When studying psychology and behavior sciences as an undergrad, Dr. Avi Mendelsohn was intrigued by the brain’s role in shaping human behavior and cognition. It led to an academic career that is now unravelling the secrets of how our memory works – specifically how the brain recollects memories over time, and convinces us that what we remember is true – even if some details are, well, a bit off. To start gaining a better understanding of the field, Mendelsohn acquired a master’s degree in Psychobiology and focused on human studies. He learned to employ advanced neuroimaging technologies such as functional MRI, to map brain activity while individuals are carrying out behavioral-cognitive tasks. With that in hand, he completed his PhD at the Weizmann Institute of Science, conducting memory research and investigating what is known as episodic memory – our ability to mentally time-travel and recall a past event along with some of its details.
Now he has joined the Sagol Department of Neurobiology and the Institute of Information Processing and Decision Making (IIPDM) at the University of Haifa, an interdisciplinary research institute providing a unique cooperative research and training environment, and has established the Human Memory Lab. “I proposed establishing a lab that is open to different areas of memory research, focusing on cognitive psychology of reallife memory and its underlying neurobiological mechanisms. The Faculty’s support for the idea was beyond expectation. The University of Haifa is exceptionally open to new ideas and paradigms,” Mendelsohn explains. “We are examining brain functions that underlie the formation of episodic memories and their recollection over the long term. When we have that information in hand, it will be possible to treat various memory-related emotional disorders like posttraumatic stress disorder [PTSD].”
An episodic memory is a mental reconstruction of an experience. It is a complex process that merges multiple cognitive and emotional factors of the experience: temporal, spatial, contextual, semantic, emotional and sensory. Studies have shown that memory is not saved passively like a snapshot. Once it is consolidated as a longterm memory it is susceptible to change upon retrieval and can be re-stored in a new form. “Our memories become notoriously inaccurate and unreliable as time goes by and we’re often pretty bad at remembering episodes. Without realizing it, we even implant false memories that never occurred.” He asserts that this is no mistake of nature. “A memory system of this kind enables us to develop novel and flexible ideas relating to the future. In his story ‘Funes the Memorious’, Borges portrays a man who, following a head injury, acquires the remarkable ability to recall every memory precisely, but who has no imagination or original ideas.
By using acquired knowledge and constructing something new, we are simulating and adjusting the way we see ourselves and how we can cope with future scenarios. “We want to understand what biological mechanisms rule these processes. Our research involves teaching episodes to subjects – the encoding of an event, and then using functional MRI to examine activations of regions in the brain and co-activations among different regions when the subjects are prompted to reenact the episodic memories at different time points thereafter.” Mendelsohn recently led and published a study demonstrating that the degree to which specific brain regions activate during memory retrieval is indicative of one’s sense of accurate recollection, whether in fact correct or fabricated.
“The results of our research give hope for some types of memory
related conditions. People suffering PTSD endure snapshots of memories that cannot be repressed and that trigger strong emotional responses. We are uncovering how and where in the brain a memory’s dynamic process is taking place in correlation with the other cognitive and emotional factors that come into play when a memory is being retrieved.” This may enable adapting memories after trauma, modifying emotional experiences associated with a memory, enhancing confidence in changed memories and alleviating the symptoms of PTSD.