The role of learning in remembered duration

In two experiments, the effects of learning on both the accuracy and bias of duration judgments were examined. In Experiment 1, subjects learned one of two tasks (i.e., using a computer software package, building a model car), containing a varying number of action steps, over a one-, three-, or five-trial period. Retrospective judgments of a task’s total duration revealed that accuracy was high at intermediate stages of learning but was low at early stages due to an overestimation bias and low at later stages due to an underestimation bias. The number of action steps within a task influenced behavior only at early learning stages where more action steps led to significantly longer duration estimates. Experiment 2 acted as a converging operation in which novice and experienced pianists were asked to estimate, in advance, how long they thought it would take them to play melodies that varied in their degree of familiarity (i.e. recently learned, well learned, extremely well learned). When these estimates were compared with the melodies’ actual playing times, results revealed a similar pattern of accuracy and bias as found in Experiment 1. These findings are discussed in terms of a “structural remembering model” that emphasizes the role of event predictability in time estimation behavior.     

Effect of task length on remembered and predicted duration

Vierordt’s (1868) law states that when estimating the duration of a previous task, people overestimate short durations and underestimate long ones. We examine whether this same pattern holds for remembered and predicted duration for tasks lasting between 1 and 15 min. In support of Vierordt’s law and its extension to future duration estimates, task duration tended to be overestimated for short tasks (less than 2 min) and underestimated for long tasks for both remembered and predicted duration.     

Task predictability and performance as determinants of confidence in multiple-cue judgments

Two experiments were performed in order to study judges' confidence in their judgments. Experiment I showed that judges' confidence is a direct function of the cue intercorrelation. r_ij in a pure judgmental task. When judges recieved feedback, the effect of r_ij on confidence was, as predicted, reduced. Confidence was, however, systematically related to neither R ²_c nor performance in the feedback condition. Experiment II was a further study of the effect of feedback on confidence. In addition, the hypothesis that the lack of relation between performance and confidence is due to judges' poor knowledge of how they actually perform in probabilistic inference tasks was tested. The experiment showed that differences among judges' confidence is a direct function of task predictability and that judges' confidence is related to how they believe that they perform rather than to how they actually perform. The theoretical as well as the practical importance of studies of confidence in probabilistic inference tasks was discussed.     

Sample-duration effects on pigeons' delayed matching as a function of predictability of duration

Three experiments assessed the impact of sample duration on pigeons' delayed matching as a function of whether or not the samples themselves signaled how long they would remain on. When duration was uncorrelated with the sample appearing on each matching trial, the typical effect of duration was observed: Choice accuracy was higher with long (15-s) than with short (5-s) durations. By contrast, this difference either disappeared or reversed when the 5- and 15-s durations were correlated with the sample stimuli. Sample duration itself cued comparison choice by some birds in the latter (predictable) condition when duration was also correlated with the reinforced choice alternatives. However, even when duration could not provide a cue for choice, pigeons matched predictably short-duration samples as accurately as, or more accurately than, predictably long-duration samples. Moreover, this result was observed independently of whether the contextual conditions of the retention interval were the same as, or different from, those of the intertrial interval. These results strongly support the view that conditional stimulus control by the samples is partly a function of their conditioned reinforcing properties, as determined by the relative reduction in overall delay to reinforcement that they signal.     

Word informativity influences acoustic duration: Effects of contextual predictability on lexical representation

Language-users reduce words in predictable contexts. Previous research indicates that reduction may be stored in lexical representation if a word is often reduced. Because representation influences production regardless of context, production should be biased by how often each word has been reduced in the speaker’s prior experience. This study investigates whether speakers have a context-independent bias to reduce low-informativity words, which are usually predictable and therefore usually reduced. Content word durations were extracted from the Buckeye and Switchboard speech corpora, and analyzed for probabilistic reduction effects using a language model based on spontaneous speech in the Fisher corpus. The analysis supported the hypothesis: low-informativity words have shorter durations, even when the effects of local contextual predictability, frequency, speech rate, and several other variables are controlled for. Additional models that compared word types against only other words of the same segmental length further supported this conclusion. Words that usually appear in predictable contexts are reduced in all contexts, even those in which they are unpredictable. The result supports representational models in which reduction is stored, and where sufficiently frequent reduction biases later production. The finding provides new evidence that probabilistic reduction interacts with lexical representation.     

Task effects reveal cognitive flexibility responding to frequency and predictability: Evidence from eye movements in reading and proofreading

It is well-known that word frequency and predictability affect processing time. These effects change magnitude across tasks, but studies testing this use tasks with different response types (e.g., lexical decision, naming, and fixation time during reading; Schilling, Rayner, & Chumbley, 1998), preventing direct comparison. Recently, Kaakinen and Hyönä (2010) overcame this problem, comparing fixation times in reading for comprehension and proofreading, showing that the frequency effect was larger in proofreading than in reading. This result could be explained by readers exhibiting substantial cognitive flexibility, and qualitatively changing how they process words in the proofreading task in a way that magnifies effects of word frequency. Alternatively, readers may not change word processing so dramatically, and instead may perform more careful identification generally, increasing the magnitude of many word processing effects (e.g., both frequency and predictability). We tested these possibilities with two experiments: subjects read for comprehension and then proofread for spelling errors (letter transpositions) that produce nonwords (e.g., trcak for track as in Kaakinen & Hyönä) or that produce real but unintended words (e.g., trial for trail) to compare how the task changes these effects. Replicating Kaakinen and Hyönä, frequency effects increased during proofreading. However, predictability effects only increased when integration with the sentence context was necessary to detect errors (i.e., when spelling errors produced words that were inappropriate in the sentence; trial for trail). The results suggest that readers adopt sophisticated word processing strategies to accommodate task demands.     

