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PubMed1990

Properties of memory for unattended spoken syllables.

Whereas previous studies on memory for unattended speech have inadvertently included acoustic interference, the present study examines memory for unattended syllables during a silent period of 1, 5, or 10 s. The primary task was to read silently (Experiments 1-3) or whisper the reading (Experiment 4). Occasionally, when a light cue occurred, the subject was to recall the most recent spoken syllable, as well as the recent reading material. Memory for both the vowels and consonants of the syllables decreased across 10 s, confirming that auditory memory does decay in the absence of acoustic interference. However, the specific patterns of memory decay for vowels versus consonants depended on task demands, including the allocation of attention and the opportunity for subvocal coding. We suggest an account of performance that includes auditory sensory and phonetic memory codes with different properties, used in combination.

Attention↗

PubMed1991

Inhibitory mechanisms of attention in identification and localization tasks: time course and disruption.

It has been proposed that 1 component of the mechanism of visual selective attention is active inhibition of distracting information. A series of studies examines the time course of inhibition and the possible interfering effects of other task demands. Results demonstrate that inhibition can last at least 7 s after selection processes and that it is unaffected by predictable, unrelated intervening events. However, intervening events that are less predictable, or are the same as the inhibited stimulus, disrupt inhibition. Such results motivate a reconsideration of the previous view of distractor inhibition as a transient, fragile phenomenon.

Adolescent↗

PubMed1996

Redistribution of spatial representation in the hippocampus of aged rats performing a spatial memory task.

Young and old rats performed on a maze according to a forced-choice and then a spatial memory procedure either in the same or a different environment. Aged rats were slower to learn the spatial memory task when tested in the same, but not in a different, room. One interpretation of this pattern of results is that although old rats learn new rules as quickly as young rats, they show less flexibility with old rules and familiar spatial information. Impaired choice accuracy during asymptote performance suggests poor processing of trial-unique information by old rats. Spatial correlates of hippocampal CA1 and hilar cells varied with task demand: CA1 cells of aged rats showed more spatially selective place fields, whereas hilar cells showed more diffuse location coding during spatial memory, and not forced-choice, tests. Such representational reorganization may reflect a compensatory response to age-related neurobiological changes in hippocampus.

Aging↗

PubMed1990

A measure of relational competence for community-dwelling elderly.

A measure of relational competence was developed to assess the skills necessary for peer friendship development among the elderly. Participants were required to respond to a series of social problem vignettes that were constructed to tap empathy, assertion, and role-taking skills. Validation data were collected as part of a larger project designed to establish indigenous, elderly peer-support telephone dyads among low-income, community-dwelling elderly women. Results indicated that the measure of relational competence was related to initial friendship formation, telephone conversational skills, and rated social competence as determined by judges' ratings of 2 telephone conversations between participants and staff members. The research illustrates the usefulness of moving away from trait conceptions of social competence to a more focused consideration of particular task demands and the skills needed to solve age-linked social problems.

Activities of Daily Living↗

PubMed1992

The role of psychosocial context, age, and intelligence in memory performance of older men.

The hypothesis that psychosocial contextual factors contribute to developmental changes in memory was examined using 326 male World War II veterans. Availability of young adult intelligence scores made it possible to separate the contributions of contextual variables and age to maintenance of general intelligence from their direct contributions to performance on 4 memory tasks. Being younger, healthier, more educated, more introverted, more intellectually active, and more satisfied with social support predicted less intellectual decline and, indirectly, better memory performance. Age, personality, locus of control, and extent of social support directly contributed to performance on 1 or more memory tasks. Age contributions were consistent with Craik's (1986) proposed continuum of task demands for self-initiated effort. Possible elaborations of Craik's hypothesis to accommodate contextual variables are suggested.

Aged↗

PubMed2000

Exploring the effects of icon characteristics on user performance: the role of icon concreteness, complexity, and distinctiveness.

Because icons, signs, and symbols are now widely used to communicate information, it is essential for system designers to know what makes them easy to use and interpret. The authors report a series of studies that examine characteristics considered central to icon usability. After quantifying the properties of icon concreteness, complexity, and discriminability, the authors assessed each property's effects on user performance when user experience, task demands, and presentation context were systematically varied. Findings indicated that the effects of icon concreteness were primarily associated with the initial grasp of meaning, whereas complexity effects were found to persist longer and to be associated with search efficacy. The effects of icon distinctiveness were complex, but distinctiveness was enhanced by using both semantic and visual contrasts. The implications of these findings for interface design are discussed.

Adult↗

PubMed2004

On the development of the mental number line: more, less, or never holistic with increasing age?

