MEMORY AND ATTENTION: THE EFFECT OF ATTENTIONAL CUEING MANIPULATIONS ON VISUAL AND AUDITORY WORKING MEMORY
by
NICOLE JESSICA BIES-HERNANDEZ
A Thesis submitted to the Graduate Faculty of
FayettevilleStateUniversity
in partial fulfillment of the
requirements for the Degree of
Master of Arts in Psychology
DEPARTMENT OF PSYCHOLOGY
Fayetteville, North Carolina
May, 2008
APPROVED BY:
______
Daniel Montoya, Ph.D.
Chair of Thesis Advisory Committee
______
Thomas Van Cantfort, Ph.D. Stephen Salek, Ph.D.
ABSTRACT
BIES-HERNANDEZ, NICOLE JESSICA. Memory and attention: The effect of attentional cueing manipulations on visual and auditory working memory (Under the direction of Daniel Montoya, Ph.D.).
Four experiments were conducted to compare the effect of exogenous-endogenous attentional cueing manipulations on visual working memory versus auditory working memory as measured through direct and indirect memory tests. Experiment 1 demonstrated that, on a direct test of visual memory, cued words were better remembered than the uncued words, and recognition of cued words were more likely than ‘Yes’ responses to new words (false alarms). In Experiments 2 & 4, these attentional manipulations had no significant effect on visual or auditory memory when measured with an indirect memory test. Experiment 3 showed that, when using a direct test of auditory memory, cueing produced a beneficial effect on memory—recognition of studied words was more likely than false alarms. These results suggest that attentional manipulations have a beneficial effect on subsequent visual and auditory working memory when measured directly, but do not influence visual or auditory working memory when measured indirectly.
DEDICATION
I wish to dedicate this document to my beloved husband, Esidro Hernandez. Without his love, understanding, and encouragement I would not have persevered in accomplishing this ambition. I would also like to dedicate this document to my parents, David and Susan Bies, and my brother, David M. Bies, who consistently support me.
ACKNOWLEDGEMENT
I want to express my sincere gratitude and appreciation to everyone who contributed to the study undertaken for this thesis. In particular, I would like to acknowledge the assistance and encouragement of my advisor, Dr. Daniel Montoya, as well as the significant support and scholarly advice provided by Drs. Thomas Van Cantfort and Stephen Salek. In addition, I want to acknowledge Jacques Arrieux for his significant assistance in recording and editing the auditory stimuli used in this study. I would also like to thank Dr. Akbar Aghjanian and the ResearchCenter for Health Disparities for their support and resources provided in the completion of this study.
TABLE OF CONTENTS
List of Tables ……………………………………………………………...vii
List of Figures……………………………………………………………...viii
List of Abbreviations……………………………………………………………...ix
Chapter IIntroduction ………………………………………………...1
Attention …………………………………………………...2
Working Memory …………………………………………..5
Direct and Indirect Memory Tests …………………………8
Interaction between Memory and Attention ……………….11
Chapter IITheoretical Framework …………………………………….13
Review of Literature ……………………………………….13
Objective …………………………………………………...16
Hypothesis …………………………………………………17
Chapter IIIExperiment 1 ………………………………………...... 18
Participants………………………………………………….19
Materials ……………………………………………………19
Apparatus …………………………………………………..20
Procedure …………………………………………………..21
Results ……………………………………………………...24
Discussion ………………………………………………….25
Chapter IVExperiment 2 ………………………………………...... 27
Participants………………………………………………….27
Materials ……………………………………………………28
Apparatus …………………………………………………..28
Procedure …………………………………………………..28
Results ……………………………………………………...28
Discussion ………………………………………………….29
Chapter VExperiment 3 ………………………………………...... 31
Participants………………………………………………….32
Materials ……………………………………………………32
Apparatus …………………………………………………..33
Procedure …………………………………………………..34
Results ……………………………………………………...36
Discussion ………………………………………………….37
Chapter VIExperiment 4 ………………………………………...... 40
Participants………………………………………………….40
Materials ……………………………………………………40
Apparatus …………………………………………………..41
Procedure …………………………………………………..41
Results ……………………………………………………...41
Discussion ………………………………………………….42
Chapter VIIComparing across Experiments ……………………………44
Chapter VIIIConclusion …………………………………………………45
References……………………………………………………………...47
Appendix A……………………………………………………………...50
LIST OF TABLES
Table 1Experiment 1:
Recognition Test Phase (Visual) ………………………….25
Table 2Experiment 2:
Word-stem Completion Test Phase (Visual) ……………..29
Table 3Experiment 3:
Recognition Test Phase (Auditory) ……………………….37
Table 4Experiment 4:
Word-stem Completion Test Phase (Auditory) …………....42
LIST OF FIGURES
Figure 1Model of working memory ……………………………...... 7
Figure 2Sequence and timing of a visual acquisition trial ...... 23
LIST OF ABBREVATIONS
LSDLeast significant difference
MSMilliseconds
