Matthew W Miller

• Ph.D.
• Professor (Full) at Auburn University

Background: Fitness is relevant for firefighter occupational performance, but its influence on exertion and cognition during occupational tasks remains unclear. We aim to determine fitness’s influence on performance, exertion, and cognition during simulated firefighter occupational tasks. Methods: Two baseline fitness assessments occurred to measur...

We aimed to determine how a bout of resistance or aerobic exercise impacts physiological responses and performance during firefighting occupational tasks. Thirty-two non-firefighters completed two baseline assessments and three trials: resistance exercise (RE), aerobic exercise (AE), or a rested control (CON). Trials were followed by an occupationa...

Purpose Acute exercise can transiently enhance cognitive flexibility. The cognitive demand of firefighters makes it relevant to understand if on-shift exercise could produce similar improvements in cognitive performance during subsequent occupational tasks. Metrics of heart rate variability (HRV), such as time- and frequency-domain outcomes, may sh...

The School of Kinesiology (KINE) at Auburn University (AU) has demonstrated exemplary commitment to diversity, equity, and inclusion, earning the 2024 American Kinesiology Association’s Inclusive Excellence Award. This article describes the strategic planning and actions taken by AU KINE over more than a decade to promote inclusive excellence by en...

In many kinesiology and health care science departments in the United States, there is a mismatch between the demographic composition of the student population and the faculty cohort. That is, although student populations are more diverse, the faculty cohort does not reflect this same diversity. The purpose of this paper is threefold: (a) Provide b...

Introduction According to reinforcement learning, humans adjust their behavior based on the difference between actual and anticipated outcomes (i.e., prediction error) with the main goal of maximizing rewards through their actions. Despite offering a strong theoretical framework to understand how we acquire motor skills, very few studies have inves...

Gait adaptation during bipedal walking allows people to adjust their walking patterns to maintain balance, avoid obstacles and avoid injury. Adaptation involves complex processes that function to maintain stability and reduce energy expenditure. However, the processes that influence walking patterns during different points in the adaptation period...

While physical activity (PA) has numerous health benefits, in rare cases it can become addictive and lead to adverse health effects. Automatic reactions to addiction-related cues are a hallmark of addiction, however, their association with exercise dependence (ED) remains unknown. This research examined the links between ED and automatic reactions...

Core temperature information is important for guiding prevention and treatment measures. Developing new physiological monitoring tools that provide reliable core temperature information is critical for heat injury prevention. The ThriveHRI sensor system is being developed as an efficient core monitoring tool in a smartwatch platform. The current st...

Uncovering the Role of Effort in the Rewarding Value of Sedentary Behavior

Purpose We aimed to determine how a bout of resistance or aerobic exercise impacts physiological responses and performance during firefighting occupational tasks. Methods Thirty-two non-firefighters completed two baseline assessments, and three trials: resistance exercise (RE), aerobic exercise (AE), or rested control (CON). Trials were followed b...

We conceptually replicated the one previous study revealing that individuals who practice a motor skill under psychological pressure (anxiety training—AT) avoid performance deterioration when exposed to higher levels of pressure. We used a >3× larger sample size than the original study and attempted to shed light on mechanisms whereby AT may promot...

The present study tested whether energy-minimizing behaviors evoke reward-related brain activity that promotes the repetition of these behaviors via reinforcement learning processes. Fifty-eight healthy young adults in a standing position performed a task where they could earn a reward either by sitting down or squatting while undergoing electroenc...

OPTIMAL theory predicts providing learners with a relatively easier criterion of success during practice enhances motor learning through increased self-efficacy, perceptions of competence, and intrinsic motivation. However, mixed results in the literature suggest this enhancement effect may be moderated by the number of successes achieved by learne...

Using computerized reaction-time tasks assessing automatic attitudes, studies have shown that healthy young adults have faster reaction times when approaching physical activity stimuli than when avoiding them. The opposite has been observed for sedentary stimuli. However, it is unclear whether these results hold across the lifespan and when error r...