Magnitude is assumed to be represented along a holistic mental number line in adults. However, the authors recently observed a unit-decade compatibility effect for 2-digit numbers that is inconsistent with this "holisticness" assumption (H.-C. Nuerk, U. Weger, & K. Willmes, 2001). This study used the compatibility effect to examine whether the mental number line representation of magnitude changes toward greater or less holisticness in children from Grades 2-5. The results indicate that decades and units of 2-digit numbers are processed separately rather than holistically from Grade 2 on. However, this separate processing seems to develop from a more sequential (left-to-right) to a more parallel processing mode. Moreover, children may use different strategies depending on task demands. The results are interpreted in the framework of Siegler's overlapping waves model.

Child↗

PubMed2005

Don't worry, be happy? Neuroticism, trait-consistent affect regulation, and performance.

People regulate their affect either to feel good or to achieve instrumental success. The present experiments show that when driven by performance goals, people can be motivated to experience unpleasant affect when it is trait-consistent, because of its instrumental benefits (e.g., M. Tamir & M. D. Robinson, 2004). In 4 studies, individuals high in neuroticism were more likely than those low in neuroticism to choose to increase their level of worry, as indicated by self-reported preferences (Study 1) and by behavioral choices in experimental settings (Studies 2-4). As predicted, such preferences were evident when expecting to perform demanding tasks but not when expecting an undemanding task (Study 2). Study 4 suggests that such preferences for short-term unpleasant affect may be beneficial to performance.

Achievement↗

PubMed2003

Attentional modulation of the visual motion aftereffect has a central cognitive locus: evidence of interference by the postcategorical on the precategorical.

An attentionally demanding task undertaken during adaptation to motion reduces the duration of the subsequent motion aftereffect (A. Chaudhuri, 1990). Previous studies have suggested that this effect is intramodal in character, reflecting the selective deployment of visual attention. The present study demonstrates that nonvisual tasks, performed concurrently with motion adaptation, can significantly reduce the duration of the ensuing aftereffect. Three experiments converge on the conclusionthat postcategorical processes can influence otherwise unrelated concurrent precategorical processes. The experiments also show that neither perceptual input nor motor output components of the attentional task are responsible for the subsequent reduction in motion of aftereffect. The results suggest a reappraisal of findings in this area and of the general distinction between perception and cognition.

Afterimage↗

PubMed2005

The effects of spatial stimulus-response compatibility on choice time production accuracy and variability.

Five experiments examined the relations between timing and attention using a choice time production task in which the latency of a spatial choice response is matched to a target interval (3 or 5 s). Experiments 1 and 2 indicated that spatial stimulus-response incompatibility increased nonscalar timing variability without affecting timing accuracy and that choice reaction time practice reduced choice time production variability. These data support a "temporal discounting" model in which response choice and timing occur in series, but the interval timed is shortened to account for nontemporal processing. In Experiment 3, feedback and anticipation task demands improved choice time production accuracy. In Experiments 4 and 5, the delay between the start-timing and choice-decision signals interacted with choice difficulty to affect choice time production accuracy and variability when timing a 3- but not a 5-s interval, suggesting that attention mediates timing before and after an interruption in timing.

Attention↗

PubMed2006

The attentional white bear phenomenon: the mandatory allocation of attention to expected distractor locations.

The authors devised a prestimulus-probe method to assess the allocation of attention as a function of participants' top-down expectancies concerning distractor and target locations. Participants performed the flanker task, and distractor locations remained fixed. On some trials, instead of the flanker display, either 2 simultaneous dots or a horizontal line appeared. The dot in the expected distractor location was perceived to occur before the dot in the expected empty location, and the line appeared to extend from the expected distractor location to the expected empty location, suggesting that attention is allocated to expected distractor locations prior to stimulus onset. The authors propose that a process-all mechanism guides attention to expected locations of all stimuli regardless of task demands and that this constitutes a major cause for failures of selective attention.

Adult↗

PubMed2006

Dissociations between reaction times and temporal order judgments: a diffusion model approach.

A diffusion model for simple reaction time (RT) and temporal order judgment (TOJ) tasks was developed to account for a commonly observed dissociation between these 2 tasks: Most stimulus manipulations (e.g., intensity) have larger effects in RT tasks than in TOJ tasks. The model assumes that a detection criterion determines the level of sensory evidence needed to conclude that a stimulus has been presented. Analysis of the performance that would be achieved with different possible criterion settings revealed that performance was optimal with a lower criterion setting for the TOJ task than for the RT task. In addition, the model predicts that effects of stimulus manipulations should increase with the size of the detection criterion. Thus, the model suggests that commonly observed dissociations between RT and TOJ tasks may simply be due to performance optimization in the face of conflicting task demands.

Algorithms↗

PubMed2005

Resolving visual interference during covert spatial orienting: online attentional control through static records of prior visual experience.

