Long-Term Memory Problems in Children and Adolescents E-Book

Milton J. Dehn

• Herausgeber: John Wiley & Sons
• Kategorie: Geisteswissenschaft
• Sprache: Englisch

Seitenzahl: 766

Veröffentlichungsjahr: 2010

Beschreibung

"This book will be a valuable resource for psychologists and educators who work with children or adolescents who are having difficulties with memory and learning. Translating theory and research into practice is a talent that Dr. Dehn possesses and we will benefit from his professional skills." -- From the Foreword by Daniel C. Miller, PhD, ABPP, ABSNP, NCSP AN INDISPENSABLE GUIDE THAT EXAMINES THE EFFECT OF LONG-TERM MEMORY FUNCTIONS ON CHILDREN'S LEARNING Long-Term Memory Problems in Children and Adolescents: Assessment, Intervention, and Effective Instruction is the first book of its kind for psychologists, school psychologists, and special education teachers who need an overview of long-term memory as it relates to learning and education. It presents the best practices for assessing long-term memory functions, as well as selecting and using evidence-based instructional practices with memory-impaired students. This useful and timely guide bridges theory and practice to provide professional guidance with coverage of: * Risk factors that can lead to long-term memory impairments * How long-term memory relates to other types of memory * The subcomponents and processes of long-term memory and how they relate to academic achievement * What is known about the neuroanatomy of how memories are formed * The developmental trajectory of memory and learning * Common types of memory dysfunction * Memory assessment strategies, interventions for memory problems, and instructional practices that support memory Author Milton Dehn draws on his extensive experience as a trainer and workshop presenter, school psychologist, and educator to present both the theory and research on long-term memory in children and adolescents in this book. Specific, step-by-step guidance and hands-on case studies enable professionals to identify how memory can be assessed as well as the interventions that can be linked to the results of the assessment.

Leseprobe

Table of Contents

Title Page

Copyright Page

Dedication

Foreword

Preface

Acknowledgments

CHAPTER 1 - Introduction and Overview

MEMORY AND LEARNING

MEMORY PROBLEMS

APPLYING MEMORY RESEARCH IN THE CLASSROOM

OVERVIEW OF THE CHAPTERS

LEARNING OBJECTIVES

CHAPTER 2 - Memory Systems and Processes

THE FLOW OF INFORMATION

SENSORY MEMORY

SHORT-TERM MEMORY

WORKING MEMORY

LONG-TERM MEMORY SYSTEMS

LONG-TERM MEMORY PROCESSES

FORGETTING

INTERFERENCE

THE ORGANIZATION OF MEMORY

IMPLICATIONS FOR MEMORY ASSESSMENT

EDUCATIONAL AND TRAINING IMPLICATIONS

MEMORY FUNDAMENTALS

CHAPTER 3 - Memory Neuroanatomy, Development, and Dysfunction

THE NEUROANATOMY OF MEMORY

SHORT-TERM AND WORKING MEMORY STRUCTURES

NEUROLOGICAL PRINCIPLES OF MEMORY

THE DEVELOPMENT OF LONG-TERM MEMORY

DEVELOPMENT OF METAMEMORY AND EFFECTIVE STRATEGIES

FUNDAMENTALS OF MEMORY DEVELOPMENT

RELATED COGNITIVE PROCESSES

MEMORY DYSFUNCTION

CHAPTER 4 - Risk Factors for Memory Impairments

ACQUIRED BRAIN INJURY

MEDICAL CONDITIONS

DEVELOPMENTAL DISORDERS

MENTAL DISORDERS

SUBSTANCE ABUSE

FINDINGS THAT APPLY TO ALL AT-RISK GROUPS

ASSESSMENT IMPLICATIONS

IMPLICATIONS FOR INTERVENTIONS AND CLASSROOM INSTRUCTION

CHAPTER 5 - Long-Term Memory Assessment Strategies

A COMPREHENSIVE EXPLICIT MEMORY ASSESSMENT

PLANNING A PERSONALIZED ASSESSMENT

CROSS-BATTERY AND SELECTIVE TESTING

MEMORY ASSESSMENT CHALLENGES

COLLECTING MEDICAL, DEVELOPMENTAL, AND ACADEMIC HISTORY

INTERVIEWING TEACHERS, PARENTS, AND STUDENTS

OBSERVATION

ASSESSMENT OF METAMEMORY AND STRATEGY DEVELOPMENT

COLLECTING CLASSROOM EXAMINATION DATA

GUIDELINES FOR ADMINISTERING STANDARDIZED MEMORY TESTS

GENERAL GUIDELINES FOR INTERPRETATION OF TEST RESULTS

ANALYSIS OF MEMORY TEST SCORES

SPECIFIC GUIDELINES FOR INTERPRETATION OF MEMORY ASSESSMENT RESULTS

CASE STUDY

CHAPTER 6 - Assessing Long-Term Memory With Standardized Tests

CALIFORNIA VERBAL LEARNING TEST—CHILDREN’S VERSION (CVLT-C)

CHILDREN’S MEMORY SCALE (CMS)

THE NEPSY II

THE RIVERMEAD BEHAVIOURAL MEMORY TEST FOR CHILDREN (RBMT-C)

TEST OF MEMORY AND LEARNING, SECOND EDITION (TOMAL-2)

WIDE RANGE ASSESSMENT OF MEMORY AND LEARNING, SECOND EDITION (WRAML2)

WECHSLER MEMORY SCALE®-FOURTH EDITION (WMS®-IV)

