Teens Connect The World: Brain, Children and Love

In the previous post, I talked about a major takeaway from the Brain Awareness Week Lecture. The surprising fact I learned is that memory is not stored like a piggy bank being slowly filled from the bottom. Rather, each memory is broken down into patterns and scattered in the form of neural connections.

The first thought that crossed my mind was — how laborious!!! Think of our class notes. It’s much harder when the notes are scattered. It takes forever to consolidate notes scattered in random order, rather than when they are organized sequentially. Like a student with scattered notes, the brain must have a hard time. So I read more to see if this was actually true. The answer was YES.

Indeed, due to this scattered fashion of memory, our brain needs to exert a great deal of energy. It needs to solve a series of challenging tasks to recreate a past experience. That is, because memory is distributed through the brain, a variety of distinct features that constitute an episode need to be tied together to recreate a perfect past. I learned that the most simply put looks something like the following:

• First, we go through the process of coordinating multiple regions and neural networks in our brain that are involved with specific past experiences.
• Second, the brain integrates information from a variety of sensory modalities, such as visual, auditory, and emotional information.
• Third, we form a coherent memory and think of it as a remembrance of a specific past experience.

Or to make it more interesting, perhaps I can draw upon a more relatable experience. Think of remembering a special event, like your last year’s birthday party. Your brain goes through the process of coordinating multiple regions that are involved with your birthday party; it integrates information from different sources such as the people you interacted with, the music that was playing, the food you ate, and the emotions experienced that day. This process requires a significant amount of cognitive resources, including attention, working memory, and executive function.

For those looking for a more academic discussion, here is what I found:

• Lila Davachi, 2012: fMRI results showed that the integration of memories from different contexts involved the hippocampus and prefrontal cortex. These brain regions were more active when participants were asked to recall events that were composed of information from multiple contexts, compared to events that were composed of information from a single context.
• Sarah Serbun, 2013: fMRI results showed that the amygdala and prefrontal cortex were involved in the integration of emotional information in memory.
• Kevin Madore, 2015: fMRI results supported the claim that the brain integrates information from different sensory modalities to form a coherent memory. The researchers found that the parahippocampal cortex and retrosplenial cortex were involved in the integration of visual and auditory information in memory.

After the binding process, there is another challenge. I learned that our memory system needs to keep these episodes separate from one another. And this may actually be an even greater feat than the foregoing, as it requires the brain to make fine distinctions between similar experiences and create distinct representations of each experience in the memory system. The hippocampus is thought to accomplish the neural mechanism called pattern separation, where the brain creates sparse, non-overlapping representations of similar experiences. This process requires a great deal of cognitive resources, including attention, working memory, and cognitive control, and can be particularly challenging in situations where memories are very similar or where there is a high degree of interference between memories.

All of this is no easy task. Our brain frequently fails in the process, causing a horde of errors.

• In first, failure to link constituent elements of an episode gives rise to a problem often referred to as ‘source memory failure,’ which leads to falsely attributing the source of a particular memory, or even failing to remember when or how that particular memory was acquired. This gives rise to many illusions and distortions.
• Failure in the second task is also critical. When episodes overlap too much but are not encoded with intervals, we may end up remembering overlapping details but fail to recall distinctive item-specific information. These are the ‘gist-based distortions’ that have been noted since Bartlett (Bartlett 1932, Brainerd & Reyna 1990, Loftus 1994).

This is just one of many many errors that we create because our brain decides to store memory in a very distributed fashion. As Daniel Schacter puts it, all of our errors can be grouped into a total of “seven sins” (Schacter, 2001). Our brain must be living in a hell of a mess.