A kinematically complex multi-articular motor skill for investigating implicit motor learning.

Here we present a task developed to probe implicit learning of a complex motor skill. This task addresses limitations related to task complexity noted in the literature for methods investigating implicit motor learning, namely the serial reaction time task and continuous tracking task. Specifically, the serial reaction time task is limited by the kinematic simplicity of the required movement and the continuous tracing task faces time-on-task confounds and limitations in the control of task difficulty. The task presented herein addresses these issues by employing a kinematically complex multi-articular movement that controls factors that contribute to task difficulty: stimulus animation velocity and trajectory complexity. Accordingly, our objective was to validate the use of this task in probing implicit motor learning, hypothesizing that participants would learn one of the repeating stimuli implicitly. Participants engaged in six blocks of training whereby they first observed and then reproduced a seemingly random complex trajectory. Repeated trajectories were embedded amongst random trajectories. In line with the hypothesis, error for the repeated trajectories was decreased in comparison to that observed for the random trajectories and 73% of participants were unable to identify one of the repeated trajectories, demonstrating the occurrence of implicit learning. While the task requires minor alteration to optimize learning, ultimately the findings underline the task's potential to investigate implicit learning of a complex motor skill.

Effects of fatigue on attention and vigilance as measured with a modified attention network test.

As part of a larger study on the effects of fatigue on various attentional and behavioural measures, we had participants complete a modified version of Luna et al.'s (J Neurosci Methods 306:77-87, Luna et al., J Neurosci Methods 306:77-87, 2018) ANTI-Vea task (mANTI-Vea) at the beginning and end (pre/post) of each of two 8-h testing sessions. Between these administrations of the mANTI-Vea our participants spent ~ 6 h performing an intervening task. Our intent in this project was two-fold: first, to replicate the pattern of effects reported in Luna et al.'s original presentation of the ANTI-Vea; second, to assay the impact of fatigue on vigilance and attention by observing shifts in mANTI-Vea performance as a function of time on task and before versus after the intervening task. With time-on-task (the mANTI-Vea is divided into six sub-blocks) we observed that participants became increasingly conservative in their biases to respond towards infrequent targets, showed a decline in sensitivity, and lapsed in responding in the psychomotor vigilance task with greater frequency. In the pre/post comparison, we observed an increase in the proportion of lapses, but not in participants' response biases. Attentional network scores were found to be somewhat insensitive to our fatigue manipulations; the effect of time-on-task was only significant for orienting scores on RT, and our pre/post comparison was only significant for RT derived executive functioning scores.

The Effect of Cigarette Packaging and Illness Sensitivity on Attention to Graphic Health Warnings: A Controlled Study.

INTRODUCTION: The social and health care costs of smoking are immense. To reduce these costs, several tobacco control policies have been introduced (eg, graphic health warnings [GHWs] on cigarette packs). Previous research has found plain packaging (a homogenized form of packaging), in comparison to branded packaging, effectively increases attention to GHWs using UK packaging prototypes. Past studies have also found that illness sensitivity (IS) protects against health-impairing behaviors. Building on this evidence, the goal of the current study was to assess the effect of packaging type (plain vs. branded), IS level, and their interaction on attention to GHWs on cigarette packages using proposed Canadian prototypes. AIMS AND METHODS: We assessed the dwell time and fixations on the GHW component of 40 cigarette pack stimuli (20 branded; 20 plain). Stimuli were presented in random order to 50 smokers (60.8% male; mean age = 33.1; 92.2% daily smokers) using the EyeLink 1000 system. Participants were divided into low IS (n = 25) and high IS (n = 25) groups based on scores on the Illness Sensitivity Index. RESULTS: Overall, plain packaging relative to branded packaging increased fixations (but not dwell time) on GHWs. Moreover, low IS (but not high IS) smokers showed more fixations to GHWs on plain versus branded packages. CONCLUSIONS: These findings demonstrate that plain packaging is a promising intervention for daily smokers, particularly those low in IS, and contribute evidence in support of impending implementation of plain packaging in Canada. IMPLICATIONS: Our findings have three important implications. First, our study provides controlled experimental evidence that plain packaging is a promising intervention for daily smokers. Second, the findings of this study contribute supportive evidence for the impending plain packaging policy in Canada, and can therefore aid in defense against anticipated challenges from the tobacco industry upon its implementation. Third, given its effects in increasing attention to GHWs, plain packaging is an intervention likely to provide smokers enhanced incentive for smoking cessation, particularly among those low in IS who may otherwise be less interested in seeking treatment for tobacco dependence.

