Working Memory

The Connected Intelligence

Tracy Packiam Alloway, Ross G. Alloway, Tracy Packiam Alloway, Ross G. Alloway

• Publisher: Psychology Press
• Year: 2013
• Print ISBN: 9781848726147
• eBook ISBN: 9781136208164
• Topic: Psychology
• Subtopic: Cognitive Psychology & Cognition
• Index: Psychology

Working memory – the conscious processing of information – is increasingly recognized as one of the most important aspects of intelligence. This fundamental cognitive skill is deeply connected to a great variety of human experience – from our childhood, to our old age, from our evolutionary past, to our digital future.

In this volume, leading psychologists review the latest research on working memory and consider what role it plays in development and over the lifespan. It is revealed how a strong working memory is connected with success (academically and acquiring expertise) and a poor working memory is connected with failure (addictive behavior and poor decision-making). The contributions also show how working memory played a role in our cognitive evolution and how the everyday things we do, such as what we eat and how much we sleep, can have an impact on how well it functions. Finally, the evidence on whether or not working memory training is beneficial is explored.

This volume is essential reading for students, researchers, and professionals with an interest in human memory and its improvement, including those working in cognitive psychology, cognitive neuroscience, developmental psychology, gerontology, education, health, and clinical psychology.

Part I

Working Memory

The Connected Intelligence

1

Working Memory

An Introduction

Ross G. Alloway

University of Edinburgh, Edinburgh, UK

Tracy Packiam Alloway

Department of Psychology, University of North Florida, Jacksonville, FL, USA

The Case of Phineas Gage

In 1848, a three-and-a-half-foot iron rod shot through the brain of Phineas Gage, and didn’t instantly kill him. After a few moments on his back, he got up, climbed into a horse cart, and went home. When the doctor arrived, he found Phineas sitting in a chair, able to discuss rationally what happened to him. The story caused a sensation in the papers, as well as in the medical community, and no one expected him to survive for long.

Phineas was a railway foreman, and the accident happened when he was setting explosives for a new rail line. His tamping rod, used to pack in the charges, sparked on a rock and detonated the blasting powder, sending the rod up through his left cheek, through the frontal region of his brain, and out the top of his skull. For a number of days following the accident, his head bled, and bone and pieces of brain fell out or were removed. But, amazingly, he survived.

What happened after the incident shocked doctors as much as his survival. They found that Phineas was profoundly altered by the damage; he had become a totally different man. Before the accident, Phineas was described as polite and hard working, the “most efficient” foreman in the company. After the accident, he became short-tempered, childish, and profane. He would constantly make new plans, invent new ideas, but never execute any of them. He was soon fired, and was eventually found begging on the street, with the iron rod from his accident.

Before Phineas, there was still considerable debate on the nature of the brain and how it influenced behavior, if at all. Because Phineas survived and because his doctor was able to document the dramatic change, scientists now had powerful confirmation that human behavior is directly related to the brain. But we would suggest that Phineas has even more to offer the world. By damaging his brain, Phineas damaged something so crucial, so intricately tied up in who he was and how he related to the world, that he was unrecognizable to those who knew him. But his loss has become our gain. We now know that the rod likely damaged his working memory when it shot through his brain (for more on Phineas Gage, see Chapter 3 by Coolidge, Wynn, & Overmann).

Working memory is the brain’s conductor. Like a conductor, it brings together all of the different areas and functions of the brain into harmony. In the same way, the brain is like an orchestra, with each area like a different section. The language center, Broca’s area, is like the articulate expressiveness of the string section. The intraparietal sulcus, the math area, is like the precise keyboard section. The amygdala, the heart of our emotions, is like the thundering percussion section that must be brought under control or it will overpower the whole orchestra. Without its conductor, the orchestra makes the jarring sounds of a cacophony. It is not until working memory walks out on stage that all instruments are brought under control, and the symphony can begin.

The ability to moderate our emotions, to control what we say and do, to form a plan and execute it, to do mental math, to perceive the needs of others, to focus on the positive and disregard the negative, to quickly shift between tasks, to write and carry on a conversation, to put names together with faces, all would be impossible without working memory. No wonder Phineas changed.

Traces of Working Memory

Though the term “working memory” is a twentieth-century invention, concepts linked with working memory have been explored throughout Western thought. A sampling of key historical figures shows that the notion of a conductor or controller moderating, organizing, and giving attention to behavior and emotions can be traced from Socrates through to René Descartes and beyond.

