Matthew P. Walker

Assistant Professor (Psychology, Neuroscience)

Web site: http://walkerlab.berkeley.edu/

Research areas: Cognitive and Behavioral Neuroscience

Research in the laboratory focuses on cognitive aspects of the sleeping brain using a multimodal imaging approach; including fMRI.

Our first main track of research explores the role of sleep in human memory processing and its relationship to brain plasticity, in healthy and disease populations. Specifically, we are investigating whether sleep triggers an overnight, plastic reorganization of memory at a systems-level, and thereby enhances retrieval the following day. Using combined electroencephalography (EEG)-fMRI technology, we are also examining whether the brain actually reactivates or “replays” recently learned information during different stages of sleep. It is our hope that these imaging studies will bridge the gap between brain and behavior, and offer a comprehensive understanding of how sleep modulates learning, memory and brain plasticity.

Our second research track examines the benefit of sleep, and the impact of a lack thereof, on human emotional brain function. Our recent findings indicate that just one night of sleep loss results in a hyper-limbic brain response to negative affective challenges, and that this amplified amygdala activity is associated with a loss of top-down prefrontal control. Thus, sleep appears to “reset” the correct emotional brain reactivity to next-day aversive challenges by maintaining functional integrity of this prefrontal-amygdala circuit. We hope this research program will provide key insights into the pervasive relationship between sleep disruption and mood disorders (e.g. major depression, PTSD), which instead of being viewed as co-occurring, may in fact be more causally related.

Selected Publications

Yoo SS, Gujar N, Hu P, Jolesz FA & Walker MP. The human emotional brain without sleep: A prefrontal-amygdala disconnect. Current Biology 2007; 17(20): 877-878.

Ellenbogen, J. Hu, P. Payne, J.D. Titone, D. Walker, M.P. Human relational memory requires time and sleep. Proc Natl Acad Sci U S A 2007; 104: 7723-7728.

Yoo SS, Gujar N, Hu P, Jolesz FA & Walker MP. A deficit in the ability to form new human memories without sleep. Nature Neuroscience 2007; 10: 385-392.

Walker, MP, and Stickgold, R. Sleep, Memory and Plasticity. Annu Rev Psychol 2006; 57: 139-166.

Stickgold R. & Walker MP. Memory consolidation and reconsolidation: What is the role of sleep? Trends in Neuroscience 2005; 28(8): 408-415.

Walker MP & Stickgold R. Sleep-dependent learning and memory consolidation. Neuron 2004; 44: 121-133.

Walker MP, Brakefield T, Hobson JA & Stickgold R. Dissociable stages of human memory consolidation and reconsolidation. Nature 2003;425(6958):616-20.

Stickgold R, Fosse R & Walker MP. Linking brain and behavior in sleep-dependent learning and memory consolidation. Proc Natl Acad Sci USA 2002;99(26):16519-21.

Walker MP, Brakefield T, Morgan A, JA Hobson & R Stickgold. Practice then Sleep Makes Perfect: Sleep Dependent Motor Skill Learning. Neuron 2002; 35(1):205-11.