An introduction to the brain

A quick overview of the brain

Two Hemispheres
Four major lobes
Cerebellum (Little Brain) coordination
Brain stem
Spinal cord


See Chudler[Chudler15:_brain_facts_figures] for more information

Note, Cerebellum innervates ipsilaterally whereas the cortex works contralaterally.

Sensory Motor cortex

Penfield's Homunculus shows a strong mapping from brain regions to the body, however sensory motor actions utilise many other regions of the brain, for example the cerebellum is clearly involved although it is still not clear how.

Visual cortex

Area function
LGNLateral geniculate nucleus Connects optic nerve to VA
IT Inferior temporal cortex Object recognition
IPLInferior parietal lobule Interpretation of facial emotions
SPLSuperior parietal lobule Orientation (connected to hand)
MSPMedial superior temporal areaOptic flow ?
VA Visual area object colour, shape etc

Flow of information

Retinal data, primarily from the fovea, travels down the optic nerve, through the optic chiasm to the Lateral geniculate nucleus. LGN transmits the information on to the primary visual area V1, and gets feedback from the visual cortex,

V2 and V2 seem to do an initial process of the visual data and then trasmit information on in two streams.

Ventral stream (what)

V1 V2 V4 V8 IT (this stream is heading towards the language areas of the brain)

Dorsal stream (where)

V1 V2 V3 V7 (this stream is heading to sensory motor areas of the brain).


[Chudler15:_brain_facts_figures] Eric Chudler, Brain Facts and Figures last checked Nov 2015