Socrates was interested in the rational control of human behavior, an ability we now associate with working memory. At the center of his enquiries was the concept of the “Soul.” In fact, “psychology” is a term with Greek roots that literally means “the study of the soul.” The concept of the Soul encompassed much of the behavior we now know is based in the brain. Socrates divided the Soul into three parts: Appetite, Spirit, and Rationality. Appetite gives us our basic drives like hunger, sex, and survival. Spirit is responsible for our virtuous qualities and emotions, including our desire for love and happiness, and is also associated with emotions like anger. The last part, Rationality, is given pride of place. It directs the other two. Like working memory, it controls our urges, harmonizes our emotions, and helps us to act in a planned and appropriate manner. In much the same way that Phineas was seen to be a different person when he damaged his working memory, how rational you are defines who you are.

Working memory also helps us categorize and make connections between things around us. We can see this process in the work of Aristotle, who wanted to understand how Rationality related to the world around him. Aristotle’s brain worked like an ancient version of Google. If you search Google for seemingly unconnected words like “baseball” and “humming bird,” you will find over a million and a half hits ranked from the most to the least relevant. In the same way, working memory allows you to search through information and to perceive connections. Aristotle didn’t have the computing power of the World Wide Web, but, like Google, he was able to perceive an order everywhere he looked. Not only was he a philosopher, he was one of the world’s first scientists to generate a taxonomy of the animal kingdom, which had a huge influence on the way we understand the natural world.

Perhaps the most memorable line from an introductory philosophy class is “Cogito ergo sum”: I think therefore I am. By writing these lines, the French philosopher René Descartes unwittingly implicated working memory in the emergence of modern philosophy, and its focus on consciousness. Descartes reasoned that the only things he could believe in were those that could not be doubted. Descartes soon realized that even his senses could be doubted because he might be dreaming, which meant that he couldn’t know for certain that he had a body. The only thing he couldn’t doubt was the fact that he was doubting. To doubt, he had to have a consciousness, and to have a consciousness, he had to exist. Cogito ergo Sum.

Consciousness is an important feature of working memory. Working memory is the space where we give our attention to information. Neuroscientists, such as Joaquin Fuster, argue that attention, or awareness, is related to consciousness and that this is deeply connected to working memory (Fuster, 1997). By working with information—for example, by processing a list of instructions or performing a multi-step mental math problem—we are giving attention to it, and therefore we are conscious of it. Of course, we use other cognitive resources when we are feeling emotions, hunger, or listening to music. But when we think about how we feel, we are giving our attention to our emotions and we are recruiting our working memory in the process. When we use our working memory, we are conscious of the task at hand. Echoing Descartes, working memory therefore consciousness.

Working Memory and the Prefrontal Cortex (PFC)

The conversation that began in philosophy was taken in a different direction by scientists who wanted to understand how the brain influences who we are. In the 1870s, the Scottish brain scientist David Ferrier discovered where working memory was located in the brain. This discovery was made possible by the concept of localization. Localization means that we can map the brain according to what it does. It was in the nineteenth century that the medulla oblongata was linked to respiration, the cerebellum was linked to equilibrium, and the language centers of the brain were discovered.

Many of the advances in nineteenth-century brain science were made possible by the use of techniques like ablation—cutting a piece of brain out to see what ability would be affected—and galvanic stimulation—attaching an electrical conductor to an exposed section of brain to stimulate it. Ferrier made huge leaps forward in understanding the motor cortex by using these methods on monkeys. Ferrier found that when he electrically stimulated the top and side of a monkey’s brain, he could make certain muscles move, but when he stimulated the front of the brain, nothing happened: No muscles moved. It wasn’t until he ablated the front of the brain that he saw something that he didn’t expect. Monkeys that had taken an interest in their surroundings before the ablation now became apathetic and lazy, they had suffered a “mental degradation,” and lost the ability to focus their attention. Ferrier argued that he had removed a center of the brain responsible for what he called inhibitory function. According to Ferrier, these centers allow us to inhibit muscle movements, focus attention, and form an idea (Macmillan, 2000).

Ferrier’s importance is not so much that he crudely conceptualized functions we now associate with working memory—this had been done since Socrates—but that he accurately associated these functions with a region of the brain. By doing so, Ferrier had discovered the seat of working memory.

We now know that working memory is located in the prefrontal cortex, also called the PFC. The PFC is located in the front of the brain, around the same area that Ferrier cut out from his monkeys. Because the monkeys had a similar brain structure to humans, Ferrier believed that his map of the monkey brain would also hold true for humans. But he wanted to know for sure that the frontal region in monkeys was also responsible for inhibition in humans. Ferrier didn’t have an fMRI scanner, so he couldn’t see what was happening in the human brain, and he couldn’t cut into the brains of live human subjects without going to jail.

