Cognitive Task Complexity Research Articles

Cognitive task complexity effects on L2 writing performance: An application of mixed-methods approaches

This paper provides a methodological review of previous research on cognitive task complexity, since the term emerged in 1995, and investigates why much research was more quantitative rather than qualitative. Moreover, it sheds light onto the studies which used the mixed-methods approach and determines which version of the mixed-methods designs was frequently used. The results reveal that many studies in the field of cognitive task-based research used quantitative rather than qualitative experimental design to collect and interpret their findings. These studies were more oriented to post-positivistim supported by an objectivist epistemology. However, limited studies utilized mixed-methods approach to consider the effects of cognitive task complexity on linguistic performance in L2 context. The theoretical perspective behind these studies was pragmatism. The mixed-methods studies only used the explanatory sequential design to collect data and interpret their findings while other versions of the mixed-methods research designs were left undefined. To conclude, the paper identifies the current gap in methodology of the studies and offers recommendations for how to obtain more comprehensive and generalizable findings by utilizing other versions of the mixed-methods studies.

Antecedent acute cycling exercise affects attention control: an ERP study using attention network test.

The purpose of this study was to investigate the after-effects of an acute bout of moderate intensity aerobic cycling exercise on neuroelectric and behavioral indices of efficiency of three attentional networks: alerting, orienting, and executive (conflict) control. Thirty young, highly fit amateur basketball players performed a multifunctional attentional reaction time task, the attention network test (ANT), with a two-group randomized experimental design after an acute bout of moderate intensity spinning wheel exercise or without antecedent exercise. The ANT combined warning signals prior to targets, spatial cueing of potential target locations and target stimuli surrounded by congruent or incongruent flankers, which were provided to assess three attentional networks. Event-related brain potentials and task performance were measured during the ANT. Exercise resulted in a larger P3 amplitude in the alerting and executive control subtasks across frontal, central and parietal midline sites that was paralleled by an enhanced reaction speed only on trials with incongruent flankers of the executive control network. The P3 latency and response accuracy were not affected by exercise. These findings suggest that after spinning, more resources are allocated to task-relevant stimuli in tasks that rely on the alerting and executive control networks. However, the improvement in performance was observed in only the executively challenging conflict condition, suggesting that whether the brain resources that are rendered available immediately after acute exercise translate into better attention performance depends on the cognitive task complexity.

The Effects of Task Complexity and Input Frequency on the Acquisition of the Past Counterfactual Construction Through Recasts

This investigation examined two techniques that may help learners focus on second language (L2) constructions when recasts are provided during meaning‐based communicative activities: altering the cognitive complexity of tasks and manipulating the input frequency distributions of target constructions. We first independently assessed the validity of our cognitive task complexity manipulation by means of expert judgments, dual‐task methodology, and eye tracking. Next, in our main study, we employed a pretest‐posttest design with two treatment sessions. The participants were 51 adult English L2 learners, randomly assigned to one of four experimental groups or a control group. All experimental groups received recasts but differed as to whether they carried out simple tasks with lower reasoning demands or complex tasks with higher reasoning demands, and whether they received skewed or balanced input of the linguistic target, the past counterfactual construction. An oral production test and two written receptive tests were utilized to measure changes in participants’ knowledge. Our results revealed no effects for the input frequency manipulations, but participants achieved higher oral production gains under the simple task condition.

