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Relationship of Sensory Modality to Retention of Episodic Memory a
a
b
a
Jeri Morris , Craig Woodworth , Amy Swier-Vosnos , Edward Rossini & Ilana Jackson a
Psychology Department , Roosevelt University , Chicago , Illinois
b
Neuropsychology, Community Rehabilitation Hospital , Indianapolis , Indiana
c
c
Chase Brexton Health Services , Gaithersburg , Maryland Published online: 05 Nov 2014.
To cite this article: Jeri Morris , Craig Woodworth , Amy Swier-Vosnos , Edward Rossini & Ilana Jackson (2014): Relationship of Sensory Modality to Retention of Episodic Memory, Applied Neuropsychology: Adult, DOI: 10.1080/23279095.2014.914517 To link to this article: http://dx.doi.org/10.1080/23279095.2014.914517
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
APPLIED NEUROPSYCHOLOGY: ADULT, 0: 1–6, 2015 Copyright # Taylor & Francis Group, LLC ISSN: 2327-9095 print=2327-9109 online DOI: 10.1080/23279095.2014.914517
Relationship of Sensory Modality to Retention of Episodic Memory Jeri Morris and Craig Woodworth Psychology Department, Roosevelt University, Chicago, Illinois
Amy Swier-Vosnos Downloaded by [University of Tasmania] at 20:13 15 January 2015
Neuropsychology, Community Rehabilitation Hospital, Indianapolis, Indiana
Edward Rossini Psychology Department, Roosevelt University, Chicago, Illinois
Ilana Jackson Chase Brexton Health Services, Gaithersburg, Maryland
This study investigated the difference between episodic memory for verbal information presented in an oral format versus equivalent material presented in a written format. The study utilized the Logical Memory subtest of the Wechsler Memory Scales-Fourth Edition and the recently validated Morris Revision-IV Paragraphs. In a sample of 97 normal participants, auditory and visual memory performances were found to be significantly correlated (r ¼ .651, p < .001). Post-hoc analysis revealed a slight though not clinically significant preference for retention in the visual modality. The results demonstrate a high-degree correlation for retention of episodic memory for these two sensory modalities in normal participants.
Key words:
memory, sensation=perception, tests
This study investigated the relationship between episodic memory for verbal information presented in an oral format versus material presented in a written format. Knowledge of whether the choice of sensory modality influences memory storage processes has important implications. For example, neuropsychologists often encounter patients with hearing loss, but current verbal memory tests are dependent on material presented aloud. Those tests could be administered in a written format to a patient with hearing loss, but as of this time, there are no data that would permit the examiner to interpret such an adaptation. Further, Address correspondence to Jeri Morris, Ph.D., Psychology Department, Roosevelt University, 18 S. Michigan Avenue, Chicago, IL 60603. E-mail: [email protected]
acquired cognitive deficits may interfere with the capacity to retain material in one sensory modality or the other. In rehabilitation settings, where much of the work of the treatment team involves teaching new information to patients, it would be beneficial to know in which modality the individual would retain the most information. The first step is to compare the relationship of retention in different presentation modalities (oral vs. written) in normal individuals. Then future studies can examine whether or not the relationship holds true for specific patient populations (e.g., those with traumatic brain injuries or stroke). Given the potential importance of understanding the relationship between learning in each of these sensory modalities, even in normal individuals, gathering empirical research is critical.
Downloaded by [University of Tasmania] at 20:13 15 January 2015
2
MORRIS ET AL.
