摘要:

AbstractThe development of coordination of leg movements of human infants is discussed from the perspective of dynamic motor theory. Even in the newborn period, leg movements have topographical and temporal organization, but it is global and inflexible. During the first year, limb segments become both disassociated from these global synergies and reintegrated into more complex coalitions. Growthrelated changes in the biodynamic properties of the body segments may be as important as neurological maturation in determining the movement outcomes and may help explain the spurts, regressions, and asymmetries seen in early infancy.

ISSN:0012-1630    

DOI:10.1002/dev.420180102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe interaction between natural visual and auditory stimulation in the control of filial behavior was studied in domestic mallard (Peking) ducklings during the first 3 days of postnatal life. Visual imprinting at 24 hr resulted in a visual preference for the familiar model over an unfamiliar model in each of two choice tests, one at 48 hr and one at 72 hr, but only if both models were silent. If both models emitted a recording of the mallard maternal call, the visual preference was found only in the later (72‐hr) test. Visuomotor experience between training and testing was found to be essential for the development of the visual preference at 72 hr, but the required experience was of a very general nature. Either a choice test with silent models or a period of social rearing (between 24 and 72 hr) provided effective experience. Thus, the ability to show a visual preference in the presence of the maternal call at 72 hr depends on experience, but not necessarily on further exposure to the imprinting object or to any specific aspects of the test situation. These results demonstrate the importance of normal visual, motor and/or social experience to the development of the visual control of filial behavior in duckling

ISSN:0012-1630    

DOI:10.1002/dev.420180103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe tadpoles ofRana pipiens, unlike those of other frogs that have been reported on, do not develop clear‐cut perceptual preferences for familiar background patterns composed of either squares or stripes. When larvae reared on white and/or patterned backgrounds are tested for preference between these backgrounds, they all exhibited a preference for white backgrounds. When the larvae were tested for preference among uniform backgrounds of varying brightness, those reared on the two brighter backgrounds showed no preference, and those reared on the two darker backgrounds preferred the brightest of the available backgrounds. The larvae ofR. pipiensbehave as if they possess an experientially modifiable defense reaction such that, when frightened, they move preferentially onto brighter backgrounds and avoid boldly patterned backgrounds. A pattern may be less aversive if it is familiar than if it is unfamiliar. Larvae from South Dakota tended to habituate more effectively to striped backgrounds, and those from Wisconsin to backgrounds composed of square

ISSN:0012-1630    

DOI:10.1002/dev.420180104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractPregnant rat dams and offspring were exposed to a 5 or 2% soy lecithin preparation or a control diet. Enrichment was either lifelong beginning at gestation, limited to the time preceding, or the time following weaning, or absent (constituting a “pure” control group). The most marked early sensorimotor deficits (reflex righting and swimming development) were seen in the 5% soy lecithin preparation group, although all soy lecithin preparation‐exposed offspring had elevated brain/body weight ratios and choline acetyltransferase levels. Later, animals exposed to lifelong 5 or 2% soy lecithin preparations were hypoactive, had poor postural reflexes, and showed attenuated morphine analgesia. The results indicate that dietary soy lecithin preparation enrichment during development leads to behavioral and neurochemical abnormalities in the exposed offs

ISSN:0012-1630    

DOI:10.1002/dev.420180105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractTaste reactivity in suckling rat pups was assessed. Five‐day‐old rats in Experiment I were equipped with tongue cannulae seated 2 mm rostral, 0–3 mm caudal, or 4–6 mm caudal to the intermolar eminence. Either water, 1.4 × 10−3QHC1, .50MNH4Cl, or .43MNaCl was delivered in one of three fashions during suckling: (1) continous: fluid was continuously available from a reservoir connected to the cannula, and could be obtained by exerting suction; (2) discrete: same procedure as above, save that fluid was available for only 30 sec every 3 min of the 30‐min test; (3) pulsatile: here, .05 ml fluid was delivered by infusion pump 8–10 sec every 3 min, provided the pups were attached to a nipple. Based on intake, time and behavioral measures, we conclude behavioral reactivity exists especially to NH4Cl and NaCl. As to quinine, Day 5 pups were responsive only when QHCl was delivered in the continuous mode. In Experiment II, rats 10, 15, and 20 days of age received the above solutions by infusions with the cannulae located in one of the three positions. Quinine reactivity developed sequentially in an anterior to posterior direction. NH4Cl disrupted behavior in 5‐, 10‐, and especilly 20‐day‐old rats. Remarkably, Day 15 rats were not behaviorally reactive to NH4Cl. Sodium chloride, especially in the anterior and middle positions, was treated as an aversive solution during suckling throughout development. Based on existing electrophysiological data, the last

ISSN:0012-1630    

DOI:10.1002/dev.420180106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420180101

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY