Introduction and application of the multiscale coefficient of variation analysis

Quantifying how patterns of behavior relate across multiple levels of measurement typically requires long time series for reliable parameter estimation. We describe a novel analysis that estimates patterns of variability across multiple scales of analysis suitable for time series of short duration. The multiscale coefficient of variation (MSCV) measures the distance between local coefficient of variation estimates within particular time windows and the overall coefficient of variation across all time samples. We first describe the MSCV analysis and provide an example analytical protocol with corresponding MATLAB implementation and code. Next, we present a simulation study testing the new analysis using time series generated by ARFIMA models that span white noise, short-term and long-term correlations. The MSCV analysis was observed to be sensitive to specific parameters of ARFIMA models varying in the type of temporal structure and time series length. We then apply the MSCV analysis to short time series of speech phrases and musical themes to show commonalities in multiscale structure. The simulation and application studies provide evidence that the MSCV analysis can discriminate between time series varying in multiscale structure and length.     

Effects of Cognitive Load on Affordance‐based Interactions

Affordances are design clues that allow users to effortlessly determine how objects should be used. Since their introduction to the human–computer interaction design community, their use within interfaces has become a staple. But, despite work to understand how affordances make an interface's available actions transparent, few empirical studies have examined the cognitive origins of this interaction type. Therefore, we explored the impact of cognitive load on affordance‐based interactions. Participants were asked to perform a series of affordance‐based interactions while under different types of working memory load (no load, verbal, spatial, and central executive). Affordance‐based interactions were consistently slowed under central executive load, but never when under verbal load. We conclude that affordance‐based interactions do require cognitive resources, but resource costs may only manifest under heavy load. With this knowledge, designers may be able to better predict when an affordance will (or will not) act as if it is resource free. Copyright © 2016 John Wiley & Sons, Ltd.     

Interactions dominate the dynamics of visual cognition

Many cognitive theories have described behavior as the summation of independent contributions from separate components. Contrasting views have emphasized the importance of multiplicative interactions and emergent structure. We describe a statistical approach to distinguishing additive and multiplicative processes and apply it to the dynamics of eye movements during classic visual cognitive tasks. The results reveal interaction-dominant dynamics in eye movements in each of the three tasks, and that fine-grained eye movements are modulated by task constraints. These findings reveal the interactive nature of cognitive processing and are consistent with theories that view cognition as an emergent property of processes that are broadly distributed over many scales of space and time rather than a componential assembly line.     

Multiplicative-cascade dynamics supports whole-body coordination for perception via effortful touch

Effortful touch by the hand is essential to engaging with and perceiving properties of objects. The temporal structure of whole-body coordination must reflect the prospective control that provides for both the engagement with and perception of properties of the hefted objects. In the present study, we found signatures of multifractality in the time series of fluctuations in Euclidean displacement in the participants' center of pressure (CoP) as they hefted weighted objects to perceive their heaviness and length. Comparisons of widths of the multifractal spectrums of CoP series with 32 Iterative Amplitude Adjusted Fourier Transform (IAAFT) surrogates provided evidence for multiplicative-cascade dynamics and interactivity across scales, through the continuous t-statistic comparing the original and surrogate widths (t_MF). After controlling for the linear properties of CoP series and their interactions with the informational variable (i.e., the moment of inertia of the hefted objects), regression modeling of unsigned error in judgments of heaviness and length revealed that the multifractal evidence for nonlinearity (t_MF) significantly influenced unsigned error. The two indicators showed opposite, task-specific effects on accuracy: accuracy in judgments of heaviness and length decreased and increased, respectively, with greater t_MF. These findings suggest that multiplicative-cascade dynamics in posture play a role in prospective coordination during the engagement with objects and perception of their properties via effortful touch by the hand. Future work may elucidate how constraint(s) on exploratory kinematics influence the multifractal behavior in such suprapostural perceptual tasks as effortful touch.     

Evidence of Poor Planning in Children with Attention Deficits

This study examined the planning performance of children with attention deficits, and also investigated the possible interactions between inattention and anxiety in the performance of executive function tasks. A group of 98 children (grades 4 and 6), derived from an initial group of 550, were assigned to an attention difficulties group (AD) and a control group (n = 49 each) based on their scores on a variety of cognitive attention measures and teacher scales of attention and hyperactivity. The two groups were matched on age, gender, parental education, non-verbal and verbal ability. They were compared on Crack-the-Code (C-t-C) action-planning task, embedded and ambiguous figures and Theory of Mind tasks. Analyses indicated that the failure of AD children on cognitive performance measures is linked to planning impairments. The co-occurrence of anxiety, in turn, did not interact with inattention to affect planning performance differentially. Implications of these findings for the current discussion about the cognitive and emotional processes underlying impaired performance among children with attention deficits on executive control tasks are discussed.     

Executive functioning and processing speed in age-related differences in time estimation: a comparison of young,old, and very old adults

Age-related differences in time estimation were examined by comparing the temporal performance of young, young–old, and old–old adults, in relation to two major theories of cognitive aging: executive decline and cognitive slowing. We tested the hypothesis that processing speed and executive function are differentially involved in timing depending on the temporal task used. We also tested the assumption of greater age-related effects in time estimation in old–old participants. Participants performed two standard temporal tasks: duration production and duration reproduction. They also completed tests measuring executive function and processing speed. Findings supported the view that executive function is the best mediator of reproduction performance and inversely that processing speed is the best mediator of production performance. They also showed that young–old participants provide relatively accurate temporal judgments compared to old–old participants. These findings are discussed in terms of compensation mechanisms in aging.     

Working Memory Constraints on Linear Reasoning with Spatial and Temporal Contents

The present article reports two experiments testing the use of working memory components during reasoning with temporal and spatial relations in four-term series problems. In the first experiment four groups of subjects performed reasoning tasks with temporal and with spatial contents either without (control) or with a secondary task (articulatory suppression, visuospatial suppression or central executive suppression). The second experiment tested the secondary task effects in a within-subjects design either on problems with a spatial content or on problems with a temporal content, and within each content domain either under conditions of self-paced or of fixed presentation of the premises. Both experiments found effects of all three secondary tasks on reasoning accuracy. This supports the hypothesis that the subjects construct spatial representations of the premise information with the support of visuo-spatial resources of working memory. The second experiment also showed that during premise intake, only visuo-spatial and central executive secondary tasks had an effect. The implications of the data for the working memory requirements of reasoning and for theories of linear reasoning are discussed.     

Separating goals from behavioral control: Implications from learning predictive modularizations

The brain may be regarded as an anticipatory machine whose behavior strongly depends on its current predictive knowledge. Behavioral decision making depends on anticipated goal states as well as on the current internal motivations of the organism. Behavioral control, on the other hand, is guided by the goals currently chosen along with additional constraints. Both, decision making and control are thus anticipatory processes. Moreover, they are mutually dependent: while action control depends on currently selected goals, goal selection depends on achievability estimates, which must be based on the system's current action control competence. An autonomous, adaptive system thus faces the challenge of learning goal representations that are suitable for both, action selection and action control. We propose that a goal processing pathway should be separated from but also strongly interact with a sensorimotor control pathway. We investigate the encoding structures expectable along these two pathways for realizing effective and flexible action decision making and control. While the goal processing pathway needs to be able to distinguish motivation-oriented relevancies for decision making, the sensorimotor pathway needs to provide control-oriented encodings. We use an evolutionary machine learning technique to investigate how important modularity may be for realizing particular sensorimotor mappings. Next, we survey the results obtained by a neural network architecture, which show that enforcing multiplicative interactions between self-organizing sensorimotor control-oriented encodings and goal-oriented interaction selection encodings enables the learning of highly flexible decision making and action control structures. Furthermore, we show that the emerging goal-oriented encodings exhibit pre-linguistic compositional structures. We conclude that for bootstrapping higher-level cognitive capabilities it may be essential on the one hand to separate sensorimotor, anticipatory, control-oriented spatial encodings from compositional, goal-oriented spaces, and on the other hand to enable bidirectional, multiplicative interactions between these two sets of spatial encodings.     

Retiring the central executive

Reasoning, problem solving, comprehension, learning and retrieval, inhibition, switching, updating, or multitasking are often referred to as higher cognition, thought to require control processes or the use of a central executive. However, the concept of an executive controller begs the question of what is controlling the controller and so on, leading to an infinite hierarchy of executives or “homunculi”. In what is now a QJEP citation classic, Baddeley [Baddeley, A. D. (1996). Exploring the central executive. Quarterly Journal of Experimental Psychology, 49A, 5–28] referred to the concept of a central executive in cognition as a “conceptual ragbag” that acted as a placeholder umbrella term for aspects of cognition that are complex, were poorly understood at the time, and most likely involve several different cognitive functions working in concert. He suggested that with systematic empirical research, advances in understanding might progress sufficiently to allow the executive concept to be “sacked”. This article offers an overview of the 1996 article and of some subsequent systematic research and argues that after two decades of research, there is sufficient advance in understanding to suggest that executive control might arise from the interaction among multiple different functions in cognition that use different, but overlapping, brain networks. The article concludes that the central executive concept might now be offered a dignified retirement.     

