In press: In: Dimitrova-Vulchanova, M - NTNU

together with the other cases of ‘supine’ locomotion. This however, does not mean that each
respective language lacks the means to express the features selected by the other two. All
three languages have verbs covering each of the three features (English crawl, wind;
Norwegian krype, skli – ‘slide’; Bulgarian izvivam se – ‘wind’, pluzgam se –‘slither/slide’),
but they are not habitually applied to the situation in question.
A biological factor which proved to be important was species, though it did not have
equal weight in all cases. Thus, for Norwegian krabbe, ‘species’ is a crucial feature,
overriding cycle or posture, with the verb used exclusively for humans, and with high
uniformity of naming for the human crawling scenes. An interesting question is to what extent
motion categorization is driven by features (e.g., shape, size) of the object moving or by the
pattern of movement, similar to the influence of object features on object categorization (cf.
Madoley & Smith 2005). We are currently investigating this option in a controlled experiment
(cf. Coventry et al., in progress).
The domains of walking and crawling generally showed to be ‘anthropocentric’, with
the clips of human locomotion scoring highest in the use of target verbs. The variation and
uncertainty in the naming of motion by non-human species, such as insects and reptiles, can
be attributed exactly to this anthropocentric emphasis at the core of lexical items denoting
walking and crawling, clearly supporting the view in Shipley (2003, current research). If
distinctions such as ‘erect’ and ‘supine’ are not relevant for the species, the choice between
existing verbs will be difficult. At the same time, it will be difficult to use any other verb, as
our whole lexicon is generally anthropocentric, reflecting the perception and categorization of
human locomotion, which prove to be easier, if the one categorizing and naming also has
relevant experience in planning and executing the same locomotion patterns (cf. Shipley
2003, Pavalova et al. 2001, among others). Also, since categorization is a learning-based
process (Giese & Poggio 2003, Giese 2004), it will be natural for a particular type of
biological motion to be most commonly associated with the species that exhibit it most often
in our experience (for the clustering of naturally co-occurring features in categorization, cf.
Rosch 1976).
5.2.2 Velocity and substrate
A factor directly related to the cycle of biological motion is velocity. This is theoretically
supported by the Froude equation, where speed, alongside gravity and limb length, is one of
the three main parameters that influence gait pattern and gait-transition (cf. Alexander 1989,
1996). It has been discovered that the transition from supported to suspended gaits happens
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