Whose Brain is THAT?!

(adapted from lesson created by Orriana Sill, Cornell University)

Channa Comer

Urban Assembly Academy of History & Citizenship for Young Men, Bronx

Summer Research Program for Science Teachers

August 2010

Introduction

This lesson plan is designed to be an introductory activity to engage students and allow them to explore, compare and contrast the brains of different animals. The notes at the end of the lesson can be used to for discussion, questions, and/or to create assessments. This lesson calls for actual brains preserved in jars of formaldehyde. I have also included resources for alternatives to real brains. If you’d like to give feedback on the lesson, please email mscomer36@yahoo.com.

Objectives:

·         Making observations about gross brain structures in three dimensions.

·         Comparing and contrasting the human brain with the brains of other animals.

•  If the brain is bigger proportion of the body, (or actually proportional to the body), the animal generally has a greater capacity to learn and perform behaviors.

• Carnivores generally have bigger brains than herbivores. Why? (Digestion competes with brain growth for energy. Digestion of meat takes less energy which is why carnivores’ brains are larger).

• Proportion of the different parts of the brain determine what the animal is capable of.

• Three main parts of the brain

  • Forebrain (cortex and dicencephalon)

    • Forebrain - In the front, used to do non-instinctual things.

      -          If the animal loses this part of the brain, it can usually recover using other neurons in this part of the brain. The earlier in brain development the damage happens, the easier it is for the brain to recover.

      ~   Human brain develops until your late teens/early 20’s

      You can be born with only half a forebrain, and still have normal intelligence

    • Cortex - Top layer of the forebrain.

      -          Animals that have a lot of cortex can learn many more things after they are born than animals with just a little cortex. Animals with lots of cortex (like humans) have lots of bumps called gyri and valleys sulci, because the cortex has a greater surface area.

      ~   Number of layers of cortex and amount of wrinkles indicate intelligence.

      ~   Animals with high intelligence - humans, dolphins, cats, dogs, pigs.

      ~  Animals with very little cortex – fish, amphibians, rabbits.

      • Diencephalon - under the cortex in the forebrain.

        Plays large role in memory, navigation, hormones and emotions.
  • Midbrain
    • Instinctual behaviors (tracking objects with our eyes, moving our head to track sound, etc.).

      §  Animals with smaller forebrains/cortex will use midbrain for more behaviors (i.e., frogs use it for things like eating and avoiding prey).

      §  If an animal has damage here, it can still live, but there will be behaviors that it can’t perform and can’t recover.

      §  A horse is born able to stand, but we aren’t because it has a larger midbrain than forebrain – they need to be able to run away from predators as soon as they are born.

    o   Hindbrain (brainstem and cerebellum)

    • Brainstem - Handles very important life functions (heart rate, breathing, wakefulness, etc.).

    • If an animal has damage here, they will probably die very soon.

    • Cerebellum - Handles things that we learn (and use the cortex to learn) that become so automatic that it no longer needs the cortex to process consciously (walking, driving, riding a bicycle, typing on a keyboard, etc.).