Inferences under time pressure: how opportunity costs affect strategy selection

Do the inference strategies people select depend on the magnitude of time pressure? Is this dependency modified by the type of time pressure? These questions are addressed in three experimental studies in which participants made inferences after having searched for information on a computerized information board. In Study 1, time pressure was induced indirectly by imposing opportunity costs of being slow, a form of time pressure that is common in daily life but that has rarely been examined in the literature. A simple lexicographic heuristic (LEX) achieved the best fit in predicting participants' inferences. Studies 2 and 3 induced high time pressure either indirectly by imposing opportunity costs in terms of time or directly by limiting the time for each choice. Regardless of how time pressure was induced, under high time pressure the inferences could be best predicted with LEX, whereas under low time pressure a weighted linear model that integrates all available information predicted the inferences best. We conclude that people select strategies adaptively depending on characteristics of the situation.     

The use of recognition information and additional cues in inferences from memory

Goldstein and Gigerenzer's (2002) "Recognition Heuristic" (RH) was tested for its empirical validity in an experimental paradigm with induced recognition of objects. RH claims that upon inferring which of two objects (e.g., cities) scores higher on a criterion (e.g., city size), a recognized object will be chosen over an unrecognized one, if the recognition is a valid predictor of the criterion without considering additional object information. Trying to avoid potential shortcomings of former studies, we (a) used the city population task, (b) provided additional cue information only for recognized cities, and (c) had participants draw inferences from memory. Participants learned city names and additional information about some cities. They also learned that recognition and the additional information were valid predictors of the criterion "city size". In a subsequent decision phase, the additional information about the cities in memory strongly affected the inferences, suggesting that recognition information is clearly integrated into judgments, but by no means in a non-compensatory fashion that would dominate every other cue.     

Age differences in memory control: evidence from updating and retrieval-practice tasks

Some contemporary approaches suggest that inhibitory mechanisms play an important role in cognitive development. In addition, several authors distinguish between intentional and unintentional inhibitory processes in cognition. We report two experiments aimed at exploring possible developmental changes in these two types of inhibitory mechanisms. In Experiment 1, an updating task was used. This task requires that participants intentionally suppress irrelevant information from working memory. In Experiment 2, the retrieval-practice task was used. Retrieval practice of a subset of studied items is thought to involve unintentional inhibitory processes to overcome interference from competing memories. As a result, suppressed items become forgotten in a later memory test. Results of the experiments indicated that younger children (8) were less efficient than older children (12) and adults at intentionally suppressing information (updating task). However, when the task required unintentional inhibition of competing items (retrieval-practice task), this developmental trend was not found and children and adults showed similar levels of retrieval-induced forgetting. The results are discussed in terms of the development of efficient inhibition and the distinction between intentional and unintentional inhibitions.     

Temporal order in memory and interval timing: an interference analysis

The effect of varying load in memory tasks performed during a time interval production was examined. In a first experiment, increasing load in memory search for temporal order affected concurrent time production more strongly than varying load in a spatial memory task of equivalent difficulty. This result suggests that timing uses some specific resources also required in processing temporal order in memory, resources that would not be used in the spatial memory task. A second experiment showed that the interference between time production and memory search involving temporal order was stronger when, during the timing task, a decision was made on the temporal position of a memory item, than when information on temporal order was retained throughout the interval to be produced. These results underscore the importance of considering the specific resources and processes involved when the interference between timing and concurrent non-temporal tasks is analyzed.     

I see into your mind too well: working memory adjusts the probability judgment of others' mental states

Although an increasing number of studies on adults have indicated that working memory (WM) contributes to the ability to understand the mental states of others (i.e., theory of mind), the detailed mechanism by which WM contributes to successful reasoning has not previously been revealed. This study shows that WM modulates the degree of attribution of one's own knowledge to others' mental states. Participants were asked to read a story twice (Experiment 2) or as carefully as possible (Experiment 3) and to estimate the probability percentages of possible choices for a naive protagonist's behavior. The participants were then asked to maintain either a two- or seven-letter alphabet string (i.e., a light or heavy WM load, respectively) during the probability estimation but not during the story comprehension. The results showed that compared to the participants with a light WM load, those with a heavy WM load estimated a significantly higher probability of the choice indicating that the protagonist would behave on the basis of a fact that the participants knew but the protagonist did not. This result indicates that WM moderates the extent to which adults attribute their own knowledge to others' mental states. The role of WM in theory of mind and in heuristic strategy for making probability judgments was then discussed.     

