Influence of Acute Stress on Motor Learning and Motor Imagery Ability in Young Population
Condition: Stress, Psychological
MeSH terms: Stress, Psychological
Study type: Interventional

Summary: 
      In motor learning, it is essential to consider that movements are produced by the cooperation
      and combination of many brain structures and are influenced by the emotions to which
      individuals are subjected. Several neural circuits have been identified that closely link the
      emotional system and the motion control system.

      Stress is a physiological or psychological response to internal or external stressors. In
      principle, it has an adaptive role. However, the neuroendocrine and autonomic response
      generated by stress can affect cognitive processes such as memory. In addition, it has been
      shown to influence motor learning, especially the execution of skills in the early stages of
      learning.

      Understanding how movement, emotions and interactions are regulated is significant because of
      the large number of movements humans perform. Of these, manual tasks represent precise
      movements that require the integration of many elements by the nervous system to perform
      these tasks successfully. It is still unknown how acute stress influence the way manual tasks
      are learned.

      On the other hand, motor imagery (MI) is a cognitive process that is an important contributor
      to how movements are planned and executed. Its use has been recommended to improve movement
      learning and task execution. For an MI program to be effective and individualized, it is
      imperative to know this ability. However, it is also still unknown how acute stress can
      affect our motor imagery ability.

      The main objective of this study is to determine and quantify the effects of acute stress in
      the learning of a precise manual task not previously trained on four parameters of fine motor
      control: trajectory error, timing error, timing accuracy, and task accuracy. On the other
      hand, the aim is to determine if the capacity of internal visual, external visual, and
      kinesthetic imagery, and the temporal congruence between movement execution and imagery
      varies when we are subjected to acute stress.

      It is expected that non-anxious, non-stressed participants who are not induced with acute
      stress will show better motor performance on the fine motor task and better motor imagery
      ability and temporal congruence. In contrast, it is expected that participants without
      anxiety and stress who are induced with acute stress will show poorer motor performance on
      the fine motor task, and poorer motor imagery ability and temporal congruence.
    

Detailed description: 
      In order to meet the study objectives of determining and quantifying the effects of acute
      stress on learning a precise manual task and on motor imagery ability, this study will be
      conducted. The development of the study will take place in a conditioned room belonging to
      the University of Alcalá, the Complutense University of Madrid, the European University of
      Madrid, or Claude Bernard University Lyon 1. The study may also be carried out in other
      Spanish and international university centers, subject to the consent and permission of the
      respective centres. The study will be carried out by all national and international laws,
      regulations, and recommendations.

      The study design will be longitudinal, experimental, randomized, and double-blind, as
      specified in the present registry.

      The study population will be composed of participants who are undergraduate and postgraduate
      students at the university centers where the study will be carried out, from which they will
      be recruited. All participants included in the study must meet the study selection criteria
      and participate voluntarily after reading the information sheet and signing the informed
      consent form.

      The study will consist of two intervention groups, in which the Maastricht Acute Stress Test
      (MAST) protocol will be performed: one group will perform the acute stress induction protocol
      (MAST stress) and the other group will perform the no stress induction control protocol (MAST
      control). Each group will consist of a minimum number of 30 subjects to be able to study the
      desired effect.

