of psychology/cognitive control. working memory model one influential model is baddeley's multicomponent model of working memory, which is composed of a central executive system that regulates three subsystems: the phonological loop, which maintains verbal information; the visuospatial sketchpad, which maintains visual and spatial information; and the more recently developed episodic buffer that integrates short-term and long-term memory, holding and manipulating a limited amount of information from multiple domains in temporal and spatially sequenced episodes. researchers have found significant positive effects of biofeedback-enhanced relaxation on memory and inhibition in children. biofeedback is a mind-body tool where people can learn to control and regulate their body to improve and control their executive functioning skills. to measure one's processes, researchers use their heart rate and or respiratory rates. biofeedback-relaxation includes music therapy, art, and other mindfulness activities. executive functioning skills are important for many reasons, including children's academic success and social emotional development. according to the study "the efficacy of different interventions to foster children's executive function skills: a series of meta-analyses", researchers found that it is possible to train executive functioning skills. researchers conducted a meta-analytic study that looked at the combined effects of prior studies in order to find the overarching effectiveness of different interventions that promote the development of executive functioning skills in children. the interventions included computerized and non-computerized training, physical exercise, art, and mindfulness exercises. however, researchers could not conclude that art activities or physical activities could improve executive functioning skills. supervisory attentional system (sas) another conceptual model is the supervisory attentional system (sas). in this model, contention scheduling is the process where an individual's well-established schemas automatically respond to routine situations while executive functions are used when faced with novel situations. in these new situations, attentional control will be a crucial element to help generate new schema, implement these schema, and then assess their accuracy. self-regulatory model russell barkley proposed a widely known model of executive functioning that is based on self-regulation. primarily derived from work examining behavioral inhibition, it views executive functions as composed of four main abilities. one element is working memory that allows individuals to resist interfering information. a second component is the management of emotional responses in order to achieve goal-directed behaviors. thirdly, internalization of self-directed speech is used to control and sustain rule-governed behavior and to generate plans for problem-solving. lastly, information is analyzed and synthesized into new behavioral responses to meet one's goals. changing one's behavioral response to meet a new goal or modify an objective is a higher level skill that requires a fusion of executive functions including self-regulation, and accessing prior knowledge and experiences. according to this model, the executive system of the human brain provides for the cross-temporal organization of behavior towards goals and the future and coordinates actions and strategies for everyday goal-directed tasks. essentially, this system permits humans to self-regulate their behavior so as to sustain action and problem-solving toward goals specifically and the future more generally. thus, executive function deficits pose serious problems for a person's ability to engage in self-regulation over time to attain their goals and anticipate and prepare for the future. teaching children self-regulation strategies is a way to improve their inhibitory control and their cognitive flexibility. these skills allow children to manage their emotional responses. these interventions include teaching children executive function-related skills that provide the steps necessary to implement them during classroom activities and educating children on how to plan their actions before acting upon them. executive functioning skills are how the brain plans and reacts to situations. offering new self-regulation strategies allow children to improve their executive functioning skills by practicing something new. it is also concluded that mindfulness practices are shown to be a significantly effective intervention for children to self-regulate. this includes biofeedback-enhanced relaxation. these strategies support the growth of children's executive functioning skills. problem-solving model yet another model of executive functions is a problem-solving framework where executive functions are considered a macroconstruct composed of subfunctions working in different phases to (a) represent a problem, (b) plan for a solution by selecting and ordering strategies, (c) maintain the strategies in short-term memory in order to perform them by certain rules, and then (d) evaluate the results with error detection and error correction. lezak's conceptual model one of the most widespread conceptual models on executive functions is lezak's model. this framework proposes four broad domains of volition, planning, purposive action, and effective performance as working together to accomplish global executive functioning needs. while this model may broadly appeal to clinicians and researchers to help identify and assess certain executive functioning components, it lacks a distinct theoretical basis and relatively few attempts at validation. miller and cohen's model in 2001, earl miller and jonathan cohen published their article "an integrative theory of prefrontal cortex function", in which they argue that cognitive control is the primary function of the prefrontal cortex (pfc), and that control is implemented by increasing the gain of sensory or motor neurons that are engaged by task- or goal-relevant elements of the external environment. in a key paragraph, they argue: we assume that the pfc serves a specific function in cognitive control: the active maintenance of patterns of activity that represent goals and the means to achieve them. they provide bias signals throughout much of the rest of the brain, affecting not only visual processes but also other sensory modalities, as well as systems responsible for response execution, memory retrieval, emotional evaluation, etc. the aggregate effect of these bias signals is to guide the flow of neural activity along pathways that establish the proper mappings between inputs, internal states, and outputs needed to perform a given task. miller and cohen draw explicitly upon an earlier theory of visual attention that conceptualises perception of visual scenes in terms of competition among multiple representations – such as colors, individuals, or objects. selective visual attention acts to 'bias' this competition in favour of certain selected features or representations. for