COGNITIVE, INTELLECTUAL, AND ACHIEVEMENT BATTERIES

OTHER SCALES WITH LONG-TERM MEMORY MEASURES

CHAPTER 7 - Interventions for Memory Problems

DESIRABLE OUTCOMES FOR MEMORY INTERVENTIONS

FACTORS RELATED TO SUCCESS

CONCERNS ABOUT MEMORY INTERVENTIONS

SELECTING AND DESIGNING INTERVENTIONS

SETTING GOALS AND MEASURING PROGRESS

GENERAL MEMORY STRATEGY TRAINING RECOMMENDATIONS

METAMEMORY: THE CORNERSTONE OF THE INTERVENTION

DEMONSTRATING THE EFFICACY OF MEMORY STRATEGIES

PROMOTING GENERALIZATION AND MAINTENANCE

LENGTH OF TRAINING

MEMORY STRATEGIES

MNEMONICS

COMPUTERIZED INTERVENTIONS

HOME INTERVENTIONS

EXTERNAL MEMORY AIDS

PSYCHOPHARMACOLOGICAL TREATMENTS

MEMORY INTERVENTIONS FOR TRAUMATIC BRAIN INJURY

INTERVENTIONS FOR OTHER DISABLED AND AT-RISK POPULATIONS

MATCHING INTERVENTIONS WITH MEMORY DEFICITS

A TYPICAL INTERVENTION

CHAPTER 8 - Classroom Instruction That Supports Memory

THE MNEMONIC CLASSROOM

METAMEMORY INSTRUCTION

INSTRUCTIONAL PRACTICES THAT ENHANCE MEMORY

STUDY SKILLS THAT ENHANCE MEMORY

INSTRUCTIONAL METHODS FOR SEVERE MEMORY IMPAIRMENTS

ACCOMMODATIONS AND MEMORY AIDS

TEACHING MEMORY STRATEGIES

TEACHING MNEMONICS

INSTRUCTION THAT REDUCES WORKING MEMORY LOAD

SUMMARY: LONG-TERM MEMORY PRINCIPLES AND RECOMMENDATIONS FOR EDUCATORS

CHAPTER 9 - Case Studies and Recommendations

ASSESSMENT CASE STUDY

INTERVENTION CASE STUDIES

ILLUSTRATIVE REPORT

RECOMMENDATIONS FOR FUTURE RESEARCH

RECOMMENDATIONS FOR MEMORY TEST DEVELOPMENT

APPENDIX A - Memory Assessment Plan

APPENDIX B - Analysis of Memory Testing Results

APPENDIX C - Conversion Table: Scaled Scores to Standard Scores*

References

Index

This book is printed on acid-free paper.

Copyright © 2010 by John Wiley & Sons, Inc. All rights reserved.

Published by John Wiley & Sons, Inc., Hoboken, New Jersey. Published simultaneously in Canada.

No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, [phone], fax [phone], or on the web at www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, [phone], fax [phone].

Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation. You should consult with a professional where appropriate. Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages.

This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold with the understanding that the publisher is not engaged in rendering professional services. If legal, accounting, medical, psychological, or any other expert assistance is required, the services of a competent professional person should be sought.

Designations used by companies to distinguish their products are often claimed as trademarks. In all instances where John Wiley & Sons, Inc., is aware of a claim, the product names appear in initial capital or all capital letters. Readers, however, should contact the appropriate companies for more complete information regarding trademarks and registration.

For general information on our other products and services please contact our Customer Care Department within the United States at [phone], outside the United States at [phone] or fax [phone].

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. For more information about Wiley products, visit our website at www.wiley.com.

Library of Congress Cataloging-in-Publication Data:

Dehn, Milton J.

Long-term memory problems in children and adolescents : assessment, intervention, and effective instruction / Milton J. Dehn.

p. cm.

Includes bibliographical references and index.

ISBN 978-0-470-43831-2 (pbk.); 978-0-470-77048-1 (ebk); 978-0-470-87206-2 (ebk); 978-0-470-87207-9 (ebk)

1. Long-term memory in children. 2. Short-term memory in children. 3. Long-term memory in adolescence. 4. Short-term memory in adolescence. I. Title.

BF723.M4D44 2010

155.41’1312—dc22

2010005948

For my children, Sonya, Alisha, Ted, and Amber. May the good memories we share last a lifetime.

Foreword

Long-term memory plays a crucial role in the formation and maintenance of our personal identity. Recalling the name of our first-grade teacher or a second cousin, remembering where we went on vacation the past summer, or remembering our first kiss are all memories of past personal experiences. Memories provide us a frame of reference based on experience and help shape our personalities. Long-term memory also includes over-learned and automatic daily activities such as remembering how to brush your teeth or drive to work. And finally, long-term memory includes our encyclopedic knowledge of information such as who the first president was or how many days there are in a calendar year.

We often take for granted the sophisticated neurological system within the brain that is required to make long-term memory a seamless process when our ability to form, store, and retrieve long-term memories is intact. However, when memory systems become impaired or disrupted there can be devastating effects on the acquisition of new learning or the retrieval of previously stored information. Dr. Dehn’s book will provide clinicians and educators a useful and timely guide on how to identify and treat memory impairments.

In this book, Dr. Dehn provides the reader with a framework of how long-term memory relates to other types of memory (e.g., short-term memory, working memory, etc.). He has also discussed the subcomponents of long-term memory and how they relate to academic achievement. Dr. Dehn reviews what is known about the neuroanatomy of how memories are formed, the developmental trajectory of memory and learning, and the common types of memory dysfunction. An important part of this book is the chapter on recognizing the risk factors that can lead to long-term memory impairments. If a memory dysfunction is suspected, it is important to pick the proper assessment instrument to confirm the presence or absence of the memory difficulties. Dr. Dehn provides a concise review of the subcomponents of long-term memory that should be assessed and reviews the major standardized instruments that assess memory and learning.

Clinical practitioners and educators have a wide variety of assessment instruments designed to assess memory and learning, many of which are theoretically based and psychometrically sound. However, the identification of memory and learning deficits cannot be the end point. Once a memory deficit has been identified, educators need guidance on what evidence-based intervention strategies are readily available. Assessment must be linked to prescriptive intervention. Dr. Dehn provides a quality review of educational interventions designed to improve memory functions. Finally, Dr. Dehn presents several case study examples that illustrate how memory can be assessed and what interventions can be linked to the results of the assessment.

Long-Term Memory Problems in Children and Adolescents: Assessment, Intervention, and Effective Instruction by Milton Dehn will be a valuable resource for psychologists and educators who work with children or adolescents who are having difficulties with memory and learning. Translating theory and research into practice is a talent that Dr. Dehn possesses, and we will benefit from his professional skills. This book will be a useful addition to Dr. Dehn’s other book, Working Memory and Academic Learning: Assessment and Intervention (2008), published by John Wiley and Sons, Inc.

Daniel C. Miller, Ph.D., ABPP, ABSNP, NCSP

Preface

One day when I was reading an article about recently discovered cases of developmental amnesia (a rare condition without identified cause in which children have extreme difficulty remembering), I was reminded of students with severe learning disabilities whom I had often encountered during my years of work as a school psychologist. It struck me that I had been missing something when I evaluated those students and made recommendations for their educational programs, and I began to wonder how many other children with academic learning and performance problems actually had underlying memory impairments. When I worked in the schools, I, like most school psychologists, seldom assessed students’ long-term memory functions. In fact, I had never been trained to do so, probably because there were no long-term memory batteries for children in existence when I was in graduate school. As I switched to private practice, I began paying more attention to the possibility of memory problems when children were brought in for evaluations and tutoring. When I administered memory scales to these children, I was astounded to discover that about half of children with significant learning problems had deficits in working memory and that a sizable number also had impairments in long-term memory. I felt for these children. So often, their poor academic performance had been attributed to everything but neurologically based memory problems. Furthermore, those who were trying to help them were neglecting the memory problems.

