Limited Attentional Resources Research Articles

Communicating with first year students; so many channels but is anyone listening? A Practice Report

Communicating with first year students has become a far more complex prospect in the digital age. There is a lot of competition for limited attentional resources from media sources in almost endless channels. Getting important messages to students when there is so much competing information is a difficult prospect for academic and professional divisions of the university alike. Students’ preferences for these communication channels are not well understood and are constantly changing with the introduction of new technology. A first year group was surveyed about their use and preference for various sources of information. Students were generally positive about the use of social networking and other new online media but strongly preferred more established channels for official academic and administrative information. A discussion of the findings and recommendations follows.

Problemy pomiaru wiedzy językowej

A key issue in research projects exploring the effectiveness of foreign language learning and teaching is precise measurement of learners’ knowledge of the targeted structure before and after the pedagogic intervention with an eye to determining the value of specific instructional options. Such measurement, however, poses a considerable challenge because traditional tests focusing on grammar or lexis only provide information about explicit, declarative knowledge, which is conscious and can primarily be applied in situations in which learners have sufficient time to plan their responses. For this reason, it is also necessary to measure implicit, procedural knowledge which is subconscious and automatic, thus enabling successful participation in spontaneous communication where limited attentional resources have to be employed in understanding and conveying messages in real time. The aim of this paper is to characterize the two types of linguistic knowledge, present the tools that can be employed in their measurement, and demonstrate how instruments of this kind can be successfully utilized in empirical investigations aiming to verify the effectiveness of techniques and procedures in teaching grammar.

Rapid learning of rapid temporal contexts

In an information-rich visual world and with limited attentional resources, what visual cues allow humans to efficiently navigate their environment? One key environmental characteristic is that stimuli rarely appear in isolation and typically coincide with other specific items that provide cues regarding where and when to guide our attention. Indeed, a predictive spatial context of distractors can enhance the deployment of attention to a target location (Chun & Jiang, 1998). However, can a predictive, temporal sequence of distractors, which do not enter working memory, cue when to allocate attention? Previous studies addressing this question have employed relatively long ( approximately < 500 msec/item) stimulus exposure durations. Thus, this temporal cuing may require extensive processing of the distractors. Here, we show that a rapidly presented (approximately 100 msec/item), predictive, temporal context, where stimuli undergo only preliminary analysis, can facilitate the deployment of attention to a specific temporal location.

Specific interference between a cognitive task and sensory organization for stance balance control in healthy young adults: Visuospatial effects

We tested the hypothesis that a computational overload results when two activities, one motor and the other cognitive that draw on the same neural processing pathways, are performed concurrently. Healthy young adult subjects carried out two seemingly distinct tasks of maintaining standing balance control under conditions of low (eyes closed), normal (eyes open) or high (eyes open, sway-referenced surround) visuospatial processing load while concurrently performing a cognitive task of either subtracting backwards by seven or generating words of the same first letter. A decrease in the performance of the balance control task and a decrement in the speed and accuracy of responses were noted during the subtraction but not the word generation task. The interference in the subtraction task was isolated to the first trial of the high but not normal or low visuospatial conditions. Balance control improvements with repeated exposures were observed only in the low visuospatial conditions while performance in the other conditions remained compromised. These results suggest that sensory organization for balance control appear to draw on similar visuospatial computational resources needed for the subtraction but not the word generation task. In accordance with the theory of modularity in human performance, the contrast in results between the subtraction and word generation tasks suggests that the neural overload is related to competition for similar visuospatial processes rather than limited attentional resources.