RTReaction time
1
CHAPTER I
INTRODUCTION
Our sensory systems are continuously bombarded by various stimuli from our environment, most of which is unimportant to us (Kellogg, 2007; Johnson & Proctor, 2004). Fortunately, due to the cognitive process of attention, only very few of the various stimuli bombarding our sensory systems reach our conscious awareness. Attention refers to a person’s unconscious and conscious ability to focus or direct our cognitive capacities on what is important to us while ignoring the rest (Kellogg, 2007; Johnson & Proctor, 2004;Jensen, Kaiser, & Lachaux, 2007). Additionally, attention influences the choices a person makes by playing a fundamental role in all aspects of perception, cognition and action (Jensen, Kaiser, & Lachaux, 2007; Johnson & Proctor, 2004; Lyon & Krasnegor, 1996). It is particularly important to all aspects of human functioning because the human sensory systems have a limited processing capacity (Johnson & Proctor, 2004; Jensen, Kaiser, & Lachaux, 2007). Without attention, a person would not be able to accomplish any desired task because he or she would be constantly distracted not only by all the stimuli in the environment but also by what is going on in his or her head (e.g., thoughts; memories; desires) (Kellogg, 2007; Johnson & Proctor, 2004). Additionally, attention is essential to the acquisition and subsequent remembering of information, and is sometimes even thought of as the beginning of memory.
The ability to recall information, such as someone’s birthday or a math equation needed for a test, are something most people take for granted. Imagine going through life being completely naïve, constantly experiencing everything for the first time. Formal language would not exist, progressing through simple tasks would be a struggle, and meaningful connections with other people would not be possible. These are examples of what life would be like without memory, which emphasizes how valuable memory is. Memory is what allows us to recognize sounds, smells and objects; it connects the past to the present, and is what gives a person identity (Johnson & Proctor, 2004; Barmeier, 1996; Radvansky, 2006). Moreover, memory is vital to a person’s cognitive functioning, particularly the cognitive processes of perception, reasoning, problem solving, and learning (Bjork & Bjork, 1996). However, memory is not the only cognitive capacity that is essential to cognitive functioning; the conscious and unconscious abilities of memory and attention, as well as their interaction, all play fundamental roles in cognitive functioning. A person’s behavior, especially the capacity to learn, depends on one’s ability to pay attention to and store important information. A person must be capable of focusing on relevant cuesfrom the environment as well as have the ability to retain and retrieve information in order to learn, remember and think (Lyon & Krasnegor, 1996; Johnson & Proctor, 2004; Radvansky, 2006). Additionally, it is arguable that a person can remember more information or remember information longer if he or she consciously attends to that information.
Attention
The construct of attention can be described in numerous ways, from the concentration of mental activity to an agent that directs cognitive resources. While attention is multi-faceted playing numerous roles, it is more generally explained through two major models—capacity and filter models. These models describe attention through the two central facets of cognitive functioning, capacity limitation and selectivity, respectively (Matlin, 2005; Johnson & Proctor, 2004; Hunt & Ellis, 2004). Based on the notion that attention is a limited-capacity resource, capacity models define attention in terms of the allocation of cognitive resources. According to these models, attention is a limited pool of resources that must be allocated, in differing amounts, to the various tasks we engage in at any given time (Hunt & Ellis, 2004; Kellogg, 2007; Johnson & Proctor, 2004). The capacity limitation of attention influences both how many tasks we can focus on simultaneously and how well we accomplish these tasks (Hunt & Ellis, 2004). On the other hand, filter models describe attention as a selective agent. Selectivity (or selective attention) refers to the unconscious and conscious ability of attention to selectively attend to only a few stimuli from our environment while ignoring other competing stimuli (Hunt & Ellis, 2004; Johnson & Proctor, 2004; Jensen, Kaiser, & Lachaux, 2007). The selective nature of attention has been shown to be important for both generating coherent behavior and performing simple and complex tasks (Johnson & Proctor, 2004). The notion of attention as a selective agent was implemented in this study, specifically participants engaged in a selective attention task requiring them to focus on one stimulus while ignoring another competing stimulus.
