Having trouble remembering where you put the keys? Try your hippocampus, a structure in the brain that plays a key role in memory. The hippocampus is the research focus of Joseph Manns, Assistant Professor of Psychology, as he works at the intersection of psychology and neuroscience.

Memory that depends on the hippocampus is often referred to as declarative memory, and it involves everyday items of recollection, such as items and events that we consciously recall from the past - from the name of a grade school teacher to the color of a shirt worn yesterday. Declarative memory, says Manns, remains tied to individual self-understanding. "What we remember is what defines us. Memory is intimately tied into our sense of self," he says.

In his dissertation, Manns studied memory in persons who experience "organic" amnesia, a disorder that is often misunderstood. "Real amnesia is not about people getting whacked on their heads and then forgetting their past," he says. Rather, it involves localized damage to the hippocampus and a unique type of subsequent memory deficit: the loss of the ability to acquire and retain new information in the present. After completing his doctoral study and a postdoctoral fellowship, Manns received a "Pathway to Independence" grant from the National Institutes of Health, a unique opportunity for young researchers to obtain two forms of support from a single NIH award, the first during a period of mentored research, the second as an independent investigator.

Manns' current research seeks to explain the intricate processes of memory gathering and retrieval within the hippocampus. To begin with, most declarative memories remain context-specific or context-dependent. Our memory of a specific "item" - whether a conversation, an event, or a person - is almost always flavored with, and shaped by, peripheral stimuli that we come to associate with that item: the room in which a conversation takes place, for example, or the look and mood of a concert hall during a musical performance. The hippocampus appears to play an active role in gathering information both about the 'item' and this surrounding context. Not only does it separate out the two areas, but it also later retrieves them during the process of recollection; in doing so, it enables an association between disparate elements in order to form a conjunctive whole. Such memories are not camcorder recordings; they are vibrant and necessarily subjective associations that serve a variety of evolutionary purposes.

To better understand how and why this neurological activity takes place, Manns has turned to animals. Though rats do not possess declarative memory in the same sense as humans, they boast a hippocampus that is remarkably similar in structure to our own. "Rats cannot verbalize, and we're not sure what it means for a rat to 'bring to mind,' but we can make a strong connection between rats and human memory by way of their similar neuroanatomy where the hippocampus is concerned," he says. "The fundamental neuro-circuitry and physiological processes of this part of the brain are closely correlated." Accordingly, the Manns Laboratory will be using computer technology to track hippocampus activity in rats. He and his assistants will put their animals through memory-testing activities and measure the brain activity that follows as rats try to perform - that is, remember - correctly. "By recording many different neurons at a time, we're trying to 'eavesdrop' on a rat's memory," Manns explains. "We can't ask them to tell us what they remember, but we can bypass that barrier by looking in their brains to see what that activity is." Call it a study of "neural language," as Manns and his research team mines the data for clues about how memories are formed or laid down and later retrieved and recalled for new purposes.

Though the research remains in the early stages, Manns is excited about its potential contributions to scholarly understanding of the brain and neuroanatomy. "Neuroscience is still, if not in its infancy, then at least in its adolescence," he says. "There is still much about how the brain operates that we don't understand."

Manns has plans to expand his new laboratory upon the completion of the new psychology building in 2009. One division of the Manns Lab will continue to work with animal subjects; another will work with humans. Manns envisions himself as a potential bridge between researchers who work with humans and those immersed in animal studies. "Emory has become particularly strong in memory research on a number of levels," he says. "I hope to learn from those strengths and to help build connections between departments."

Next semester, Manns will teach "The Neurobiology of Memory" to graduate students. He will offer the same course in coming years to undergraduates. "I want to get students excited about the brain," he says. "I want them to grapple with the details, to try to decide what will make or break a study on memory." In the process, he hopes to cast new light on an enduring riddle: how memory shapes us, even as we shape and create our memories.