Determinism and predictability

Theoretical determinism, as it is usually ascribed to Laplace, is neither verifiable nor falsifiable and has therefore no real content. It is not the same as predictability of actually observable phenomena. On the other hand, predictability is not an abstract principle; rather it is true to a certain degree, depending on the phenomena considered. It can be discussed only by examining the scientific state of affairs. This is done in some detail for classical statistical mechanics. Much of a recently published debate on determinism (Amsterdamski et al. 1990) is thereby obviated.     

Manual pointing to remembered targets...but also in a remembered visual context

In this paper we investigated whether visual background information available during target presentation influences manual pointing to remembered targets. Younger and older participants manually pointed with their unseen hands to remembered or visible targets that were presented or not over a structured visible background. The results indicated that a structured visual background biased movement planning processes, but did not influence motor control processes, regardless of the fact that target location and the background were visible or remembered. How one uses visual background information for movement planning is not modified by aging.     

Task dependent modulation of exogenous attention: Effects of target duration and intervening events

Inhibition of return (IOR) consists of slower reaction times in response to stimuli appearing at previously attended or inspected locations. The exact mechanisms underlying the effect have not yet been determined. In the present work, we manipulated two variables, target duration and intervening event (fixation cue between cue and target), through which we modulated the IOR effect as a function of task. When the target was presented until response, the presence of an intervening event made the cueing effect more negative in all tasks, although facilitation in the absence of an intervening event was only observed in discrimination and go–no-go tasks. When the target duration was 50 ms, the effect of the intervening event on cueing was also only observed for the discrimination and go–no-go tasks. Target duration had no effect at all in the discrimination task. Possible mechanisms for these modulations (detection cost and spatial selection benefit, both of which are based on cue–target integration processes) are discussed.     

Relational judgments with remembered stimuli

Two experiments investigating the effect of the direction of a relational judgment on the speed of the judgment are reported. In both experiments, college students required more time to select the smaller of a pair of large animals than to select the larger. Conversely, the smaller of a pair of small animals was selected more quickly than was the larger. The magnitude of this “cross-over effect” was fully graded, increasing regularly with extremity, but the variability of the response times in each direction was unrelated to extremity. Individual animals were classified as “small” or “large” with almost perfect consistency. This pattern of results is used to evaluate several models of relational judgment; of these, the congruency model is shown to be inconsistent with these data.

     

Psychophysical functions for perceived and remembered distance

Two separate groups of subjects made magnitude estimations of the distances to fifteen objects (from 20 ft to 14.28 miles away) situated in a landscape. On day 1 of the experiment both groups learned the names and locations of the objects while viewing them from the top of a small mountain. On day 2 the perception group (N = 19) judged the distances to the objects while viewing them from the top of the mountain, whereas the memory group (N = 18) judged the distances while visualizing the landscape from memory. The data for both groups were well fit by power functions; the exponent was reliably smaller for the memory group (0.596) than for the perception group (0.811). Both groups drew maps of the landscape (reproduction task) from memory and the exponents were 0.483 and 0.514 for the memory and perception groups, respectively. The results are discussed in light of possible transformations performed on the original stimulus inputs by the sensory/perceptual and the memorial systems.     

The discriminability of remembered magnitudes

Psychometric functions and the associated indices of discriminative performance (i.e., the point of subjective equality [PSE], 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.     

Prismatic displacement and the remembered location of targets

Following adaptation, only the trained limb misreaches to the remembered location of targets. This suggests a change in the feit position of the trained limb, but conflicts with recent reports, and with the hypothesis that when a limb changes, the remembered location of targets encountered only by that limb undergo some change too. It suggests that information is stored independently of the mode of acquisition.     

Directional scanning of remembered visual patterns

We report a set of experiments that helps to define the conditions under which mental image scanning may be used spontaneously for specific, practical purposes. Subjects were shown a dot pattern, followed by an arrow, and their task was to say whether the arrow was pointing at any of the previously seen dots. When no advance information was provided about the arrow's location, reaction time for correctly verifying that an arrow was pointing at a dot increased linearly with increasing arrow-dot distance, and the subjects almost always reported scanning a mental image in order to make their judgments. However, when a cue for the arrow's location was presented 2 sec beforehand, reaction time was uncorrelated with distance, and most of the subjects reported using an alternative strategy based on the determination in advance of correct directions from that location to the dots. When given only 1 sec of advance information about arrow location, most subjects reported using a combined image-scanning and advanced determination strategy, resulting in a reaction time function that increased only for the farthest distances. Because in each of these experiments instructions to form or to scan mental images were never given, these findings address the most common criticisms of the image-scanning paradigm.