Exploring Gaze Behavior in Action Execution and Motor Imagery during Manual Interception
|2014/09/15 - 2017/09/14||80.000 Euro|
Mentally rehearsing a motor task elicits similar neural activity and involves similar perceptual processes to when the same action is physically performed (e.g. Grèzes & Decety, 2001). It has been postulated that the two simulation conditions could access the same motor representations (Jeannerod, 1994; 2001) although the extent to which the same covert mechanisms are shared is still not clear. In the domain of visual perception, it has been demonstrated that some spatio-temporal characteristics of gaze metrics between motor imagery and action execution are preserved (Causer, McCormick, & Holmes, 2013). This evidence supports the idea of the existence of a partially shared neural network between motor imagery and action execution. Nevertheless, investigations exploring gaze metrics during motor imagery are confined to the laboratory environment, limited to self-paced manual actions, and focusing on general characteristics of eye movements.
In order to tackle these issues, the goal of the current project is to explore to degree of neural 'sharedness' between motor imagery and action execution by 1) exploring the spatio-temporal characteristics of eye movements for a more complex class of visuo-motor tasks, such as the manual interception of a moving target, and by 2) examining several ocular parameters during the unfolding of the interceptive task. Moreover, 3) we will extend our findings to more naturalistic environments. Within this scenario, we advance two main plausible hypotheses. If gaze behaviour during motor imagery is the result of visuo-motor strategies underlying eye-hand motor processing, then a similar gaze behavior would be displayed for both action execution and motor imagery. Conversely, gaze parameters between the two conditions would be quantitatively different for the interceptive task.
With this aim, a first study was designed to explore how visual tracking behavior change between executed and mentally simulated movements for an interceptive task where the visual stimulus is visible. An exploratory analysis was conducted on data from 24 right-handed participants who took part in the experimentation. Overall participants were asked to track and intercept a target as rapidly and as accurately as possible a horizontally transient target moving across the computer display. To this regard, we wanted to assess whether the time required to perform in each experimental condition (i.e. action execution, guided motor imagery, and control) were different as well as the general pattern of saccadic behavior prior to the physical or mentally simulated interception.
Preliminary evidence from our first study indicates that a mechanism of saccadic suppression (Mrotek & Soechting, 2007) might be re-enacted both during the execution and the mental simulation of the interception task rather than pure visual-tracking. This suggests that not only eye movements during motor imagery are not epiphenomenal, but also that visual perceptual processes are similarly affected by covert motor processes during action simulation. In further analyses we will assess the extent to which the spatio-temporal gaze features are shared amongst experimental conditions during the interception task. In short, assessing eye movements? differences and similarities between action execution and motor imagery allows for the understanding of covert motor-perceptual processes and provides us with an objective behavioral outcome for the comprehension of how humans act and anticipate actions. This is particularly important when technical platforms have to be designed with the aim of understanding and interacting with humans.
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