Imagining the way forward: A review of contemporary motor imagery theory.

Over the past few decades, researchers have become interested in the mechanisms behind motor imagery (i.e., the mental rehearsal of action). During this time several theories of motor imagery have been proposed, offering diverging accounts of the processes responsible for motor imagery and its neural overlap with movement. In this review, we summarize the core claims of five contemporary theories of motor imagery: motor simulation theory, motor emulation theory, the motor-cognitive model, the perceptual-cognitive model, and the effects imagery model. Afterwards, we identify the key testable differences between them as well as their various points of overlap. Finally, we discuss potential future directions for theories of motor imagery.

Are observed effects of movement simulated during motor imagery performance?

Motor learning relies on adjusting the performance of movements via error detection and correction. How motor learning proceeds via motor imagery, the imagination of movement, is not understood. Motor imagery-based learning is thought to rely on comparing the predicted effect of movement, resulting from the forward model, against its intended effect. Whether motor imagery-based learning uses the observed effect of movement, simulated in motor imagery, to make comparisons to the intended effect to permit error detection and correction, is an open question. To address this, transcranial magnetic stimulation was used to inhibit the left inferior parietal lobe (L_IPL) after each trial of a task requiring participants to reproduce complex trajectories via motor imagery. From past work, we speculated the L_IPL was a candidate for integrating simulated feedback about task performance (simulated observed effects), hypothesizing inhibition of the L_IPL would impair learning, suggesting simulated observed effects of movement are used in motor imagery-based learning. Participants received stimulation to the L_IPL or over the vertex of the head after each trial. Learning was defined as reduced error on a repeated trajectory in comparison to randomly generated trajectories. Regardless of group participants learned, a finding countering our hypothesis, suggesting (a) observed effects of movement are not simulated in motor imagery; (b) the L_IPL is not involved in integrating simulated observed effects of movement; or (c) the timing of the stimulation did not align with the speculated role of the L_IPL. Results encourage further research probing simulated feedback in motor imagery and its neural correlates. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Imagined movement accuracy is strongly associated with drivers of overt movement error and weakly associated with imagery vividness.

Theories of motor imagery conflict in their account of what happens during an imagined movement, with some suggesting that movement is simulated while others suggest it involves creating and elaborating upon an internal representation of the movement. Here we report evidence that imagery involves the simulation of a movement and that it varies in accuracy. Two groups of participants performed a motor task focused on challenging movement execution either overtly or via motor imagery. Overt performance was used to model expected performance given required movement characteristics (i.e., speed, complexity, familiarity), which was then compared with self-reported accuracy during imagery. Movement characteristics had a large effect on self-reported accuracy compared with a small effect of imagery vividness. Self-reported accuracy improved across trials with familiar movements compared with novel movements in a similar manner for each group. The complexity of the imagined movement did not influence movement time during imagery or overt trials, further suggesting that imagined movements are simulated rather than abstractly represented. Our results therefore support models of motor imagery that involve the simulation of a movement and its viability, which may be the basis of imagery-based motor learning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

How Does Spatial Attention Influence the Probability and Fidelity of Colour Perception?

Existing research has found that spatial attention alters how various stimulus properties are perceived (e.g., luminance, saturation), but few have explored whether it improves the accuracy of perception. To address this question, we performed two experiments using modified Posner cueing tasks, wherein participants made speeded detection responses to peripheral colour targets and then indicated their perceived colours on a colour wheel. In E1, cues were central and endogenous (i.e., prompted voluntary attention) and the interval between cues and targets (stimulus onset asynchrony, or SOA) was always 800 ms. In E2, cues were peripheral and exogenous (i.e., captured attention involuntarily) and the SOA varied between short (100 ms) and long (800 ms). A Bayesian mixed-model analysis was used to isolate the effects of attention on the probability and the fidelity of colour encoding. Both endogenous and short-SOA exogenous spatial cueing improved the probability of encoding the colour of targets. Improved fidelity of encoding was observed in the endogenous but not in the exogenous cueing paradigm. With exogenous cues, inhibition of return (IOR) was observed in both RT and probability at the long SOA. Overall, our findings reinforce the utility of continuous response variables in the research of attention.