      After each participant freely chooses to participate in the study, an initial questionnaire
      will be administered to ensure that they meet the criteria for inclusion in the study. At
      this point, they will be coded by assigning them a number, which will serve to identify each
      participant throughout the study. Participants will take the State-Trait Anxiety Inventory
      (STAI), one of the most widely used instruments for the self-reported assessment of anxiety
      and equivalent to a measure of stress, as it considers the amount of stressful stimulus.
      Thus, the two components of anxiety will be assessed: state anxiety and trait anxiety.
      Participants with scores indicative of state or trait anxiety will be excluded from the
      study, and those with scores indicating neither trait anxiety nor state anxiety will be
      included. Included participants will be randomized through sealed envelopes stratified by
      gender to one of two experimental groups: MAST stress, or MAST control. They will also take
      the Edinburgh Handedness Inventory (EHI) to determine the participant's laterality, and the
      Movement Imagery Questionnaire-3 (MIQ-3) to measure internal visual, external visual,
      kinaesthetic imagery capacity. At the same time of MIQ-3, the experimenter will record the
      execution and imagery times were recorded (for subsequent calculation of the time discrepancy
      between executed and imagery as a measure of temporal congruence between them). Depending on
      the group to which they have been assigned, they will perform the corresponding MAST protocol
      (stress or control). MAST stress is a non-invasive protocol to induce acute stress in the
      laboratory that combines components of psychological stress (evaluative social threat,
      uncontrollability, and unpredictability) and physical stress (sensation of pain through
      intense cold). The MAST control is a homologous protocol to the stress protocol but has no
      psychological or physical stressor components. After MAST protocol, participants will learn a
      precise manual task with the non-dominant hand. The task will consist of going over a 127 mm
      circumference on a graphics tablet at a rate of 2 seconds per lap, which will be set by a
      metronome using a wireless pen that will leave no trace of ink but will store the data in the
      MATLAB program via the graphics tablet. Thus, data from the acquisition and short-term
      retrieval of the task will be recorded. Afterward, there will be a 20-minute break during
      which participants will perform the MIQ-3 and the experimenter will record the execution and
      imagery times again. Finally, the task data will be collected to record the long-term
      retrieval of the manual task.

      In addition, during all experiments, electrodermal activity and heart rate variability will
      be recorded using the Empatica E4 physiological variable measurement wristband. This
      measurement of physiological variables will serve to confirm that a significant emotional
      effect has been generated and to test motor imagery processes since both acute stress and
      motor imagery produce activation of the autonomic nervous system.

      The analysis and processing of data from MATLAB version R2020b, and the Empatica E4 wristband
      will be performed using RStudio software and Kubios HRV software (for HRV analysis).

      First, appropriate statistical analyses will be performed to see if the data are distributed
      according to a standard curve through the Shapiro-Wilk test and to assess the influence of
      sex and age.

      Subsequently, the descriptive analysis of the relative and absolute frequencies for the
      qualitative variables of gender and age will be carried out, and their homogeneity will be
      tested using the Chi-square test. The descriptive analysis of the quantitative variables of
      trajectory error, timing error, timing accuracy, task accuracy, electrodermal activity, heart
      rate variability, kinaesthetic, internal visual, and external visual imagery, and discrpenacy
      times will also be carried out. If the variable conforms to the normal, the mean, range, and
      standard deviation shall be calculated. If it does not conform to the normal, non-parametric
      tests will be performed.

      Comparative analysis will be performed using mixed ANOVA to see the differences in the mean
      values respective to motor control (trajectory error, timing error, timing accuracy, and task
      accuracy). A further ANOVA analysis will take place for imagery ability and discrepancy
      times, comparing the results obtained at the two respective points during the experiment.

      The effect of learning between laps will be analyzed by repeated-measures ANOVA comparing
      each motor control measurement parameter with respect to the lapping factor. Electrodermal
      activity, and heart rate variability during the measurement of imagery ability, emotional
      state induction, manual task acquisition, and its retrieval in the short and long term will
      also be studied by repeated-measures ANOVA.

      For hypothesis testing, a significance level of 0.05 will be set.
    

Intervention name(s): Stress group; Control group
Intervention type(s): Other; Other
Intervention description(s): This group will perform the MAST stress protocol; This group will perform the MAST control protocol
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: As participants complete the State-Trait Anxiety Inventory, and are found to be free of trait anxiety, and state anxiety, they will be randomised in parallel to one of the two intervention groups.
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Basic Science
Keywords: Stress, Psychological; Learning; Memory; Movement