A vast amount of research that has been conducted related to selective attention. Two prominent paradigms used to investigate visual and auditory selective attention are the Stroop task and the dichotic listening task, respectively. The Stroop task is a classical psychological test from 1935 that examines interference through a task that requires the cognitive mechanism of visual selective attention (Stroop, 1935). This task involves the name of a word (e.g., blue, green, red, yellow) to be printed in a color differing from the color expressed by the word’s semantic meaning (e.g., the word “blue” being printed in green ink). For this task, what is referred to as the Stroop effect occurs when one is more readily capable of reading the word than naming the color in which the word is displayed. The Stroop effect shows the interference that occurs between the automatic process of reading the word itself and our ability to selectively attend to the ink color of the word (Stroop, 1935). This effect demonstrates that irrelevant stimulus information can affect a person’s performance on a task (Stroop, 1935; Johnson & Proctor, 2004).
Analogous to the Stroop task is the dichotic listening task, which is a paradigm commonly used to examine selective attention in the auditory system. The dichotic listening task was created by researchers to enable them to obtain more control of the presentation of stimuli when studying auditory attention (Johnson & Proctor, 2004). This paradigm involves two separate sources of auditory information being presented at the same time, one to each ear. This task has been used to study both divided and selective attention. When this task is used to study selective attention, the participant is required to selectively attend to only one of the messages while ignoring the other, and then typically is asked to shadow (or repeat aloud) the content from the attended ear (Johnson & Proctor, 2004; Wood & Cowan, 1995). Commonly, following this task, the participants are asked what they remember about the content of the attended channel, unattended channel or both. This paradigm has been used extensively, and generally, the findings have indicated the limits on attention (Johnson & Proctor, 2004; Ellis & Hunt, 2004).
Since the development of these selective attention tasks, attention has remained a major area of interest within the fields of psychology, neuroscience and education. Over the years, researchers have used these two selective attention paradigms and other techniques to study attention. A popular technique that has been employed is the manipulation of attention through cues, specifically through two distinctive methods of cueing—exogenously and endogenously (Hauer & MacLeod, 2006; Johnson & Proctor, 2004). Exogenous attentional cueing involves cues that attract attention towards a stimulus; this type of manipulation is thought to be externally controlled and automatically processed (Johnson & Proctor, 2004; Hauer & MacLeod, 2006; McCormick, 1997; Theeuwes, 1991). On the other hand, endogenous attentional cueing directs attention towards the target location of a stimulus. With endogenous cueing manipulations, attention must be voluntarily shifted towards the stimulus, thus these manipulations are internally controlled and thought to involve conscious control (Hauer & MacLeod, 2006; McCormick, 1997; Johnson & Proctor, 2004). These exogenous-endogenous attentional cueing manipulations have been used to examine the mechanism of attention as well as the relationship between attention and cognitive processing. However, this technique of orienting attention has only been employed to study the relationship between visual attention and other cognitiveprocesses, particularly memory. In this study, exogenous-endogenous attentional cueing manipulations were used to investigate the potential benefit on visual and auditory memory of directing and attracting a person’s attention.
Working Memory
Receiving, storing, organizing, altering, and retrieving information is accomplished through the cognitive process of memory. For over a century, researchers have been trying to describe the construct of memory through various models and theories. A common approach has been to divide memory into different parts or types of memory. A popular general model of memory, proposed by Atkinson and Shiffrin (1968), involves a distinction between two primary memory storage systems: short-term memory and long-term memory (Terry, 2006; Hunt & Ellis, 2004). The basic differences between short-term and long-term memory lies in the amount of information each system can store and the duration of memory retention. Short-term memory is a memory storage system that holds a limited amount of information for a brief period, while long-term memory is thought to be a memory storage system of virtually limitless capacity and duration (Terry, 2006). Atkinson and Shiffrin’s model of memory has led to a vast amount of research examining these two memory systems. The evidence from this research has not supported the notion that short-term memory is purely a temporary storage system (Hunt & Ellis, 2004; Terry, 2006). To emphasize that short-term memory is not a passive storage system, the working memory model was proposed to enhance and expand on the earlier concept of short-term memory (Terry, 2006; Johnson & Proctor, 2004; Hunt & Ellis, 2004).