Objective: Having learners practice a motor skill with the expectation of teaching it (versus an expectation of being tested on it) has been revealed to enhance skill learning. However, this improvement in skill performance is lost when the skill must be performed under psychological pressure due to 'choking under pressure.' The present study inve...

Using computerized reaction-time tasks assessing automatic attitudes, studies have shown that healthy young adults have faster reaction times when approaching physical activity stimuli than when avoiding them. The opposite has been observed for sedentary stimuli. However, it is unclear whether these results hold across the lifespan and when error r...

The role of affective responses to effort in the regulation of physical activity behavior is widely accepted. Yet, to investigate these affective responses during physical activity, most studies used direct self-reported measures that are prone to biases (e.g., social desirability, ability to introspect). To reduce these biases, we used an indirect...

Enhanced expectancies and autonomy-support through self-controlled practice conditions form the motivation pillar of OPTIMAL theory (Wulf & Lewthwaite, 2016). The influence of these practice variables on motor learning was recently evaluated in two separate meta-analyses. Both meta-analyses found that the published literature suggested a moderate a...

This chapter provides background knowledge and definitions for readers who may be unfamiliar with foundational knowledge in this area. Specifically, the chapter provides a physiological framework of what EEG frequency measures reflect in human participants. It outlines methodological commonalities that cut across most measures of frequency analyses...

Enhanced expectancies and autonomy-support through self-controlled practice conditions form the motivation pillar of OPTIMAL theory (Wulf & Lewthwaite, 2016). The influence of these practice variables on motor learning was recently evaluated in two separate meta-analyses. Both meta-analyses found that the published literature suggested a moderate a...

The OPTIMAL theory of motor learning predicts enhanced expectancies facilitate learning. This meta-analysis investigated this prediction by quantifying effect sizes from studies manipulating feedback after good trials, comparative feedback, perceived task difficulty, conceptions of ability, self-modeling, or extrinsic rewards, and assessing learnin...

Motor skills learned implicitly should be less susceptible to deterioration under psychological pressure (i.e., choking) than skills learned more explicitly. In this systematic review and meta-analysis, we investigated that prediction. A systematic search was conducted for articles that had participants learn a motor skill implicitly relative to a...

Track and Field athletes perform different types of warm-ups at varying levels of volume and/or intensity prior to competition. Theoretically, this prepares sport specific muscles for activity by increasing muscle temperature, thus mitigating the chance for injury. There is a paucity of information regarding the optimum level for warm-ups regarding...

Giving learners control over their feedback schedule has been shown to enhance motor learning. This effect has been attributed to enhanced intrinsic motivation via fulfilling learners’ needs for feelings of autonomy and competence, and greater information processing through provoking learners to estimate their errors. However, there is a lack of st...

The theory of effort minimization in physical activity argues that individuals have an automatic attraction toward effort minimization. To engage in a physically active behavior, this automatic attraction needs to be overridden by controlled processes. However, direct evidence showing that inhibitory control is required to avoid effort minimization...

Although the learning benefits of interleaved practice schedules relative to blocked schedules are well-reported, the mechanisms underlying these effects are not fully understood. Researchers have generally suggested that random schedules of practice increase task-related information processing which arises due to switching between variations of th...

The theory of effort minimization in physical activity (TEMPA) argues that individuals have an automatic attraction toward effort minimization. To engage in a physically active behavior, this automatic attraction needs to be overridden by controlled processes. However, direct evidence showing that inhibitory control is required to avoid effort mini...

The theory of effort minimization in physical activity (TEMPA) argues that individuals have an automatic attraction toward effort minimization. To engage in a physically active behavior, this automatic attraction needs to be overridden by controlled processes. However, direct evidence showing that inhibitory control is required to avoid effort mini...

Objective Interest in automatic associations of exercise and physical activity as potential contributors to behavior is rising. However, the measurement of these associations presents a challenge, since the reliability and validity of behavioral tests (despite their widespread usage) is unsatisfactory by most accounts. As a possible alternative, an...

Introduction The slope of the electroencephalography (EEG) power spectrum (also referred to as 1/f noise) is an important consideration when calculating narrow-band power. However, psychophysiological data also suggest this slope is a meaningful signal itself, not merely background activity or noise. We present two different methods for quantifying...

