By Gianna Absi
Do you ever think about your childhood or replay an event in your head that happened 15 years ago but its so vivid that it seems like it happened yesterday? Do you ever hear something and think it sounds like your favorite song and then start singing that song? These are memories that were formed in your brain that are replayed as a result of a specific stimulus. For a long time scientists believed that memories were formed, processed, and sent to different destinations in the brain. Dr. Wilder Penfield was one of the first to accidentally discover this. In the 40s he electrically stimulated different areas of his patients’ brains while they were under local anesthesia and found that the region he stimulated would elicit specific memories in the patient’s life (see video below). For example, in one of his patients he stimulated her temporal lobe (auditory cortex) and she started to hum her favorite song out loud. This suggested that the memory of this song was stored in the place where it was processed or originated (i.e. the auditory cortex processed the first time she listened to the song). Penfield concluded that the cortex (the outer layers of the brain) stored the “complete record of the stream of consciousness; all those things in which a man was aware at any time…” Until recently, scientists have believed this phenomenon.
Have you ever watched the show “I Didn’t Know I Was Pregnant”? I don’t know about you, but I have never understood how that could happen, because of all of the symptoms and telltale signs that come with pregnancy. What I am about to talk about is a condition that is completely opposite of this reality television show. It is a condition where a woman actually believes she is pregnant and gets all of the symptoms, including an enlarged belly and breasts, but there is no baby inside of her. This is called Pseudocyesis, or more commonly, Phantom Pregnancy.
I am assuming that whoever is reading this right now has had a dream before. Am I right? But have you ever had a dream with a person in it whom you have never seen before in your life? It may seem that way, but it is impossible. It is believed that the human brain is incapable of ”creating” a new face. Every person you dream of has been someone you have either known personally or merely came across looking through your friend’s Facebook photos. Even those whom you do not consciously notice but still look at as you pass by may be an implanted image in your brain and show up later when you are dreaming.
Sigmund Freud is most famous for his definition and study of dreams. He taught about the unconscious and based it on repression and how some ideas and events in one’s life are repressed and brought up later in life. Freud believed in a cycle where these repressed ideas remain in the mind while removed from consciousness. They reappear and become a part of our consciousness only at specific times, for example, in our dreams.
Ever wonder why children can learn certain things, such as languages, faster than adults? There is a time in every human’s life called the critical period, and it takes place during the most intense period of development, childhood. During this time a child’s brain has high neuroplasticity, almost like a sponge. Many new pathways are formed as the child experiences new things. It has always been believed that when our critical period ends it never comes back but recent study has been done with the drug Valproate that increased neural plasticity in adults and may have reopened this critical period.
Valproate is a drug most commonly used for bipolar disorder and epilepsy. It is also known to inhibit an enzyme called histone- deacetylase, or HDAC. HDAC is an enzyme in the brain that slows down neural plasticity. Inhibition of this enzyme by Valproate allows the reopening of pathways in the brain, increasing neuroplasticity, thus reopening the critical period.