I found this info:
Does anything about this system strike you as odd? The olfactory system disobeys a general rule of sensory systems - it does not have to pass through thalamus before reaching cortex. However, there is a very good reason why not; olfactory cortex is an old and primitive structure, and in fact has only four cellular layers, unlike the 6-layered cortex we are accustomed to. The rule that sensory information must pass through thalamus to get to cerebral cortex is still true, but only for 6-layered cortex, or neocortex. This description applies to almost every area in the frontal, parietal, occipital, and temporal lobes.
It also seems like the olfactory bulb does a lot of the processing and sends sensory info directly to the olfactory cortex.
The sense of smell can bypass the thalamus, it is only secondarily sent through it when you are analyzing or comparing it to other smells.
The sense of smell can bypass the thalamus, it is only secondarily sent through it when you are analyzing or comparing it to other smells.
smell
Smell
A person's sense of smell does not first need to be processed by the Thalamus before entering the Cortex. This is often times why a smell can cause a memory recall faster than other kinds of sensory input.
The sense of smell is directed through the limbic system without passing through the thalamus first.
Its smell Information goes to olfactory cortex of the frontal lobe without going through the thalamus. Its the only major sense that does not go through the thalamus
Thalamus
The sense of Olfaction or smell. Unlike the rest of the senses which are routed through the thalamus, olfaction goes through the olfactory cortex in the temporal lobe and to the limbic system which is associated with memory. That is the reason smell is strongly associated with emotion is due to it's ties to the limbic system. Source; http://en.wikipedia.org/wiki/Olfaction
Thalamus
Thalamus
thalamus (novanet)