Cognitive Task Complexity and Iranian EFL Learners’ Written Linguistic Performance across Writing Proficiency Levels

Recently tasks, as the basic units of syllabi, and the cognitive complexity, as the criterion for sequencing them, have caught many second language researchers’ attention. This study sought to explore the effect of utilizing the cognitively simple and complex tasks on high- and low-proficient EFL Iranian writers’ linguistic performance, i.e., fluency, accuracy, lexical complexity, and structural complexity. At first, based on their scores on the writing test of TOFEL (2003), participants were assigned to high- and low-proficient writers. Participants in both groups first accomplished the simple task which was the narration of a story based on a set of pictures. One week later, they were asked to perform the complex task which was writing about a topic requiring reasons. Then the written productions were encoded on the measures of fluency, accuracy, lexical complexity, and structural complexity. Four two-way mixed-design ANOVAs were conducted. The results revealed that the learners significantly generated less accurate, more structurally complex, and more fluent language in the complex task. No significant effect was found for the lexical complexity measure. The high-proficient group performed significantly better in the four measures. The interaction between task complexity and writing proficiency did not yield any significant results. On the whole, based on the findings, the ‘limited attentional model’ was shown to be more accurate in comparison with ‘cognition hypothesis’ and the ‘threshold level hypothesis’ was not confirmed.

Sources of Individual Differences in L2 Narrative Production: The Contribution of Input, Processing, and Output Anxiety

Abstract The aim of this study was to investigate the effects of cognitive task complexity and individual differences in input, processing, and output anxiety (IPOA) on L2 narrative production. The participants were enrolled in a bilingual secondary educational program. They performed two narrative tasks in speech and writing. The participants’ level of anxiety was assessed using the IPOA scale (MacIntyre and Gardner 1994). The results demonstrate that spoken and written modalities are influenced differently by anxiety with the impact of output anxiety being significantly stronger in speech than in writing. Another important finding was that input and processing anxiety had both facilitating and debilitating effects on learners’ L2 output. As regards the effect of task complexity on participants’ narratives, the findings suggest that the different stages of language production need to be taken into account when categorizing tasks on the basis of the cognitive load they impose on learners.

The effect of cognitive task complexity on gait stability in adolescents following concussion

Concussion has been reported to result in disturbances to motor and cognitive functions. One way to examine these disturbances is through a dual-task assessment. Many secondary cognitive tasks have been proposed as appropriate tools during concussion assessment; however, task complexity has not been compared within a dual-task investigation. The purpose of this study was to prospectively examine how gait balance control was affected by three secondary cognitive tasks of varying complexity following concussion. Forty-six adolescents completed a dual-task walking protocol which included walking without any cognitive task (WALK), walking while completing a single auditory Stroop (SAS), multiple auditory Stroop (MAS), and a question and answer task (Q&A). Those who sustained a concussion (n = 23, mean age 15.4 ± 1.3 years) reported to the laboratory within 72 h of injury and in the following time increments: 1 week, 2 weeks, 1 month, and 2 months post-injury. Twenty-three healthy control subjects (mean age 15.4 ± 1.3 years), individually matched to each concussion subject, completed the same protocol in similar time increments. The concussion group demonstrated greater total center of mass (COM) medial/lateral displacement in the MAS and Q&A conditions compared with the control group. The concussion group also displayed the greatest peak COM anterior velocity in the least complex condition (WALK), and a significant decrease was observed as task complexity increased (SAS > MAS > Q&A). These findings indicate that gait balance control may be affected by task complexity following concussion and represent a way to identify motor recovery following concussion.

The adaptive aging brain: evidence from the preservation of communication abilities with age

Neurofunctional reorganization with age is suspected to occur for many cognitive components including communication abilities. Several functional neuroimaging studies of elderly individuals have reported the occurrence of an interhemispheric neurofunctional reorganization characterized by more bilateral activation patterns. Other studies have indicated that the preservation of some other cognitive abilities is associated with some intrahemispheric reorganization following either a posterior-anterior or an anterior-posterior shift in aging. Interestingly, other studies have shown that age-related neurofunctional reorganization is task-load-dependent. Taken together, these studies suggest that neurofunctional reorganization in aging is based on a more dynamic, flexible and adaptive neurofunctional process than previously proposed. This review summarizes the different factors that are thought to support the preservation of the semantic processing of words in aging, and highlights a multidetermined and complex set of processes such as the nature of the specific cognitive processes, task complexity and cognitive strategy, characterizing the neurofunctional reorganization in aging that allows for optimal cognitive abilities. In so doing, it provides the background for future study looking at the neurofunctional dimensions of the impact of neurodegenerative diseases on cognitive abilities.

