1. University Studies 15A: Consciousness I
Brains

2. Brains: More than we can hope to learn
Brain Details: What and Why?
“Why” will lead us to ‘What”
We want to know about consciousness as the quality of first-person experience of the world.
We want to know about the “I think,” “I see,” “I feel.”
“What” we want to know about in the brain is what is important for the creation of this first-person quality.

3. Some aspects of the brain will not matter that much:
The actual biochemistry of neuronal firing
The actual biology of “long-term potentiation”
We will need to know some of the basics of brain structure (i.e. neuroanatomy)
We will need to know some of the basics of functional organization (covered in greater detail in later lectures)
Today we start with the basics of brain structure

4. A Final Point about Actual Neurons:
Note the myelin sheath surrounding the axon.
These glial cells are basically fat. They serve to insulate the axon and make its electrical transmission more efficient.
Neurons that have acquired the myelin sheath form the “white matter” of the brain.

5. Although as “species-ists,” we are most interested in the human brain, some perspective is useful.

6. Brain Parts: the Early Version
Brain Stem:
Much nervous system housekeeping (breathing, heart beat) Connects the spinal cord to the brain
Cerebellum:
Muscle control
Olfactory bulb & Optic Lobe:
Brain hardware devoted to handling smell and sight

7. For Humans, same basics + expanded cortex:
Let’s follow Baar’s and Gage’s approach and build from the brainstem up.

8. The Brainstem, Pons, and Thalami:
thalamus
Pons

9. The Brainstem, Pons, Thalami, Hippocampi, and Amygdalas:
hippocampus
amygdala

10. Brainstem, Pons, Thalami, Hippocampi, Amygdalas, and Everything Else:
White Matter
Basal ganglia
Cortex
Cerebellum
The basic human brain

11. Another Drawing of the Same Structures + Reticular Formation

12. In humans, the cortex grows somewhat slowly:

13. More crucial for us are two other aspects of maturation:
Dendritic Arborization: the creation of new dendrites
Myelination: the covering of the axons with myelin

14. The Neocortex is a made of six layers of cells which grows in an “inside-out” pattern.

15. The Neocortex is a made of six layers of cells which grows in an “inside-out” pattern starting with Layer 6.
Layer 1: Not many actual cells Mainly dendrites from cells in other layers to allow dense horizontal connections
Layers 2 - 3: Horizontal connections (like Layer 1) Axons leading to cells in Layers 4-6
Layer 4: Most input (axons from White Matter) end here Mainly dendrites from cells in other layers
Layers 5-6: Output neurons to other areas of brain

16. Terms you might as well learn: Dorsal: Up Ventral: Down Lateral:
The Cortex
Central Sulcus
Terms you might as well learn:
Dorsal: Up
Ventral:
Down
Lateral:
On the side
Medial:
In the middle
The Four Lobes:
Sylvian (Lateral) Fissure
Occipital Lobe
Two Major Lines:
Parietal Lobe
Central Sulcus
Temporal Lobe
Sylvian (Lateral) Fissure
Frontal Lobe

17. Functional Organization of the Cortex
Motor Cortex
Primary Somatosensory Cortex
Premotor Cortex
Somatosensory Association Areas
Visual Association Areas
Prefrontal Cortex
Primary Visual Cortex
Auditory Cortex

18. On the Two Sides of the Central Sulcus
In front of the central sulcus, the motor cortex
Behind the central sulcus, the primary somatosensory cortex

19. “White Matter” Fiber Pathways
(Back of the Brain to the Left)

20. One Last Neuroanatomical Slide: The Medial Temporal Lobe Structures
Limbic Cortex (Paleocortex) goes with Limbic System

21. One Last Neuroanatomical Slide (Really): The Medial Temporal Lobe Structures
Anterior Cingulate cortex
Parahippocampal cortex