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In this study, we examined electromyographic activity for an ensemble of hindlimb muscles during spontaneous activity in chick embryos to advance understanding of early motor coordination and its relationship to later emerging behaviors. Four-channel recordings were obtained from 6 muscles in ovo at embryonic Days 9 and 10. Analyses indicated that when(More)
The chick's relationship to its environment changes dramatically over 21 days of embryonic development. At early ages embryos are buoyant; their posture and movements are relatively unconstrained. As embryos grow and fluid level in ovo decreases, movements are increasingly constrained by gravitational forces and reactive forces due to body contact with the(More)
Based on studies using direct observation methods, type I motility, the first motility pattern to emerge in chick embryos, is characterized as random, uncoordinated movement. Yet, electromyographic (EMG) studies indicate that leg muscles are recruited in orderly patterns of alternating flexor and extensor activity during type I motility. It has been(More)
From birth to postnatal day 60, neuromuscular patterns for airstepping and treadmill stepping were assessed in kittens spinalized (T12) at birth (Day-1) or at the end of the second postnatal week (Day-14). Within 72 h after spinalization, all kittens displayed stepping motions, but exteroceptive facilitation (e.g. tail pinch) was required to initiate and(More)
This paper presents ILGM (the Infant Learning to Grasp Model), the first computational model of infant grasp learning that is constrained by the infant motor development literature. By grasp learning we mean learning how to make motor plans in response to sensory stimuli such that open-loop execution of the plan leads to a successful grasp. The open-loop(More)
It has long been known that the chick initiates spontaneous motility early in embryogenesis, that the distribution of this activity is episodic, and that it varies both quantitatively and qualitatively with age. It is also well established that embryonic motility is controlled by spinal circuits and features of motility at early stages of development are(More)
Neuromuscular patterns associated with the development of hindlimb stepping behaviors were studied from birth to postnatal day 60 in normal kittens. Hindlimb muscles were chronically implanted with EMG electrodes at birth to characterize interlimb coordination and intralimb synergies during development of overground and treadmill stepping. Airstepping was(More)
Tactile placing and associated responses of the fore and hind paws to a light tactile stimulus were studied in normal young-adult cats and kittens and their spinal littermates. All spinal transections were performed at T12 on the 14th postnatal day. In the first study, responses of normal and spinal young-adult cats were compared at 9 to 10 months of age.(More)
Over the course of embryonic development, chick embryos express 3 different types of motility (I, II, III). Although neural pattern generators appear to control embryonic motility, the mechanisms responsible for the sequential emergence and/or transformations in these behaviors are not known. Given the early presence of functional sensory connections and(More)
Spinal neural circuits can recruit muscles to produce organized patterns of activity early in embryonic development. In a previous study, using multichannel electromyographic (EMG) recordings, we characterized burst parameters for these patterns in the legs of chick embryos during spontaneous motility in ovo at embryonic days (E) 9 and E10 (Bradley and(More)