The Use of Conjunctions in Cognitively Simple Versus Complex Oral L2 Tasks

ABSTRACTThe present study explores the use of conjunctions in simple versus complex argumentative tasks performed by second language (L2) learners as a specific measure for the amount of reasoning involved in task performance. The Cognition Hypothesis (Robinson, 2005) states that an increase in cognitive task complexity promotes improvements in L2 performance. This effect should become particularly visible when task‐specific performance measures are used (Robinson & Gilabert, 2007). This article evaluates these claims by investigating the oral performance of 64 L2 learners on cognitively simple, as compared with cognitively complex, oral argumentative reasoning tasks. The analysis focuses first on the overall frequency and occurrence of conjunctions. Next, 5 conjunctions that are considered to be highly task‐relevant are examined more closely. Results are discussed in light of the speech production of 44 native speakers who performed the same tasks under the same conditions. The discussion addresses implications of the findings for the cognitive approach to task‐based L2 research in light of Robinson's (2005) Cognition Hypothesis. From the standpoint of research methodology it highlights the benefits of native speaker data as a baseline for comparison.

Characterization of cognitive and motor performance during dual-tasking in healthy older adults and patients with Parkinson’s disease

The primary purpose of this study was to investigate the effect of dual-tasking on cognitive performance and gait parameters in patients with idiopathic Parkinson's disease (PD) without dementia. The impact of cognitive task complexity on cognition and walking was also examined. Eighteen patients with PD (ages 53-88, 10 women; Hoehn and Yahr stage I-II) and 18 older adults (ages 61-84; 10 women) completed two neuropsychological measures of executive function/attention (the Stroop Test and Wisconsin Card Sorting Test). Cognitive performance and gait parameters related to functional mobility of stride were measured under single (cognitive task only) and dual-task (cognitive task during walking) conditions with different levels of difficulty and different types of stimuli. In addition, dual-task cognitive costs were calculated. Although cognitive performance showed no significant difference between controls and PD patients during single or dual-tasking conditions, only the patients had a decrease in cognitive performance during walking. Gait parameters of patients differed significantly from controls at single and dual-task conditions, indicating that patients gave priority to gait while cognitive performance suffered. Dual-task cognitive costs of patients increased with task complexity, reaching significantly higher values then controls in the arithmetic task, which was correlated with scores on executive function/attention (Stroop Color-Word Page). Baseline motor functioning and task executive/attentional load affect the performance of cognitive tasks of PD patients while walking. These findings provide insight into the functional strategies used by PD patients in the initial phases of the disease to manage dual-task interference.

Task complexity and interaction

This paper presents the overarching conclusions of three consecutive investigations into task-based L2 performance. It aims at giving a better understanding of how changes in the number of elements referred to in a task affect L2 production, and how this relates to cognitive task complexity. Furthermore, it evaluates differences between monologic and dialogic tasks, and searches for combined effects of the factors ‘± elements’ and ‘± monologic’. Analyses examined the oral task performances of 152 participants by using global measures of linguistic complexity, accuracy, and fluency as well as a task specific measure. Results revealed hardly any effects of the manipulation of the number of elements. Dialogic tasks, however, consistently guided L2 performers towards greater accuracy, lexical complexity, and fluency. The discussion compares these findings to native speaker baseline data, reviews the results in light of Robinson’s (2005) Cognition Hypothesis, and highlights the cognitive impact of the factor ‘± monologic’.

Effects of task complexity and English proficiency on EFL learners’ task production in SCMC (Synchronous Computer-Mediated Communication).