With all of the resources our culture invests in the education of children and adolescents, I find it incredible that educators, parents, psychologists, and everyone else involved in the education and psychology of youth do not pay more attention to the most important variable in the learning equation—memory. Obviously, learning and memory go together; one cannot exist without the other. Yet, initial learning does not guarantee long-term retention and recall. Some students who learn easily also forget quickly, while others who struggle with learning retain the information well once it reaches long-term memory. Children and adolescents who forget too much or who struggle with learning because of memory problems are not difficult to understand or to help. Adults who want to understand and help can begin by learning more about memory. Books and research articles on memory from the fields of neuroscience, neuropsychology, cognitive psychology, and educational psychology are abundant and readily available. The applied science also exists. We know how to help children learn and remember more effectively. For example, one approach involves teaching strategies that improve encoding and retrieval. If what is known about memory functions was consistently applied in the classroom and everyday life, learning and memory would be enhanced, and wasted effort and frustration with learning would be reduced.

Perhaps scant attention has been paid to memory assessment, intervention, and memory-enhancing instruction because of the pervasive belief that memory impairments in youth are so rare. Everyone knows that children and adolescents who have experienced a traumatic brain injury are likely to have persistent memory problems that will make learning a challenge. But what everyone doesn’t know is that there are many other children who fail to realize their academic potential because they have memory dysfunctions or because they have not learned how to effectively utilize their memory capabilities. How many? There’s almost no hard data to answer that question. One study in the United Kingdom found that up to 5.9% of normal, elementary-age children had specific long-term memory difficulties (Temple & Richardson, 2006). Given that approximately one quarter of K-12 students struggle with academic learning and perhaps half of them have underlying memory problems, I estimate that as many as 10 to 12% of students have long-term memory impairments or don’t know how to effectively use their memory abilities. Also, the large numbers of children with disorders and health conditions, such as diabetes, who are at-risk for long-term memory problems, is undeniable (see Chapter 4). Whatever the exact figure, it is evident to me that we are failing to identify and serve a population of children who are failing to achieve because of underlying memory problems. How could we be missing so many children with memory impairments? The answer is that we and the students themselves misattribute the behaviors and problems to factors such as motivation or low average intelligence. The situation is similar to Attention Deficit Hyperactivity Disorder (ADHD). We were unaware of the existence of ADHD in so many children until we learned what it was and how to diagnose it. Prior to “discovering” ADHD, we misattributed the behaviors and problems it causes.

This book is not solely about the children and adolescents with diagnosable memory disorders or severe memory dysfunctions. Rather, this book is primarily about the large numbers of children and adolescents of school age who have mild to moderate difficulties with one or more aspects of long-term memory. Although the memory difficulties of the majority of these students go unrecognized, their memory challenges often impede their academic learning and the long-term retention of knowledge that they will need throughout their lives. In addition to those students who have neurologically based memory impairments, there are many other students who are not realizing their scholastic potential because they have not discovered or learned how to use effective memory strategies and mnemonics. Often these students are naïve in regards to their memory functions and don’t understand how to regulate them. A minimal amount of metamemory and strategy instruction may be all that is necessary to improve their retention and recall.

I have written this book so that those adults who educate and work with youth can learn more about identifying, helping, and educating the memory-impaired children and adolescents that we so often overlook. This book is written for school psychologists, clinical psychologists, neuropsychologists, special educators, classroom teachers, and related professionals who teach and work with children and adolescents. Although the school environment is emphasized in this text (as it is where children and adolescents spend most of their daytime hours), the information also can be applied in medical and private-practice settings. In this book I have mainly attempted to: (a) describe the various memory systems and processes; (b) explain how memory works at the neurological level; (c) interpret memory research; (d) identify the disorders and conditions that put children at-risk for memory problems; (e) emphasize the importance of metamemory development and the acquisition of effective memory strategies; (f) structure selective, cross-battery testing of memory so that memory assessment is comprehensive but efficient; (g) explain how to interpret results from various memory scales; (h) review contemporary memory scales that are designed for children and adolescents; (i) apply interventions to school settings; and (j) encourage educators to adopt more memory-enhancing instructional practices (see Chapter 1 for an overview of each chapter). For those who will pursue memory assessment, intervention, and instruction, this book is intended to be a resource and reference. Those who read and apply the information in this book will acquire enough expertise in long-term memory functions to effectively identify and help children and adolescents with memory problems.

Acknowledgments

I am indebted to my soul mate and intellectual partner, Paula A. Dehn, whose ideas, encouragement, and support made this book a reality. I wish to thank Benjamin R. Burns for gathering the literature, editing the manuscript, and providing feedback from a practitioner’s viewpoint. I am also grateful to Joci Newton for providing feedback on chapters.

CHAPTER 1

Introduction and Overview

Memory is an unique psychological construct and cognitive function in that almost everyone is interested in or concerned about his or her memory at some point in life. Nearly every person, even a 4-year-old child, has a concept of memory and an awareness of how his or her memory functions. Almost everyone knows that short-term memory is limited in capacity and duration, that long-term memory has an immense capacity, and that memories can last for a lifetime. Even a young child knows that people quickly forget most information and that there are strategies that help memories endure. Nearly everyone also understands that memory is necessary for learning to occur and that personal memories define each individual. Yet, most children have misconceptions about memory and how it functions, misconceptions that can be detrimental to learning. For example, many children erroneously believe that the intention to remember something will increase the probability of later retrieval or that delayed recall will be just as strong as immediate recall. Similarly, there are disagreements about memory structure and functions among researchers and practitioners who are concerned with human memory. For example, there has been an ongoing dispute about how memories become solidified through the process of consolidation. Most of the discord arises from the fact that memory is extremely complex, consisting of several systems, with each system serving different purposes and incorporating somewhat different cognitive processes (Tulving, 1985). Indeed, memory is not a single homogenous entity but a composition of many distinct interacting brain systems (Emilien, Durlach, Antoniadis, Van Der Linden, & Maloteaux, 2004). It is only recently that neuroscientists and other researchers have begun to unravel the incredibly sophisticated mental function known as memory.

Driven by advances in neuroscience and brain imaging, the past 20 years has seen a resurgence of research on the memory functions of children and adolescents. Although many of the contemporary investigations have focused on working memory (see Dehn, 2008), a sizable portion concern long-term memory systems and processes and how they relate to academic learning. The subjects of these studies are no longer limited to children with severe acquired brain injuries. A variety of at-risk populations (see Chapter 4), as well as normal learners, have been studied. A few investigations have reported on low incidence disorders, such as developmental amnesia, while numerous studies have focused on children with more common medical conditions, such as childhood diabetes, that can damage the hippocampus (the brain’s key long-term memory structure). Also, more studies are taking place in educational environments in an attempt to understand how memory impairments affect academic learning. Furthermore, there has been an explosion of neuropsychological research on the memory dysfunctions of adults with debilitating medical conditions, such as Alzheimer’s. Although the memory problems suffered by adults are somewhat different from those experienced by youth, most of the empirical findings are applicable to children because long-term memory systems and processes are essentially in place by 6 years of age. For example, depression affects memory functioning in youth in much the same way it affects the memory functioning of adults. As the number of references in this text will attest to, there is an abundance of scientific literature on populations with memory impairments, the characteristics of memory disorders, measurement of memory, interventions, and even on instructional practices that enhance memory for what has been learned. This scientific literature, along with books like this one, allows psychologists, educators, and related professionals to more fully understand how to identify and help youth with memory problems.

