“Sensitive Periods in the Development of the Brain and Behavior.”

Department of Neurobiology, Stanford University School of Medicine, Sherman Fairchild Sciences Building, Stanfrord, CA 94305-5125, USA.
Journal of Cognitive Neuroscience (Impact Factor: 4.09). 11/2004; 16(8):1412-25. DOI: 10.1162/0898929042304796
Source: PubMed


Experience exerts a profound influence on the brain and, therefore, on behavior. When the effect of experience on the brain is particularly strong during a limited period in development, this period is referred to as a sensitive period. Such periods allow experience to instruct neural circuits to process or represent information in a way that is adaptive for the individual. When experience provides information that is essential for normal development and alters performance permanently, such sensitive periods are referred to as critical periods. Although sensitive periods are reflected in behavior, they are actually a property of neural circuits. Mechanisms of plasticity at the circuit level are discussed that have been shown to operate during sensitive periods. A hypothesis is proposed that experience during a sensitive period modifies the architecture of a circuit in fundamental ways, causing certain patterns of connectivity to become highly stable and, therefore, energetically preferred. Plasticity that occurs beyond the end of a sensitive period, which is substantial in many circuits, alters connectivity patterns within the architectural constraints established during the sensitive period. Preferences in a circuit that result from experience during sensitive periods are illustrated graphically as changes in a ''stability landscape,'' a metaphor that represents the relative contributions of genetic and experiential influences in shaping the information processing capabilities of a neural circuit. By understanding sensitive periods at the circuit level, as well as understanding the relationship between circuit properties and behavior, we gain a deeper insight into the critical role that experience plays in shaping the development of the brain and behavior.

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    • "It is important to note recent work suggesting that the brain retains the capacity to adapt and change throughout the lifespan (Keuroghlian & Knudsen, 2007). However, the foundation of brain architecture must lie in the early developmental years, and that the influence of childhood environment is much more salient in such basic cognitive processes as sensory perception (Amedi et al., 2007; Knudsen, 2004; Pascual-Leone et al., 2005). Each sensory and cognitive system reaches a unique sensitive period (Daw, 1997), and thus identical environmental conditions will result in very different cognitive and emotional experiences for a child, depending upon his or her age (Amedi et al., 2007; Trachtenberg & Stryker, 2001; Tritsch, Yi, Gale, Glowatski, & Bergles, 2007). "
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    ABSTRACT: Early life events can exert a powerful influence on both the pattern of brain architecture and behavioral development. The paper examines the nature of nervous system plasticity, the nature of functional con-nectivities in the nervous system, and the application of connectography to better understand the concept of a functional neurology that can shed light on approaches to instruction in preschool and primary education. The paper also examines the genetic underpinnings of brain development such as synaptogenesis, plasticity, and critical periods as they relate to numerosity, language and perceptual development. Discussed is how the child's environment in school and home interact with and modify the structures and functions of the developing brain. The role of experience for the child is to both maintain and expand the child's early wiring diagram necessary for effective cognitive as well as neurological development beyond early childhood. Los primeros acontecimientos vitales pueden ejercer una enorme influencia tanto en el patrón de arqui-tectura cerebral como en el desarrollo del comportamiento. En este trabajo exploraremos la naturaleza de la plasticidad del sistema nervioso, la naturaleza de sus conexiones funcionales y la aplicación de la tractografía, para lograr una mejor explicación del concepto de neurología funcional que pueda arrojar luz sobre las teorías de la instrucción en la enseñanza preescolar y primaria. El trabajo analiza también los fundamentos genéticos del desarrollo del cerebro tales como la sinaptogénesis, la plasticidad y los periodos críticos en lo que respecta a su relación con el desarrollo numérico, lingüístico y perceptivo. Se aborda cómo interactúa el entorno del niño en la escuela y en casa con las estructuras y funciones del cerebro en desarrollo y las modifica. El papel de la experiencia temprana será tanto mantener como expandir los circuitos neurales necesarios para un desarrollo efectivo (tanto cognitivo como neurológico) más allá de la temprana infancia.
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    • "Additionally, focusing this study on the visual modality alone allows us to eventually examine whether SCAP in mate preferences is limited to visual signals only or both visual and vibratory signals. Second, studies on imprinting have emphasized a " sensitive period " (Lorenz 1935; Bateson 1979; Knudsen 2004) during which the development of mating behaviors occurs at an early life stage. The sensitive period has been strongly studied in songbirds, in the framework of sexual imprinting and song learning. "
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    ABSTRACT: Females often prefer males with bright, showy, or large secondary sexual characters. However, social experience can result in variation in female preferences, with evidence of sexual imprinting in some taxa. In the brush-legged wolf spider, Schizocosa ocreata, asynchrony of maturation provides a time period in which imprinting may occur. We tested whether adult females demonstrated plasticity in their visual preferences for male leg tuft size after experience with digitally courting males during their penultimate stage. Penultimate instar females were presented visual courtship signals from males with small, average, or large tufts; a mixture of tuft sizes; or no males at all. During Week 2 of adulthood, each female was presented playback of digital courting small- and/or large-tufted males in both no-choice and two-choice presentations. Adult female preferences varied significantly with prior experience. Females exposed to only large-tufted males or males with a mixture of tuft sizes demonstrated more receptivity displays to large-tufted males than small-tufted males. Females exposed to only small-tufted males demonstrated more receptivity displays toward small-tufted males than large-tufted males. Because results suggested the possibility of sexual imprinting, we tested for reversibility. A subset of females was retested for selectivity in two-choice trials, revealing a positive correlation between Week 2 and Week 5 female selectivity. Females previously exposed to small-tufted males, however, no longer maintained their preference for small-tufted males in Week 5. This study demonstrates the effects of an individual’s social environment on mating preferences, and the importance of age and timing when studying sexual imprinting.
    Behavioral Ecology 09/2015; DOI:10.1093/beheco/arv143 · 3.18 Impact Factor
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    • "Sensitive periods are properties of emerging neural circuitries (Knudsen, 2004) and have mostly been investigated in animal research using a visual deprivation approach (see pioneer work of Wiesel & Hubel, 1965). In humans only few models exist that allow for a systematic investigation of the time course and neural mechanisms of sensitive periods: such opportunities arise for example, when the re-afferentation of a deprived modality is possible. "
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    ABSTRACT: Naturally occurring sensory deprivation in humans provides a unique opportunity to identify sensitive phases for the development of neuro-cognitive functions. Patients who had experienced a transient period of congenital visual deprivation due to bilateral dense cataracts (congenital cataract, cc) have shown, after visual re-afferentation, deficits in a number of higher visual functions including global motion and face processing. By contrast, biological motion (BM) perception seemed to be spared. The present study investigated the neural correlates of BM processing in a sample of 12 congenital cataract-reversal individuals who had underwent visual restoration surgery at the age of a few months up to several years. The individual threshold for extracting BM from noise was assessed in a behavioral task while event-related potentials (ERPs) were recorded in response to point-light displays of a walking man and of a scrambled version of the same stimuli. The threshold of the cc group at detecting BM did not differ from that of a group of matched controls (mc). In both groups, the N1 was modulated by BM. These largely unimpaired neural responses to BM stimuli together with a lack of behavioral group differences suggest that, in contrast to the neural systems for faces the neural systems for BM processing specialize independent of early visual input. Copyright © 2015. Published by Elsevier Ltd.
    Cortex 08/2015; 71. DOI:10.1016/j.cortex.2015.07.029 · 5.13 Impact Factor
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