Individual differences in working memory capacity and distractor processing: Possible contribution of top–down inhibitory control

Working memory capacity (WMC) represents proficiency in allocating limited attentional resources. Previous studies on individual differences in WMC have shown that high WMC subjects have a superior ability to inhibit goal-irrelevant information, while low WMC subjects have difficulty in inhibiting such information. The present study aimed to reveal the neural structure that differentiates the inhibitory ability between subjects with high and low WMC. In the present fMRI study, activities of the bilateral inferior frontal gyrus (IFG), the fusiform gyrus (FFG) and the left middle frontal gyrus (MFG) were measured while participants were engaged in a face working memory task with distraction. Behavioral results showed that the performance of high WMC subjects was superior to low WMC subjects. As expected, the bilateral IFG showed greater activation in the stronger distraction condition; however, the magnitude did not differ between WMC groups, suggesting that the IFG functions to inhibit intensive distractors, but appears to be independent of the individual differences in inhibitory ability. On the other hand, the activation of the bilateral FFG in the low WMC group was stronger than in the high WMC group, while the activation of the left MFG was stronger in the high WMC group than in the low WMC group. These results indicate that the superior inhibitory ability in high WMC subjects may depend on the efficient top–down modulation from the left MFG to the posterior perceptual areas.

The Impact of Social Presence on Voluntary and Involuntary Control of Spatial Attention

The present study examined whether and how the presence of an invisible person can affect the control of visuospatial attention on the basis of cues. In two experiments, participants reported the identity of a target letter that was shown at variable peripheral locations. In Experiment 1, a central (i.e., symbolic) cue reliably informed participants about the location of the subsequent target stimulus; central cues are typically used to control attention endogenously. In Experiment 2, a peripheral (i.e., physical) cue preceded the target stimulus with equal probability at the valid or at the invalid location; peripheral cues are known to attract attention exogenously. Crucially, in both experiments the experimenter was either present in the laboratory room or not. The results showed that the presence of the experimenter did not affect the processing of peripheral cues, but disrupted the use of central cues, probably because of competition for limited working memory and/or attentional resources.

Effect of Working Memory and Spatial Attention Tasks on Gait in Healthy Young and Older Adults

Changes in gait parameters induced by the concomitant performance of one of two cognitive tasks activating working memory and spatial attention, was examined in healthy young adults (YA) and older adults (OA). There was a main effect of task condition on gait-speed (p = .02), stride-length (p < .001) and double-support time (p = .04) independent of the group. There were no significant differences between working memory and spatial attention associated gait changes. Working-memory and spatial-attention dual-tasking led to a decrease in gait-speed (p = .09 and 0.01) and stride-length (p = .04 and 0.01) and increase in double-support time (p = .01 and 0.03) in YA and decrease in stride-length (p = .04 and 0.01) alone in OA. Cognitive task associated changes in gait may be a function of limited attentional resources irrespective of the type of cognitive task.

Age-effects on associative object–location memory

Aging is accompanied by an impairment of associative memory. The medial temporal lobe and fronto-striatal network, both involved in associative memory, are known to decline functionally and structurally with age, leading to the so-called associative binding deficit and the resource deficit. Because the MTL and fronto-striatal network interact, they might also be able to support each other. We therefore employed an episodic memory task probing memory for sequences of object–location associations, where the demand on self-initiated processing was manipulated during encoding: either all the objects were visible simultaneously (rich environmental support) or every object became visible transiently (poor environmental support). Following the concept of resource deficit, we hypothesised that the elderly probably have difficulty using their declarative memory system when demands on self-initiated processing are high (poor environmental support). Our behavioural study showed that only the young use the rich environmental support in a systematic way, by placing the objects next to each other. With the task adapted for fMRI, we found that elderly showed stronger activity than young subjects during retrieval of environmentally richly encoded information in the basal ganglia, thalamus, left middle temporal/fusiform gyrus and right medial temporal lobe (MTL). These results indicate that rich environmental support leads to recruitment of the declarative memory system in addition to the fronto-striatal network in elderly, while the young use more posterior brain regions likely related to imagery. We propose that elderly try to solve the task by additional recruitment of stimulus–response associations, which might partly compensate their limited attentional resources.