Objective: Having learners practice a motor skill with the expectation of teaching it (versus an expectation of being tested on it) has been revealed to enhance skill learning. However, this improvement in skill performance is lost when the skill must be performed under psychological pressure due to 'choking under pressure.' The present study will...

Background: Adverse childhood experiences, depressive symptoms, and functional dependence are interrelated. However, the mechanisms underlying these associations remain unclear. The authors investigated the potential of depressive symptoms to mediate the effect of adverse childhood experiences on functional dependence in older age and whether phys...

Recent evidence suggests humans have an automatic attraction to effort minimization. Yet, how this attraction is associated with response inhibition is still unclear. Here, we used go/no-go tasks to capture inhibitory control in response to stimuli depicting physical activity versus physical inactivity in 59 healthy young individuals. Higher commis...

It is unknown whether rewards improve the capability to select appropriate targets for one’s movement (action selection) and/or the movement itself (action execution). Thus, we devised an experimental task wherein participants categorized a complex visual stimulus to determine toward which one of two targets to execute an action (putt a golf ball)...

Recent evidence suggests humans have an automatic attraction to effort minimization. Yet, how this attraction is associated with response inhibition is still unclear. Here, we used go/nogo tasks to capture inhibitory control in response to stimuli depicting physical activity versus physical inactivity in 59 healthy young individuals. Higher commiss...

Reward sensitivity and emotional reactivity have been identified as two candidate mechanisms of anhedonia in depression. However, there is a paucity of research examining whether deficits in reward sensitivity and emotional reactivity can be modified through brief, behavioral interventions. Therefore, the purpose of this study was to examine the ef...

Attentional capture by exercise-related stimuli is important for the regulation of physical activity. Attentional processing underlying this capture has been investigated with indirect behavioral measures based on reaction times. To investigate more direct measures of visual spatial attention toward physical activity (vs. inactivity) stimuli, we us...

The “feel better” phenomenon of exercise is well established, yet little is known regarding the mechanisms of post-exercise affective responses. Two objective neural markers that can be used to better understand affective responses following exercise include the reward positivity (RewP) and late positive potential (LPP) of the event-related potenti...

Attentional capture by exercise-related stimuli is important for the regulation of physical activity. Attentional processing underlying this capture has been investigated with indirect behavioral measures based on reaction times. To investigate more direct measures of visual spatial attention toward physical activity (vs. inactivity) stimuli, we us...

While several studies have examined attentional reserve (via event-related potentials) and mental effort (via EEG spectral content) from various cortical regions during dual-task walking, none have assessed changes in the magnitude of interregional (cortico-cortical) communication as a measure of mental workload. Therefore, by deploying a tradition...

Reward positivity (RewP) is an EEG component reflecting reward-prediction errors. Using multilevel models, we measured single-trial RewP amplitude from trial-to-trial, while reward and prediction varied during learning. Sixty participants completed a category-learning task in either engaging or sterile conditions with the RewP time-locked to feedba...

Objectives This study aimed to evaluate the influence of lower limb loss (LL) on mental workload by assessing neurocognitive measures in individuals with unilateral transtibial (TT) versus those with transfemoral (TF) LL while dual-task walking under varying cognitive demand. Methods Electroencephalography (EEG) was recorded as participants perfor...

Background Variability in gait speed is influenced by age and health status. However, no study has investigated the effects of different instructions on gait speed. Research question This study investigated how walking prompts contributed to variability in gait speed. Methods Participants walked on a pressurized walkway. Gait speed variability wa...

Some models of motivation distinguish between intrinsic and extrinsic motivation. While past work has examined the neural and cognitive correlates of extrinsic motivation, research on intrinsic motivation has relied primarily on behavioral measures of performance and learning. In particular, no past work has examined the neural and cognitive correl...

Poor neighborhood conditions are associated with lower levels of physical activity for older adults but socio-ecological models posit that physical activity depends on both environmental and individual factors. Older adults’ ability to overcome environmental barriers to physical activity may partially rely on cognitive resources. However, evidence...

