L5 - Lecture 5 Experience Dependent Refinement of Neural...

Info icon This preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 5: Experience Dependent Refinement of Neural Connections in CNS (outline) I. Critical periods. II. Visual deprivation and ocular dominance plasticity. III. Hebb’s law and cellular mechanisms for activity- dependent plasticity. Required reading: Purves et al. Ch24 Supplemental reading: Bear et al. Ch23 (p709-716)
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Lecture 5: Experience Dependent Refinement of Neural Connections in CNS (outline) I. Critical periods.
Image of page 2
Critical Periods: -- temporal windows when environmental factors play critical role in influencing the development of the nervous system . Example 1: parental imprinting in birds. Konrad Lorenz and his geese. Goslings follow the first large, moving object they see and hear during their first day of life . Cues could be visual/auditory, as well as olfactory/gustatory.
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Critical Periods: -- temporal windows when environmental factors play critical role in influencing the development of the nervous system . Example 1: parental imprinting in birds. Example 2: bird song. -- Three stages of song learning: Sensory acquisition: juvenile birds listen to and memorized the song of its adult tutor. Vocal learning: juvenile birds matches its own song to memorized tutor model via auditory feed back. Song stabilization. -- Some species (eg. zebra finches): song learning is limited to a time period - critical period. Other species (eg. canaries) can develop new songs even as sexually mature adults.
Image of page 4
Critical Periods: -- temporal windows when environmental factors play critical role in influencing the development of the nervous system . Example 1: parental imprinting in birds. Example 2: bird song. Example 3: language development in human. Fluency in language decrease with age
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 6
Critical Periods: -- Temporal windows when environmental factors play critical role in influencing the development of the nervous system . Example 1: parental imprinting in birds. Example 2: language development in human. Example 3: bird song sensory motor learning. -- Conclusion: Young brain is very dynamic and responsive to experience. As animals get older, the brain becomes increasingly refractory to the lessons of experience. -- Two possible mechanisms involved in experience dependent plasticity: 1) experience promote the growth of rudimentary circuitry; 2) unused circuits are weakened and eliminated.
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Lecture 5: Experience Dependent Refinement of Neural Connections in CNS (outline) I. Critical periods. II. Visual deprivation and ocular dominance plasticity.
Image of page 8
Plasticity and critical period in visual cortex Why visual system: amenable to experimental manipulations. David Hubel and Torsten Wiesel: Deprivation animals of normal visual experience during a restricted period ( critical period ) of early postnatal life irreversibly alters neuronal connections and functions (eg. ocular dominance) in the visual cortex. 1981 Nobel Prize
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Ocular dominance columns in visual cortex Visual pathways: Retina -> (some optic nerves cross at optic chiasm) -> LGN -> (optic radiation) -> primary visual cortex (V1, striate cortex) -> V2 -> where/what pathways In humans and most primates, inputs from the left and right eyes remain
Image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern