. Human Relations, 7, 117–140.] theory of social comparison.     

Recency discrimination predicted from absolute lag judgments

An experiment is described which tests the plausibility of the assumption that two-alternative forced-choice (2AFC) recency discrimination is based on an independent lag estimate of each item. 39 Ss made absolute recency judgments for items (common nouns) at varying lag intervals while an independent group of 74 Ss made 2AFC judgments for pairs of items at comparable lag combinations. It was found that the absolute judgment data generated accurate predictions of 2AFC performance.     

A new scaling technique for absolute judgments

The results of an experiment using the method of absolute judgments can be viewed as a matrix of conditional probabilities in which the rows represent stimuli and the columns responses. The cosine of the angle between two row vectors is a measure of the similarity of the corresponding stimuli. This cosine provides the basis for a method of scaling the stimuli. Unlike the method of paired comparisons, this new technique does not require arbitrary fixing of a unit of measurement. A numerical example is given.     

Effect of a mid-series anchor on absolute judgments of duration by schizophrenics, neurologically impaired, and normals.

36 normal, 36 schizophrenic, and 36 neurologically impaired Ss were compared for their ability to temporally discriminate brief auditory stimuli. The experimental task was the absolute judgment of 3, 5, or 9 stimuli ranging in duration from 0.10 to 1.90 sec. Half of the Ss in each group were "assisted" by the presentation of a repeated mid-series anchor. The interval between the presentation of the anchor and the variable stimuli was varied. With the addition of a mid-series anchor, normal Ss demonstrated an increase in information transmission and a decrease in response stereotypy; schizophrenics demonstrated a slight decrease in information transmission and a slight increase in response stereotypy; neurologically impaired Ss were essentially unaffected. Changes in interstimulus interval on the anchored judgment task did not influence information transmission.     

Relative cues and absolute distance perception

It is possible, in theory, for the simultaneous occurrence of several different relative cues of distances to increase the veridicality of the perception of absolute distance. To test whether this actually occurs, a three-dimensional display was viewed monocularly while moving the head laterally, under conditions in which some error in perceived absolute distance was expected. The perceived absolute distance of the display was measured with the number of relative cues of distance within the display varied. No systematic reduction was found in the error in perceived absolute distance as a consequence of the variation in the number of relative cues. The study provides no evidence that the potential source of absolute distance information provided by relative cues is utilized by the visual system.