This study investigates the effects of the cognitive complexity of tasks and pair proficiency on task production in Synchronous Computer Mediated Communication. In particular, this study explores whether task complexity and EFL learners’ proficiency have an effect on the accuracy, the fluency, and the use of strategy of task production in SCMC. 90 Korean high school EFL learners collaboratively completed the cognitively simple and complex tasks, using a browser-based chat program. Based on learners’ English proficiency, each dyad was composed of three different sets: High-High pair, High-Low pair, and Low-Low pair. The data were analyzed by a 2 X 4 analysis of variance (ANOVA). Error-free C-units, words per C-unit were served as dependent variables. Results show that the cognitive complexity of a direction-giving map task significantly affects task production. Pair composition also significantly affects the number of error-free C-units, words per C-unit and the use of strategy. This study confirms a previously reported increase in quantity of strategy used by students of the pairs with different English proficiency levels, compared to other pairs with similar English proficiency levels. The findings offer pedagogical implications for designing task-based synchronous interaction to facilitate Korean EFL learners’ accuracy, fluency and the use of strategy.

Cognitive and Motor Mechanisms Underlying Older Adults' Ability to Divide Attention While Walking

An impaired ability to allocate attention to gait during dual-task situations is a powerful predictor of falls. The primary purpose of this study was to examine the relative contributions of participant characteristics and motor and cognitive factors to the ability to walk while performing cognitive tasks. The impact of cognitive task complexity on walking also was examined. A cross-sectional, exploratory study design was used. Seventy-seven community-dwelling older adults with a mean (SD) age of 75.5 (5.8) years completed comprehensive testing. Participant characteristics were assessed via questionnaires. The motor test battery included measures of strength (force-generating capacity), gait speed, and static and dynamic balance. The cognitive abilities test battery assessed psychomotor and perceptual speed, recall and working memory, verbal and spatial ability, and attention (sustained, selective, and divided). Time to walk while performing 4 cognitive tasks was measured. In addition, dual-task costs (DTCs) were calculated. Multiple hierarchical regressions explored walking under dual-task conditions. The ability to walk and perform a simple cognitive task was explained by participant characteristics and motor factors alone, whereas walking and performing a complex cognitive task was explained by cognitive factors in addition to participant and motor factors. Regardless of the cognitive task, participants walked slower under dual-task conditions than under single-task conditions. Increased cognitive task complexity resulted in greater slowing of gait: gait DTCs were least for the simplest conditions and greatest for the complex conditions. Limitations Walking performance was characterized by a single parameter (time), whereas other spatiotemporal parameters have been related to dual-task performance. However, this type of measurement (timed performance) will be easy to implement in the clinic. Two factors-participant characteristics and motor abilities-explained the majority of variance of walking under dual-task conditions; however, cognitive abilities also contributed significantly to the regression models. Rehabilitation focused on improving underlying balance and gait deficits, as well as specific cognitive impairments, may significantly improve walking under dual-task conditions.

A Valid and Reliable Instrument for Cognitive Complexity Rating Assignment of Chemistry Exam Items

The design and use of a valid and reliable instrument for the assignment of cognitive complexity ratings to chemistry exam items is described in this paper. Use of such an instrument provides a simple method to quantify the cognitive demands of chemistry exam items. Instrument validity was established in two different ways: statistically significant correlations between expert-based cognitive complexity ratings and student performance (as measured through statistical difficulty of items), and statistically significant correlations between expert-based cognitive complexity ratings and student mental effort ratings. Key benefits associated with instrument use include an enhanced understanding of the cognitive complexity of chemistry assessment tasks and as a means for characterizing exam content for the measurement of cognitive development.

