I do not feel I manipulate the shape of the left tongue as I do the right in speech. I think I maneuver the tongue as a whole based on the right in a positive sense (where it is) the left in a negative sense (will it get hurt there). When I am in left tongue mode I have very little sense of the right's position. Lingual experts are aware of Left Right asymmetries in the use of the tongue but seem to view the tongue as one tongue with two sides instead of two tongues co-joined. What I am saying does not make sense conventionally. I do not know what others are doing inside their mouths. I am making many unsupported assertions based on the discrepancies I feel in my left tongue/throat/face and right tongue/throat/face muscular use. There are times in playing with the left tongue the movements are very strong powerful and very strangely unfamiliar.
Left right asymmetry in use of the tongue
Lingual asymmetry is common in static postures (cf., Story et al., 1996, Stone and
Lundberg, 1996) and in movements (Stone, 1990). LR asymmetry in tongue movement is
especially apparent in repetitive tasks such as syllable repetition. Two reasons for LR asymmetry
are biomechanical imprecision and purposeful rotation. We believe both effects occurred here as a result of rapid repetitive motion and coarticulatory accommodation.