Perceived Effort: along a hallway vs. up a stairway

November 20th, 2012 by Phil Weiser Leave a reply »

One day last week, I put Perceived Effort to another test.

As I walked along a hallway, and since I am “an anticipation machine,” (Freyd, 1987, cited by Siegel, 1999), I noticed a stairway at its end. Aha. What if I just kept up this momentum and start up the stairs two steps at a time. “But I might fall on my nose,” I thought. “So I will not change my speed.”

Sure enough, as my right leg made the first double-step, I noticed that I was falling. Well, I also noticed my body sagging as I stepped. And then I felt a definite shift, as my body went to the left leg for the second double-step. Without thinking I pushed harder and arched my back to sorta leap over those next two steps. And a seemingly unconscious leap also happened for the third double-step using my right leg again.  This time I did not arch my back. Whoa! What happened? How did this just happen!?

My body seemed to ignore my request to “keep on keeping on”. It leaped. It was not into teleoanticipation; it did a face saving maneuver. How? (Rather than “How come?” or “Why?”)

Let me hazard a guess: if it was not seemingly conscious, then it was done subconsciously. Okay, then how? Perhaps “not falling on my face” mainly by using vestibulomotor and leg motor reflexes as like a musical score. Maybe the musical managing council was the subcortical locomotor control network comprised of the basal ganglia, the medullary and subthalamic locomotor regions, and the cerebellar locomotor regions. And the musical section leaders were the thoracic and lumbar locomotor regions making sure my arms were coordinated with my legs. Finally, my leg muscles compensated for the muscles in my overly bent right leg via were mediated by musical players in the hemi-spinal  central pattern generators and their contralateral interneurons. Wow, what a modern neurobiological summary gifted by the works of Grillner et al. (2008) and la Fougère et al. (2010).

And where is the word: “Effort”? Well, it is hidden in the phrase, “change my speed”.

So, how do I know how fast I am going?

Please tune in next week…..

References:

Freyd JJ (1987) Dynamic mental representations. Psychological Reviews 94: 427-438.

Grillner S, Wallén P, Saitoh K, Kozlov A, Robertson B (2008)Neural bases of goal-directed locomotion in vertebrates—An overview. Brain Research Reviews 57: 2-12l.

la Fougère C, Zwergal A, Rominger A, Förster F, Fesl G, Dieterich M, Brandt T, Strupp M, Bartenstein P, Jahn K (2010) Real versus imagined locomotion: A [18F]-FDG PET-fMRI comparison, NeuroImage 50: 1589-1598.

Siegel DJ (1999) “The Developing Mind” New York: Guilford Press. p 30.

 

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