Cognitive Task Complexity and L2 Narrative Writing Performance

The present study was an attempt to chart the effects of two task design features, namely pre-task planning time and immediacy on written narrative performance. This is of pronounced importance since the synergistic effects of these two task features have gone largely unheeded in task-based research except for a smattering of studies (e.g., Gilabert, 2007). Accordingly, 123 participants were assigned to one of the 4 groups in the study, i.e., No planning & Here-and-Now, No planning & There-and-Then, Planning & Here-and-Now, and Planning & There-and-Then to write out a narrative task based on a series of pictures. The participants’ output was coded and measured for grammatical accuracy, syntactic complexity, lexical complexity, and fluency. Results showed that only pre-task planning time significantly promoted grammatical accuracy albeit with a small effect size. Pre-task planners complexified their discourse more than no-planners. In addition, displacedness of time and space coupled with pre-task planning led to significantly higher gains in syntactic complexity. However, lexical complexity measures did not yield any significant results across the groups of participants. Finally, both provision of pre-task planning time and immediacy of time and space led to significantly more fluent production.

The Impact of Group Cognitive Complexity on Group Satisfaction: A Person-Environment Fit Perspective

Groups have the potential to increase the satisfaction of their members (Campion, Medsker, & Higgs, 1993; Gladstein, 1984; Hackman, 1987; Katzell & Guzzo, 1983; Mason & Griffin, 2002, 2003). Thus, consideration of group characteristics in organizations is an important issue (Druckman & Bjork, 1991). In this study, the interactive influence of group cognitive complexity, task complexity, and group structure with satisfaction was analyzed. The findings suggest that when a task is complex, a decentralized structure leads to greater satisfaction than a centralized structure. Furthermore, groups lower in cognitive complexity were influenced more than complex groups by a mismatch between task complexity and group structure.

Searching for words: One strategic use of the mother tongue by advanced Spanish EFL writers

Studies of cognitive processes in SL writing have paid attention to the strategies that writers use to tackle problems in composing. In text-generation, finding lexical items in the L2 to express their meanings is one of the most crucial problems writers have to face, for reasons related to the availability and accessibility of relevant linguistic knowledge. However, L2 writers have a resource at their disposal: their mother tongue. Our study used think-aloud (TA) protocols to explore the strategic use of the L1 by a group of seven advanced Spanish learners of EFL engaged in solving lexical problems in two tasks: a narrative and an argumentative essay. We analysed the effect of task difficulty on the number and type (compensatory/upgrading) of lexical problems these writers tackled using their mother tongue and attempted to categorise the specific purposes for which the L1 was used. Our results indicate that the cognitive difficulty of the task plays a role in determining the number of lexical searches (LSs) undertaken and the type of search in which the writer uses the L1. The amount of L1 use is also affected by task. These findings will be interpreted from a number of perspectives including individual differences and theories of cognitive task complexity, multicompetence, and the language learning potential of L2 writing.

Deficits of long-term memory in ecstasy users are related to cognitive complexity of the task

Despite animal evidence that methylenedioxymethamphetamine (ecstasy) causes lasting damage in brain regions related to long-term memory, results regarding human memory performance have been variable. This variability may reflect the cognitive complexity of the memory tasks. However, previous studies have tested only a limited range of cognitive complexity. Furthermore, comparisons across different studies are made difficult by regional variations in ecstasy composition and patterns of use. The objective of this study is to evaluate ecstasy-related deficits in human verbal memory over a wide range of cognitive complexity using subjects drawn from a single geographical population. Ecstasy users were compared to non-drug using controls on verbal tasks with low cognitive complexity (stem completion), moderate cognitive complexity (stem-cued recall and word list learning) and high cognitive complexity (California Verbal Learning Test, Verbal Paired Associates and a novel Verbal Triplet Associates test). Where significant differences were found, both groups were also compared to cannabis users. More cognitively complex memory tasks were associated with clearer ecstasy-related deficits than low complexity tasks. In the most cognitively demanding task, ecstasy-related deficits remained even after multiple learning opportunities, whereas the performance of cannabis users approached that of non-drug using controls. Ecstasy users also had weaker deliberate strategy use than both non-drug and cannabis controls. Results were consistent with the proposal that ecstasy-related memory deficits are more reliable on tasks with greater cognitive complexity. This could arise either because such tasks require a greater contribution from the frontal lobe or because they require greater interaction between multiple brain regions.