It is a popular viewpoint outside the scientific community that individuals have learning styles that predispose them to learn better in specific modalities of presentation materials (Pashler, McDaniel, Rohrer, & Bjork, 2008). In other words, a ‘‘visual learner’’ should learn best from visual presentation of information while a ‘‘verbal learner’’ should profit most from oral presentations. Although research in this area is extensive, in a review of the literature on learning styles, Pashler et al. (2008) concluded that there is no empirical evidence supporting the hypothesis that an individual with one learning style will retain more information when it is presented in the matching format. Pashler and his colleagues found that most studies in this category were not conducted as experimental designs, and the few studies that followed an experimental design produced results that contradicted the prevalent hypothesis that learning styles exist. Furthermore, the literature uses inconsistent definitions of verbal and visual learning styles. The terms are poorly described, with ‘‘verbal’’ often referring to auditory or visual presentation of words, as though it was assumed there was no difference when, in actuality, that has never been established. In fact, authors often compared their own findings in which materials presented in one sensory modality to studies in which materials were presented in another (Litzinger, Lee, Wise, & Felder, 2007). Further, when referring to ‘‘visual learners,’’ visual sometimes refers to visual presentation of languagerelated material and sometimes to visuospatial material such as pictures or designs (Kramer, Rosenberg, & Thompson, 2009). Only two previous studies were found that assessed sensory modality effects with paragraph-length material. Taub and Kline (1976) used the parallel, though not equivalent, forms provided within the original Wechsler Memory Scales (WMS). By this means, they attempted to assess the influence of sensory modality on episodic memory in a sample of 96 elderly individuals. They found no differences in recall between the presentation conditions. However, there were significant limitations to their study. First, this investigation employed parallel rather than equivalent paragraphs. Therefore, they were not psychometrically interchangeable (Morris, Kunka, & Rossini, 1997). In addition, the results are limited in their generalizability because the sample was more than 90% female and entirely older than 65 years of age and both their health status and cognitive status were unreported. More recently, Mahendra, Bayles, and Harris (2005) evaluated the effect of sensory presentation modality on episodic memory in 30 healthy elders and 30 individuals with Alzheimer’s disease using short stories. They presented three stories in auditory, written, and combined auditory–written conditions and assessed recall immedi-
ately and at 15-min and 30-min delays. They found that after controlling for hearing loss among individuals with Alzheimer’s disease, written presentation resulted in slightly superior immediate retention than did auditory and combined auditory–written presentation. They also found no differences in recall between presentation conditions for healthy elders. The authors suggested, however, that one possible explanation for the lack of difference in retention between sensory modalities in healthy elders could be the limited sensitivity in their measurement techniques; each story contained 17 story elements to be remembered. In comparison, the Logical Memory subtest of the Wechsler Memory Scales-Fourth Edition (LM-IV) contains 50 story elements (Wechsler, 2009). Another possible limitation to this null finding is the smaller sample size used in the Mahendra et al. study. Morris et al. (2011; 2014) constructed the Morris Revision-IV Alternate Paragraphs (MR-IV) to be linguistically identical to the original paragraphs so they would function as an equivalent form of the LM-IV. A comparison of the logical and linguistic characteristics is presented in Table 1. Standard administration of these tests requires the participant to listen as each paragraph is read, then repeat back verbatim as much of the paragraph as they can remember. Morris and her colleagues (2014) provided the complete stories as well as scoring information, the method of development, and psychometric information. Study Rationale The purpose of this study is to assess whether sensory modality of presentation, be it visual or auditory, influences episodic memory of paragraph-length material. This was accomplished using the LM-IV and the equivalent alternative MR-IV paragraphs. Results from two separate samples established that the MR-IV TABLE 1 Lexical and Linguistic Characteristics of the LM-IV and the MR-IV Paragraphs LM-IV
MR-IV
Index
Anna
Joe
Greg
Rick
Total ‘‘ideas’’ in paragraph Total sentences Total words Total syllables Mean syllables=word Mean sentence length Flesch-Kincaid Index Flesch Reading Ease Index Fog Index
25 3 65 88 1.35 21.67 10 59 10.67
25 5 86 124 1.44 17.20 9 64 10.08
25 3 65 87 1.34 21.67 10 66 10.70
25 5 86 120 1.40 17.20 8 63 10.48
LM-IV ¼ Logical Memory subtest of the Wechsler Memory ScalesFourth Edition; MR-IV ¼ Morris Revision-IV Alternate Paragraphs.