The growing interest in memory has made many psychologists and related practitioners realize that there are many school-age youth with unidentified memory impairments. This realization, coupled with advances in understanding memory functions, has led to a growing demand for memory assessment instruments and to the refinement of existing measures. For example, more cognitive scales have recently added working memory subtests, and memory batteries like the Wechsler Memory Scale®-Fourth Edition (Wechsler, 2009) have incorporated the latest empirical findings about long-term memory. Despite the availability of technically adequate tools, practitioners who evaluate children and adolescents seldom conduct comprehensive assessments of memory. Consequently, many students with long-term memory dysfunctions remain unidentified or are misidentified. For example, students receiving educational services for learning disabilities are likely to have underlying memory impairments. Yet, this significant learning impediment often goes unrecognized. In addition, there are significant numbers of children and adolescents with memory problems who are never referred because they appear to be “normal” students. In the United Kingdom, Temple and Richardson (2006) screened more than 300 normal children aged 8 to 12 years for episodic and semantic memory problems. Temple and Richardson discovered that 5.8 to 5.9% of the students with average IQ had specific memory difficulties. Given that this study excluded children with below-average IQ and identified learning problems, the number of students actually suffering from memory problems may be twice as high. One reason for the under-identification is that young children rarely complain of memory problems (Middleton, 2004). Even adolescents who have had memory deficits all their lives may be unaware of their deficits. Another reason students with memory problems are not referred or identified is that their academic learning and performance problems are attributed to other causes.

Furthermore, beliefs regarding the efficacy of memory interventions and instruction may limit the number of students referred for a memory assessment, based on the belief that there’s no point in identifying problems that can’t be remediated. Many educators and psychologists assume that there are no scientifically based interventions for memory impairments and dysfunctions, or that such interventions cannot be applied in an educational environment. Neither assumption is true; efficacious memory interventions that can be applied in education settings are well documented in the scientific literature (see Chapters 7 and 8). Adding to the lack of identification and intervention is the No Child Left Behind and Response-to-Intervention (Brown-Chidsey & Steege, 2005) educational movements, where the emphasis is strictly on academic skills interventions. Proponents of Response-to-Intervention argue that the cognitive cause of a student’s learning problems is irrelevant and that generic academic interventions will work regardless of the underlying reasons for the learning problems. Sadly, this philosophy may deprive many students of the understanding, assistance, and interventions that might allow them to succeed (Kipp & Mohr, 2008). For instance, some reading disabilities are due to long-term memory problems rather than deficient phonological processing skills. Addressing the long-term memory problems of such children will be more beneficial than additional training in phonemic awareness, a skill they already possess.

In the school environment, the rapid acquisition and long-term retention of facts and concepts is fundamental to success. The ability to rapidly and continuously process new information and store it for later recall is essential in the relentlessly demanding educational environment where a new memory may need to be created as often as once every 10 seconds (Newall & Simon, 1972). Every aspect of acquiring and applying academic skills and knowledge depends on adequately functioning long-term memory structures and processes. Reading decoding, reading comprehension, mathematics, spelling, basic writing skills, written expression, and academic subjects, such as science and social studies, all require effective encoding, storage, and retrieval of vast amounts of information. For example, progress in mathematics depends on the retention and efficient recall of basic math facts, and advances in written communication depend on remembering grammatical rules. The acquisition of academic knowledge depends on both the episodic (memory for events) and semantic (memory for facts and concepts) systems, as well as the effective functioning of memory processes, such as encoding, consolidation, and retrieval (see Chapter 2). Because many semantic memories result from the accumulation of episodic memories acquired during multiple learning events, episodic memory ability (once thought to be autobiographical only) is just as important for classroom learning as semantic memory. For example, a student’s recall of the personal experiences and contextual cues stored as episodic memories can facilitate retrieval of academic knowledge stored in semantic memory (Hood & Rankin, 2005). Thus, all long-term memory systems, including the subconscious implicit memory system (see Chapter 2) play a role in academic learning and performance. Moreover, the short-term and working memory systems are indispensible when students are committing information to memory (Dehn, 2008).

When students experience learning and memory problems in the classroom, there is often an underlying impairment, dysfunction, or inefficiency in encoding, consolidating, or retrieving information. That is, apparent long-term memory problems are seldom due to an inability to store a tremendous amount of information for long periods of time. The first potential impediment is impaired encoding, which can arise from ineffective encoding procedures or from a less than fully functional hippocampus. Encoding transfers information from short-term and working memory into long-term storage. Many times, the target information has been encoded but it is difficult to recall over time because it was not encoded in a manner that facilitates retrieval. At other times, encoding may be functioning properly but memories are not maintained because they are not integrated with related memories or are not transferred to permanent storage regions in the brain, a process known as consolidation (see Chapter 2). Difficulties retrieving information from long-term storage can also be the source of memory performance problems. In addition, poor self-awareness and self-regulation of memory functions (known as metamemory), along with the use of ineffective memory strategies, can reduce efficiencies and exacerbate minor memory problems. Also, subaverage related cognitive and executive processes, such as inhibitory control, can further complicate matters. Consequently, ferreting out the impaired processes underlying memory problems can be an assessment challenge.