Native Speakers and Task Performance: Comparing Effects on Complexity, Fluency, and Lexical Diversity

This article argues that a native‐speaker baseline is a neglected dimension of studies into second language (L2) performance. If we investigate how learners perform language tasks, we should distinguish what performance features are due to their processing an L2 and which are due to their performing a particular task. Having defined what we mean by “native speaker,” we present the background to a research study into task features on nonnative task performance, designed to include native‐speaker data as a baseline for interpreting nonnative‐speaker performance. The nonnative results, published in this journal (Tavakoli &amp; Foster, 2008) are recapitulated and then the native‐speaker results are presented and discussed in the light of them. The study is guided by the assumption that limited attentional resources impact on L2 performance and explores how narrative design features—namely complexity of storyline and tightness of narrative structure—affect complexity, fluency, accuracy, and lexical diversity in language. The results show that both native and nonnative speakers are prompted by storyline complexity to use more subordinated language, but narrative structure had different effects on native and nonnative fluency. The learners, who were based in either London or Tehran, did not differ in their performance when compared to each other, except in lexical diversity, where the learners in London were close to native‐speaker levels. The implications of the results for the applicability of Levelt's model of speaking to an L2 are discussed, as is the potential for further L2 research using native speakers as a baseline.

Compromising Postural Balance in the Elderly

Background: Additional tasks that are assumed to disturb standing postural control can be divided in added motor or added cognitive tasks. It is unknown which type of task causes the most disturbances of postural control in elderly. Objective: The aim of this study was to determine whether the dual tasking disturbance of postural control in elderly is caused by vocal articulation or by limited attentional resources. Methods: 39 elderly (81 ± 7 years) were tested on a force plate in a two-legged standing position. Seven balance variables were assessed: maximum displacement and standard deviation amplitude in the medial-lateral (ML, SDML) and anterior-posterior (AP, SDAP) direction, average speed of displacement (V) and the area of the 95th percentile ellipse (AoE) and sway path (PL) per given time. The following task combinations were tested: no secondary task, repeating a number aloud (articulation), counting backwards aloud (articulation and attention), and counting backwards silently (attention). All tasks were tested with and without vision. Results: A factorial ANOVA revealed main effects of additional tasks in PL, ML, SDML, AP, AoE and V. Bonferroni post-hoc analysis in a vision situation showed significant difference between no task and counting backwards aloud task in balance variables ML (p = 0.006), SDML (p = 0.002), AP (p = 0.020) and V (p = 0.003), respectively. All no-vision situations showed no significant difference between the different tasks. Conclusion: The findings suggest that the combined articulation and attention-demanding secondary task stressed the attentional system of elderly to such an extent that it compromised the performance of the primary task (quiet standing). The counting backwards aloud task may be used as dual task for clinical balance assessment in at-risk populations. This task was best able to disturb postural control.

Using Informative Peripheral Visual and Tactile Cues to Support Task and Interruption Management

This study examined the effectiveness of using informative peripheral visual and tactile cues to support task switching and interruption management. Effective support for the allocation of limited attentional resources is needed for operators who must cope with numerous competing task demands and frequent interruptions in data-rich, event-driven domains. One prerequisite for meeting this need is to provide information that allows them to make informed decisions about, and before, (re)orienting their attentional focus. Thirty participants performed a continuous visual task. Occasionally, they were presented with a peripheral visual or tactile cue that indicated the need to attend to a separate visual task. The location, frequency, and duration parameters of these cues represented the domain, importance, and expected completion time, respectively, of the interrupting task. The findings show that the informative cues were detected and interpreted reliably. Information about the importance (rather than duration) of the task was used by participants to decide whether to switch attention to the interruption, indicating adherence to experimenter instructions. Erroneous task-switching behavior (nonadherence to experimenter instructions) was mostly caused by misinterpretation of cues. The effectiveness of informative peripheral visual and tactile cues for supporting interruption management was validated in this study. However, the specific implementation of these cues requires further work and needs to be tailored to specific domain requirements. The findings from this research can inform the design of more effective notification systems for a variety of complex event-driven domains, such as aviation, medicine, or process control.

