Noninvasive Functional and Anatomical Imaging of the Human Medial Temporal Lobe

Abstract

The ability to remember life's events, and to leverage memory to guide behavior, defines who we are and is critical for everyday functioning. The neural mechanisms supporting such mnemonic experiences are multiprocess and multinetwork in nature, which creates challenges for studying them in humans and animals. Advances in noninvasive neuroimaging techniques have enabled the investigation of how specific neural structures and networks contribute to human memory at its many cognitive and mechanistic levels. In this review, we discuss how functional and anatomical imaging has provided novel insights into the types of information represented in, and the computations performed by, specific medial temporal lobe (MTL) regions, and we consider how interactions between the MTL and other cortical and subcortical structures influence what we learn and remember. By leveraging imaging, researchers have markedly advanced understanding of how the MTL subserves declarative memory and enables navigation of our physical and mental worlds.O ne of the central aims of cognitive neuroscience research is to understand how human brain function relates to the mnemonic experiences that define much of who we are as individuals. Recent advances in noninvasive human neuroimaging have given rise to novel insights about the neural foundations of human memory, and have allowed neuroscientists to draw important connections between human and nonhuman animal research. Although noninvasive imaging techniques remain limited in their spatial resolution (we cannot yet describe the behavior of individual neurons in the human brain without implanting electrodes in patients undergoing brain surgery), they also have important strengths that have allowed researchers to significantly advance mechanistic accounts of learning and memory. In this review, we begin with a historical perspective on noninvasive neuroimaging techniques and their application to the study of memory encoding. We then introduce more recent cutting-edge methodological approaches, as we discuss specific domains of memory theory that they have helped advance. Drawing on research examining the medial temporal lobe (MTL), we emphasize the power of such imaging techniques to allow scientists to make inferences about the types of mnemonic information represented by distinct brain areas, and to understand how the funcEditors: Eric R. Kandel, Yadin Dudai, and Mark R. Mayford Additional Perspectives on Learning and Memory available at

Inter-hemispheric functional dysconnectivity mediates the association of corpus callosum degeneration with memory impairment in AD and amnestic MCI

“…Memory impairment is associated with neuropathology within the hippocampal/medial temporal lobe8. In addition, based on present results and recent literature910, inter-hemispheric interactions might play a secondary role in memory impairment.…”

Memory Retrieval in Mice and Men

“…Such conditions may result in generalization/inference (Moses et al 2006;Shohamy and Wagner 2008;Kumaran and McClelland 2012), interfer-ence (Müller and Pilzecker 1900;Anderson 2003;Wixted 2004), or creation of false memories Loftus 2005). Increasingly sensitive analyses methods of human brain imaging provide improved abilities to probe the interactions between encoding of new information and reactivation of previous representations (Staresina et al 2012b;Ben-Yakov et al 2014;Brown et al 2015).…”

Paradoxical olfactory function in combat Veterans: The role of PTSD and odor factors

“…Yet the olfactory system and odor functioning has important differences from other sensory systems/cues, such that probing this particular system would likely enhance our current understanding of the brain processes involved in stress-related disorders like PTSD. Unlike other sensory systems, the anatomy of the olfactory system (Gottfried, 2006; Kilpatrick & Cahill, 2003; Sevelinges, Gervais, Messaoudi, Granjon, & Mouly, 2004; Stockhorst & Pietrowsky, 2004; Winston, Gottfried, Kilner, & Dolan, 2005; Zald & Pardo, 1997; Zatorre, Jones-Gotman, Evans, & Meyer, 1992) heavily overlaps with the same limbic brain structures and medial temporal lobe circuits that support declarative memory (Brown, Staresina, & Wagner, 2015; Gabrieli, Brewer, & Poldrack, 1998) and emotion processing (Phan, Wager, Taylor, & Liberzon, 2002). Accordingly, odors have the unique ability to trigger some of our oldest and most emotional memories (Chu & Downes, 2002; Nickell & Uhde, 1994; Willander & Larsson, 2006), including memories of traumatic experiences which have been described in a series of case reports (Hinton, Pich, Chhean, Pollack, & Barlow, 2004; Kline & Rausch, 1985; Vermetten & Bremner, 2003).…”