Working Memory and Language in the Modular Mind

John Truscott

• Publisher: Routledge
• Year: 2022
• eBook ISBN: 9781000597073
• Topic: Psychology
• Subtopic: History & Theory in Psychology
• Index: Psychology

The book explores two fundamental aspects of the human mind and their relation to one another. The first is the way that information is put to use in the mind. When we are doing a mental arithmetic problem, for example, how do we bring the relevant bits of information to mind and hold them there while carrying out the series of calculations? This is working memory, the subject of an enormous research literature in psychology, neuroscience, and a great many other disciplines. Characterizing the working memory process is now a major part of efforts to understand the human mind. How we characterize this process depends of course on how we characterize the human mind as a whole. In particular, is the mind made up of a number of distinct units, each carrying out a specialized function? There is considerable reason to say that it is, and this modular view of the mind has become prominent in a great deal of academic work, notably in cognitive neuroscience, with important implications for our understanding of how working memory works. But these implications have received surprisingly little consideration to this point. The aim of the book is to explore this relation between working memory and modularity, first in general terms and then using a specific modular view of the mind – the Modular Cognition Framework. The ideas are illustrated and further developed through an application to language and especially second language acquisition and use.

1 INTRODUCTION

DOI: 10.4324/9781003158172-1

This book is about psychology – cognitive psychology, to be a bit more precise. What that means is that it is part of the effort to achieve a scientific understanding of the human mind. The aspect of mind that I focus on is called working memory, and it turns out to be surprisingly important for the broader task of understanding the mind as a whole. To understand its nature and its significance, the place to start is with some examples of working memory in action.

First Thoughts: Arithmetic in the Mind

First, consider this simple problem. Try doing it in your head, and notice what you are doing as you perform the task:

One thing that can be readily observed is that before actually carrying out the task we have the visual experience of seeing the numbers and the layout, the latter indicating the nature of the problem. A prerequisite for seeing these things is that you pay attention to what is on the page. And this is based on how you feel about what I’ve asked you to do; in other words, how you value this little task. If you don’t value it at all, or value it negatively, as a waste of time and effort, you will skip over the numbers. If, on the other hand, you do value it enough to look at the numbers and do the multiplication, this means you have established a goal of doing it, a goal that is supported by the value attached to it. This goal then remains active until the task is completed, or abandoned.

The visual portion of the experience actually involves many complexities, most of which can be dispensed with for the moment. One essential point, though, is that the work of the visual system is finished only when its product, a mental image, is connected to knowledge that you already have, namely the knowledge of what those marks on the page mean; in other words, the visual process must awaken the relevant bits of your long-term memory.

Doing the multiplication then involves keeping these bits of knowledge awake and manipulating them according to the rules of multiplication. The actual calculation can be done in a number of ways; I will focus on what might be considered the textbook method.

The first manipulation is to multiply 8 × 7, producing the number 56 or, more accurately, awakening the number where it sits in your long-term memory. The 5 and the 6 are then set aside for the moment, after each has been mentally set in its proper place. At this point, we cease to be aware of them for the moment, but they are nonetheless kept readily available for use. After this, the rules call for multiplication of 8 × 2 and therefore for the awakening of 16. The 5 is then reawakened, brought back to a state of awareness, and added to the 16, producing (awakening) 21. The original 6 is then reawakened, the 21 is mentally set beside it, and the result, 216, becomes the focus of attention and awareness.

This is an example of working memory in action. As the term is commonly used, working memory (WM) is about making information temporarily available, as needed, for use by cognitive processes like multiplication. It is closely related to short-term memory (STM), the difference lying in whether you are simply holding the information in an active state (STM) or manipulating or managing it in some way (WM). Remembering a phone number long enough to make the call is an STM task; doing mental multiplication is a WM task. Working memory is clearly the more interesting of the two, as it is inseparable from intelligent thinking. Performance on WM tests is in fact strongly correlated with intelligence and a variety of cognitive abilities.

