Application: Phonological Loop

Today I started reading Alan Baddeley’s Working Memory, Thought and Action

working_memory_book

One of my reasons was to understand myself: I have long entertained the idea that there was something slightly abnormal about my memory.  This afternoon, I may have stumbled on an explanation of my difficulties. I wanted to share my idea because it nicely illustrates how theoretical concepts can enrich and improve people’s lives.

Context

When I was in high school, I got the standard pitch about long-term memory and short-term memory. It turns out that, here, curriculum lags research by several decades. Short-term memory as a conceptual entity was dismissed during the 1980s. Working memory was its replacement.

working_memory

In his book, Baddeley describes the two primary functional components of his model: the phonological loop, and the visuo-spatial scratchpad. The former is activated when you rehearse information, often subvocally (“that person at the wedding was named Audrey.. Audrey.. Audrey”).  This loop helps to reinforce memory traces, and has been shown to operate near the language centers of the brain (left hemisphere).  The scratchpad, by contrast, is associated with spatial reasoning (“if I take three lefts and then a right I’ll escape this corn maze”).  Neuroimaging has localized this mechanism to the right hemisphere of the brain.

Symptoms

  1. I read textbooks out loud to myself. Literature like Baddeley’s is often dense and requires careful attention. When I am not distracting anyone, I revert to this recitation exercise, and it helps me concentrate.
  2. I have always been a visually oriented creature. A detailed schematic holds more weight in my mind than a chapter’s worth of text.
  3. As I was being introduced to the notion of the phonological loop, I decided to try it for myself. During his experiments, Baddeley often directs his subjects to recite five or six letters or numbers to establish the loop. I began to subvocalize the first seven letters of the alphabet to myself, silently reciting ‘a’ through ‘g to myself over and over. But the singsong quality of this exercise did not persist, and before long I noticed that I was imagining typing those letters with my left hand.

Diagnosis

My phonological loop is weak.

In symptom 3 above, the acoustic qualities of my recitation weakened over time. Not content to watch the cycle deteriorate, my visuo-spatial sketchpad swung online with its image of a keyboard, significantly easing the task burden. Symptom 2 can be interpreted as a long-standing preference for the sketchpad. And what is Symptom 1 other than my mind being forced to augment the phonological loop with real, sometimes loud, verbal stimuli?

Concluding Thoughts

The point of the above is not medical, my symptoms are well within the range of a functional human being. Neither is this intended to be original research: I am just beginning to engage the professional literature.

All I am hoping to illustrate is how cognitive science can enrich how we understand our inner lives. With the theoretical tools outlined in the Context section above, I moved from a “that’s funny” stance towards something a little more informed. Perhaps I am on the right track, and should learn to accommodate my suite of genetic (dis-) endowments. Or, perhaps there is some proven technique to restore phonological loops and improve one’s GPA. 🙂 One can always dream.

Baddeley: Working Memory Quotes

Representational Neglect
Of particular relevance to [the case for regarding the sketchpad as a workspace rather than a perceptual gateway] is the phenomenon of representational neglect. Bisiach and Luzzatti (1978) report the case of two patients who were asked to describe from memory the cathedral square in Milan, their native city. In both cases they gave a good description, except that the left side of the square was hardly mentioned. They were then told to imagine walking around the square, turning round, and again giving a description. This time the previously neglected part of the square was on their right, and was now described in detail; the side that was previously well-described was now ignored. Baddeley and Lieberman (1980) suggested that this might represent the impairment of a system for representing information within the visuospatial sketchpad.
(Baddeley, Working Memory, pp 93)

3D Image Rotation
Much of the research on imagery was initially stimulated by the classic demonstration by Shepard and Metzler (1971) who required subjects to judge whether two representations of three-dimensional object were identical or whether one was the mirror image of another. The two were presented in different relative orientations. Response time proved to be a linear function of the difference in orientation between the two, just as if the subjects were mentally rotating one of the objects until it lined up with the other, and then making the judgment…

[Description of Kosslyn’s (1978) computational model of the brain literally rotating a data structure.]

Intons-Peterson (1996) showed that the speed of ‘visual scanning’ varied depending on semantically relevant but non-visual factors such as whether the whether the the subject were imagining herself carrying a weight or not…

Equally problematic for Kosslyn’s interpretation was a study by Hinton and Parsons (1988) who asked their subjects to imagine a wire cube sitting on a shelf in front of them. They were then asked to take hold of the nearest lower right-hand corner, and the furthest [upper] left-hand corner, and then orient the cube such that their left hand was immediately above their right. The task then was to describe the location of the remaining corners. Almost everyone reports that they lay upon a horizontal line, like a cubic equator. In fact, they form a crown shape. Hinton and Parsons suggest that rather than actually manipulating the representation as Shepard or Kosslyn might suggest, subjects attempt to simulate it. When a problem is complex, they simply fail.
(Baddeley, Working Memory, pp 94-95)