Age-Related Changes in Posture Control are Differentially Affected by Postural and Cognitive Task Complexity

The simple postural task of quiet standing, which requires minimal attentional resources, is generally paired with cognitive activity. Competition for attentional resources is a consequence of simultaneously performing balance tasks and cognitive tasks, and impairment of attentional resource allocation with aging leads to increased risks of fall. We investigated age-related changes in posture control during dual task performance, using a paradigm that crossed a static (quiet standing) and a dynamic (keeping balance on a translational force plate) postural task and cognitive tasks of low demand (mental arithmetic) and high demand (spatial memory). Postural performance was analyzed through center-of-pressure displacements using both statistical (body sway area/sway velocity) and nonlinear (wavelet transform) methods in three age groups (younger, middle-aged, and older healthy participants). Results showed that 1) the nonlinear analysis method was more sensitive than the traditional approach in distinguishing performance between age groups, a result that explains discrepancies in the dual-task literature; 2) dual-tasking costs were dependent on both postural task difficulty and cognitive task complexity, corroborating previous investigations; 3) younger adults improved their postural performance during dual-tasking, but older adults lowered their performance; 4) balance recovery strategies in the dynamic postural task appeared to differ in younger versus older adults. Together, our findings on dual-tasking can be interpreted within the conceptual frame of task prioritization: shifting attention away from postural task automates posture control in the younger adults, whereas prioritization of postural task and selection of compensatory strategy are the main characteristics of posture control in the older population.

Impact of Cognitive Task Complexity on Drivers’ Visual Tunneling

Cognitive distractions have been shown to affect drivers adversely and are a leading cause of accidents. Research indicates that drivers alter how they allocate their visual attention while engaging in secondary cognitive tasks. To evaluate the potential impact of secondary cognitive tasks on the allocation of drivers’ visual attention and on vehicle control, drivers were presented with increasingly complex forms of an auditory cognitive task while driving an instrumented vehicle. Measures of vehicle performance and eye gaze were assessed. Consistent with theories of visual tunneling, gaze distributions were significantly smaller while drivers performed certain levels of the secondary task; peripheral vision was thereby reduced. During the most difficult level of the secondary task, gaze dispersion was smaller than during any other level of the task. Changes in visual attention may provide earlier indications of cognitive distraction than changes in vehicle control, the latter of which were observed only during the most difficult level of the secondary task. Observed changes in vertical eye position suggest that drivers compensate for moderate cognitive demands by increasing their sight distance before further incremental increases in workload exceeded their abilities. In summary, the workload of a secondary cognitive task affected drivers’ visual attention. A low to moderate increase in workload was detectable as a change in gaze before vehicle control suffered. Gaze restriction appears related to the degree of cognitive workload. This work shows that visual attention is a potential method of detecting changes in driver state associated with cognitive workload.

Walking speed during single and dual tasks in Parkinson's disease: Which characteristics are important?

The impact of dual tasks on gait in Parkinson's disease (PD) reveals lack of automaticity and increased cognitive demands. We explored which characteristics explained walking speed with and without dual task interference and if they reflected the cognitive demands of the task. In 130 people with PD, gait performance was quantified in the home using accelerometers allowing estimates of single and dual task walking speed and interference (difference between dual and single task). Multiple regression analysis was used to explore the effect of 12 characteristics representing four domains (personal, motor symptoms, cognitive, affective) on gait outcomes. Thirty-seven percent of variance in single task speed was explained by increased fear of falling, sex, age, disease severity, and depression; 34% of variance in dual task speed was explained by increased fear of falling, disease severity, medication, and depression; 12% of variance in interference scores was explained by greater disease severity and impaired executive function. Personal, motor, affective, and cognitive characteristics contribute to walking speed and interference, highlighting the multifactorial nature of gait. Different patterns of characteristics for each outcome indicates the impact of cognitive demand and task complexity, providing cautious support for dual task speed and interference as valid proxy measures of cognitive demand in PD gait.