Downloaded by [University of Tasmania] at 20:13 15 January 2015
SENSORY MODALITY AND EPISODIC MEMORY
paragraphs are strongly correlated with the LM-IV paragraphs (Study 1 r ¼ .71; Study 2 r ¼ .61). Consequently, the MR-IV paragraphs can be considered an alternate form to the LM-IV paragraphs. Historically, the correlations between the alternate forms in each of those studies were consistent with the typical correlations found in other instruments accepted as alternate forms. For example, the California Verbal Learning Test-Second Edition (CVLT-II) reports correlations of .61 for Short Delayed Cued Recall, and all other comparisons of the CVLT-II standard and alternate forms have similar correlations, with a high of .69. Further, for the MR-Revised, accepted as an alternate form of the standard WMS-Revised (Morris et al., 1997), showed a similar correlation (r ¼ .73). Further, the LM-Third Edition and MR-Third Edition were similarly correlated (r ¼ .63; Morris, Kopald, Glass, Jackson, & Ryan, 2009). Knowing whether the modality of presentation influences retention will inform clinical judgment, as it will determine if one modality can be substituted for another in testing and in treatment. METHODS Participants A power analysis was conducted to determine the sample size necessary to detect a significant effect (Cohen, 1992). For a large effect size, an alpha set at .05, a power of .80, and the use of a Pearson product–moment correlation, Cohen (1992) suggests a minimum sample size of 28 participants. However, to provide a more rigorous test of the study hypothesis and to allow for the possibility of post-hoc analyses, a larger sample than required was recruited. Participants included 56 individuals from a university student population and 52 other adults from the greater Chicago area. It was intended that broadening participant recruitment outside of the traditional college undergraduate sample would increase the generalizability of the results. Participants with uncorrected sensory deficits in vision or hearing were excluded from the analysis. All exclusions were made by participant self-disclosure. Although no participants were excluded for uncorrected vision, 3 were excluded due to self-reported hearing loss. Participants were also excluded for any self-reported learning disorder or other neurological impairments. Three participants reported a diagnosis of attentiondeficit hyperactivity disorder and were excluded from final analyses. One participant was excluded because English was not his primary language. The final exclusionary criterion was determined using the Wechsler Test of Adult Reading (WTAR; Wechsler, 2001), an
3
instrument that is often used to estimate IQ (Wechsler, 2001). Participants scoring more than one standard deviation below average (Estimate Full-Scale Intelligence Quotient [EFSIQ] < 85) were excluded from the statistical analysis. This resulted in an additional 4 participants being excluded from the analyses, for a total of 11 excluded participants. After exclusions, 97 participants remained in the sample. This included 50 students and 47 community members. The mean age for students was 22.4 years, and the mean age for community members was 45.5, while the mean years of education were 15.0 years for student and 16.9 years for community members. Demographic data are available in Table 2. Measures Episodic memory was measured using two alternative sets of two paragraphs each. There are 25 scorable units in each paragraph. For the LM-IV, each scorable unit receives 1 point if it meets the criteria given in the WMS-Fourth Edition manual (Wechsler, 2009) and 0 points if it does not meet the criteria. Similarly, for the MR-IV, each scorable unit receives 1 point if it meets the criteria published in the Morris et al. (2014) article. The first set of paragraphs was the LM-IV, while the second set of paragraphs was the MR-IV. Procedure Using a Latin square presentation model, four testing conditions were counterbalanced by order of presentation and by presentation modality. One quarter of the participants read the MR-IV and then listened to the LM-IV, one quarter listened to the MR-IV and then read the LM-IV, one quarter listened to the LM-IV and then read the MR-IV Alternative Paragraphs, and one quarter read the LM-IV and then listened to the MR-IV TABLE 2 Participant Demographics by Sample Student n (Percentage) Community n (Percentage) Gender Male Female Race White Black Asian Latino Multicultural
Age Years of education
6 (12%) 44 (88%)
22 (46.8%) 25 (53.2%)
20 17 2 10 1
38 1 7 1 0
(40%) (34%) (4%) (20%) (2%)
(80.9%) (2.1%) (14.9%) (2.1%) (0%)
Student M (SD)
Community M (SD)
22.4 (5.2) 15.0 (1.9)
45.5 (17.1) 16.9 (2.3)
Downloaded by [University of Tasmania] at 20:13 15 January 2015
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MORRIS ET AL.