Hypnotizability and temporal dynamics of attention: a study on the Attentional Blink effect

AbstractThis study was designed to seek hypnotizability‐related differences in attention temporal dynamics. For this purpose, an iconic version of the Attentional Blink Task (AB) was performed on 18 highly (Highs, score 9–12, SHSS form C) and 18 low susceptible individuals (Lows, score 0–3). The procedure consisted of two tasks in which two animal shapes (a coloured animal, Target, and a black butterfly, Probe) appeared in close temporal proximity within a rapid stream of distractors (black animals). In the Single task only Probe detection was required; in the Conditional task, Target identification was also requested. In this case, competition between Target and Probe for limited attentional resources decreases Probe visibility as a function of the time lag from Target (AB effect). A similar AB effect occurred in the two groups; nonetheless, Probe detection scores at the shorter lags were frequently higher in Highs than in Lows. This suggests that time constraints could affect the performance of Highs less than Lows, but also that the two groups could differ in attention capturing mechanisms, i.e. automatic capture by colour at the shorter lag. Moreover, Highs scores on Target identification were lower than Lows' ones indicating an impairment of Highs when engaged in dual tasks.

On the nonautomaticity of visual word processing: Electrophysiological evidence that word processing requires central attention.

The present study used event-related potentials (ERPs) to determine the degree to which people can process words while devoting central attention to another task. Experiments 1-4 measured the N400 effect, which is sensitive to the degree of mismatch between a word and the current semantic context. Experiment 5 measured the P3 difference between low- and high-frequency words. Because these effects can occur only if a word has been identified, both ERP components index word processing. The authors found that the N400 effect (Experiments 1, 3, and 4) and the P3 difference (Experiment 5) were strongly attenuated for Task 2 words presented nearly simultaneously with Task 1. No such attenuation was found when the Task 1 stimulus was presented but required no response (Experiment 2). Strong attenuation was also evident when the Task 2 word was presented before the Task 1 stimulus (Experiment 4), suggesting that central resources are not allocated to stimuli first-come, first-served but rather are strategically locked to Task 1. The authors conclude that visual word processing is not fully automatic but rather requires access to limited central attentional resources.

Enhanced Processing of Threat Stimuli under Limited Attentional Resources

The ability to process stimuli that convey potential threat, under conditions of limited attentional resources, confers adaptive advantages. This study examined the neurobiology underpinnings of this capacity. Employing an attentional blink paradigm, in conjunction with functional magnetic resonance imaging, we manipulated the salience of the second of 2 face target stimuli (T2), by varying emotionality. Behaviorally, fearful T2 faces were identified significantly more than neutral faces. Activity in fusiform face area increased with correct identification of T2 faces. Enhanced activity in rostral anterior cingulate cortex (rACC) accounted for the benefit in detection of fearful stimuli reflected in a significant interaction between target valence and correct identification. Thus, under conditions of limited attention resources activation in rACC correlated with enhanced processing of emotional stimuli. We suggest that these data support a model in which a prefrontal “gate” mechanism controls conscious access of emotional information under conditions of limited attentional resources.

Role of attentional resources on gait performance in Huntington's disease

Patients with Huntington's disease (HD) suffer from cognitive deficits with impaired executive functions, including limited attentional resources. We sought to use a dual-task paradigm to evaluate attentional demands and the ability of patients with HD to concentrate on two tasks simultaneously. We analyzed the interference effects of cognitive and motor tasks on walking in HD and the contribution of clinical symptoms to gait disturbances. Patients and controls were asked to perform either a motor task (carrying a tray with four glasses), a cognitive task (counting backwards), or no task at all while walking at their preferred speed. Kinematic spatial parameters, temporal parameters, and angular parameters related to gait were recorded in 15 patients and 15 controls by means of a videomotion analysis system. Gait instability was assessed using the stride-to-stride variability of the various gait parameters. For patients with HD, performing a concurrent cognitive task resulted in a lower gait speed (compared with free walking), with decreased cadence and stride length. However, this effect was not observed in controls. Performing a motor task did not change any kinematic gait parameters in either HD or control subjects. We found correlations between gait speed in the dual cognitive/walking task on one hand and the motor UHDRS score, cognitive status and executive function on the other. Patients with HD had greater difficulty walking while performing a concurrent cognitive task; the drain on attentional resources deteriorated walking performance.