The multiplication example shows several significant characteristics of WM. While most seem commonplace and obvious, it is not so obvious why they exist or how they are to be explained. First, WM involves sticking to a task and shifting between different parts of the task as appropriate (multiplying 8 × 7, then mentally placing the resulting 5 and 6 in their proper positions, then multiplying 8 × 2, and so on). Conscious experience jumps along with these shifts: when multiplying 8 × 2 the earlier numbers, 5 and 6, are not part of the experience, but they return to awareness when they are needed. One thing we know about such problems is that as the number of digits increases the problem becomes steadily more difficult (try multiplying 347 times 9,827 in your head); there are only so many things we can hold on to at one time. These capacity limits are a major theme of research on working memory. We also know that we can get better at tasks like this through practice, showing that some sort of underlying change is occurring. We know that some people are better at it than others – there are individual differences in working memory, differences that are, again, strongly related to intelligence. We know that the ability is related to age: small children are not very good at tasks like this and old age tends to bring a decline in our abilities.

Most of these points, again, seem ordinary and obvious. But to the student of psychology, this does not make them uninteresting. In fact, it enhances their interest. The business of psychology is to explain the ordinary and the obvious, and this task often turns out to be extremely difficult, yielding results that are far from ordinary and obvious. The study of working memory is an example.

Second Thoughts: Vision and Language in the Mind

I began with arithmetic because it illustrates main ideas in a relatively neat way. Let’s turn now to some additional types of mental processes, which point to complications in the picture, complications that will be important throughout this book.

Start with vision, which is probably the best-understood part of the human mind, largely because it is a well-understood part of the human brain. The most important point is that vision is a complex construction process, not a matter of bringing a picture of the world into your head. The visual system has a number of component parts, each responsible for a particular aspect of the scene, such as color, motion, and shape. The scene that we are ultimately aware of is the result of these separate processes coming together. The other most important point is that almost everything going on in this construction process is unconscious and effortless; we are aware of the product – the image – but not of the process by which it is produced.

Cases like this are not normally included in the study of working memory, and I suspect that most people in the field would not wish to apply the term to them (though I could be wrong).¹ But information is certainly being made available to the cognitive processes, is being kept available for a time, and is actively manipulated during that time. So working memory is at work here. On the other hand, this case is different, dramatically different, from the arithmetic example. We are not aware of anything except the final result of the processing – the visual scene; there is no awareness of the information that is being made available and put to use by the various subsystems. Nor is there any sense of effort involved in the process. It is doubtful that increasing age has any effect, except possibly in cases of dementia in which the whole brain is in bad shape. The existence of individual differences is also doubtful. The apparent conclusion is that we have two different types of working memory.

Next, consider the use of language, specifically the way we understand a sentence that we hear. This again is a complex construction process, consisting of multiple steps. Vibrations in the air lead to vibrations in the ears, triggering electrical signals which set the brain’s auditory system to work. The process here parallels that for vision, multiple subsystems collaborating to construct the ultimate representation of the sound. This representation then triggers a complex linguistic construction process, starting with a representation of the sound in linguistic terms – a phonological representation. This serves as the basis for construction of the formal structure of the sentence, first in terms of nouns, verbs, etc., and then the combination of these pieces into phrases and ultimately a complete sentence. This syntactic representation is purely structure; in itself it has no meaning. The job of putting meaning into the sentence is done by an additional part of the system, the semantic or conceptual component. To complicate things further, the process does not proceed simply in one direction; there is continuous back-and-forth communication among the phonological, syntactic, and conceptual components.

As in the case of vision, relevant information is constantly being made available to the various linguistic processes and is constantly being manipulated by those processes. In other words, working memory is crucially involved in the understanding of speech. But again it is a very different sort of working memory from that seen in the arithmetic example. Notably absent, as in the case of vision, is conscious awareness of the construction process and its various components.