Models of attentional control usually describe online shifts in control settings that accommodate changing task demands. The current studies suggest that online control over distractor exclusion--a core component of visual selection--can be accomplished without online shifts in top-down settings. Measurements of target discrimination accuracy suggested that the degree of distractor exclusion was guided by retinotopic maps of the prior probability of distractor interference at the attended locations. These probability maps can be retrieved via object-based cues, and they interact with shifts of attention to elicit increased levels of distractor exclusion when it is most needed. Thus, static probability maps can provide an internal template that guides the resolution of visual interference as spatial attention traverses the visual field.

Attention↗

PubMed2005

Multiple processes in prospective memory retrieval: factors determining monitoring versus spontaneous retrieval.

Theoretically, prospective memory retrieval can be accomplished either by controlled monitoring of the environment for a target event or by a more reflexive process that spontaneously responds to the presence of a target event. These views were evaluated in Experiments 1-4 by examining whether performing a prospective memory task produced costs on the speed of performing the ongoing task. In Experiment 5, the authors directly tested for the existence of spontaneous retrieval. The results supported the multiprocess theory (M. A. McDaniel & G. O. Einstein, 2000) predictions that (a) spontaneous retrieval can occur and can support good prospective memory and (b) depending on task demands and individual differences, people rely to different degrees on monitoring versus spontaneous retrieval for prospective remembering.

Attention↗

PubMed2005

Category representation for classification and feature inference.

This research's purpose was to contrast the representations resulting from learning of the same categories by either classifying instances or inferring instance features. Prior inference learning research, particularly T. Yamauchi and A. B. Markman (1998), has suggested that feature inference learning fosters prototype representation, whereas classification learning encourages exemplar representation. Experiment 1 supported this hypothesis. Averaged and individual participant data from transfer after inference training were better fit by a prototype than by an exemplar model. However, Experiment 2, with contrasting inference learning conditions, indicated that the prototype model was mimicking a set of label-based bidirectional rules, as determined by the inference learning task demands in Experiment 1. Only the set of rules model accounted for all the inference learning conditions in these experiments.

Humans↗

PubMed2006

Comprehensive computerized assessment of cognitive sequelae of a complete 12-16 hour fast.

Food deprivation has been shown to deleteriously affect human cognition, but findings are equivocal, and few studies have examined several cognitive domains. In this study, the authors used computerized testing to describe the profile of shifts in cognition attributable to short-term religious fasting. Multiple cognitive domains were evaluated at midday and late afternoon following complete abstention from eating and drinking beginning at midnight. Cross-domain, fasting-related deficits were found for tasks requiring perception of spatial relations. Fasting-related information processing deficits were found for response time but not accuracy for test levels of intermediate difficulty. Time-of-day effects often reflected poorer afternoon performance. These findings provide a detailed profile of cognitive consequences of food deprivation, affected by time of day, task demands, and type of outcome.

Adult↗

PubMed2006

The influence of APOE status on episodic and semantic memory: data from a population-based study.

In a prospective cohort study, the authors demonstrated a more pronounced epsilon4-related deficit for participants 70 years of age and older in tasks assessing episodic recall. Apolipoprotein E (APOE) and age interacted for episodic memory tasks, whereas the interaction for semantic memory tasks was between APOE and test wave. Heterozygotes of epsilon4 between middle-age and young-old participants performed at a higher level than noncarriers of this allele in recall tasks. A dose effect was found such that carriers of 2 epsilon4 alleles failed more profoundly in acquiring and recollecting episodic information than carriers of 1 epsilon4 allele, who in turn failed more than carriers of non-epsilon4 alleles. The pattern of findings observed for older epsilon4 carriers suggests that these individuals have particular difficulty when the executive task demands are high. Several factors (e.g., smaller hippocampal volumes, less effective neural repair mechanisms) may account for these findings. On the basis of the data obtained, the authors argue that analyses of the effect of specific genes in cognition should be accompanied by assessment of performance at a specific level, with due attention to the individual's age.

Adult↗

PubMed2007

A pilot investigation of the effects of stress on neuropsychological performance in Asian-Indians in the United States.

The present study evaluated the effects of stress and the ethnicity of the examiner on neuropsychological performance in a sample of Asian-Indian males in the United States. Participants were 60 Asian-Indian college students randomly assigned to one of four conditions in a 2 x 2 factorial design. The first factor was level of stress induction and the second was ethnicity of examiners. Results suggested that both stress inducing instructions and examiner ethnicity impacted highly demanding tasks, while moderately difficult tasks were less sensitive to ethnicity of the examiner. Results also indicate that examiners should recognize the potential impact of ethnicity and heightened level of stress when administering and interpreting neuropsychological measures.

Acculturation↗