Large lateral head movements and postural control

We investigated whether there is a trade-off between magnitude of perceived depth and that of perceived motion, using density changes (expansion/contraction) in a random-dot pattern yoked to lateral head movements. We simulated sine-wave surfaces with a depth of 0, 1, 2, 4, 8, and 16 cm. Subjects viewed the patterns monocularly while moving their heads from side to side laterally, and reported the magnitude of perceived depth and that of perceived motion. When simulated depth was less than 4 cm, the surfaces looked stationary and the amount of perceived depth was the same as that of simulated depth. When it was more than 4 cm, the surfaces appeared to move in a rocking motion and the amount of perceived depth was smaller than that of simulated depth. The trade-off implies a mechanism which transduces single visual input into depth or motion.

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Lateral Head Movements as a Sign of Tricuspid Insufficiency

Cardiology ◽

10.1159/000169169 ◽

1967 ◽

Vol 50 (3) ◽

pp. 140-146 ◽

Cited By ~ 1

Author(s):

A.A. Luisada ◽

S. Wissner ◽

P.D. Gupta

Keyword(s):

Head Movements ◽

Tricuspid Insufficiency ◽

Lateral Head

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Apparent motion of monocular stimuli in different depth planes with lateral head movements

Vision Research ◽

10.1016/j.visres.2007.01.012 ◽

2007 ◽

Vol 47 (8) ◽

pp. 1027-1035 ◽

Cited By ~ 5

Author(s):

K. Shimono ◽

W.J. Tam ◽

H. Ono

Keyword(s):

Apparent Motion ◽

Head Movements ◽

Lateral Head

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A multivariate clustering approach to display repertoire analysis: headbobbing in Anolis equestris

Amphibia-Reptilia ◽

10.1163/156853889x00476 ◽

1989 ◽

Vol 10 (3) ◽

pp. 331-344 ◽

Cited By ~ 9

Author(s):

Matthew Kramer ◽

Enrique Font

Keyword(s):

Unbiased Estimate ◽

Head Movements ◽

Repertoire Size ◽

Motor Patterns ◽

Repertoire Analysis ◽

Long Duration ◽

Threat Displays ◽

Clustering Approach ◽

Multivariate Clustering ◽

Lateral Head

AbstractDisplay repertoire analysis requires and unbiased estimate of the number of different displays. Anolis lizards, with easily quantifiable visual displays, provide a system amenable to determining display repertoire size. We used multivariate clustering techniques to classify Anolis equastris headbobbing displays. Forty displays, to conspecifics and mirrors, were graphed and 23 variables from each were used in a cluster analysis. Displays were classified into four distinct groups and a single odd display. The most important variables for classifying displays, assessed with a stepwide discriminant analysis, were associated with the general cadence, number of headbobs, and location of large and small headbobs. Most headbobbing displays ended in lateral head movements, possibly arising from ritualized mouth-wiping. All displays analyzed were apparently aggressive ("threat") displays, suggesting a rich display repertoire for this species but leaving unexplained the reasons so many display types are used. Social and defensive displays, while sharing a number of motor patterns, are readily distinguished by the long duration of dewlap extension and gaping in defensive behavior.

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The effect of voluntary head movements on postural kinetics in the standing cat

PeerJ ◽

10.7717/peerj.8186 ◽

2019 ◽

Vol 7 ◽

pp. e8186

Author(s):

Yang Song ◽

Meizi Wang ◽

Julien Steven Baker ◽

Yaodong Gu

Keyword(s):

Kinetic Parameters ◽

Contact Area ◽

Peak Pressure ◽

Head Position ◽

Head Movements ◽

Whole Body ◽

Postural Adjustment ◽

Vestibular Loss ◽

The Right ◽

Lateral Head

Background Although the postural instability accompanying bilateral vestibular loss in human and quadrupeds during lateral head movements are well-known, it is still unclear whether or not lateral head turns would indeed activate the postural control system to maintain balance. This study aimed to examine the kinetic parameters in freely standing intact cats during head movements in order to further answer the above question. Methods Six intact cats were trained to stand, unrestrained on a force plate and perform voluntary head movements to the left and right positions in response to visual cues. Each trial was divided into two phases, quiet standing with the cat’s head maintaining a straight forward and lateral head position after voluntary head movements. Kinetic parameters including peak pressure and contact area under each limb as well as center of pressure (COP) displacements of the whole body were measured. Results Compared to the neutral head position, peak pressure and contact area of the left head position were significantly smaller for the left forelimb while greatly larger for the right forelimb. An exact opposite case of peak pressure and contact area in the forelimbs was found between the right and neutral head positions. In addition, the COP displacements altered oppositely to the head movements, and presented a significantly right shift in the left position and a significantly left shift in the right position. Conclusion These results demonstrate that the lateral displacement of the head in standing intact cats does activate the postural adjustment to maintain balance, which is consistent with the concept that vestibular input can contribute to postural balance during voluntary head turns.

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