Short Article: Emotional and Neutral Scenes in Competition: Orienting, Efficiency, and Identification

To investigate preferential processing of emotional scenes competing for limited attentional resources with neutral scenes, prime pictures were presented briefly (450 ms), peripherally (5.2 degrees away from fixation), and simultaneously (one emotional and one neutral scene) versus singly. Primes were followed by a mask and a probe for recognition. Hit rate was higher for emotional than for neutral scenes in the dual- but not in the single-prime condition, and A' sensitivity decreased for neutral but not for emotional scenes in the dual-prime condition. This preferential processing involved both selective orienting and efficient encoding, as revealed, respectively, by a higher probability of first fixation on--and shorter saccade latencies to--emotional scenes and by shorter fixation time needed to accurately identify emotional scenes, in comparison with neutral scenes.

Neural correlates of dual task performance in patients with Parkinson’s disease

Background:Patients with Parkinson’s disease (PD) have great difficulty in performing two tasks simultaneously, but the neural contribution to this problem has not been identified. In the current study, we investigated...

Aging and goal-directed emotional attention: Distraction reverses emotional biases.

Previous findings reveal that older adults favor positive over negative stimuli in both memory and attention (for a review, see Mather & Carstensen, 2005). This study used eye tracking to investigate the role of cognitive control in older adults' selective visual attention. Younger and older adults viewed emotional-neutral and emotional-emotional pairs of faces and pictures while their gaze patterns were recorded under full or divided attention conditions. Replicating previous eye-tracking findings, older adults allocated less of their visual attention to negative stimuli in negative-neutral stimulus pairings in the full attention condition than younger adults did. However, as predicted by a cognitive-control-based account of the positivity effect in older adults' information processing tendencies (Mather & Knight, 2005), older adults' tendency to avoid negative stimuli was reversed in the divided attention condition. Compared with younger adults, older adults' limited attentional resources were more likely to be drawn to negative stimuli when they were distracted. These findings indicate that emotional goals can have unintended consequences when cognitive control mechanisms are not fully available.

Gap duration discrimination for frequency-asymmetric gap markers: Psychophysical and electrophysiological findings

This study investigated gap duration discrimination (GDD) for frequency-asymmetric gap markers, where one marker was a two-tone complex consisting of a primary tone and a secondary tone, and the other marker was the primary tone alone. Three experiments were undertaken to examine the order effect wherein performance is better when the two-tone marker is the leading marker than when it is the trailing marker. Experiment 1 demonstrated that GDD for frequency-asymmetric markers is intermediate between the boundaries of within-frequency-channel versus across-frequency-channel processing. Experiment 2 compared psychophysical performance with auditory brainstem responses (ABRs) elicited by the same stimuli. Whereas GDD thresholds were elevated for a complex trailing marker relative to a within-frequency-channel baseline, ABRs elicited by the complex marker were more robust. Experiment 3 tested the hypothesis that poor GDD performance with frequency-asymmetric markers is due to some form of nonenergetic, or informational, masking. The results did not support a role for informational masking conferred by synthetic listening; however, informational masking conferred by the occurrence of novel spectral events provided a parsimonious account. One possible interpretation is that the capacity to accurately encode a gap is undermined by the occurrence of novel spectral events that engage limited attentional resources.

Enhanced identification of smoking-related words during the attentional blink in smokers

The attentional blink (AB) occurs when ongoing processing of one target (T1) in a series of rapidly presented stimuli impairs processing of a subsequently presented second target (T2), such that T2 cannot be consciously perceived or reported. There is evidence that the AB can be influenced by the emotional or motivational salience of T2. We examined whether the AB could be attenuated by smoking-related stimuli in smokers. Heavy smokers ( N = 55) performed an AB task on two occasions, once following 12-h of abstinence and once following ad libitum smoking. T2s were either smoking-related or neutral (household-related) words, and lagged T1 by 0 to 7 distracter words. T1s were all neutral words. Each word was presented for 130 ms. Subjects were required to recall T1 and T2 immediately after each trial. There was a significant word type by lag interaction, whereby smoking-related T2s were recalled better than neutral T2s at early, but not late, lags. The word type effect at early lags was significantly associated with attentional bias assessed on the smoking Stroop task, but was not significantly moderated by abstinence. These data indicate that, in heavy smokers, smoking-related stimuli are more likely to engage conscious awareness than neutral words under conditions of limited attentional resources.