MEMORY AND LEARNING

Differentiating Memory and Learning

There is no learning without memory, and there is no memory without learning. Memory, the indicator that learning has occurred, can be inferred from the ability to recall information, performance on a measure of retention, or a change in behavior. The bilateral relationship between learning and memory is not limited to directed efforts to acquire and retain facts and knowledge. Because people learn from their experiences, the interdependency of memory and learning exists any time humans are mentally processing information. Although learning and memory are tightly interwoven and often viewed as equivalent constructs, it is possible to distinguish between the two. As memory expert L. R. Squire (1987, p. 3) put it, “Learning is the process of acquiring new information, while memory refers to the persistence of learning in a state that can be revealed at a later time.” In this book, a similar division of learning and memory is applied. “Learning” refers to the acquisition of knowledge; in other words, getting information into memory is considered the learning phase. Because learning depends primarily on the memory process of encoding, learning and encoding are viewed as essentially equivalent. Of course, learning opportunities are seldom limited to a single episode. Multiple opportunities to learn mean that consolidation and retrieval processes also become involved, as initially learned information is recalled, restructured, and reinforced. Nonetheless, in this text “learning” mainly refers to the initial learning event and is mainly associated with encoding. In contrast, “memory” includes and depends on the learning (encoding) phase, but the term is mainly applied to retention processes and the ability to recall information when needed. Thus, learning refers to the initial acquisition and immediate retention of new material, as measured within seconds and minutes; whereas, memory involves retrieval of that learning after an interval of several minutes, hours, or days. Consequently, learning is associated more with short-term than with long-term memory, and memory is mainly associated with retention of learning over extended intervals of time. Evidence for the separability of learning and memory is provided by the fact that individual differences in learning do not always translate into similar differences in memory. For example, an individual who learns new material very quickly may not retain the material as well as an individual who takes longer to learn it. Furthermore, many variables that have sizable effects on the rate of learning appear to have very little, if any, effect on how long information is retained in memory (Bloom & Shuell, 1981). Consequently, it is possible to obtain substantial improvements in memory without corresponding improvements in initial learning and vice versa.

Learning Rate and Forgetting

As learning proceeds, more and more information is retained and recalled. Each round of exposure, practice, or study of new material or a new skill produces higher recall. The degree of improvement over multiple learning episodes is known as the learning rate, and plotting learning across trials produces a learning curve. Learning curves demonstrate that acquisition of new knowledge or skills increases rapidly at first but then levels off, with each subsequent round of practice, review, or study producing smaller and smaller improvements in performance (Anderson, 2000). Despite diminishing improvements, the old adage that “practice makes perfect” definitely holds true for learning and memory: Recall of information improves the more it is practiced. Even after a learner has reached 100% recall of the material, further practice improves memory, as indicated by faster retrieval speed. Moreover, with each round of practice, the skill or knowledge is relearned more quickly, indicating that memory for the material is becoming stronger and stronger. Although most skills and knowledge eventually become ingrained in memory after numerous rounds of practice, rehearsal, review, or study, there are scientifically based learning and encoding methods that can improve the efficiency and effectiveness of learning (see Chapters 7 and 8). For example, strategies that involve in-depth processing of information produce better recall than rote learning. Given the fact that most students do not engage in enough study to fully master material, strategies that enhance learning and memorability are definitely advantageous. For students with memory problems, the application of effective strategies becomes even more important.

According to classical learning theory, a faster learning rate translates into slower forgetting, and slower learning is connected with faster forgetting. However, for many students, learning rate and forgetting rate may actually have a weak and inconsistent relationship (Brainerd & Reyna, 1995). In fact, Shuell and Keppel (1970) reported only minimal differences between fast and slow learners’ rates of forgetting. Thus, assumptions about retention of information should not be based on rate of learning. Some individuals are fast, and apparently successful, learners but don’t retain new learning very well. Others are slow learners but successfully retain what they have acquired. Instead of initial learning speed, the number of additional learning events required to fully retain material may be a better predictor of forgetting rate. A potential confound when examining these relationships is the fact that students who learn more slowly are usually provided with more learning opportunities. The fact that learning opportunities increase as learning rate decreases may compensate for the faster forgetting rates among slow learners (Brainerd & Reyna, 1995).

One of the goals of education is for students to retain important knowledge and skills for a lifetime. When learning is effective, students with normal memory functioning are capable of just that. In studies of very long-term retention of academic knowledge (reviewed in Cohen, 2008a), a prominent finding is that the level of original learning predicts the degree of retention. That is, students who initially learned more, mastered the material, or acquired more advanced knowledge, remembered more over extended periods of time. Other factors that influence long-term retention include the amount and spacing of the original training, the level of expertise originally attained (grades being one method of determining this), and the extent to which the information can be reconstructed from schemas. In one study of Spanish language retention, individuals who had not used Spanish during their lifetime were tested 50 years after initially studying it. Amazingly, 40% of the original knowledge could still be recalled and 60% of it was recognized (Bahrick, 1984). These longitudinal studies reveal that knowledge declines exponentially for about three to six years and then stabilizes before a final slight decline after 30 years.

MEMORY PROBLEMS

As used in this book, the term “memory problems” is used in a generic, inclusive sense. Memory problems exist whenever an individual has significantly subaverage ability in one or more aspects of memory, as indicated by subaverage performance on a formal measure of memory, difficulties performing tasks that require effective memory functioning, or difficulties retaining scholastic learning at a normal level. Memory problems are especially indicated when the subaverage performance or difficulty is also a significant intra-individual weakness relative to overall learning potential or intelligence. Thus, memory problems include memory weaknesses, impairments, deficits, disorders, dysfunctions, and deficiencies (see Chapter 3 for further clarification). It is presumed that there is either a neurological impairment underlying the memory problem or ineffectual use of normal memory capabilities. Memory problems in children and adolescents become worthy of concern, and assessment and intervention, when they either impede academic learning or impair daily functioning.

Because memory problems cover a continuum from mild to severe, they can be much more than minor inconveniences. In extreme cases, such as global amnesia, the individual may have difficulty coping with daily routines. In children and adolescents, even mild to moderate memory problems can impair many types of learning, leading to lifelong limitations. For example, a verbal memory impairment in a young child will affect the development of language and literacy. However, even significant memory problems can be difficult to detect and identify, leading to some assessment and diagnostic challenges. For example, not all memory problems are evident during early childhood. Most tend not to become apparent until learning challenges are encountered during the school years. Even then they are likely to be attributed to other factors. Also, many memory problems are subtle, which is why they are misunderstood. Subtlety, however, does not mean that the memory problems are not interfering with the effective learning and functioning of otherwise normal individuals. Nor does subtlety obviate the need for investigation, evaluation, and appropriate interventions and instruction. Educators and psychological practitioners need to remember that subtle or mild memory problems have an additive effect during the educational years, with the end result being fewer acquired skills, less knowledge, and failure to achieve important life goals.

Memory problems and their undesirable consequences may occur even when there is no underlying memory impairment. There are times when problems with encoding, storing, and retrieving information are not due specifically to abnormalities in the brain’s memory structures. What is observed as a limitation in one or more memory structures or functions may actually stem from a broader cognitive disability or from a domain-specific impairment. For example, a child or adolescent with a general intellectual impairment is unlikely to demonstrate average memory performance. Also, individuals with a general verbal processing disability, such as those with a language impairment, are typically going to have weaknesses in any type of verbal memory function. Separating memory functions from the influences of related cognitive processes should be attempted during assessment, but whether or not poor memory performance is part of a broader cognitive disability is somewhat irrelevant. The fact is that students with cognitive disabilities benefit from memory interventions and memory-based instruction as much as students with intra-individual memory deficits. Therefore, those with cognitive disabilities also should be considered as having memory problems and provided with appropriate services. Finally, there is another group of children and adolescents whose subaverage memory performance is due to neither cognitive processing limitations nor specific memory impairments. These are youth with otherwise normal cognitive and memory abilities who have not yet figured out how to effectively utilize their memory capabilities due to delayed metamemory development or failure to apply effective strategies. In this book, they are also classified as having memory problems.