Alternative Paragraphs. After exclusions, there were 25, 25, 23, and 25 participants in the four testing conditions, respectively. In the auditory presentation conditions, participants were given instructions from the LM-IV. The same instructions were used for both sets of paragraphs under the auditory conditions, as identical instructions across testing conditions minimize experimenter bias. It was necessary to alter the instructions for the presentation of visual materials, but these instructions were kept as parallel to the auditory instructions as possible. Instead of asking participants to ‘‘listen carefully,’’ as in the auditory instructions, with the visual presentation, the instructions requested that the participant ‘‘read silently through the paragraph’’ to make the visual presentation condition as equivalent to the auditory condition as possible. Presentation of the auditory paragraphs was also standardized by using pre-recorded narrations of the paragraphs. Researchers prepared these recordings for a prior study that standardized the two sets of paragraphs (Morris et al., 2009). Visual materials were presented in the form of standardized typewritten materials. For maximized readability, each paragraph was printed on a separate page in double-spaced, 14-point Times New Roman font. Participants were permitted to read at their own rate. However, it should be noted that self-paced reading typically takes less time than auditory presentation (Taub & Kline, 1976). Visual presentation was not timed to avoid the introduction of demand characteristics, where the participants would form interpretations about the experiment’s purpose and unconsciously alter their behavior based on these assumptions. Participants’ immediate verbal recall of the paragraphs was audio-recorded for scoring purposes. Immediate recall instructions from the LM-IV were used in all four conditions. Recordings of each paragraph were scored in a randomized order to ensure that the scorer was blind to the presentation condition and the identity of all participants. This was accomplished by recording the response onto an iPod and using the ‘‘shuffle’’ feature to randomize the order in which the paragraphs were played back. Participant identification number was the only identifying information on all recordings. Data Analysis Before executing the planned statistical analyses, tests of statistical assumptions were conducted. This included assessment of the normality of the distribution for skew and kurtosis, as well as linearity and homogeneity of variance. All variables were found to be normally distributed except chronological age, which had a bimodal distribution. Within the student and community
subsamples, age was normally distributed. As expected, age was significantly and positively correlated with education (r ¼ .40, p < .01). Missing data were also assessed to determine if such data related to any demographic variables; no such relationships were found. Statistical transformations were not needed to address outliers, as an analysis of the variable distributions and Mahalanobis distances indicated no outliers. As expected, performance on the WTAR was found to be significantly and positively related to age (r ¼ .49), education (r ¼ .39), LM-IV performance (r ¼ .24), and MR-IV performance (r ¼ .32), all at p < .01. A within-subjects comparison of episodic memory performance was conducted using the equivalent forms in the visual and auditory presentations. This comparison was made with a Pearson product-–moment correlation using the total raw scores. For each individual, two paragraphs were presented in each modality (visual and auditory). Thus, the total score measures the total number of elements recalled from the paragraphs and has a maximum possible score of 50 for each of the two modalities.