Often viewed as an alternative to short-term memory, working memory is a limited memory system that is responsible for the temporary storage, maintenance and manipulation of information relevant to active or current undertakings, particularly complex tasks and thoughts (Baddeley, 2000; King, 2007; Johnson & Proctor, 2004; Morrison, 2005). The most widely accepted model of working memory is the model developed by Baddeley & Hitch (1974; 2000). Baddeley & Hitch (1974) originally proposed their model of working memory as a three-component model, but revised it in 2000 to a four-component model of working memory.The four components are the visuo-spatial sketchpad, phonological loop, central executive and episodic buffer. Figure 1 illustrates Baddeley & Hitch’s (2000) revised model of working memory.
Figure 1:Model of working memory
Baddeley & Hitch’s current model of working memory (Baddeley, 2000).
The visuo-spatial sketchpad and phonological loop are modality-specific slave systems that areresponsible forthe short-term storage, manipulation and rehearsal of information (Baddeley, 2000; Morrison, 2005). The visuo-spatial sketchpad is responsible for visual information, while the phonological loop responsible for is auditory information (Baddeley, 2000; Johnson & Proctor, 2004; Morrison, 2005).These modality-specific systems are managed and directed by the central executive (Baddeley, 2000; Johnson & Proctor, 2004). Coordination of the visuo-spatial sketchpad and phonological loop is not the only responsibility of the central executive; the central executive, more generally, is thought of as an all-purpose attentional controller with the capacity for switching attention between competing tasks or stimuli, to focus attention on relevant stimuli, and to divide attention between tasks or stimuli (Baddeley, 2000; Baddeley, 2002). The fourth component of this model, the episodic buffer, was added to Baddeley and Hitch’s original model of working memory to account for some of the functions that had been implicitly allocated to the central executive in the original model (Baddeley, 2000 Baddeley, 2002). Specifically, it was added to account for the integration of information from the modality-specific systems and long-term memory in a manner that permits active maintenance and manipulation(Baddeley, 2002).The episodic bufferis thought to bea limited capacity system that temporarily stores information in a multimodal code.This multimodal code allows for the binding of information fromthe visuo-spatial sketchpad, phonological loop and long-term memory into a unitary episodic representation (Baddeley, 2000).The central executive is presumed to control the episodic buffer, and have the ability to retrieve information from the episodic buffer through conscious awareness, contemplate that information and, if needed, manipulate and modify it (Baddeley, 2000). All of these components just described work together to make up the active short-term memory system of working memory proposed by Baddeley & Hitch (1974; 2000). As a whole, working memory can be thought of as a mental “work bench” that allows for the temporary storage, maintenance and manipulation of information relevant to active tasks, particularly complex tasks involving learning, reasoning, language comprehension, problem solving, and decision making (King, 2007; Baddeley, 2000; Morrison, 2005).
Direct and Indirect Memory Tests
Memory has been studied extensively in the past century by many different researchers in numerous ways. Over the years, the study of memory has lead to the classification of two main categories of memory tests: direct and indirect tests of memory. The difference between direct (or explicit) and indirect (or implicit) memory tests is in the way a person’s memory is assessed. The major distinction between these categories of memory tests is that an explicit test of memory involves a procedure that instructs participants to reference previously studied material, whereas implicit memory tests involve measuring knowledge indirectly without reference to previously studied information (Terry, 2006; MacDonald & MacLeod, 1998; Johnson & Proctor, 2004).
Direct tests of memory require a person to intentionally retrieve information from memory. There are two basic types of direct memory tests, which are tests of recall and recognition. The difference between these two categories of explicit memory tests lies in the way a person is required to remember studied information. Recall tests require a person to retrieve (or recall) previously studied information (Terry, 2006; Hauer & MacLeod, 2006; Johnson & Proctor, 2004). There are three types of recall tests: free recall, serial recall, and cued recall. Free recall and serial recall tests are similar, but differ in the order a person must recall the information; with free recall tests the person merely is instructed to recall the studied information in any order, while with serial recall tests the person is instructed to recall the studied information in the order it was presented (Terry, 2006; Kellogg, 2007). Whereas, on cued recall tests people are given some type of cue to help facilitate recall of studied information (Terry, 2006). In contrast, with recognition memory tests a person must simply identify studied information (Terry, 2006; Hauer & MacLeod, 2006; Johnson & Proctor, 2004). Typically, recognition tests present a person with a list of items and ask the person to identify the previously studied items. This type of direct test of memory is associated with a feeling of familiarity because people may be able to recognize previous information but not be capable of reproducing that information. In this study, when memory was assessed explicitly, a yes/no recognition test was used. Specifically, the recognition test presented the participants with both previously studied items and unstudied or distractor items to assess how accurately and quickly they could identify previously studied information.