Motor imagery in spinal cord injured people is modulated by somatotopic coding, perspective taking, and post‐lesional chronic pain

Abstract

Motor imagery (MI) allows one to mentally represent an action without necessarily performing it. Importantly, however, MI is profoundly influenced by the ability to actually execute actions, as demonstrated by the impairment of this ability as a consequence of lesions in motor cortices, limb amputations, movement limiting chronic pain, and spinal cord injury. Understanding MI and its deficits in patients with motor limitations is fundamentally important as development of some brain-computer interfaces and daily life strategies for coping with motor disorders are based on this ability. We explored MI in a large sample of patients with spinal cord injury (SCI) using a comprehensive battery of questionnaires to assess the ability to imagine actions from a first-person or a third-person perspective and also imagine the proprioceptive components of actions. Moreover, we correlated MI skills with personality measures and clinical variables such as the level and completeness of the lesion and the presence of chronic pain. We found that the MI deficits (1) concerned the body parts affected by deafferentation and deefferentation, (2) were present in first- but not in third-person perspectives, and (3) were more altered in the presence of chronic pain. MI is thus closely related to bodily perceptions and representations. Every attempt to devise tools and trainings aimed at improving autonomy needs to consider the cognitive changes due to the body-brain disconnection.

Spinal cord lesions shrink peripersonal space around the feet, passive mobilization of paraplegic limbs restores it

“…Conversely, people affected by PCL who regularly perform sport become more expert than healthy people and PCL patients who do not practise sport when discriminating upper body parts 36 . Moreover, somato-topographic changes concerning the sense of ownership and motor imagery have been demonstrated in people with SCI 32 34 . Thus, somatic afferences and motor efferences play a crucial role in building, maintaining and adapting the representations of one’s own body and in all the high cognitive functions which are connected in some way to body perception and action.…”

“…Previous research has shown that SCI induces brain plasticity 27 28 29 30 31 with changes in bodily representations 32 33 , in motor imagery 34 , in mental rotation of body parts 35 and in the visual discrimination of body actions and forms 36 . Interestingly, these changes seem to follow somato-topic rules 32 34 35 36 .…”

A Different Point of View: The Evaluation of Motor Imagery Perspectives in Patients With Sensorimotor Impairments in A Longitudinal Study

“…Moreover, Kalicinski, Kempe (28) recommended, that the task complexity should be taken into account when MI ability is assessed, as complexity of a task might affect MI performance (a more di cult task leads to reduced MI ability score) (50).…”

“…Several authors described that the use of both MI perspectives could be bene cial in different ways depending on the motor task to be imagined and what aspect of the performance should be enhanced (13,50). White and Hardy (20) described that imagery from an internal perspective improved motor performance accuracy, thus imagery from an external perspective improved speed.…”

“…karate (22). Thus, knowledge about type of activity may be relevant to explain the choice of a particular MI perspective (50).…”