Which part of the brain is most involved in processing smell?

The olfactory bulb is the primary region in the brain responsible for processing smell. Located at the base of the brain, it receives sensory input from the olfactory receptor neurons in the nasal cavity. When we breathe in molecules from our environment, these molecules bind to the receptors on the olfactory sensory neurons, which then send signals directly to the olfactory bulb.

Once the olfactory bulb processes these signals, it relays information to other parts of the brain, including areas involved in memory and emotion such as the hippocampus and the amygdala. This direct pathway to the olfactory bulb bypasses the thalamus, which is typically a relay station for other sensory inputs. The specificity and unique processing capabilities of the olfactory bulb make it essential for our sense of smell, differentiating it from areas like the cerebellum, which is largely responsible for motor control, and the thalamus, which is not primarily involved in olfactory sensory processing.