background and aim: the video head-impulse test (vhit) measures the vestibulo-ocular reflex (vor) driven by each semicircular canal, follo­wing high-acceleration head rotations. the main measurable response is the ratio of eye mov­ement velocity to the angular head velocity, which reflects canal function. although norma­tive data is available for vor gain, most studies only report horizontal vo...

Background Deficits in motor movement in children with autism spectrum disorder (ASD) have typically been characterized qualitatively by human observers. Although clinicians have noted the importance of atypical head positioning (e.g. social peering and repetitive head banging) when diagnosing children with ASD, a quantitative understanding of head movement in ASD is lacking. Here, we conduct a...

Head movement is the case of Move-α where the value of α is X°. As a case of Move-α, standard conditions on movement apply to it. These include locality, structure preservation, and the requirement that movement leave a well-formed trace. The principal locality condition on head movement is the Head Movement Constraint (HMC), originally proposed by Travis (1984) and given informally in (1): (1)...

BACKGROUND Horses show compensatory head movement in hindlimb lameness and compensatory pelvis movement in forelimb lameness but little is known about the relationship of withers movement symmetry with head and pelvic asymmetry in horses with naturally occurring gait asymmetries. OBJECTIVES To document head, withers and pelvic movement asymmetry and timing differences in horses with naturally...

Caenorhabditis elegans is suitable for studying the nervous system, which controls behavior. C. elegans shows sinusoidal locomotion on an agar plate. The head moves not only sinusoidally but also more complexly, which reflects regulation of the head muscles by the nervous system. The head movement becomes more irregular with senescence. To date, the head movement complexity has not been quantit...

In his account of the mirror principle, Baker (1988) relies crucially on head (X) movement, to which he (compellingly) argues that the GF changing processes can be reduced. This move, along with the head movement constraint (Travis, 1984), allow Baker to account for the mirror principle. Head movement however, seems to have very different properties from phrasal (XP) movement. For example, head...