APPLYING MEMORY RESEARCH IN THE CLASSROOM

For decades, research by experimental, cognitive, and educational psychologists, as well as neuropsychologists and neuroscientists has documented the efficacy of numerous memory interventions, strategies, mnemonics, and instructional practices. Yet, many of these evidence-based practices have not been consistently applied in the classroom, an environment that continually places high demands on memory. The lack of application originates with teacher training programs that pay little attention to psychological research on memory and the educational applications of memory research. Consequently, relevant empirical findings and evidence-based practices have had very little influence on pedagogy and instructional practices in the classroom. Although effective teacher behaviors and evidence-based instructional practices generally support memory functioning (Rosenshine, 1995), approaches that specifically address memory functions can further enhance the academic learning and performance of all students (see Chapter 8). Teachers who address memory challenges, teach memory strategies and mnemonics, and adopt more instructional practices that specifically support memory, may ultimately reduce their burdens rather than adding to them, mainly because memory-based methods should increase the efficiency of student learning. Even students recognize the benefits of memory-based instruction. For instance, Scruggs and Mastropieri (1990) reported that the learning disabled students in their study greatly preferred memory-based instruction over traditional instruction. In reality, classroom-based memory interventions may be the only viable approach to serving the needs of students with memory impairments, as the funds, resources, and personnel available for pull-out services is very limited. Accordingly, one of the primary objectives of this book is to provide educational consultants, school psychologists, special education teachers, and classroom teachers with all of the information they need to successfully implement evidence-based memory practices in the classroom.

OVERVIEW OF THE CHAPTERS

Chapter 2, Memory Systems and Processes, describes and differentiates the functions of the major memory systems, the types of memory that comprise each system, and the memory processes involved. After discussing the structure, organization, and interrelationships of short-term, working, and long-term memory, the focus shifts to the two major divisions of explicit memory—episodic and semantic—and the primary long-term memory processes: encoding, consolidation, and retrieval. Following an explanation of the interdependency of episodic and semantic memory, the pivotal role of consolidation in the formation of enduring semantic memories is proposed. Essentially, the chapter provides a comprehensive review of theories and research about human memory. The chapter concludes with implications for the assessment and intervention topics addressed in subsequent chapters.

Chapter 3, Memory Neuroanatomy, Development, and Dysfunction, examines memory from a neuropsychological perspective, as opposed to the cognitive perspective in Chapter 2. The neuroanatomy section describes how memories are formed through synaptic changes and strengthening, as well as alterations in neural pathways that connect related networks of neurons spread throughout the brain. The focus is on the medial temporal lobe and hippocampus, the two most critical brain structures in the encoding, consolidation, and retrieval of long-term memories. The section on development of long-term memory includes an in-depth discussion of metamemory and the vital role it plays in developing the child’s ability to remember more and more information. The chapter concludes with a discussion of memory dysfunctions, such as amnesia, that can impair learning and daily functioning.

Chapter 4, RiskFactors for Memory Impairments, is potentially the most interesting and alarming chapter in this text because it reviews the memory research on approximately 30 disorders and medical conditions that place children at-risk for memory impairments. For example, the hippocampus of children with poorly controlled diabetes can suffer irreparable damage from repeated hypoglycemic episodes. The review attempts to identify specific memory components and processes that are most likely to be affected by each risk factor, leading to identification of specific memory components that should be addressed during assessment and intervention when a child or adolescent has experienced one of these risk factors.

Chapter 5, Long-Term Memory Assessment Strategies, promotes a hypothesis-driven approach to comprehensive memory assessment that incorporates selective, cross-battery procedures. The chapter begins with the identification of and rationale for specific memory components that should be considered for testing. In addition to standardized testing, the chapter details informal assessment procedures, including sample items for interviews and observation. The recommended assessment strategies are unique in that the assessment of metamemory development, strategy use, and classroom examination performance is included. The chapter concludes with a case study that illustrates clinical analysis procedures for identifying intra-individual weaknesses and deficits.

Chapter 6, Assessing Long-Term Memory with Standardized Tests, critically examines memory batteries and memory subtests from cognitive scales that are suitable for testing the memory functions of children and adolescents. For each memory scale reviewed, there is information on the structure, technical properties, and general interpretative procedures, followed by a brief critique of the scale. For each long-term memory subtest included, there is a description of the task, identification of the specific memory components it measures, and interpretative suggestions, along with implications of low performance. To facilitate selective, cross-battery testing, the chapter includes tables that identify the specific memory components tapped by subtests from several memory and cognitive scales.

Chapter 7, Interventions for Memory Problems, guides the reader through a step-by-step approach to selecting interventions, setting goals, measuring progress, and general training procedures for strategies. After confronting the challenges and concerns regarding memory interventions, there is an emphasis on metamemory training and demonstrating the efficacy of strategies and mnemonics. Then the details needed for implementation are provided for several evidence-based memory strategies and mnemonics, followed by an overview of non-strategic interventions, such as memory aids. Following a discussion of special methods recommended for children with traumatic brain injury, the chapter concludes with the typical sequence and activities recommended for a one-on-one intervention with a child or adolescent who has mild to moderate memory problems.

Chapter 8, Classroom Instruction That Supports Memory, focuses on instructional practices that enhance the memory functioning of students, especially those with memory problems. Underlying the recommendations in this chapter is the presumption that these instructional practices and the teaching of memory strategies will be most successful in a classroom that is oriented towards supporting the memory of learners, an environment and approach referred to as the “mnemonic classroom.” The chapter, written with teachers and educational consultants in mind, includes details for evidence-based instructional practices that can easily be incorporated in the classroom. For each of the recommended practices and memory strategies, there is a discussion regarding what it is, how it works, why it works, who it benefits, the research supporting it, and how to apply it in the classroom. The chapter concludes with tips for reducing working memory load in the classroom and a summary of key memory principles that apply to classroom instruction.

Chapter 9, Case Studies and Recommendations, integrates many of the ideas discussed throughout the book by illustrating how memory impairments might be manifested in children’s behavior and learning. In addition to providing all the assessment details about two cases introduced earlier in the book, the chapter relates everything that occurred during the actual intervention sessions with a 13-year-old student. In addition, student comments, reflections, and plans are reported from another intervention case. The chapter concludes with recommendations for future research and memory test development.

