Neurodevelopment: Deprivation and Enrichment

• Most research on the effects of experience on the development of the brain has focused on sensory and motor systems—which lend themselves to experiential manipulation.
• Early research focused on two general manipulations of experience:sensory deprivation and enrichment.
• An important feature of the effects of experience on development is that they are time-dependent: The effect of a given experience on development depends on when it occurs during development
• Experience have become more selective. Many of these selective manipulations of early experience have revealed a competitive aspect to the effects of experience on neurodevelopment.
• Depriving one eye of input for a few days early in life has a lasting adverse effect on vision in the deprived eye, but this does not happen if the other eye is also blindfolded.
• Vertebrate brains formed all their neurons in embryological development or early infancy at the latest. Beyond that point, neurons could modify their shape, but the brain could not develop new neurons.
• Neuroplasticity was once thought to be restricted to the developmental period.
• Mature brains were considered to be set in their ways, incapable of substantial reorganization.
• Now, the accumulation of evidence has made clear that mature brains are continually changing and adapting.
• Reports of adult neurogenesis were not embraced by a generation of neuroscientists who had been trained to think of the adult brain as fixed
• In adult humans, neurogenesis has been observed in the striatum and in the hippocampus, but not in the olfactory bulbs.
• Within the striatum, there are two main divisions, the dorsal striatum, and the ventral striatum.
• The dorsal striatum is primarily involved in control over conscious motor movements and executive functions.
• Hippocampus is a complex brain structure embedded deep into temporal lobe. It has a major role in learning and memory.
• Now established that neurons generated during adulthood survive, become integrated into neural circuits, and begin to conduct neural signals.
• Most research on the function of adult-generated neurons has focused on the hippocampus.
• Some researchers have proposed a role for these new hippocampal neurons in memory function, including forgetting.
• One currently popular theory is that adult hippocampal neurogenesis is important for pattern separation: pattern separation refers to our ability to separate distinct percepts into individual memories for storage.
• It was also proposed that adult hippocampal neurogenesis serves a role in mood and anxiety regulation.
• Freund et al. (2013) took a naturalistic approach to studying the role of adult hippocampal neurogenesis: They monitored the exploratory behavior of a large number of genetically identical mice in a complex enriched environment over the course of 3 months. Variations increased.
• A role of adult hippocampal neurogenesis might be to allow us to adapt to complex environments.
• Experience in adulthood can lead to the reorganization of sensory and motor cortical map.
• Adult musicians who play stringed instruments that are fingered with the left hand (e.g., the violin) have an enlarged hand-representation area in their right somatosensory cortex.
• Adult neuroplasticity warrants special attention because it demonstrates an important aspect of this plasticity.
• Autism spectrum disorder (ASD) - is a complex neurodevelopmental disorder. Almost always apparent before the age of 3 (1) a reduced capacity for social interaction and communication and (2) restricted and repetitive patterns of behavior, interests, or activities.
• Intensive behavioral therapy can improve the lives of some individuals
• ASD is a heterogeneous in the sense that affected individuals may be severely impaired in some respects but may be typical, or even superior, in others.
• ASD savants are persons with developmental disabilities who nevertheless display amazing and specific cognitive or artistic abilities.
• William's syndrome like is a neurodevelopmental disorder associated with intellectual disability and with a heterogeneous pattern of abilitiesand disabilities
• Williams - sociable, empathic, talkative