Linking Executive Function and Peer Problems from Early Childhood Through Middle Adolescence

Peer interactions and executive function play central roles in the development of healthy children, as peer problems have been indicative of lower cognitive competencies such as self-regulatory behavior and poor executive function has been indicative of problem behaviors and social dysfunction. However, few studies have focused on the relation between peer interactions and executive function and the underlying mechanisms that may create this link. Using a national sample (n?=?1164, 48.6 % female) from the Study of Early Child Care and Youth Development (SECCYD), we analyzed executive function and peer problems (including victimization and rejection) across three waves within each domain (executive function or peer problems), beginning in early childhood and ending in middle adolescence. Executive function was measured as a multi-method, multi-informant composite including reports from parents on the Children’s Behavior Questionnaire and Child Behavior Checklist and child’s performance on behavioral tasks including the Continuous Performance Task, Woodcock-Johnson, Tower of Hanoi, Operation Span Task, Stroop, and Tower of London. Peer problems were measured as a multi-informant composite including self, teacher, and afterschool caregiver reports on multiple peer-relationship scales. Using a cross-lagged design, our Structural Equation Modeling findings suggested that experiencing peer problems contributed to lower executive function later in childhood and better executive function reduced the likelihood of experiencing peer problems later in childhood and middle adolescence, although these relations weakened as a child moves into adolescence. The results highlight that peer relationships are involved in the development of strengths and deficits in executive function and vice versa.     

人类工作记忆的事件相关电位研究

20世纪90年代以来,采用ERP技术对人类工作记忆脑机制的研究已取得大量的成果。主要探讨了特定类型的工作记忆（词语、空间、客体工作记忆）是否存在与其贮存、复述以及中央执行功能相关的特异性ERP成分,并从它们的时间进程及头皮分布来考察工作记忆的心理过程和神经机制。研究结果对于Baddeley的认知结构模型提供了有益的修正和补充。     

The central executive as a search process: priming exploration and exploitation across domains

The trade-off between exploration and exploitation is common to a wide variety of problems involving search in space and mind. The prevalence of this trade-off and its neurological underpinnings led us to propose domain-general cognitive search processes (Hills, Todd, & Goldstone, 2008). We propose further that these are consistent with the idea of a central executive search process that combines goal-handling across subgoal hierarchies. In the present study, we investigate 3 aspects of this proposal. First, the existence of a unitary central executive search process should allow priming from 1 search task to another and at multiple hierarchical levels. We confirm this by showing cross-domain priming from a spatial search task to 2 different cognitive levels within a lexical search task. Second, given the neural basis of the proposed generalized cognitive search process and the evidence that the central executive is primarily engaged during complex tasks, we hypothesize that priming should require search in the sense of a self-regulated making and testing of sequential predictions about the world. This was confirmed by showing that when participants were allowed to collect spatial resources without searching for them, no priming occurred. Finally, we provide a mechanism for the underlying search process and investigate 3 alternative hypotheses for subgoal hierarchies using the central executive as a search process model (CESP). CESP envisions the central executive as having both emergent and unitary processes, with one of its roles being a generalized cognitive search process that navigates goal hierarchies by mediating persistence on and switching between subgoals.     

Deictic codes for the embodiment of cognition

To describe phenomena that occur at different time scales, computational models of the brain must incorporate different levels of abstraction. At time scales of approximately 1/3 of a second, orienting movements of the body play a crucial role in cognition and form a useful computational level--more abstract than that used to capture natural phenomena but less abstract than what is traditionally used to study high-level cognitive processes such as reasoning. At this "embodiment level," the constraints of the physical system determine the nature of cognitive operations. The key synergy is that at time scales of about 1/3 of a second, the natural sequentiality of body movements can be matched to the natural computational economies of sequential decision systems through a system of implicit reference called deictic in which pointing movements are used to bind objects in the world to cognitive programs. This target article focuses on how deictic binding make it possible to perform natural tasks. Deictic computation provides a mechanism for representing the essential features that link external sensory data with internal cognitive programs and motor actions. One of the central features of cognition, working memory, can be related to moment-by-moment dispositions of body features such as eye movements and hand movements.     

Cognitive control and attentional functions

Cognitive control is essential to flexible, goal-directed behavior under uncertainty, yet its underlying mechanisms are not clearly understood. Because attentional functions are known to allocate mental resources and prioritize the information to be processed, we propose that the attentional functions of alerting, orienting, and executive control and the interactions among them contribute to cognitive control in the service of uncertainty reduction. To test this hypothesis, we examined the relationship between cognitive control and attentional functions. We used the Majority Function Task (MFT) to manipulate uncertainty in order to evoke cognitive control along with the Revised Attention Network Test (ANT-R) to measure the efficiency and the interactions of attentional functions. A backwards, stepwise regression model revealed that performance on the MFT could be significantly predicted by attentional functions and their interactions as measured by the ANT-R. These results provide preliminary support for our theory that the attentional functions are involved in the implementation of cognitive control as required to reduce uncertainty, though further investigation is needed.     