LEARNING OBJECTIVES

After reading, studying, and applying the information and practices discussed in this book, the reader will be able to:

1. Describe the unique characteristics of and key differences among short-term, working, and long-term memory systems.

2. Delineate the functions of episodic and semantic memory and the interdependency between them.

3. Explain the roles of encoding, consolidation, and retrieval on the formation, retention, and recollection of memories.

4. Envision the creation, strengthening, and interconnectivity of memories at the cellular and neural network levels.

5. Unequivocally understand the crucial role of the hippocampus in the encoding and consolidation of episodic and semantic memories.

6. Describe various aspects of metamemory and how a well-developed metamemory can enhance memory functions.

7. Explain how comparing performance on uncued recall tasks with performance on recognition tasks helps to determine whether a retention or a retrieval problem underlies difficulty recalling information.

8. Recognize more than two dozen medical conditions and disorders that place children and adolescents at-risk for memory impairments.

9. Plan a comprehensive, but efficient assessment of memory and related processes that addresses the referral concerns.

10. Complete informal memory assessment procedures that include interviews, observations, and an evaluation of metamemory development.

11. Properly analyze and interpret test scores derived from a cross-battery assessment.

12. Given a variety of memory and cognitive scales, select appropriate subtests for the measurement of specific memory components.

13. Given a child or adolescent with mild to moderate memory problems, select appropriate evidence-based strategies, mnemonics, and other methods.

14. Convincingly illustrate the efficacy of memory strategies and mnemonics while conducting an intervention.

15. Provide training that promotes the development of metamemory self-awareness and self-regulation.

16. Recognize the procedures and rationale for memory interventions reserved for students with severe memory impairments, such as those who have suffered a severe traumatic brain injury.

17. Effectively consult with classroom teachers about evidence-based instructional practices that enhance students’ encoding, consolidation, and retention of learning.

18. Provide the rationale for teaching evidence-based memory strategies and mnemonics in the classroom.

19. Understand many of the intricacies that will need to be incorporated if a one-on-one intervention with a student is to succeed.

20. Structure and write an evaluation report about an examinee’s memory functions that is understandable to all readers.

CHAPTER 2

Memory Systems and Processes

A middle school student named “Abby” was brought in by her mother for an evaluation and tutoring. Abby had been adopted at birth. Not much was known about the birth mother’s health or behavior during pregnancy, but the use of crack cocaine was suspected. Academics had always been challenging for Abby, but with tutoring and her parents’ support, she had acquired average skills in oral language, reading decoding, mathematics calculation, and spelling. Abby was well organized, well behaved, very attentive, and studied much longer than the average student. Despite her skills and efforts, Abby, who wanted to do well in school, was struggling in most of her academic subjects, especially science, social studies, and mathematics. Her borderline failing grades were mainly due to poor performance on classroom exams, even though her mother helped her study for each exam. Abby’s mother reported that Abby seemed to know and understand the material when they studied but often performed poorly when tested. Most of Abby’s teachers attributed her poor performance to lack of effort and motivation, an attribution her mother thought was untrue. When her mother suggested that Abby might have a memory problem, Abby’s teachers were skeptical. The teachers argued that Abby seemed to learn new material just fine, and when quizzed immediately following a lesson, she could recall the information as well as other students. Abby’s early development was normal and there was nothing noteworthy in her health history. Abby’s adoptive mother reported that the first indication that Abby might be having learning problems came to light when Abby was having difficulty remembering nursery rhymes that were read to her day after day.

After a comprehensive psychoeducational evaluation was completed, the explanation for Abby’s poor test performance became evident. Abby had mid-average verbal and auditory abilities, with low-average visual processing, fluid reasoning, and processing speed. Her academic skills were commensurate with her intellectual abilities. There was no evidence of a specific learning disability. The telling scores were her memory scores. Her learning, short-term memory, and working memory scores were average. As observed by her teachers, Abby could learn new material and recall it well immediately and shortly after it was learned. However, Abby’s long-term retention of that same information was clearly deficient. Within 30 minutes, she was forgetting more content than would be expected. Even with prompts and cues her recall did not improve much, and on the standardized memory test her recognition standard scores were not significantly higher than her uncued recall scores, an indication that the information had actually been forgotten. Only her long-term memory for narrative information was normal. Abby’s long-term memory deficit was corroborated by her mother and by the tutors who would later work with her. Without frequent review, Abby had an unusually rapid rate of forgetting. The explanation for Abby’s poor test performance and rapid forgetting was obvious. Abby had significant difficulty consolidating and retaining new learning. Abby’s teachers had been correct. Abby’s “memory” was fine; however, the memory that was normal was only short-term memory, not long-term memory. (See Chapters 5 and 9 for more details on Abby’s assessment and intervention results.)

Abby’s case illustrates what most people know: There’s more than one type of memory. Humans have multiple, distinct, but interrelated memory systems, and each of these systems is comprised of storage components and a set of correlated processes (Tulving, 1985). Memory systems can be defined in terms of content, structure, and function (Squire, 2004). Wilson (2009, p. 1-2) neatly summarized the different types of human memory systems and functions:

We can consider memory in terms of the length of time for which memories are stored, the type of information to be remembered, the modality the information is in, the stages in the process of remembering, explicit or implicit memory, whether recall or recognition is required, (and) whether the memory is retrospective or prospective.

Human memory systems have different functions and handle distinct types of information. Not only do separate memory systems deal with distinct kinds of information, but they operate according to different principles and rely on different neural structures and processes (Tulving, 1993). Nonetheless, each cognitive event or learning experience draws on a unique combination of components from one or more memory systems. That is, there is seldom a one-to-one correspondence between the information being encoded and a particular memory system. However, memory systems can operate independently of one another. For instance, an individual who appears to have total amnesia for explicit forms of memory can still learn and remember through the implicit (unconscious) memory system. Despite the diversity of storage systems, a common set of cognitive processes enables much of the encoding, storage, and retrieval of information.

The purpose of this chapter is to help readers begin to unravel the complexities and mysteries of human memory and to gain an understanding of how all the pieces and processes work in unison. The chapter will begin by discriminating among short-term, working, and long-term memory, and by examining the components of each. The discussion will then focus on the divisions of long-term memory, with emphasis on the types of memory most closely related to academic learning. Details on all of the memory processing from input to output will then be provided, along with a discussion of forgetting and some cognitive theories of memory organization. By the end of the chapter the reader should have a grasp of memory fundamentals and begin to foresee assessment possibilities and educational implications. This chapter focuses on cognitive models of memory, whereas Chapter 3 describes memory functions from a neurological perspective.