RESULTS The Pearson product–moment correlation coefficient showed that episodic memory for auditory presentation of paragraph-length linguistic material displayed a moderate positive correlation with episodic memory for visual presentation of equivalent linguistic material, r ¼ .65, p < .001. The strength of the relationship (r2 ¼ .43) falls within an acceptable range for alternate forms of psychological measures and is consistent with the level of correlation previously found for equivalent forms of these paragraphs (Morris et al., 2014). Similarly, the interscorer reliabilities between the two presentation forms were equivalent. A two-tailed student’s t test was used to test for potential differences in performance between the visual and auditory presentation conditions. The mean recall of the visually presented story was significantly higher than the mean recall of the auditory presentation, t(96) ¼ 4.46, p < .001, d ¼ 0.91. On average, participants retained 2.4 more story elements of the 50 possible elements in the visual modality. This suggests that cognitively normal individuals have a slight advantage toward the retention of visually presented linguistic information. A two-tailed student’s t test revealed no significant difference in the mean performance between the two forms of the paragraphs, t(96) ¼ 1.76, p > .05. This study also compared the performance on the memory tests by sample. All analyses were reconducted within the student and community subsamples and by gender. Consistent with previous results, no differences were
SENSORY MODALITY AND EPISODIC MEMORY TABLE 3 Results by Sample Student M (SD) Visual Auditory r t Logical Memory Morris Revision r t
25.14 21.88 .60 3.97 24.44 22.58 .52 2.05
(7.08) (5.58)
(6.93) (6.07)
Community M (SD) 28.38 26.87 .69 2.22 27.70 27.55 .66 0.21
(5.31) (6.29)
(5.30) (6.39)
p < .001.
TABLE 4 Results by Gender
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Male M (SD) Visual Auditory r t Logical Memory Morris Revision r t
27.50 26.00 .66 1.64 26.11 27.39 .65 –1.39
(5.59) (6.10)
(5.63) (6.09)
Female M (SD) 26.39 23.61 .66 4.20 25.99 24.01 .62 2.80
(6.80) (6.45)
(6.70) (6.70)
p < .001.
found in paragraph recall between performance on the alternate paragraphs and the original paragraphs for either sample or gender. Tables 3 and 4 present the descriptive statistics and test results for these more focal analyses.
DISCUSSION Overall, the results of this study supported the hypothesis that in a population of cognitively normal individuals, episodic memory for auditory presentation of paragraph-length linguistic material was strongly correlated with episodic memory for visual presentations of equivalent linguistic material. Historically, the correlations between alternate forms in each of our studies have been consistent with the typical correlations found in other instruments that are accepted as alternate forms, as discussed earlier. This high level of correlation indicates that the alternative administration procedures possess adequate equivalent form reliability to be used when auditory presentation of materials is contraindicated. We can infer that visual presentation of either the LM-IV or the MR-IV can serve as an alternative in cognitively normal individuals with hearing loss. The results showed a very slight preference for retention of material presented in a visual sensory modality.
5
As the difference was only 2.4 raw score points, this statistical difference has little clinical relevance. Similarly, Mahendra et al. (2005) found a slight preference for immediate recall of visually presented stories among a sample of patients with Alzheimer’s disease but were unable to find such a difference in a group of healthy elders. In the current study, it is possible, though unlikely, that some participants may have re-read some or all of the paragraph, though they were instructed to read it once only and the examiner observed them as they were doing it. The population of the current student was largely female, perhaps limiting generalizability of the study findings. It also used adults who, on average, had at least some college education, another potential limiting factor. Thus, this study has taken the first step and established that with regard to immediate memory for paragraph-length material, there is essentially no clinical difference between written and oral presentations in normal individuals. Next, it would be important to investigate whether or not this relationship holds true for specific patient populations. If individuals with specific disorders (e.g., individuals with traumatic brain injury, those who are HIV-positive, and those with multiple sclerosis) show the same pattern in which there is no difference between modality of administration, then it would permit us to test them in either format with the confidence of obtaining valid results. Alternatively, if these future studies in clinical populations demonstrate differences or more variability than in normal individuals, then individuals with neurological disorders could be tested in both modalities. By that means, we would discover whether that particular individual learns best from hearing information or reading it and could determine which modality to use in rehabilitation or other settings when teaching that person. REFERENCES Cohen, J. (1992). A power primer. Psychological Bulletin, 112, 155–159. doi:10.1037=0033–2909.112.1.155 Kramer, D., Rosenberg, L., & Thompson, S. (2009). The neural correlates of visual and verbal cognitive styles. Journal of Neuroscience, 29, 3792–3798. Litzinger, T., Lee, S., Wise, J., & Felder, R. (2007). A psychometric study of the Index of Learning Styles. Journal of Engineering Education, 96, 309–319. Mahendra, N., Bayles, K., & Harris, F. (2005). Effect of presentation modality on immediate and delayed recall in individuals with Alzheimer’s disease. American Journal of Speech-Language Pathology, 14, 144–155. doi:10.1044=1058-0360(2005=015) Morris, J., Glass, L., Ryan, J., Czipri, S., Herst, S., Jackson, A., & Kopald, B. (2011, August). Development of alternate paragraphs for the Logical Memory subtest of the Wechsler Memory Scale-IV. Paper presented at the 119th annual convention of the American Psychological Association, Washington, DC.