Planning in young children: A review and synthesis

Research on the development of planning is reviewed in the context of a framework that considers the role of three types of cognitive flexibility in planning development: event-independent temporal representation, executive function, and self-projection. It is argued that the emergence of planning abilities in the preschool period is dependent upon the development of event-independent temporal representation. Research on the development of executive function suggests that its sub-components, in particular inhibitory control, may be linked to developmental improvements on planning tasks. Recently, new paradigms have established that self-projection to the future appears to develop over the preschool period. We consider how these different forms of cognitive flexibility may themselves be related in development.     

Executive control of married and cohabiting couples

Attention mechanisms of 125 couples were assessed to determine whether married and cohabiting couples differ in their levels of executive control. Executive control is the attention network that is responsible for resolving cognitive conflicts among competing responses. Of the 125 couples, 85 were married (48 after premarital cohabitation) and 40 were in cohabiting unions. Executive control was assessed with a cognitive task, the Attentional Network Task. The participants’ task was to identify the direction of a central arrow that was surrounded by flanker arrows. As predicted, cohabiting couples exhibited stronger deficits in executive control than married ones, after controlling for demographic confounders. Moreover, similar differences in executive control were observed between the subsample of married couples who cohabited with their spouses prior to marriage and currently cohabiting couples. Taken together, our results reveal that cohabiting couples have more trouble responding to some stimuli while ignoring extraneous stimuli.     

体感游戏促进儿童的执行功能：运动强度和认知参与的作用

为了考察体感游戏促进儿童执行功能的作用机制, 采用2(运动强度：高/低) × 2(认知参与：高/低) × 3(测量时间：前测、一次性训练后测、长期训练后测)的三因素混合实验设计, 对122名4~6岁儿童进行6周(每周3次)的体感游戏训练。结果发现：在一次性训练中, 体感游戏中的运动强度而不是认知参与显著促进儿童执行功能, 尤其是工作记忆; 在长期干预中, 体感游戏中的运动强度和认知参与都显著促进儿童执行功能, 且认知参与的作用大于运动强度。这一结果不但验证了体感游戏对儿童执行功能的益处, 并且阐明了体感游戏中的哪些特征能对儿童执行功能具有短期的和长期的效果。     

The impact of aerobic activity on cognitive function in older adults: A new synthesis based on the concept of executive control

Numerous reaction time studies have suggested that age-related declines in cognitive function might be ameliorated by lifestyles involving aerobic activity or by interventionist programmes of aerobic exercise. These studies are far from conclusive, however, reflecting a failure to factor out cognitive from sensory and motor processes. Following a critical review of the literature, we report on recent developments that differentiate cognitive processes involving executive vs non-executive control, the former being associated with frontal lobe function. Three key studies suggest that aerobic exercise primarily improves executive control.     

Correlations among measures of executive function and positive psychological attributes in college students

Executive functions are cognitive abilities that allow for more goal-oriented and autonomous behavior. The authors examined the relationship between self-rated executive functions and 3 positive personality attributes (satisfaction with life, gratitude, and forgiveness) in a nonclinical community sample. The authors used self-report scales (Executive Function Index, Heartland Forgiveness Scale "other" subscale, Satisfaction With Life Scale, and the Gratitude Questionnaire) to examine how executive functions related to the positive psychology attributes. After controlling for age, sex, and formal education, positive relationships emerged among gratitude, satisfaction, and executive function scales of motivational drive, empathy, and strategic planning. However, an inverse relationship emerged between impulse control and forgiveness, perhaps relating to cautiousness and suggesting finer distinctions between adaptive and maladaptive forms of forgiveness. These findings suggest common psychological and neurobiological substrates for executive functions and positive psychology attributes, warranting further, more direct biobehavioral research.     

Effects of attentional focus on movement coordination complexity

Attentional focus affects performance and learning of motor tasks. An external attentional focus (on the effects of movement) can lead to more efficient and effective movements compared to an internal focus (on body movement itself). According to the “constrained action hypothesis”, an external focus facilitates fast and reflexive movement control while an internal focus leads to disruption of automatic coordination processes. Such disruption should be apparent in the complexity of movement. In this study, multiscale entropy measures were used to investigate if the external focus is related to superior coordination complexity compared to internal focus. Twenty participants were divided in two groups that balanced over an unstable platform in fourteen trials over two days, either with internal or external focus of attention instructions, followed by seven retention trials on the third day. Multiscale entropy measures were used to quantify complexity of motions of the platform, the participant, and the composite of participant and platform motions. Results were contrary to expectations. For the external focus group, despite better overall performance, multiscale entropy values of participant and composite motions were lower in some scales compared to the internal focus group, especially in the first and last days. This may be consistent with previous findings that predictability increases during learning of a balance task. Results also indicate the need to identify the correct physiological interpretation of single or multiscale entropy measures. Further investigation is needed to establish if entropy differences are causally related to performance and learning advantages of the external focus.