THE FLOW OF INFORMATION

Memory has been investigated since the early days of psychology (Ebbinghaus, 1913), but only in recent decades have psychologists reached a consensus about its structures and functions. There was even uncertainty over the division of memory into short-term and long-term components until early neuropsychological studies in the 1940s confirmed the distinction. Building on this finding, cognitive models of memory and information processing originated in the 1950s and evolved into the elaborate multi-component models that are now supported by neuroscientists’ brain imaging research. It is difficult to represent complex human memory structures and functions in a figure, and consequently the general information processing model has been criticized as being overly simplified. Nonetheless, the classic model (see Figure 2.1) illustrates the usual flow of information and the fact that memory components and processes form the core of information processing.

Information flows through several components as it travels from the environment to long-term memory and then from long-term memory into a behavior or expression. Incoming information passes through sensory memory, short-term memory, and working memory before taking up residence in long-term memory stores. Outgoing information is activated in long-term memory before passing through working memory and being expressed behaviorally. Along its course, the information is selected, winnowed, manipulated, transformed, stored, retrieved, evaluated, and expressed. In memory terminology, the information is encoded, consolidated, stored, and retrieved. As information from the external world proceeds through the sequence of processes, progressively higher level representations of the perceived information are formed (Simons & Spiers, 2003). In the process, different features of the event or related information are associated and integrated into a bound memory representation. Current goals and task demands may guide the construction of these representations, and these structures will be modified as they are accessed in the future.

Figure 2.1The flow of information through memory components

SENSORY MEMORY

The first memory system to process and store incoming information is usually referred to as sensory memory (Atkinson & Shiffrin, 1968) but is also known as the sensory register. Visual sensory memory is known as iconic memory, and auditory sensory memory is known as echoic memory. Sensory memory is not a specific brain or memory structure, but rather a stage of processing. Environmental stimuli that impinge on the human senses and are perceived by the brain are momentarily held in perceptual form. This perceptual information is available for a fraction of a second before it is overwritten by new incoming information. The duration is barely long enough for attentional processes to select input for further processing in short-term memory. Individuals with a dysfunction in the sensory memory systems are usually considered as having visual or auditory perceptual disorders, not a memory impairment. Given that sensory memory relates more to perception than memory, it will not be discussed further in this book.

SHORT-TERM MEMORY

Very little of the sensory information that is perceived and briefly stored actually reaches short-term memory. When humans are actively processing information, they can consciously influence which incoming information is selected for further processing and storage by selectively attending to it. Thus, attentional processes are crucial learning and memory functions. If an individual wants to learn and remember information, she or he must first pay attention to it. When a person is not interested in or not paying attention to available input, some sort of automated filtering device is presumed to allow only a limited amount of the vast information in the passive sensory store to transfer to short-term memory. In short-term memory, active processing of the input is possible or short-term memory can just passively hold information. Active processing consists mainly of rehearsal that serves to extend the retention interval. Without rehearsal, information will be lost from short-term memory within a matter of seconds. In addition to temporal limits, short-term memory has a typical adult capacity of about seven items or chunks. Much of the information that reaches short-term memory will automatically be encoded into long-term memory processing areas or will automatically activate relevant long-term memory structures. Information that is the focus of attention will be processed further in working memory before being encoded or used to achieve an immediate goal. In common usage, people think of short-term memory as extending for several minutes if not hours. Actually, any information recalled after several seconds is most likely being retrieved from long-term memory. Thus, immediate memory may be a more accurate descriptor of short-term memory.

In contemporary memory models, short-term memory is thought to be embedded within the working memory system (Dehn, 2008). In an unconscious mode, short-term memory can operate independently of working memory, but whenever short-term memory content is being managed, working memory is performing that executive function. Both short-term memory and working memory can be divided into auditory-verbal and visuospatial components. Although short-term and working memory are not the focus of this book, they are inextricably linked with long-term memory and thus need elaboration.

Phonological Short-Term Memory

Although frequently referred to as auditory or verbal short-term memory, phonological short-term memory is a more appropriate term because auditory input is processed and encoded phonologically. Phonological short-term memory, also referred to as the phonological loop or the articulatory loop, is a limited capacity, speech-based store of verbal information (Baddeley, 1986, 2003). Oral input gains immediate, direct, and automatic access to short-term memory, where it is briefly stored in phonological form (Hitch, 1990; Logie, 1996). Baddeley (1986), who developed the predominant working memory model, subdivides phonological short-term memory into passive phonological storage and subvocal, articulatory rehearsal. Short-term phonological capacity is analogous to an audio tape recorder loop of a specific length. Words or other auditory units are recorded in the order they are perceived, and they will quickly decay or be recorded over by new auditory units unless rehearsal rerecords them onto the tape. Amazingly, this phonological loop is only two seconds in duration, regardless of the individual’s age.

The number of verbal items that can fit into the phonological loop depends on the time taken to articulate them. Longer words take longer to articulate and therefore take up more of the phonological loop. This phenomenon explains why recall of one-syllable words is better than that of multiple-syllable words. Adult sequential recall of five monosyllabic words is about 90%; whereas, it drops to about 50% when the equivalent number of words consists of five syllables each (Baddeley, 2003). The capacity of the phonological loop can be expressed as this: number of retained words equals the length of the loop times speech rate (Hulme & Mackenzie, 1992). That is, the typical adult can recall only a sequential span that he or she can articulate within 2 seconds (Baddeley, 1986; Hulme & Mackenzie, 1992). For instance, if an individual’s speech rate is two words per second, his or her memory span will be about four words. The number of words recalled is not a function of how many items are presented within 2 seconds but rather the number of words the individual can articulate within 2 seconds. The implication is that the amount of information that can be rehearsed and consequently retained is constrained by the 2-second loop and speech rate. Furthermore, subvocal rehearsal rate is thought to be equivalent to overt speech rate. This relationship accounts for the findings that verbal short-term memory span varies according to the length of the items and the individual’s speech rate; individuals with faster articulation rates can maintain more items than individuals who are slow articulators (Hulme & Mackenzie, 1992).

For adults, normal phonological memory span has long been assumed to be approximately seven units (Miller, 1956). The span is typically measured with tasks such as digit or word span and is often referred to as verbal span. The finding that span is highly related to the time it takes to articulate the stimulus words implies that short-term memory is not necessarily limited to seven, plus or minus two, units of information as is usually believed. The immediate serial recall of word sequences decreases as the constituent words become longer (Baddeley, 1990). This phenomenon, known as the word length effect, has been attributed to the greater time it takes to subvocally rehearse items of longer articulatory duration. The crucial feature is the spoken duration of the word and not the number of syllables. When subvocal articulation of the sequence exceeds the brief retention interval, errors begin to occur. Therefore, verbal memory span can be equated with the number of words that can be articulated in approximately 2 seconds, rather than thinking of it as a specific number of spoken words. Even the classic digit span task is subject to this rule. For instance, the digit span of Welsh children is substantially lower than that of English speaking children because Welsh digits consist of more than one syllable (Ellis & Hennelley, 1980).