Your Genes and Your Memory

 

Since my last post on Eric Kandel's In Search of Memory regarding the cellular neurobiology of the brain, I've continued to follow Kandel's discussion as he moves into molecular biology and the role which genes play in memory formation. Kandel draws three fascinating conclusions: 1) Activating long-term memory requires the switching on of genes. 2) To switch on these genes, one kind of protein must be activated and another kind, which suppresses memory-enhancing genes, must be turned off: "The fact that  a gene must be switched on to form long-term memory shows clearly that genes are not simply determinants of behavior but are also responsive to envirnonment stimulation, such as learning." There is a biological constraint on what experiences get stored in memory. (3) The growth and maintenance of new synaptic terminals makes memory persist. "Therefore, to rephrase Kandel, if you remember later anything of this post, it will be because your brain is slightly different after you have finished reading it." 276

The Man Who Mistook His Wife for a Hat

I'm reading this morning again from In Search of Memory, specifically about cognitive psychology and how our perceptions are stored in the brain. "The belief that our perceptions are precise and direct is an illusion-- a perceptual illusion. The brain does not simply take the raw data that it receives through the senses and reproduce it faithfully." Instead, each sensory system analyzes and deconstructs then reconstructs  the raw incoming information according to its own built-in connections and rules. To summarize, "sensation is an abstraction, not a replication, of the real world.  302

When it comes to vision, aspects of visual perception like motion, depth, form, and color are separated and carried along separate neural pathways to the brain, where they are coordinated into a unified perception. In the primary visual are of the cortex, "what" pathways (information about what an object looks like) are separate from "where" pathways (where it is, how the object is moving in space). Unfortunately, some people have defects in their cortexes and aren't able to put Humpty Dumpty back together again. For example, neurologist-neuropsychologist Oliver Sacks shares how  once upon a time he had a a patient who failed to recognize his wife sitting next to him and, thinking she was his hat, tried to pick her up on his head as he was about to leave the doctor's office. 303 Hope you haven't tried to do that!

Teaching an Old Dog New Tricks

My parents have a 14-year old dog they inherited from my sister a few years back. Because of a new carpet put in downstairs a couple of years ago, the dog was forbidden from going downstairs. She kept the rules obediently.

While on home assignment in the U.S. in Maryland, however, I've taken it upon myself to retrain this old dog. One evening last year in fear of a thunderstorm when no one else was in the house, she crept downstairs to hop into my lap so she wouldn't be all alone during the terrible storm. There was no retribution for this little infraction. Another week some months later, while I was house-sitting when my folks were away, the dog similarly snuck downstairs to have someone to hang out with. Now, whenever my folks head out the door, as soon as they prepare to head toward the garage the old dog moves to the top of the stairs and cranes its neck around to make sure the coast is clear before sneaking surreptitiously down the steps. She now knows only to make her move as they are leaving or already left (although she still needs to work on the angle of sneaking back UP the stairs unnoticed when her owners return).

I didn't think it would be possible to impart such scheming cunning and trickery to such an old animal in such a short time while on home assignment. Thank you for your giving to the Great Commission Fund, which has enabled me to corrupt this poor creature while living on home assignment allowance in the U.S. Oh, and my parents know and laugh with me about the dog's duplicious behavior.

Male Machismo: That'll Teach 'Em

Sunday afternoon after helping the pastor of the local church and his family here in Maryland hand out fliers for an outreach, I invited one of his sons to join me fishing. One of his sisters joined us (they have 8 kids total) also and she outfished us both in the hour or so we were out there: 4 to 0 to 0!!! Ouch. A wound to our male egos!!!

A little later we were back at church for the weekly "skate church" outreach with ramps for bikers and skateboarders as well as ultimate frisbee. Praise God: the outreach was very-well attended by first-time guests and we showed a Rob Bell video I recommended at a break in order to share part of the "Beautiful News" (according to Matt Redman) of Jesus Christ.

Afterward, I played ultimate frisbee, along with several of the pastor's kids. Alas, in a moment of male competitive fervor (our team was getting skunked pretty bad), I used my superior height (not to mention girth) to swat down a shot by one of the pastor's littlest girls. She's probably only 5 or 6!!! What a mean thing to do! I immediately felt convicted. But hey, we had to get back in the game somehow.

Transformed Minds

The last few weeks I've been reading In Search of Memory by Eric R. Kandel, who with his family immigrated to the U.S. as a child from Vienna shortly after the Nazis invaded Austria and began persecuting Austrian Jews in 1939. As a young man Kandel was heavily influenced by the work of his Viennese compatriot Sigmund Freud to the extent that he too resolved to pursue a career in pyschoanalysis. However, Kandel's interest in behavioral science gradually shifted over to the uncharted territory of molecular biology of the brain. He won a Nobel Prize for his work on memory in 2000.

Regarding memory, what did Kandel research? Neurons are the fundamental unit of the neural system and the starting point for learning about memory. Memory derives from changes in the synapses of neural circuits.  On the one hand, short-term memory derives from functional changes involving ungated sodium and voltage-gated potassium ion-channels which create voltage differentials allowing for the signaling of visual experiences, movements, thoughts, and memories sent from one end of a neuron to another. On the other hand, long-term memory derives from structural changes in neurons and the brain itself!

The brain is mapped out and hard-wired to different body parts and functions in a most fascinating manner (Kandel only briefly delves into this, but try googling "brain region" with other keywords such as "language comprehension", "language expression", "cortical map" etc). For example, the size of brain regions mapped to certain fingers change over time and with respect to other people or even the other hand of the same person, as say, someone learns to study violin from a young age on. So the brain and its neural circuits change over time in response to various stimuli.

I find all this especially interesting from a Christian perspective. First, in spite of being one of God's chosen, Kandel doesn't come across as one who believes in God, but his discoveries and observations regarding the intricacies of the mind nevertheless give glory to God as the Creator of the universe and of humankind. Secondly, his observations reflect spiritual truth. For example, a friend of mine remarked to me yesterday that one of her family members seems to be moving progressively further and further away from God as he grows older. Moreover, millions of people the world over suffer from various addictions.  From a scientific vantage point, could it be that their brains are actually  physically changing as a result of prior experiences and poor decision-making? A good reminder from science to obey the Lord's exhortation to stay close to Him at all times, to set our minds on things above, to dwell on that which is pure, honorable, right, and to be transformed always by the renewing of our minds.