example, imagine that you are waiting at a busy train station for a friend who is wearing a red coat. you are able to selectively narrow the focus of your attention to search for red objects, in the hope of identifying your friend. desimone and duncan argue that the brain achieves this by selectively increasing the gain of neurons responsive to the color red, such that output from these neurons is more likely to reach a downstream processing stage, and, as a consequence, to guide behaviour. according to miller and cohen, this selective attention mechanism is in fact just a special case of cognitive control – one in which the biasing occurs in the sensory domain. according to miller and cohen's model, the pfc can exert control over input (sensory) or output (response) neurons, as well as over assemblies involved in memory, or emotion. cognitive control is mediated by reciprocal pfc connectivity with the sensory and motor cortices, and with the limbic system. within their approach, thus, the term "cognitive control" is applied to any situation where a biasing signal is used to promote task-appropriate responding, and control thus becomes a crucial component of a wide range of psychological constructs such as selective attention, error monitoring, decision-making, memory inhibition, and response inhibition. miyake and friedman's model miyake and friedman's theory of executive functions proposes that there are three aspects of executive functions: updating, inhibition, and shifting. a cornerstone of this theoretical framework is the understanding that individual differences in executive functions reflect both unity (i.e., common ef skills) and diversity of each component (e.g., shifting-specific). in other words, aspects of updating, inhibition, and shifting are related, yet each remains a distinct entity. first, updating is defined as the continuous monitoring and quick addition or deletion of contents within one's working memory. second, inhibition is one's capacity to supersede responses that are prepotent in a given situation. third, shifting is one's cognitive flexibility to switch between different tasks or mental states. miyake and friedman also suggest that the current body of research in executive functions suggest four general conclusions about these skills. the first conclusion is the unity and diversity aspects of executive functions. second, recent studies suggest that much of one's ef skills are inherited genetically, as demonstrated in twin studies. third, clean measures of executive functions can differentiate between normal and clinical or regulatory behaviors, such as adhd. last, longitudinal studies demonstrate that ef skills are relatively stable throughout development. banich's "cascade of control" model this model from 2009 integrates theories from other models, and involves a sequential cascade of brain regions involved in maintaining attentional sets in order to arrive at a goal. in sequence, the model assumes the involvement of the posterior dorsolateral prefrontal cortex (dlpfc), the mid-dlpfc, and the posterior and anterior dorsal anterior cingulate cortex (acc). the cognitive task used in the article is selecting a response in the stroop task, among conflicting color and word responses, specifically a stimulus where the word "green" is printed in red ink. the posterior dlpfc creates an appropriate attentional set, or rules for the brain to accomplish the current goal. for the stroop task, this involves activating the areas of the brain involved in color perception, and not those involved in word comprehension. it counteracts biases and irrelevant information, like the fact that the semantic perception of the word is more salient to most people than the color in which it is printed. next, the mid-dlpfc selects the representation that will fulfill the goal. the task-relevant information must be separated from other sources of information in the task. in the example, this means focusing on the ink color and not the word. the posterior dorsal acc is next in the cascade, and it is responsible for response selection. this is where the decision is made whether the stroop task participant will say "green" (the written word and the incorrect answer) or "red" (the font color and correct answer). following the response, the anterior dorsal acc is involved in response evaluation, deciding whether one's response were correct or incorrect. activity in this region increases when the probability of an error is higher. the activity of any of the areas involved in this model depends on the efficiency of the areas that came before it. if the dlpfc imposes a lot of control on the response, the acc will require less activity. recent work using individual differences in cognitive style has shown exciting support for this model. researchers had participants complete an auditory version of the stroop task, in which either the location or semantic meaning of a directional word had to be attended to. participants that either had a strong bias toward spatial or semantic information (different cognitive styles) were then recruited to participate in the task. as predicted, participants that had a strong bias toward spatial information had more difficulty paying attention to the semantic information and elicited increased electrophysiological activity from the acc. a similar activity pattern was also found for participants that had a strong bias toward verbal information when they tried to attend to spatial information. assessment assessment of executive functions involves gathering data from several sources and synthesizing the information to look for trends and patterns across time and settings. apart from standardized neuropsychological tests, other measures can and should be used, such as behaviour checklists, observations, interviews, and work samples. from these, conclusions may be drawn on the use of executive functions. there are several different kinds of instruments (e.g., performance based, self-report) that measure executive functions across development. these assessments can serve a diagnostic purpose for a number of clinical populations. behavioural assessment of dysexecutive syndrome (bads) behavior rating inventory of executive function (brief). ages 2-90 covered by different versions of the scale. barkley deficits in executive functioning scales (bdefs) behavioral dyscontrol scale (bds) comprehensive executive function inventory (cefi) cogscreen continuous performance task (cpt) controlled oral word association test (cowat) d2 test of attention delis-kaplan executive function system (d-kefs) digit vigilance test figural fluency test halstead category test hayling and brixton tests iowa gambling task jansari assessment of executive functions (jef) kaplan baycrest neurocognitive assessment (kbna) kaufman short neuropsychological assessment paced auditory serial addition test (pasat) pediatric attention disorders diagnostic screener (padds) rey-osterrieth complex figure ruff figural fluency test stroop task tasks of executive control test of variables of attention