A recent theory contends that behaviors minimizing energetic cost are rewarding (Cheval et al., 2018). However, direct experimental evidence supporting this theory is lacking. To fill this knowledge gap, we investigated the effect of energy expenditure on reward-related brain activity in a pre-registered study. This preregistered study included thi...

A recent theory contends that behaviors minimizing energetic cost are rewarding (Cheval et al., 2018). However, direct experimental evidence supporting this theory is lacking. To fill this knowledge gap, we investigated the effect of energy expenditure on reward-related brain activity. Thirty-one participants were equipped with an electroencephalog...

Individuals who have sustained loss of a lower limb may require adaptations in sensorimotor and control systems to effectively utilize a prosthesis, and the interaction of these systems during walking is not clearly understood for this patient population. The aim of this study was to concurrently evaluate temporospatial gait mechanics and cortical...

Self-control of task-relevant parameters during practice results in superior learning. However, the mechanisms underlying this effect remain unclear. To investigate these effects, we collected frontal alpha asymmetry (ΔFAS) and midline frontal theta (ΔMFT). Sixty novice participants were randomized into a self-controlled group, controlling difficul...

Poor neighborhood conditions are associated with lower levels of physical activity in older age, but socio-ecological models put forth that physical activity is dependent on both environmental and individual factors. Older adults’ abilities to overcome environmental physical activity barriers may partially rely on cognitive resources. However, evid...

The primary means for disseminating sport and exercise science research is currently through journal articles. However, not all studies, especially those with null findings, make it to formal publication. This publication bias towards positive findings may contribute to questionable research practices. Preregistration is a solution to prevent the pub...

Past research has revealed practicing and studying a motor skill with the expectation of teaching it to another person increases the amount of time participants spend preparing for movement during practice trials of the skill. However, it is unknown whether the increased motor preparation time explains the benefit of expecting to teach on motor lea...

When practicing a motor skill, learners who are expecting to teach it to another person exhibit superior gains in skill execution and declarative knowledge. Since skills acquired with large gains in declarative knowledge are highly susceptible to decrement under psychological pressure, it is possible the advantage of expecting to teach is lost when...

The allocation of mental workload is critical to maintain cognitive-motor performance under various demands. While mental workload has been investigated during performance, limited efforts have examined it during cognitive-motor learning, while none have concurrently manipulated task difficulty. It is reasonable to surmise that the difficulty level...

Considerable research has been devoted to understanding how intrinsic motivation can augment the learning of motor skills. Many manipulations targeting intrinsic motivation have led to improved learning, but the mechanisms underlying this effect are not known. Replicating a previous study, we manipulated intrinsic motivation by giving one group sel...

Expecting to teach and (actually) teaching has been shown to enhance learning academic information, possibly due to increased motivation and engagement. Recently, expecting to teach has been shown to augment motor learning. The present study investigated whether expecting to teach and teaching enhances motor learning, and whether motivation or enga...

This study assessed whether a multi-ingredient energy supplement (MIES) could enhance cerebral-cortical activation and cognitive performance during an attention-switching task. Cerebral-cortical activation was recorded in 24 young adults (12 males, 12 females; 22.8 ± 3.8 yrs) via electroencephalography (EEG) both at rest and during the attention-sw...

Recent evidence suggests practicing a motor skill with the expectation of teaching it enhances learning by increasing information processing during motor preparation. However, the specific motor preparatory processes remain unknown. The present study sought to address this shortcoming by employing EEG to assess participants’ motor preparatory proce...

A novel ERP approach was proposed to index variations in mental workload, particularly in attentional reserve, which is complementary to EEG spectral content thought to reflect mental effort. To our knowledge, no study has assessed mental effort and attentional reserve simultaneously in EEG gel-based and, importantly, dry systems, which are particu...

Previous work focused on assessing cognitive workload has suggested EEG spectral content and component amplitudes of the event-related potential (ERP) waveform may index mental effort and attentional reserve, respectively. Although few studies have assessed attentional reserve and mental effort during upper-extremity performance, none employed a co...

The Reflective-Impulsive Model (RIM) has been employed to explain various health behaviors. The present study used RIM to predict a spontaneous physical activity behavior. Specifically, 107 participants (75 females; Mage = 20.6 years, SD = 1.92 years) completed measures of (1) reflections about spontaneous physical activity, as indexed by self-repo...

While the concepts of cognitive workload and attentional reserve have been thought to have an inverse relationship for some time, such a relationship has never been empirically tested. This was the purpose of the present study. Aspects of the electroencephalogram were used to assess both cognitive workload and attentional reserve. Specifically, spe...

The present study investigated whether motivation and augmented feedback processing explain the effect of an incidental choice on motor learning, and examined whether motivation and feedback processing generally predict learning. Accordingly, participants were assigned to one of two groups, choice or yoked, then asked to practice a non-dominant arm...

There is some evidence that people learn academic (declarative) information better when studying with the expectation of having to teach, but this has not been demonstrated for perceptual-motor skills, which also rely on declarative information but more heavily on procedural knowledge. To address this possibility, participants studied golf putting...

Recent research has revealed that having learners study and practice a motor skill with the expectation of having to teach it enhances motor learning. However, the mechanisms underlying this effect remain unknown. We attempted to replicate this effect and elucidate the mechanisms underlying it. Thus, participants studied golf putting instructions a...

The present study explored the relationship between motor-preparatory electroencephalographic (EEG) activity, motivation, and motor performance (specifically premotor reaction time [RT]). Participants performed a RT task by squeezing a hand dynamometer in response to an auditory “go” signal. We recorded EEG and electromyography to index beta-suppre...

Appropriate statistical analysis is essential for accurate and reliable research. Statistical practices have immediate impacts on the perceived results of a single study, but also remote effects on the dissemination of information among scientists and the cumulative nature of research. To accurately quantify potential problems facing the field of m...

Skilled individuals demonstrate a spatially localized or relatively lower response in brain activity characterized as neural efficiency when performing within their domain of expertise. Elite athletes are experts in their chosen sport and thus must be not only adept in the motor domain but must be resilient to performing under the stress of high-le...

From a neurobiological and motivational perspective, the feedback-related negativity (FRN) and reward positivity (RewP) event-related potential (ERP) components should increase with reward magnitude (reward associated with valence (success/failure) feedback). To test this hypothesis, we recorded participants’ electroencephalograms while presenting...

Appropriate statistical analysis is essential for accurate and reliable research. Statistical practices have an immediate impact on the perceived results of a single study but also remote effects on the dissemination of information among scientists and the cumulative nature of research. To accurately quantify potential problems facing the field of...

To test effects of contextual priming (both conscious and nonconscious) in relation to complex human behavior, the present studies investigated (1) whether nonconscious priming of exercise and antiexercise goals can increase and decrease exercise, respectively; (2) whether conscious priming of exercise goals can increase exercise; and (3) how nonco...

Background: Video games and virtual environments continue to be the subject of research in health sciences for their capacity to augment practice through user engagement. Creating game mechanics that increase user engagement may have indirect benefits on learning (ie, engaged learners are likely to practice more) and may also have direct benefits...

The preservation of attentional resources under mental stress holds particular importance for the execution of effective performance. Specifically, the failure to conserve attentional resources could result in an overload of attentional capacity, the failure to execute critical brain processes, and suboptimal decision-making for effective motor per...

When students begin a course, they generally enter with expectations of what will and will not happen. On the other hand, faculty members also enter a classroom with perceptions of what students expect from a course. Having a mismatch between these sets of expectations is natural, but can prove detrimental to learning. This paper compares results f...

We examined whether the utility of a recently developed auditory probe technique for indexing cognitive workload was dependent on the stimulus properties of the probes. EEG was recorded while participants played a videogame under various levels of cognitive workload. At each level of workload, participants were probed with one of four different typ...

Cognitive workload is an important element of cognitive-motor performance such as that exhibited during the piloting of an aircraft. Namely, an increase in task demands on the pilot can elevate cognitive information processing and, thus, the risk of human error. As such, there is a need to develop methods that reliably assess mental workload in pil...