Effects of aging and divided attention on episodic feeling-of-knowing accuracy

This research investigated the effect of aging on episodic feeling-of-knowing (FOK) using a divided attention (DA) paradigm in order to examine whether DA in younger adults mimics the effects of aging when decreasing either memory encoding or monitoring processes. To that end, four groups of participants were tested on the FOK task: young adults (control group), young adults under DA at encoding, young adults under DA when making FOK judgments, and older adults. Our results showed that DA at encoding in young adults mimicked the effect of aging on memory performance, and also on FOK magnitude and accuracy, supporting the memory-constraint hypothesis ( Hertzog et al., 2010). However, our results do not completely contradict the monitoring-deficit hypothesis, as DA during FOK judgments also affected FOK accuracy, but to a lesser extent than the aging effect or DA during encoding. We suggest that the age-related FOK deficit may be due to a lower level of deep encoding, leading to difficulty retrieving target-related contextual details enabling accurate prediction of subsequent recognition.     

Investigating the visual span in comparative search: the effects of task difficulty and divided attention

In three experiments, participants' visual span was measured in a comparative visual search task in which they had to detect a local match or mismatch between two displays presented side by side. Experiment 1 manipulated the difficulty of the comparative visual search task by contrasting a mismatch detection task with a substantially more difficult match detection task. In Experiment 2, participants were tested in a single-task condition involving only the visual task and a dual-task condition in which they concurrently performed an auditory task. Finally, in Experiment 3, participants performed two dual-task conditions, which differed in the difficulty of the concurrent auditory task. Both the comparative search task difficulty (Experiment 1) and the divided attention manipulation (Experiments 2 and 3) produced strong effects on visual span size.     

Effects of aging and divided attention on memory for items and their contexts

It is commonly found that memory for context declines disproportionately with aging, arguably due to a general age-related deficit in associative memory processes. One possible mechanism for such deficits is an age-related reduction in available processing resources. In two experiments we compared the effects of aging to the effects of division of attention in younger adults on memory for items and context. Using a technique proposed by Craik (1989), linear functions relating memory performance for items and their contexts were derived for a Young Full Attention group, a Young Divided Attention group, and an Older Adult group. Results suggested that the Old group showed an additional deficit in associative memory that was not mimicked by divided attention. It is speculated that both divided attention and aging are associated with a loss of available processing resources that may reflect inefficient frontal lobe functioning, whereas the additional age-related decrement in associative memory may reflect inefficient processing in medial-temporal regions.     

Effects of age and a divided attention task presented during encoding and retrieval on memory

The present studies were designed to examine age differences in memory when attention was divided during encoding, retrieval, or at both times. In Experiment 1, Ss studied categorized words while performing a number-monitoring task during encoding, retrieval, or at both times. Older Ss' free recall and clustering performance declined more than that of young Ss when attention was divided at encoding, but there was no similar age interaction when divided attention occurred at retrieval. In Experiment 2, the task demands at retrieval were increased by using a fast-paced, cued-recall task. The results remained unchanged from Experiment 1. Again, an age interaction occurred with divided attention at encoding but not at retrieval. These results were unexpected, given the emphasis in the memory-aging literature on increased difficulty of retrieval by older adults. The findings pose difficulties for limited processing resource views of age differences in memory.     

Effects of aging and divided attention on recognition memory processes for single and associative information

In the divided attention paradigm to test age-related associative memory deficits, whether the effects of divided attention occur at encoding or retrieval has not been clarified, and the effect on retention has not been studied. This study explored whether and how much divided attention at either encoding, retention, or retrieval diminished accuracy in recognizing a single feature (object or location) and associated features (object+location) by 23 elderly people (13 women; M age = 70.6 yr., SD = 2.8) recruited from a neighborhood community circle, and 29 female college students (M age = 20.8 yr., SD = 1.1). The results showed a significant decline in memory performance for both age groups due to divided attention in location and associative memory at retention, suggesting that the retention process demands attentional resources. Overall, regardless of their relative deficiency in associative memory, older adults showed an effect of divided attention comparable to that of younger adults in a recognition task.     

Effects of bilingualism, aging, and semantic relatedness on memory under divided attention.

We examined how encoding and retrieval processes were affected by manipulations of attention, and whether the degree of semantic relatedness between words in the memory and distracting task modulated these effects. We also considered age and bilingual status as mediating factors. Monolingual and bilingual younger and older adults studied a list of words from a single semantic category presented auditorily, and later free recalled them aloud. During either study or retrieval, participants concurrently performed a distracting task requiring size decisions to words from either the same or a different semantic category as the words in the memory task. The greatest disruptions of memory from divided attention (DA) were for encoding rather than retrieval. The effect of semantic relatedness was significant only for DA at encoding. Older age and bilingualism were associated with lower recall scores in all conditions, but these factors did not influence the magnitude of memory interference. The results suggest that encoding is more sensitive to semantic similarity in a distracting task than is retrieval. The role of attention at encoding and retrieval is discussed.     

Effects of divided attention in the word-fragment completion task with unique and multiple solutions

A study with 114 young adults investigated the correlations of intelligence factors and working-memory capacity with reaction time (RT) tasks. Within two sets of four-choice RT tasks, stimulus–response compatibility was varied over three levels: compatible, incompatible, and arbitrary mappings. Two satisfactory measurement models for the RTs could be established: A general factor model without constraints on the loadings and a nested model with two correlated factors, distinguishing compatible from arbitrary mappings, with constraints on the loadings. Structural models additionally including factors for working memory and intelligence showed that the nested model with correlated factors is superior in fit. Working-memory capacity and fluid intelligence were correlated strongly with the nested factor for the RT tasks with arbitrary mappings, and less with the general RT factor. The results support the hypothesis that working memory is needed to maintain arbitrary bindings between stimulus representations and response representations, and this could explain the correlation of working-memory capacity with speed in choice RT tasks.     

Effects of age and divided attention on memory components derived for the category exemplar generation task

Age differences in memory performances on a conceptually driven task, the category exemplar generation (CEG) test, were investigated. Thirty-six younger adults and 36 healthy older adults studied word lists in full and divided attention conditions. Recall was tested with category names. The process-dissociation procedure was used to derive estimates of controlled and automatic memory. Old-old adults (70-84 years) exhibited poorer conscious recollection than both younger (18-24) and young-old adults (59-69). In contrast, no age differences were found in estimates of automatic memory. For the younger and older adults, the divided encoding manipulation reduced both the consciously controlled and automatic estimates of memory. The results suggest that the few prior findings of age deficits in priming on the CEG may have been an artifact of contamination from conscious retrieval processes. They also indicate that the opportunity for greater semantic processing enhances the conceptual priming of both younger and older adults.     

Sensation seeking and selective attention: focused and divided attention on a dichotic listening task.

Differences in selective attention as a function of sensation seeking, extraversion, neuroticism, and psychoticism were examined in 108 undergraduates using a dichotic listening task. Dependent measures included shadowing performance, reaction times to a secondary light task, target detection, and recall. The results suggested that high sensation seekers have better focused attention than low sensation seekers, and these effects were strongest on the 1st trials of the shadowing tasks. High sensation seekers did not attend differently than low sensation seekers to words related to their interests (sexual, violent, or drug related). Extraversion was associated with greater recall of these kinds of words, although there were no overall differences in selective attention as a function of Eysenck's dimensions. The role of arousal in personality and attention is discussed, particularly in regard to the response of sensation seekers to task novelty.     

Private speech on an executive task: relations with task difficulty and task performance

Measures of private speech and task performance were obtained for a sample of 46 5- and 6-year-olds engaged on a mechanical version of the Tower of London (ToL) task. Two different sets of four puzzles of increasing difficulty were attempted on two occasions. In line with Vygotskian predictions, there was a quadratic relation between private speech and task difficulty, but no evidence of a shift towards self-regulatory sub-types of private speech with increasing task difficulty. Levels of self-regulatory private speech were significantly related to concurrent, but not subsequent, task performance. We discuss the significance of these findings for the Vygotskian view that private speech has an adaptive function in the self-regulation of behaviour.     

Full versus divided attention and implicit memory performance

Effects of full and divided attention during study on explicit and implicit memory performance were investigated in two experiments. Study time was manipulated in a third experiment. Experiment 1 showed that both similar and dissociative effects can be found in the two kinds of memory test, depending on the difficulty of the concurrent tasks used in the divided-attention condition. In this experiment, however, standard implicit memory tests were used and contamination by explicit memory influences cannot be ruled out. Therefore, in Experiments 2 and 3 the process dissociation procedure was applied. Manipulations of attention during study and of study time clearly affected the controlled (explicit) memory component, but had no effect on the automatic (implicit) memory component. Theoretical implications of these findings are discussed.     

Evidence of preliminary response preparation from a divided attention task

In a divided attention situation, preliminary response activations produced by stimuli on one channel were revealed through their effects on responses to stimuli on a secondary probe channel. Subjects performed concurrent but independent four-choice reaction-time tasks using the same four response fingers (middle and index fingers on both hands). In the main task, targets were large and small Ss and Ts, and medium-sized Ss and Ts sometimes appeared as distractors. Targets in the probe task were squares differing in location. A response to a probe square was faster if a distractor letter presented just before it had the same name as the target letter corresponding to that square (i.e., assigned to the same response key) than if the distractor letter had a different name--a result indicating that distractor letters cause partial response preparation. The timecourse of the effect demonstrated that preparation was based on preliminary information about distractor name that was available before distractor size had been determined. The results support models in which response preparation can sometimes begin before stimulus recognition has finished.     

Effects of goal difficulty, self-set goals, and monetary rewards on dual task performance

The present study tests the effects of goal difficulty, goal origin (self-set vs assigned), and monetary rewards (present vs absent) on the simultaneous performance of two tasks (dual-task paradigm). Participants were 32 students working simultaneously on a computerized task of letter typing with the right hand and digit classification with the left hand. A 2 (self-set vs assigned goals) × 2 (present vs absent contingent monetary rewards) × 3 (easy, moderate, and difficult goals) factorial design with goal difficulty as the repeated factor was employed. Each task element was performed under easy, moderate, and difficult goals, which appeared in six consecutive trials of varied order within each experimental condition. Results indicate that self-set goals without monetary rewards led to the highest performance levels, whereas the combination of self-set goals and monetary rewards was detrimental to performance. These findings occurred (except in one case) only when goals were of either moderate Or high difficulty.     

Effects of task difficulty on use of advice

Although prior studies have found that people generally underweight advice from others, such discounting of advice is not universal. Two studies examined the impact of task difficulty on the use of advice. In both studies, the strategy participants used to weigh advice varied with task difficulty even when it should not have. In particular, the results show that people tend to overweight advice on difficult tasks and underweight advice on easy tasks. This pattern held regardless of whether advice was automatically provided or whether people had to seek it out. The paper discusses implications for the circumstances under which people will be open to influence by advisors. Copyright © 2006 John Wiley & Sons, Ltd.     

The effects of music and task difficulty on performance at a visual vigilance task

Forty subjects performed a visual vigilance task in music or noise and when the task was difficult or easy. Response measures taken were: correct detections, commission errors, detection latencies and d' values. For the difficult version of the task a significant increase in detection latencies was found which music prevented. Broadly similar findings were obtained for correct detections. The results are compared with other studies of detection latency and task difficulty and are discussed in terms of arousal.     

The effects of aging and divided attention on memory for item and associative information

The present study examined how aging and divided attention influence memory for item and associative information. Older adults and younger adults working under full-attention conditions and younger adults working under divided-attention conditions studied unrelated word pairs. Memory for item information was measured by later recognition of the 2nd word in the pair, and associative information was measured by recognition of the entire pair. Both older adults in the full-attention condition and younger adults in the divided-attention condition performed more poorly than younger adults in the full-attention condition, with the deficit in associative information being greater than the deficit in item information. In addition, a differentially greater associative decrement was found for the older adults, as shown by their heightened tendency to make false-alarm responses to re-paired (conjunction) distractors. The results are discussed in terms of an age-related reduction in processing resources compounded by an age-related increase in older adults' reliance on familiarity in associative recognition memory.     

The relationship between task difficulty and motor performance complexity

Difficult tasks are commonly equated with complex tasks across many behaviors. Motor task difficulty is traditionally defined via Fitts’ law, using evaluation criteria based on spatial movement constraints. Complexity of data is typically evaluated using non-linear computational approaches. In this project, we investigate the potential to evaluate task difficulty via behavioral (motor performance) complexity in a Fitts-type task. Use of non-linear approaches allows for inclusion of many features of motor actions that are not currently included in the Fitts-type paradigm. Our results indicate that tasks defined as more difficult (using Fitts movement IDs) are not associated with complex motor behaviors; rather, an inverse relationship exists between these two concepts. Use of non-linear techniques allowed for the detection of behavioral differences in motor performance over the entire action trajectory in the presence of action errors and among neutrally co-constrained effectors not detected using traditional Fitts’-type analyses utilizing movement time measures. Our findings indicate that task difficulty may potentially be inferred using non-linear measures, particularly in ecological situations that do not obey the Fitts-type testing paradigm. While we are optimistic regarding these initial findings, further work is needed to assess the full potential of the approach.     

Prospective memory: Effects of divided attention on spontaneous retrieval

We examined the effects of divided attention on the spontaneous retrieval of a prospective memory intention. Participants performed an ongoing lexical decision task with an embedded prospective memory demand, and also performed a divided-attention task during some segments of lexical decision trials. In all experiments, monitoring was highly discouraged, and we observed no evidence that participants engaged monitoring processes. In Experiment 1, performing a moderately demanding divided-attention task (a digit detection task) did not affect prospective memory performance. In Experiment 2, performing a more challenging divided-attention task (random number generation) impaired prospective memory. Experiment 3 showed that this impairment was eliminated when the prospective memory cue was perceptually salient. Taken together, the results indicate that spontaneous retrieval is not automatic and that challenging divided-attention tasks interfere with spontaneous retrieval and not with the execution of a retrieved intention.