The type of WM seen in the arithmetic case can be a part of language use, though. It appears for example when the input is difficult to understand, because of noise, unfamiliar accent, mistakes, unknown words, length or complexity, and so on. When problems occur, we can consciously hold on to a troublesome part and deliberately look for ways to interpret it. This kind of WM is also very common in the acquisition and use of a foreign language, especially when the learning occurs in a formal classroom situation. If your efforts to speak in the language involve thinking about the rules you learned and effortfully coming up with appropriate words, we see the same kind of WM phenomena encountered in the case of mental multiplication.

We can thus identify two types of working memory cases. The familiar, widely studied type is represented by the arithmetic example and the very deliberate kinds of language use while visual processing and ordinary language comprehension illustrate the other variety. Importantly, the latter is by no means limited to vision and language. It is found all through the human mind, in each domain of processing. An account of working memory needs to accommodate it.² The first type, what is commonly treated under the term “working memory”, might in fact be best seen as a special case of the second, that in which the various local processes are coming together. This idea will be developed in detail in later chapters.

The Nature of the Mind: Modularity

Working memory is about making relevant information temporarily available to processes that need it. To understand working memory, then, we have to understand what the information and the processes look like, at least in general terms. At this point, it would be exceedingly brave, foolish in fact, to suggest that anyone knows what these things really look like. We have lots of relevant information about them, but the proper interpretation of it is far from settled. I am interested in one general type of interpretation, one that is popular in a variety of areas, most notably in neuroscience. This is the idea that the mind is modular.

I have been told that many people find the term “modularity” intimidating and would prefer not to deal with it. But the idea is actually quite simple. The mind contains a number of distinct components, like language and vision perhaps, each carrying out its own specialized function, and the mind as a whole is to be analyzed in terms of these functions and their interaction. Complexities arise when we get more specific about what the modules actually are and how they operate, but complexity is just a fact of life when you are trying to understand the human mind. To me the modular conception is the neatest, most intuitively appealing way to approach the problem. It also fits the facts rather well, as I will argue throughout this book.

So, there is a need to explore WM within the assumption that the mind is modular. That is the business of this book. The exploration will lead to a conception of WM that is similar in some respects to that found in familiar work on the subject but also differs substantially from it – to a conception that I suggest is neater and more intuitively appealing, and maybe even does a better job of accommodating the facts.

The Need for a Broad Framework

The first half of this book will explore the questions in general terms: If the mind is modular then what should WM look like? But it is also worthwhile to get a bit more specific, to see how these general considerations can be instantiated and developed in a specific cognitive framework. Given our very incomplete understanding of the human mind, any such framework is necessarily provisional. But anything that is said about working memory, or anything else related to the mind, will inevitably rest on assumptions about the nature of the cognitive system. These assumptions need to be made explicit and they need to be coherent and defensible. In other words, the questions need to be addressed within an established cognitive framework. The value of a framework is that it can bring together existing research findings in a coherent way and thereby set a context in which theories can be proposed, tested, and further developed. Describing such a framework and applying it to working memory will be the business of the second half of the book.

Is There Really Such a Thing as Working Memory?

Throughout this book, I will be concerned with a major, but rarely addressed question: When we look at the big picture – the mind as a whole – do we find there a thing called “working memory”? Or does this thing that we are trying to understand turn out instead to be an abstraction from other, more real characteristics of the mind, an abstraction that has been useful for our current, preliminary work but must ultimately be replaced by a more fundamental explanation? Before directly addressing this question, it is useful to step back and take a broader look at the way psychologists have tried to understand the mind, considering especially the dominant concepts which have defined the areas of research within psychology.

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Table of contents

• Cover
• Half Title
• Title
• Copyright
• CONTENTS
• List of Figures
• Acknowledgments
• List of Abbreviations
• 1 Introduction
• 2 Working Memory: A Perspective on the State of the Field
• 3 The Modular Mind, and the Place of Working Memory
• 4 Multiple Working Memories: A Distinct Working Memory for Each Module
• 5 Working Memory Across Modules: Activation and Coordination of Activity
• 6 The Modular Cognition Framework
• 7 Working Memory in the Framework
• 8 Working Memory and Language
• 9 Conclusion
• References
• Index