Fortunately for Ferrier, he heard how Phineas’ behavior was similar to his ablated monkeys, and he wondered if Phineas’ injuries would match up. When he looked at photographs of Phineas’ skull it was a true Eureka moment. Ferrier believed that the damage to Phineas matched the same region as his monkeys, and wasted no time in publicizing his discovery in a series of sensational lectures.

Phineas is so important to the story of working memory because he demonstrated that when the PFC is damaged, so is working memory. After the rod shot through the front of Phineas’ brain, he became unable to inhibit his anger, he acted impulsively, he was unable to execute his plans, he swore excessively, he acted in a socially inappropriate manner, and appeared unintelligent for his age and experience. His behavior matches up with those who have severely impaired working memory. The behavioral evidence combined with analysis of the probable trajectory of the steel rod strongly suggests that his PFC was injured and that this had seriously degraded his working memory. When his working memory changed, so too did Phineas (see Damasio, Grabowski, Frank, Galaburda, & Damasio, 1994). Unfortunately, Ferrier neglected his thesis, and the study of what came to be known as working memory lay dormant for over eighty years.

The Modern-Day Phineas

In the 1960s, psychologists believed that short-term memory was responsible for helping us to learn new information. The prevailing idea was that we learn and store new information with short-term memory and it is transferred to long-term memory.

Then, in a remarkable repeat of history, a modern-day Phineas emerged. When KF drove his motorcycle into a tree in the 1960s, psychologists were once again offered a clue to how the brain works. Although KF walked away alive, he sustained serious brain injuries. His memory, in particular, was severely affected. For example, in a gold standard test of short-term memory—remembering a string of numbers in the correct sequence—KF could usually remember only two numbers. As a result, he was diagnosed with having a short-term memory deficit.

The prevailing view of the time was that short-term memory functioned like working memory: it was a mental workspace to remember and process information. It also served as a gateway to transfer new information into long-term memory. A major problem with this view soon became apparent. Patient KF continued to function well in other areas of his life. He could even learn new information, sometimes even faster than normal controls, and could still remember this information months later. How could this be if his short-term memory (which was supposed to be his gateway to learning new information) was impaired?

Touchdown Moment

This is the question that two British psychologists, Alan Baddeley and Graham Hitch, came to ask. In the early 1970s in the UK, American football was unfamiliar, and very few people knew about a linebacker, Hail Mary, or running back. Though football fascinated him, Baddeley hadn’t grown up playing it or watching it on television. It took him some time to understand the different plays and terminology, in part because he could only find his games on the radio. He describes how listening to the commentator and reconstructing the plays in his head was a very mentally demanding task (A. Baddeley, personal communication, February 10, 2011).

One day, while driving, he was so engrossed with listening and imagining the game on the radio that he hadn’t realized his car was weaving around the road! But he didn’t crash. He was able to recover and realized that something more than his short-term memory was at work. When he was driving and listening to the game, he was doing more than remembering information; he was switching between two different tasks. There had to be something else—another brain function that could let him jump between two different things.

That was the “touchdown moment” for Baddeley. He realized that we need a “controller,” something that can keep a goal in mind, bring in cognitive resources from different parts of the brain, and also manage incoming information. So Baddeley and Hitch started formulating their view of working memory as the controller that allows us to do all these things.

But Baddeley and Hitch couldn’t write a paper about listening to the radio while driving. To prove that short-term memory couldn’t account for his experience, he would have to demonstrate it in an experiment. The only problem was that brain injury patients who had damaged their short-term memory were so few and far between that it would be hard to prove they had a controller. So they came up with an innovative plan to “create” short-term memory deficits in undergraduate psychology students. Using the same number task that patient KF did, Baddeley and Hitch gave the students increasingly long number sequences until their memory failed them and their performance looked very much like a patient with a short-term memory deficit. At the same time, they gave students logic and reasoning problems. If they could do the problems with their overloaded short-term memories, it would prove that something else was at work. Baddeley and Hitch discovered that the students could still do the problems (Baddeley & Hitch, 1974).

Baddeley and Hitch’s framework for working memory was almost not published. Scientific journals typically accept well-established and empirically solid results, not speculative ...

Table of contents

• Cover Page
• Half Title page
• Series page
• Title Page
• Copyright Page
• Contents
• List of Contributors
• Foreword
• Part I Working Memory The Connected Intelligence
• Part II Working Memory Across the Lifespan
• Part III Working Memory and Expertise
• Part IV Working Memory and the Body
• Part V Working Memory and Decision Making
• Part VI The Future of Working Memory Training
• Index