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Morris, J., Kopald, B., Glass, L., Jackson, I., & Ryan, J. J. (2009, February). Alternate paragraphs for the Logical Memory subtest of the Wechsler Memory Scale-IV. Poster session presented at the 37th annual meeting of the International Neuropsychological Society, Atlanta, GA. Morris, J., Kunka, J., & Rossini, E. (1997). Development of alternate paragraphs for the Logical Memory subtest of the Wechsler Memory Scale-Revised. Clinical Neuropsychologist, 11, 370–374. doi:10.1080=13854049708400465 Morris, J., Swier-Vosnos, A., Woodworth, C., Umfleet, L. G., Czipri, S., & Kopald, B. (2014). Development of alternate paragraphs for the Logical Memory subtest of the Wechsler Memory Scale-IV.
Applied Neuropsychology: Adult, 21, 143–147. doi:10.1080= 09084282.2013.780172 Pashler, H., McDaniel, M., Rohrer, D., & Bjork, R. (2008). Learning styles: Concepts and evidence. Psychological Science in the Public Interest, 9, 105–119. doi:10.1111=j.1539-6053.2009. 01038.x Taub, H., & Kline, G. (1976). Modality effects and memory in the aged. Educational Gerontology, 1, 53–60. Wechsler, D. (2001). Wechsler Test of Adult Reading. San Antonio, TX: Psychological Corporation. Wechsler, D. (2009). Wechsler Memory Scale-Fourth Edition. San Antonio, TX: Psychological Corporation.
Applied Neuropsychology: Adult Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/hapn21
Click for updates
Relationship of Sensory Modality to Retention of Episodic Memory a
a
b
a
Jeri Morris , Craig Woodworth , Amy Swier-Vosnos , Edward Rossini & Ilana Jackson a
Psychology Department , Roosevelt University , Chicago , Illinois
b
Neuropsychology, Community Rehabilitation Hospital , Indianapolis , Indiana
c
c
Chase Brexton Health Services , Gaithersburg , Maryland Published online: 05 Nov 2014.
To cite this article: Jeri Morris , Craig Woodworth , Amy Swier-Vosnos , Edward Rossini & Ilana Jackson (2014): Relationship of Sensory Modality to Retention of Episodic Memory, Applied Neuropsychology: Adult, DOI: 10.1080/23279095.2014.914517 To link to this article: http://dx.doi.org/10.1080/23279095.2014.914517
PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions
APPLIED NEUROPSYCHOLOGY: ADULT, 0: 1–6, 2015 Copyright # Taylor & Francis Group, LLC ISSN: 2327-9095 print=2327-9109 online DOI: 10.1080/23279095.2014.914517
Relationship of Sensory Modality to Retention of Episodic Memory Jeri Morris and Craig Woodworth Psychology Department, Roosevelt University, Chicago, Illinois
Amy Swier-Vosnos Downloaded by [University of Tasmania] at 20:13 15 January 2015
Neuropsychology, Community Rehabilitation Hospital, Indianapolis, Indiana
Edward Rossini Psychology Department, Roosevelt University, Chicago, Illinois
Ilana Jackson Chase Brexton Health Services, Gaithersburg, Maryland
This study investigated the difference between episodic memory for verbal information presented in an oral format versus equivalent material presented in a written format. The study utilized the Logical Memory subtest of the Wechsler Memory Scales-Fourth Edition and the recently validated Morris Revision-IV Paragraphs. In a sample of 97 normal participants, auditory and visual memory performances were found to be significantly correlated (r ¼ .651, p < .001). Post-hoc analysis revealed a slight though not clinically significant preference for retention in the visual modality. The results demonstrate a high-degree correlation for retention of episodic memory for these two sensory modalities in normal participants.
