Be wary of your memories, they are ever-changing: experts

You may think that you remember important moments of your life accurately, but the truth is you can’t completely trust your memory, said speakers at the two-day Essentials of Neuroscience course at Aga Khan University.

Neuroscience researchers noted that most people believe their memories are like permanent recordings whereas our recollections are often ‘revised’ in light of new information. They noted that when we tell stories about our past, we often exaggerate or exclude details depending on who is listening or what interests the audience. Similarly, if something we recall is disputed by many other people, we may believe that we are mistaken and alter our memory of the past.

Just like a game of Chinese whispers in which a message changes as it is repeated, memories can also be influenced in the process of being recalled. For example, studies into how people recall major events such as the September 11^th attacks show that strong emotions can often warp details about the timing, location and sequence of events.

Speakers also noted that the public’s understanding of neuroscience: the study of the brain, the mind (the metaphysical creation of the brain), and the spinal cord, contains a number of myths and misunderstandings. While speaking about memory, Professor Ather Enam, a neuroscientist and chair of surgery at AKU, noted that a layperson is familiar with explicit memory such as our recollection of facts and events, but not implicit memory. Our implicit memory governs a vast range of essential, motor functions which means that we inherently remember how to ride a bike or how to write with a pen.

Another misconception relates to those with ‘photographic memories’. He noted that most people feel that those with strong visual memory recall things flawlessly even though research shows that they forget the majority of details of past events. Studies into the reliability of testimony by eyewitness have also demonstrated that people often make mistakes in remembering a suspect’s face and are prone to doubting their recollections in the face of strong questioning or if their views are challenged.

“We tend to think of our memory as being a recording of a point in time. In truth, our mind isn’t a static device but a dynamic time machine,” said Professor Ather Enam. “It moves back and forth between thoughts of the past and the future to create a narrative, or a reality, that makes sense to you.”

Another misperception about memory is that people tend to think all memories are stored in a single part of the brain. This isn’t true. For example, when you remember an important event of your life, each part of the memory is stored in a different part of the brain. The sounds in the auditory cortex, the visual cues in the fusiform gyrus and your feelings in the amygdala and structures connected to it.

All these parts of the memory are pieced together by a structure in the medial temporal lobe, called the hippocampus. And so, you don’t really recall a memory, you ‘rehearse’ it with different parts of your brain all playing a role in this performance. These complex, autobiographical memories are referred to as the episodic memory. Dr Enam noted that studies using magnetic resonance imaging scans of the brain, show that the same parts of the brain light up when we think about the past or imagine the future. This too is evidence of how memories aren’t locked away in a single place and of how they are recreated or reimagined.

During the course, Professor William Klein from Northwestern University explained a paradox that the same protein that causes Alzheimer’s, a harmful disease that leads to a loss of memory and cognitive decline, also plays a helpful role in the building of vital connections in developing brains.

Speakers at the conference also addressed the widespread myth that intelligent people have a larger brain. They said that an elephant has a brain twice the size of a human, yet it is clearly not as intelligent as a human. This is because intelligence has more to do with the connections between different parts of the brain in areas called the association cortex.  These interconnections, which are more prominent in human brains, are strengthened as a consequence of practice, the pursuit of knowledge or as a result of healthy habits such as regular sleep, a healthy diet, meditation and exercise.

One of the lecturers, Dale Purves, the Geller Professor of Neurobiology Emeritus at Duke University, who is also patron of the course, commented that such courses and events bring individuals together from across the world.

The conference was jointly organised by faculty at Aga Khan University and members of the Pakistan Society of Basic and Applied Neuroscience. The two-day event was attended by national and international experts in neuroscience as well as students and young researchers to discuss key topics in the field.

-AKUH Press Release