Kay Tye is an Assistant Professor at the Picower Institute for Learning and Memory at Massachusetts Institute of Technology. She does pioneering research on how environmental stimuli affect behavioral responses. She tries to understand the underlying neurophysiology behind the formation, revision, and extinction of associative memories. One tool she uses to help her understand the above processes is optogenetics. Optogenetics is a fairly new neuroscience technique utilizing light to control neurons after they have been sensitized to it. Dysfunctions in the neurophysiology of reward processing, fear, motivation, memory or inhibitory control have been seen to lead to substance abuse, anxiety, depression, and attention-deficit disorder. They also show high co-morbidity with each other suggesting they are related and also reinforce one another.