Selective and divided attention in a Stroop task.

Three experiments employed a modified version of the Stroop Color-Word Test to document some conditions under which attention may be differentially deployed. Ss were 66 undergraduates. Within limits, Ss chose either to selectively attend to a single stimulus or to distribute processing resources over several stimuli. Thus, attentional strategies may be actively chosen to suit prevailing conditions. Once established, these different modes of attending were themselves differentially open to strategic modulation. (French abstract) (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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 time (RT) to a secondary light task, target detection, and recall. Results suggested that high sensation seekers have better focused attentions than low sensation seekers, and these effects were strongest on the 1st trials of the shadowing tasks. Higher 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of aging and task difficulty on divided attention performance.

We report two experiments that compare the performance of young and older adults on perceptual-motor tasks involving division of attention. Previous studies have shown older people to be especially penalized by divided attention situations, but the generality of this finding was recently challenged by Somberg and Salthouse (1982). The present study was conducted to investigate the possibility that age differences in dual-task performance are amplified by an increase in the difficulty of the constituent tasks, where difficulty was manipulated by varying the central, cognitive nature of the tasks (Experiment 1) or the degree of choice involved (Experiment 2). With the present tasks, strong evidence was found for an age-related decrement in divided attention performance. Contrary to our original expectations, however, it does not seem that division of attention presents some especial difficulty to older people. Rather, division of attention is one of several equivalent ways to increase overall task complexity. In turn, age differences are exaggerated as tasks are made more complex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gaze perception requires focused attention: Evidence from an interference task.

The direction of another person's gaze is difficult to ignore when presented at the center of attention. In 6 experiments, perception of unattended gaze was investigated. Participants made directional (left-right) judgments to gazing-face or pointing-hand targets, which were accompanied by a distractor face or hand. Processing of the distractor was assessed via congruency effects on target response times. Congruency effects were found from the direction of distractor hands but not from the direction of distractor gazes (Experiment 1). This pattern persisted even when distractor sizes were increased to compensate for their peripheral presentation (Experiments 2 and 5). In contrast, congruency effects were exerted by profile heads (Experiments 3 and 4). In Experiment 6, isolated eye region distractors produced no congruency effects, even when they were presented near the target. These results suggest that, unlike other facial information, gaze direction cannot be perceived outside the focus of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facilitation of unattended semantic information in Alzheimer's disease: Evidence from a selective attention task.

Processing of unattended semantic information was examined in 13 patients with Alzheimer's disease (AD) and 23 normal controls (NC) using a selective attention, priming task. Two vertically aligned pictures of objects served as primes, and object names were targets. Participants were instructed to attend to only 1 picture, defined by color, in the prime display. NC participants showed facilitation only for target items that were the name of the attended prime picture, but AD patients showed facilitation from the attended and unattended prime pictures. Two accounts of these data posit a deficit in the initiation of the selection component of selective attentional processing in AD. On the basis of spotlight theories, a 3rd account posits a deficit in AD patients' ability to adjust the scope of the selection "beam." Last, facilitation of attended and unattended information may be due to crosstalk between accurately selected and unselected information. Implications of the activation of irrelevant information to language function in AD are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Motor coactivation revealed by response force in divided and focused attention.

Four experiments examined effects of bimodal stimulation on response force (RF) in addition to reaction time (RT). In a divided-attention task (Exps 1–3), Ss were asked for a speeded response to either a visual or an auditory signal. In unimodal signal trials, either a visual or auditory signal was presented alone, and in redundant-signals trials, both signals were presented simultaneously. The same stimulus arrangement was used in a focused-attention task (Exp 4), but Ss had to withhold their response when an auditory signal was presented alone. In all experiments, the fastest RTs were attained in redundant-signals trials. In addition, RF was largest in redundant-signals trials, especially in the divided-attention task, suggesting a motor coactivation hypothesis. The results indicate that the type of stimulation influences not only when a response is initiated but also how the response is executed. This finding challenges the view, commonly held in mental chronometry, that late motoric processes remain untouched by experimental manipulations. A detailed analysis of the relationship between RT and RF revealed that these variables are not inherently redundant measures, and therefore, RF recording may supplement the traditional RT measurement in mental chronometry. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Online response preparation in a rapid serial visual search task.

Online response preparation was assessed in a visual search task using rapid serial visual presentation. In each trial, a series of letters was presented sequentially, and participants were instructed to make a target-present response if a prespecified target letter was presented or a target-absent response if it was not. Measurements of response preparation using both probe reaction time and the lateralized readiness potential indicated that preparation of the target-absent response increased near the end of the sequence. Most of the increase appeared to be due to direct priming of the target-absent response by nontarget letters, but part was due to the increased conditional probability of this response near the end of the sequence. These results extend previous studies of response preparation by showing online response preparation during a temporally extended reaction time task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response selection and response execution in task switching: Evidence from a go-signal paradigm.

