SUMMARY: This post explores sensory gating of external and internal sensation. Can our reticular thalamic nuclei keep out or reduce ‘irrelevant’ sensory information for the endurance athlete?

EVIDENCE FOR SENSORY GATING

Student: That summary looks familiar: gating in sensory information and gating out other sensations.

Professor: Yes. (See more at: The Sensory Gate is Real.) First, let’s briefly review the evidence for sensory gating (SG).                                                                        .

• The ability to do pre-attentive filtering of background sounds (Kisley et al, 2004).
• The loss of filtering ability due to strokes which include the ventral posterior lateral thalamic nuclei (VPL) and results in flooding of sensory gates (Staines et al., 2002).
• The second of paired inspiratory occlusions is reduced (Chan et al., 2008).
• The thalamus has a thin ‘skin,’ the reticular nuclei, whose function is to help focus our attention, allowing only ‘unusual’ activity to pass through gates (Halassa et al., 2014; Ward, 2013).

INDIVIDUAL DIFFERENCES IN SENSITIVITY

Student: Another way of looking at SG evidence is to notice individual differences in sensitivity.

Professor: The evidence does show that some individuals have

• too much sensorimotor sensitivity: anxious persons are very aware of background sounds, and/or
• too little sensorimotor sensitivity: depressed individuals show too little awareness (Paulus & Stein, 2010).

Student: Are there any scales for measuring individual sensorimotor sensitivity?

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Summary: List blog topics that will help prepare review for a journal about fatigue.

Student: You have been invited to write a review about Fatigue and RPE. Congratulations!

Professor: Thank you, Simone Cairns of Auckland University of Technology, New Zealand for setting up the invitation. The actual invitation came from Fred Friedberg, for his journal: “Fatigue: Biomedicine, Health & Behavior”

And its temporary title is, “How can our perceptions become factors limiting prolonged performance?”

Student: First of all, what do you do this summer?

Professor: Anne and I spent a wonderful week at Lake Dunmore visiting with her Vermont son and his family. Below is an evening photo from the dock with canoe and kayak below the cottage.

Dock on Lake Dunmore

Student: Well did you do anything related to exercise science?

Professor: Yes. I did get in some interesting reading about:

• High Intensity Interval Training (HIIT, Ref. 1); my brother, Karl, mentioned this to me. I discovered that this has become my preferred exercise mode since I was about 60 years old, about 12 years ago!
• Fatigue and Fatigability; Enoka (Ref. 2) helped me bridge my conceptual gap that existed between acute and chronic fatigue.
• Talk Test (Ref. 3); hey, I used this with cardiac and pulmonary patients 30+ years ago to avoid talking to themselves in paragraphs and not exercise hard enough.
• Pacing and decision making; a recent review by Smits, Pepping, & Hettinga (Ref. 4) validated my concepts about perception merging into action by using Cizek’s Affordance Competition Hypothesis (e.g., see Sensory Processing Part 2).

Student: And what are your proposed topics for Fall 2014?

Professor: First I suggest we review the following:

• What limits the ‘mix’ of perceptions that one experiences?
  • Reticular thalamic sensory gates do not allow passage of ‘unwanted’ info and
  • Use of ‘searchlight’ by posterior insula during body scan to change ‘mix.’
• How are the intensities of perceptions estimated and reported?
  • Anterior-middle insula estimates the magnitude of the intensity, and
  • Internal talk sets up the reporting of symptom intensity.
• How do I
  • process my perceptions,
  • select my actions from predictions of possible outcomes, and
  • report my symptoms?

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