COGNITIVE
SCIENCE
17
What’s A
Brain?
Part 2
Jaime A. Pineda, Ph.D.
Brain Quiz
• What did the right hemisphere say to the left hemisphere when
they could not agree on anything?
– “Let’s split”
• What do you call a group of brains that form a singing group in
school?
– A glia club
• What do you get when you cross a thought with a light?
– A bright idea
• What is the brain’s favorite television channel?
– The Neural Network
• What do neurons use to talk to each other?
– Cell-ular phones
• What did the Hollywood director say after making a movie about
myelin?
– “That’s a wrap”
Principles of Brain Organization
• Subdivided into 3 primary
and 5 secondary regions
– Forebrain
• Telencephalon (endbrain)
• Diencephalon (interbrain)
– Midbrain
• Mesencephalon
– Hindbrain
• Metencephalon
• Myelencephalon
Neural plate > neural tube
Principles (cont.)
• Brain contains an
interconnected system
of ventricles
Principles (cont.)
Brain contains a protective covering (meninges)
Cerebral
Spinal
Fluid (CSF)
Hydrocephalus
Principles (cont.)
• Brain is composed of two
hemispheres connected by
a set of fibers (corpus
callosum)
• 200-250 million fibers
• Monotremes and
marsupials do not have a
corpus callosum
• Agenesis and split brain
patients
Principles (cont.)
• Cortex is subdivided
into four major
external lobes (plus
the internal limbic
lobe)
Limbic lobe
Found only in the
medial view of the
brain.
Its major responsibilities
include olfaction and
emotions
Principles (cont.)
• Cortex is subdivided into areas of
specialized function
Principles (cont.)
• Some areas of cortex
(primarily sensory
and motor areas) are
topographically
mapped.
V1 (retinotopic)
A1 (tonotopic)
M1 (mototopic)
S1 (somatotopic)
Anterior-Posterior Organization
Dorsal-Ventral Organization
Left-Right Organization