The present study used a go/no-go signal delay (GSD) to explore the role of response-related processes in task switching. A go/no-go signal was presented at either 100 ms or 1,500 ms after the stimulus. Participants were encouraged to use the GSD for response selection and preparation. The data indicate that the opportunity to select and prepare a response (i.e., long GSD) resulted in a substantial reduction of task-shift costs (Experiment 1) and n-2 task-repetition costs (i.e., backward inhibition; Experiment 2) in the current trial. These results suggest that interference from the preceding trial can be resolved during response selection and preparation. Furthermore, the shift costs and the n-2 repetition costs after no-go trials with long GSD (i.e., response selection but no execution) were markedly smaller than after go trials. These findings suggest that the interference that gives rise to shift costs and n-2 repetition costs is related not solely to response selection but also to response execution. Thus, the present study demonstrates dissociable contributions of response selection and response execution to interference effects in task switching. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Do response modality effects support multiprocessor models of divided attention?

Some studies have suggested that dual-task interference is greatly reduced when tasks requiring very different types of responses (e.g., manual and vocal) are combined. However, in those studies, the order of stimuli varied unpredictably. In Exps 1 and 2, with 33 undergraduates, variable stimulus order greatly inflated interference between 2 manual tasks, whereas interference between a manual and a vocal task was only slightly exacerbated. However, central interference (the psychological refractory period) persisted even with the manual/vocal combination. Selection of 2 manual responses with unknown stimulus order may require a special strategy to prelude intertask intrusion errors. Exp 3, with 12 undergraduates, demonstrated that such errors could be provoked with speed stress. Together, these results reconcile response modality effects with the response selection bottleneck model for dual-task interference (once it is suitably amended). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Distinguishing response conflict and task conflict in the Stroop task: Evidence from ex-Gaussian distribution analysis.

It has been suggested that performance in the Stroop task is influenced by response conflict as well as task conflict. The present study investigated the idea that both conflict types can be isolated by applying ex-Gaussian distribution analysis which decomposes response time into a Gaussian and an exponential component. Two experiments were conducted in which manual versions of a standard Stroop task (Experiment 1) and a separated Stroop task (Experiment 2) were performed under task-switching conditions. Effects of response congruency and stimulus bivalency were used to measure response conflict and task conflict, respectively. Ex-Gaussian analysis revealed that response conflict was mainly observed in the Gaussian component, whereas task conflict was stronger in the exponential component. Moreover, task conflict in the exponential component was selectively enhanced under task-switching conditions. The results suggest that ex-Gaussian analysis can be used as a tool to isolate different conflict types in the Stroop task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The attentional demands of encoding and retrieval in younger and older adults: I. Evidence from divided attention costs.

Four studies examined the effects of divided attention in younger and older adults. Attention was divided at encoding or retrieval in free recall (Experiment 1), cued recall (Experiments 2 and 3), and recognition (Experiment 4). Dividing attention at encoding disrupted memory performance equally for the two age groups; by contrast, for both age groups, dividing attention at retrieval had little or no effect on memory performance. Secondary task reaction times (RTs) were slowed to a greater extent for the older adults than for the younger adults, especially at retrieval. Age-related differences in RTs costs at retrieval were largest in free recall, smaller in cued recall, and smallest in recognition. These results provide evidence for an age-related increase in the attentional demands of encoding and retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Controlling Stroop interference: Evidence from a bilingual task.

Skilled performance is often associated with automaticity. Automatic processes are generally thought of as uncontrollable so that automaticity implies the lack of control. The Stroop Color and Word Test is one of the most cited examples of automaticity and uncontrollability of word reading. This task is also employed extensively to investigate the structure of the bilingual lexicon. The present work employed a Hebrew-Arabic bilingual Stroop task in 2 separate experiments. To induce controlled processing, the authors varied the Ss' expectations regarding the written (irrelevant) color words. The Stroop interference effect was always present, but Ss were able to control (reduce) it in their native language but not in their second language. In addition, the presumed structure of the bilingual lexicon seems to change in accordance with proficiency in the second language. It is suggested that automaticity and control are both characteristics of skilled performance with each of them reflecting a different aspect and each subserving a different function of our cognitive system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preschoolers' strategies of attention on a same-different task.

Forty-six preschoolers were asked to decide whether two rows of drawings, objects were exactly the same by opening the doors that covered the drawings. Four-year-olds, but generally not 3-year-olds, used the most efficient strategy, opening vertically aligned pairs of doors to compare spatially corresponding parts of the rows. Producing this strategy was associated with more accurate same–different judgments. Furthermore, the 4-year-olds improved their strategies significantly, although modestly, over some of the six trials. Earlier phases of strategy development were seen in the use of inefficient, but systematic, spatial strategies in 3-year-olds and partial use of efficient or inefficient strategies in both 3- and 4-year-olds. Children rarely gathered information randomly. Results are discussed in terms of a multifaceted change in strategy production and utilization that extends over several years. Several limitations of 4-year-olds' strategic behavior were also identified. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interference effects from divided attention during retrieval in younger and older adults.

The authors examined how retrieval, under divided attention (DA) conditions, is affected by the type of material in a concurrent task, and whether aging produces larger interference effects on memory. Young and old adults studied a list of unrelated words under full attention, and recalled them while performing either an animacy decision task to words or an odd-digit identification task to numbers. The animacy-distracting task interfered substantially with retrieval, and the size of the effect was not amplified in older compared with younger adults. DA using the odd-digit task did not produce as large an interference effect. These findings support the component-process model of memory, and pose problems for resource models of interference from DA at retrieval. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic processing of psychological distance: Evidence from a Stroop task.

A picture-word version of the Stroop task was used to test the automatic activation of psychological distance by words carrying various senses of psychological distance: temporal (tomorrow, in a year), social (friend, enemy), and hypotheticality (sure, maybe). The pictures implied depth, with the words appearing relatively close to or distant from the observer. The participants classified the spatial distance of words faster when the word's implicit psychological distance matched its spatial distance (e.g., a geographically close word was classified faster when it was "friend" than when it was "enemy"). The findings are consistent with the idea that psychological distance is accessed automatically, even when it is not directly related to people's current goals, and suggest that psychological distance is an important dimension of meaning, common to spatial distance, temporal distance, social distance, and hypotheticality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lingering misinterpretations in garden-path sentences: Evidence from a paraphrasing task.

Using a forced-choice question-answering paradigm, K. Christianson, A. Hollingworth, J. F. Halliwell, and F. Ferreira (2001) showed that the original misinterpretation built during the analysis of a garden-path sentence lingers even after reanalysis has occurred. However, their methodology has been questioned (R. P. G. van Gompel, M. J. Pickering, J. Pearson, & G. Jacob, 2006). In this study, the authors report evidence for lingering misinterpretations using a paraphrasing methodology, which is less biased than previous methodologies. Using paraphrasing, they found that garden-path sentences are paraphrased according to a partially reanalyzed interpretation. This finding suggests that the arguments put forward by Christianson et al. are correct: Comprehenders' final interpretations of sentences are often incorrect and do not correspond to the initial input. These findings support the theory that comprehension can occur in a good-enough manner (F. Ferreira, V. Ferraro, & K. G. D. Bailey, 2002; F. Ferreira & N. Patson, 2007). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic interference in a delayed naming task: Evidence for the response exclusion hypothesis.

In 2 experiments participants named pictures of common objects with superimposed distractor words. In one naming condition, the pictures and words were presented simultaneously on every trial, and participants produced the target response immediately. In the other naming condition, the presentation of the picture preceded the presentation of the distractor by 1,000 ms, and participants delayed production of their naming response until distractor word presentation. Within each naming condition, the distractor words were either semantic category coordinates of the target pictures or unrelated. Orthogonal to this manipulation of semantic relatedness, the frequency of the pictures' names was manipulated. The authors observed semantic interference effects in both the immediate and delayed naming conditions but a frequency effect only in the immediate naming condition. These data indicate that semantic interference can be observed when target picture naming latencies do not reflect the bottleneck at the level of lexical selection. In the context of other findings from the picture-word interference paradigm, the authors interpret these data as supporting the view that the semantic interference effect arises at a postlexical level of processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attributions of familiarity in amnesia: Evidence from a fame judgment task.

To evaluate the extent to which amnesic patients can attribute the source of familiarity to its correct source during a fame judgment task, gains in familiarity were placed in opposition to conscious recollection. In the 1st experiment, patients and controls were told specifically that nonfamous names presented just prior to a fame judgment task were not famous; in the 2nd experiment they were told that nonfamous names were in fact famous. Although such instructions produced dramatically different results in the fame judgment performance of normal control Ss, minimal change in attribution of fame occurred for the amnesic Ss. It is concluded that the amnesic Ss were unable to attribute the familiarity of a previously presented name to its correct source because of their inability to recollect a name's prior presentation. Hence, it may be the nature of the memory query rather than the adequacy of a specific memory system that determines whether or not an amnesic patient can access information in memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related declines in working-memory skills: Evidence from a complex calculation task.

16 young, 16 middle-aged, and 16 older adults practiced an algorithm for squaring 2-digit numbers for 6 sessions. Errors were classified as failures of working-memory processes (e.g., substitutions, deletions, omissions) or as calculation errors (e.g., fact-retrieval errors). Practice reduced both working-memory and calculation errors for all age groups and eliminated initial age-related differences in the rates of calculation errors. The older cohort was associated with both a greater frequency and a greater proportion of working-memory errors relative to the young group. In contrast with calculation, however, age-related differences in working-memory efficiency appeared to be reduced only modestly by practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved)