Friday, May 12, 2006

A Scrap from the Bottom of the Barrel!

I don't have time for a real post today, but (of course) that doesn't mean I can't dig up something from way back in my past. Today's somewhat moldy dish a paper I wrote for my psychology class; yes, it's a hack job, but my teacher liked it, and that's what counts. I quote poetry in it, if that interests you. Besides, some of you (okay, one of you) have expressed interest in reading this paper, so that's probably a good enough excuse. Here it is:

Most Fresh Sting: Memory Storage and Retrieval

In the Australian children's story Wilfrid Gordon McDonald Partridge by Mem Fox, a little boy name Wilfrid who lives next to a retirement home seeks the answer to a simple question: "What is a memory?" Wilfrid asks this question in hopes of somehow restoring the memory of his friend, Miss Nancy, who is suffering from memory-loss. Wilfrid Gordon's neighbors had many different answers to his question, and one gets the feeling that, if modern psychologists were approached on the subject, a similarly varied response would result. The question of Wilfrid Gordon McDonald Partridge still lingers a little in the world of psychology, though perhaps in more complex forms. Psychologists might have moved beyond simply seeking a definition for memory, and instead are asking themselves questions relating to memory storage and retrieval. It is this topic of storage and retrieval that I intend to survey in this paper, focusing also on the role of the olfactory receptors in memory recall.

The concept of memory storage that probably many of us have in the back of our minds is the idea that we store our memories in a little corner of our brain, in a room, perhaps with a sign above the door, labeled "Memories". This is a nice, neat theory of memory, and, of course, it's wrong.

In the early 1900s, psychologists began a search for such a room, a search that more or less continues to this day. These researchers, like the little boy in the story at the beginning of this paper, were looking for memory. But how exactly does one pinpoint memory? Is it localized in one spot (as our imagination might have us believe), or is it spread across the brain? One famous researcher, Harvard psychologist Karl Lashley, went a long way in answering these questions.
Lashley's method was ingenious, though perhaps cruel. According to author Mark Pendergrast (1996), Lashley started by teaching several rats to complete a complex maze. After that, finding where the rats stored their memory would be relatively simple. Lashley would systematically remove sections of the different rat’s brains and let the rats try their luck in the maze again. If a rat demonstrated a total lack of memory for the maze after a certain section of the brain was removed then the search for the memory's storehouse would be complete. But surprisingly, no matter which part of the brain Lashley removed, the rat always retained at least some memory of the maze; it was not where the brain was affected, but how much it was affected that made the difference in how well the rat remembered the maze (pp. 101-102). Lashley’s conclusion: We store memory all over our brain, not just in one localized area.

As "Psychology Today" journalist Jill Neimark (1995) puts it: "Memory is not a single entity residing in a single place.” Neimark goes on to say that memory “is the likelihood that the pathway of neurons and connections an experience forges in the brain can be reactivated again." (Neimark, 13 Ways of Looking at the Brain section, para. 5).

How, then, is a memory formed? We know that a memory starts as an experience. This experience then passes through the hippocampus, where psychologists believe that memory is received, and then the hippocampus decides whether to relay the experience or discard it. (Neimark). If relayed, the experience will be stored along a complex network of neurons. The neural bonds that are formed may then be strengthened over time by recollection.
In William Morris's poem "The Defence of Guenevere" Arthur's runaway queen ponders the phenomena of recollection; what Neimark describes as a “pathway of neurons” being reactivated:

In the lone sea, far off from any ships
Do I not know now of a day in Spring?
No minute of that wild day ever slips

'From out my memory: I hear thrushes sing,
And wheresoever I may be, straightway
Thoughts of it all come up with most fresh sting (103-108)

If memory recall (surely the lifeblood of memory) is the reactivation of such "neural pathways", how does this reactivation occur? Before attempting to answer this question, let us look at the two different types of memory. In the poem above, Queen Guenevere is referring to what’s called “explicit” memory, that is, the memory that records events, people, conversations, and so forth. The other kind of memory, called “implicit” memory, is what’s being referred to when someone says, "Once you learn to ride a bicycle, you never forget it”. Implicit memories are the memories of the unconscious: skills, routines, strategies, and the like. I do not intend to delve into the recall of implicit memory in this paper, but instead propose to explore briefly the effects of certain sensory stimuli on the minds explicit memory.

We know from experience that a familiar taste, the whiff of a scent can trigger memories long thought forgotten. An unpleasant car trip, and exciting family adventure, a time of great loss, the intimacy of relationship. Consider this quote about the power of the sense of smell to release a flood of memories:

“My grandfather died three years ago, and his image in (a photograph), caught in a moment of posed reunion, often reminds me of my boyhood, when he doted on me as his hunting and fishing companion. Yet the recollections are vague and distant.
Recently, however, I took his old deerskin hunting vest out of the closet and on an impulse pressed it to my face and sniffed. Abruptly there came over me a rush of emotion and memory as intimate as it was compelling. No longer was I an adult squinting across a chasm of years at dim events: Suddenly I was a boy again, and there in all but the flesh was my grandfather, methodically reloading his shotgun as the flushed quail sailed beyond the mesquite.
This was no hazy reverie. I could feel his whiskered cheek against mine and smell his peculiar fragrance.” (Boyd Gibbons)

This only makes sense, considering that the olfactory receptors have a direct link to what is thought to be one of the key areas in memory processing in the brain.

In conclusion we see that, while Wilfrid Gordon may not find a definite answer to his question, the field of the study of memory is beginning to cement some of the foundational concepts of memory, including memory storage, and is also advancing in the study of what sensory stimuli strengthen and trigger memory.

Fox M. Wilfrid Gordon McDonald Partridge (1989) Kane/Miller Book Publishers
Gibbons B. as quoted in Creating Understanding by Donald K. Smith (1992). Zondervan Publishing House.
Morris W. (1909-14). The Defence of Guenevere. The Harvard Classics.
Neimark J. (1995). It s magical. It s malleable. It s..memory. Psychology Today, 13 Ways of Looking at the Brain section, para. 5.
Pendergrast, M. (1996). Victims of Memory (pp. 101-102). Upper Access, Inc. Book Publishers.

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