How an injury to the CNS affect our ability to recall experiences?

How an injury to the CNS affect our ability to recall experiences?

Updated on 15th March, 2022

Author: Kshitij Vashisth

Every day, as you wake up, you may crave your favorite cup of coffee. However, even before you actually get up to make this coffee, you can possibly visualize, smell and taste it (Figure 1).  In fact, you may also be able to feel your fingers on your favorite coffee mug. The ability to perceive these sensations even when you are still in bed is known as mental imagery (MI). In simple words, it is the ability to imagine experiences in your life. This experience is quasi-perceptual and it does not need any external stimulus [Kaur et al, 2019].  These experiences, more recently, are proven to have tremendous potential in the field of neuro-rehabilitation of patients with chronic conditions like multiple sclerosis, stroke, and spinal cord injury [Kaur et al, 2020].

Figure 1

In spinal cord injury (SCI) patients, there is an injury to the spinal cord which is an integral component of our central nervous system (CNS). It has a central role in our day-to-day life and is the path any impulse must take before reaching the processing center of the nervous system, the brain. In SCI patients, there is a break in the continuity of this pathway.

In a recent cross-sectional study by a group of scientists, relationships between clinical and psychological variables and MI ability in individuals with SCI were assessed [Kaur et al, 2022]. They concluded that injury in the cervical region(high-level injuries) corresponded to very low MI scores when compared with thoracic region injury (Figure 2). In other words, the higher they looked at the spine, the lower scores on MI were observed (in terms of SCI)! Completeness of injury that is the absence of motor and sensory inputs to the brain also affected the MI ability significantly. Even stress and depression (psychological variables) made it hard to imagine the taste of your coffee.

Figure 2

Note: They are not actually tasting your coffee, trust me.

This study involved 130 SCI participants who filled up the following questionnaires:

  1. Kinesthetic and Visual Imagery Questionnaire (KVIQ) – assessed the ability to visualize and experience imagined movements.
  2. Vividness of Motor Imagery Questionnaire 2 (VMIQ-2) – assessed the vividness of imagery.
  3. Perceived Stress Scale and Patient Health Questionnaire 9 (PHQ-9)were used for the assessment of stress and depression respectively.

The research was pivotal in establishing the effect of type of injury and psychological variables on the MI ability of SCI patients. Interventions based on imagery (MI) should be designed after considering identified factors that yield effects on their outcomes. 

References:

  1. Jaskirat Kaur, Shampa Ghosh, Asish Kumar Sahani, Jitendra Kumar Sinha (2019). “Mental imagery training for treatment of central neuropathic pain: a narrative review”
    Acta Neurologica Belgica DOI: 10.1007/s13760-019-01139-x
  2. Jaskirat Kaur, Shampa Ghosh, Asish Kumar Sahani, Jitendra Kumar Sinha (2020). “Mental Imagery as a Rehabilitative Therapy for Neuropathic Pain in People With Spinal Cord Injury: A Randomized Controlled Trial” Neurorehabilitation and Neural Repair DOI: 10.1177/1545968320962498
  3. Jaskirat Kaur, Shampa Ghosh, Prabhakar Singh, Alok Kumar Dwivedi, Asish Kumar Sahani, Jitendra Kumar Sinha (2022). “Cervical Spinal Lesion, Completeness of Injury, Stress, and Depression Reduce the Efficiency of Mental Imagery in People With Spinal Cord Injury” American Journal of Physical Medicine & Rehabilitation DOI: 10.1097/PHM.0000000000001955

Reviewer: Manish Verma

Illustrations: Joyobrata Sarkar