Features of graded category structure: Generalizing the family resemblance and polymorphous concept models

Many real-world categories contain graded structure: certain category members are rated as more typical or representative of the category than others. Research has shown that this graded structure can be well predicted by the degree of commonality across the feature sets of category members. We demonstrate that two prominent feature-based models of graded structure, the family resemblance (Rosch & Mervis, 1975) and polymorphous concept models (Hampton, 1979), can be generalized via the contrast model (Tversky, 1977) to include both common and distinctive feature information, and apply the models to the prediction of typicality in 11 semantic categories. The results indicate that both types of feature information play a role in the prediction of typicality, with common features weighted more heavily for within-category predictions, and distinctive features weighted more heavily for contrast-category predictions. The same pattern of results was found in additional analyses employing rated goodness and exemplar generation frequency. It is suggested that these findings provide insight into the processes underlying category formation and representation.     

Working memory and planning during sentence production

Speakers retrieve conceptual, syntactic and lexical information in advance of articulation during sentence production. What type of working memory (WM) store is used to hold the planned information before speaking? To address this question, we measured onset latencies when subjects produced sentences that began with either a complex or a simple initial noun phrase, while holding semantic, phonological or spatial information in WM. Although we found that subjects had longer onset latencies for sentences beginning with a complex noun phrase, showing a phrasal scope of planning, the magnitude of this complexity effect was not affected by any type of WM load. However, subjects made more syntactic errors (but not lexical errors) for sentences beginning with a complex noun phrase, suggesting that advance planning for these phrases occurs at a syntactic rather than lexical–semantic level, which may account for the lack of effect with various types of WM load in the current study.     

Verbal, visual, and spatial working memory in written language production

College students wrote definitions of either abstract or concrete nouns in longhand while performing a concurrent working memory (WM) task. They detected either a verbal (syllable), visual (shape), or spatial (location) stimulus and decided whether it matched the last one presented 15-45s earlier. Writing definitions of both noun types elevated the response time to verbal targets above baseline. Such interference was observed for visual targets only when defining concrete nouns and was eliminated entirely with spatial targets. The interference effect for verbal targets was the same whether they were read or heard, implicating phonological storage. The findings suggest that language production requires phonological or verbal WM. Visual WM is selectively engaged when imaging the referents of concrete nouns.     

When working memory updating requires updating: Analysis of serial position in a running memory task

This study aimed to investigate updating in working memory (WM), analyzing the effects of task demand and memory resources on serial position curve (SPC), in a running memory task with slow pace presentation and a probed recognition procedure. These task conditions were supposed to produce an easier WM updating task, which may allow evidencing whether the task is performed through an active or a passive updating.     

Children's verbal working memory: relative importance of storage, general processing speed, and domain-general controlled attention

This study evaluated multiple constraints of verbal working memory in typically developing 7- to 11-year-olds. Multiple measures of verbal working memory and the predictors-short-term memory storage, general speed, and domain-general controlled attention were used. General linear modeling (GLM) showed that storage and the efficiency of controlled attention (i.e., speed of updating information during attention switching) contributed to significant variance in children's verbal working memory. In a secondary analysis verbal storage and domain-general attention (focus switching accuracy and speed of updating on switch) emerged as significant predictors. Results suggest domain-general attention and verbal storage mechanisms to be independent constraints of verbal working memory.     

Cognitive control in context: Working memory capacity and proactive control

Working memory is important for maintaining critical information in an active state to guide future behavior. The executive-attention theory of working memory capacity (WMC; Engle & Kane, 2004) argues that goal maintenance is important for response selection when stimuli are associated with competing responses. Braver, Burgess, and Gray (2007) have labeled this type of preparatory activity proactive control. Previous WMC studies have not allowed individuals to use goal information to prepare a specific response in advance of the stimulus. The current experiment used different versions of a cue-probe task to examine the relationship between individual differences in WMC and proactive control. Across three versions of the AX version of the Continuous Performance Test, the proportion of targets was manipulated to affect both the predictive validity of the A cue and the prepotency of the target response to X probes. The results indicated that the high-WMC individuals used the cue information to prepare responses in advance only when a specific probe was likely to occur. In contrast, the performance of the low-WMC individuals was less dependent upon the cue and more contingent upon overall response frequencies. The results indicate that individual differences in WMC are related to proactive control and anticipation, and important for translating cognition into action.     

