According to PET scans, there was much more activation in the left inferior prefrontal cortex in the semantic task. In another study, encoding was associated with left frontal activity, while retrieval of information was associated with the right frontal region Craik et al. There also appear to be specific neurotransmitters involved with the process of memory, such as epinephrine, dopamine, serotonin, glutamate, and acetylcholine Myhrer, There continues to be discussion and debate among researchers as to which neurotransmitter plays which specific role Blockland, Repeated activity by neurons leads to increased neurotransmitters in the synapses and more efficient and more synaptic connections.
This is how memory consolidation occurs. It is also believed that strong emotions trigger the formation of strong memories, and weaker emotional experiences form weaker memories; this is called arousal theory Christianson, For example, strong emotional experiences can trigger the release of neurotransmitters, as well as hormones, which strengthen memory; therefore, our memory for an emotional event is usually better than our memory for a non-emotional event.
When humans and animals are stressed, the brain secretes more of the neurotransmitter glutamate, which helps them remember the stressful event McGaugh, This is clearly evidenced by what is known as the flashbulb memory phenomenon.
A flashbulb memory is an exceptionally clear recollection of an important event [link]. Most likely you can remember where you were and what you were doing.
This is an example of a flashbulb memory: a record of an atypical and unusual event that has very strong emotional associations. Even flashbulb memories can have decreased accuracy with the passage of time, even with very important events. Bush responded inaccurately. In January , less than 4 months after the attacks, the then sitting President Bush was asked how he heard about the attacks. He responded:. I was sitting there, and my Chief of Staff—well, first of all, when we walked into the classroom, I had seen this plane fly into the first building.
There was a TV set on. And you know, I thought it was pilot error and I was amazed that anybody could make such a terrible mistake. Greenberg, , p. Researchers have been able to trace memory down to the structural and even the molecular level in recent years, showing that memories are stored throughout many brain structures in the connections between neurons, and can even depend on a single molecule for their long-term stability.
The brain stores memories in two ways. Short-term memories like a possible chess move, or a hotel room number are processed in the front of the brain in a highly developed area called the pre-frontal lobe, according to McGill University and the Canadian Institute of Neurosciences, Mental Health and Addiction.
It is the most recent addition to the mammalian brain, and is involved in many complex cognitive functions. Human neuroimaging studies using magnetic resonance imaging MRI machines show that when people perform tasks requiring them to hold information in their short-term memory , such as the location of a flash of light, the PFC becomes active.
There also seems to be a functional separation between left and right sides of the PFC: the left is more involved in verbal working memory while the right is more active in spatial working memory, such as remembering where the flash of light occurred.
QBI newsletters Subscribe. Help QBI research Give now. Download the pdf. Download printable poster. Skip to menu Skip to content Skip to footer. Site search Search. Site search Search Menu. Where are memories stored in the brain?
The parts of the brain involved in memory Illustration by Levent Efe. A short-term memory can be consolidated into an enduring long-term memory. This involves a system of brain structures within the medial temporal lobe that are essential for forming declarative memories.
The hippocampus is a key region in the medial temporal lobe, and processing information through the hippocampus is necessary for the short-term memory to be encoded into a long-term memory. The long-term memory does not remain stored permanently in the hippocampus. These long-term memories are important and having them stored in only one brain location is risky — damage to that area would result in the loss of all of our memories. Instead, it is proposed that long-term memories become integrated into the cerebral cortex responsible for the higher order functions that make us human.
This process is referred to as cortical integration; it protects the information stored in the brain. However, damage to areas of the brain, particularly the hippocampus, results in loss of declarative memories, which is known as amnesia.
Removal of the temporal lobe, including the hippocampus, led to the inability to form new memories, known as anterograde amnesia. However H. These are called neurofibrillary tangles and amyloid-beta plaques. Amyloid plaques disrupt communication between neurons.
Damage to neurons in the hippocampus prevents the formation of new memories and also disrupts neurons that have formed networks encoding existing memories.
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