Olfaction the amygdala and is involved in emotional and autonomic responses to odor. It also projects to the hippocampus and is involved in motivation and memory. Odor information is stored in long-term memory and has strong connections to emotional memory. This is possibly due to the olfactory system's close anatomical ties to the limbic system and hippocampus, areas of the brain that have long been known to be involved in emotion and place memory, respectively. Since any one receptor is responsive to various odorants, and there is a great deal of convergence at the level of the olfactory bulb, it may
Short-term memory for words from earlier in the list (it is presumed, stored in long-term memory) unaffected; other manipulations (e.g., semantic similarity of the words) affect only memory for earlier list words, but do not affect memory for the last few words in a list. These results show that different factors affect short-term recall (disruption of rehearsal) and long-term recall (semantic similarity). Together, these findings show that long-term memory and short-term memory can vary independently of each other. Not all researchers agree that short-term and long-term memory are separate systems. Some theorists propose that memory is unitary over all time scales, from