Time perception and temporal order memory

The purpose of this research was to investigate the relation between the attentional resources underlying time perception and temporal order memory. Subjects made judgments about temporal attributes associated with a series of wordlists. Each word was displayed for 1.4 s, and the lists contained 10 words (14 s total), 15 words (21 s total), or 20 words (28 s total). Subjects judged either the list duration, the temporal order of the words, or both duration and temporal order. In addition, there were three mental workload conditions: control (no additional task requirements), and two mental arithmetic tasks (subtract 3 or subtract 7 from a series of random numbers). The results showed a pattern of bidirectional interference between timing and temporal order: the concurrent temporal order task interfered with duration judgments, and the concurrent timing task interfered with temporal order judgments. Bidirectional interference also occurred between the mental workload task and both duration judgments and temporal order judgments. The results indicate that duration and temporal order are closely related temporal attributes, and suggest that the processing of these attributes relies on a common set of executive attentional resources.     

Differential involvement of internal clock and working memory in the production and reproduction of duration: a study on older adults

The present study uses the inter-individual variability in time perception of a group of elderly participants to differentiate the processes underlying time production and time reproduction. Participants performed duration production and reproduction tasks. They were also administered working memory tests and a spontaneous motor tempo task. The findings suggest that duration production and duration reproduction involve different mechanisms. Correlational analyses revealed a double dissociation: production was only correlated with spontaneous motor tempo and reproduction only with working memory measures. These findings suggest that the internal clock rate modulates the production of duration and that reproduced duration varies according to working memory capacities.     

From models to rules: mechanization of reasoning as a way to cope with cognitive overloading in combinatorial problems

It is hypothesized that the transition from unfamiliar problems to familiar, well-learned problems coincides with the transition from a model-based style of reasoning to a rule-based style of reasoning; model-based style of reasoning helps understanding the problem structure, but can overload working memory when the number of models required increases; rule-based style of reasoning avoids cognitive overloading, at the cost of making individuals liable to mechanization errors. In Experiment 1, the number of models required to respond to a verification task affected response latencies with unfamiliar problems, but not with familiar problems, supporting the initial hypothesis. In Experiment 2, participants were prone to mechanization errors when confronted with slightly modified problems in the late stages of the experiment, supporting the hypothesis that they had developed a reasoning rule in the early stages and were blindly applying it. The findings suggest that model-based reasoning and rule-based reasoning serve different purposes and have different costs and benefits, are both available to human reasoners, and familiarization with a problem may induce the transition from the former to the latter. The findings also suggest that mechanization of reasoning may be the first step along a gradient of decreasing cognitive load, whose end-point is automatization, as discussed in theories of automatization of information processing.     

Matching perceived depth from disparity and from velocity: Modeling and psychophysics

We asked observers to match in depth a disparity-only stimulus with a velocity-only stimulus. The observers’ responses revealed systematic biases: the two stimuli appeared to be matched in depth when they were produced by the projection of different distal depth extents. We discuss two alternative models of depth recovery that could account for these results. (1) Depth matches could be obtained by scaling the image signals by constants not specified by optical information, and (2) depth matches could be obtained by equating the stimuli in terms of their signal-to-noise ratios (see Domini & Caudek, 2009). We show that the systematic failures of shape constancy revealed by observers’ judgments are well accounted for by the hypothesis that the apparent depth of a stimulus is determined by the magnitude of the retinal signals relative to the uncertainty (i.e., internal noise) arising from the measurement of those signals.     

Glimpses of a one-speed mind: Focus-switching and search for verbal and visual, and easy and difficult items in working memory

We investigated focus-switching and search rates in an N-Back task for stimuli presumably encoded either in a phonological/semantic or an abstract-visual format. Experiment 1 used Chinese characters and tested Chinese speakers and non-Chinese speakers; character frequency and visual complexity were also manipulated. Experiment 2 presented Chinese characters and English words to non-Chinese English speakers. Effects of focus-switching on accuracy were larger for abstract-visual stimuli and for more difficult stimuli; effects on RT were larger for abstract-visual stimuli, but there was no effect of difficulty, with the exception of the most difficult stimulus set in Experiment 1. Search slopes outside the focus of attention did not covary with either type of code or item difficulty. The decline in accuracy over set-size was stronger for the items coded in abstract-visual format. This suggests that item availability is sensitive to robustness of the memory representations, but item accessibility is not. The data fit well with a model of STM in which a fixed number of ‘slots’ are searched at a constant rate, regardless of the slot’s contents.     

Person memory and judgment

Two general types of information about a person are considered in this article: One pertains to specific behaviors a person has manifested, and the other refers to more abstract personality dispositions or behavioral tendencies. A theoretical model of person memory that incorporates both types of information is developed. The model accounts for a large number of factors that are known to affect the recall of social information, the making of interpersonal judgments, and the relation between what is recalled and the judgments that are made. A major strength of the model is its applicability to a wide range of person memory and judgment phenomena that are observed in several different experimental paradigms.