Key words:
memory, sensation=perception, tests
This study investigated the relationship between episodic memory for verbal information presented in an oral format versus material presented in a written format. Knowledge of whether the choice of sensory modality influences memory storage processes has important implications. For example, neuropsychologists often encounter patients with hearing loss, but current verbal memory tests are dependent on material presented aloud. Those tests could be administered in a written format to a patient with hearing loss, but as of this time, there are no data that would permit the examiner to interpret such an adaptation. Further, Address correspondence to Jeri Morris, Ph.D., Psychology Department, Roosevelt University, 18 S. Michigan Avenue, Chicago, IL 60603. E-mail: [email protected]
acquired cognitive deficits may interfere with the capacity to retain material in one sensory modality or the other. In rehabilitation settings, where much of the work of the treatment team involves teaching new information to patients, it would be beneficial to know in which modality the individual would retain the most information. The first step is to compare the relationship of retention in different presentation modalities (oral vs. written) in normal individuals. Then future studies can examine whether or not the relationship holds true for specific patient populations (e.g., those with traumatic brain injuries or stroke). Given the potential importance of understanding the relationship between learning in each of these sensory modalities, even in normal individuals, gathering empirical research is critical.
Downloaded by [University of Tasmania] at 20:13 15 January 2015
2
MORRIS ET AL.
It is a popular viewpoint outside the scientific community that individuals have learning styles that predispose them to learn better in specific modalities of presentation materials (Pashler, McDaniel, Rohrer, & Bjork, 2008). In other words, a ‘‘visual learner’’ should learn best from visual presentation of information while a ‘‘verbal learner’’ should profit most from oral presentations. Although research in this area is extensive, in a review of the literature on learning styles, Pashler et al. (2008) concluded that there is no empirical evidence supporting the hypothesis that an individual with one learning style will retain more information when it is presented in the matching format. Pashler and his colleagues found that most studies in this category were not conducted as experimental designs, and the few studies that followed an experimental design produced results that contradicted the prevalent hypothesis that learning styles exist. Furthermore, the literature uses inconsistent definitions of verbal and visual learning styles. The terms are poorly described, with ‘‘verbal’’ often referring to auditory or visual presentation of words, as though it was assumed there was no difference when, in actuality, that has never been established. In fact, authors often compared their own findings in which materials presented in one sensory modality to studies in which materials were presented in another (Litzinger, Lee, Wise, & Felder, 2007). Further, when referring to ‘‘visual learners,’’ visual sometimes refers to visual presentation of languagerelated material and sometimes to visuospatial material such as pictures or designs (Kramer, Rosenberg, & Thompson, 2009). Only two previous studies were found that assessed sensory modality effects with paragraph-length material. Taub and Kline (1976) used the parallel, though not equivalent, forms provided within the original Wechsler Memory Scales (WMS). By this means, they attempted to assess the influence of sensory modality on episodic memory in a sample of 96 elderly individuals. They found no differences in recall between the presentation conditions. However, there were significant limitations to their study. First, this investigation employed parallel rather than equivalent paragraphs. Therefore, they were not psychometrically interchangeable (Morris, Kunka, & Rossini, 1997). In addition, the results are limited in their generalizability because the sample was more than 90% female and entirely older than 65 years of age and both their health status and cognitive status were unreported. More recently, Mahendra, Bayles, and Harris (2005) evaluated the effect of sensory presentation modality on episodic memory in 30 healthy elders and 30 individuals with Alzheimer’s disease using short stories. They presented three stories in auditory, written, and combined auditory–written conditions and assessed recall immedi-
ately and at 15-min and 30-min delays. They found that after controlling for hearing loss among individuals with Alzheimer’s disease, written presentation resulted in slightly superior immediate retention than did auditory and combined auditory–written presentation. They also found no differences in recall between presentation conditions for healthy elders. The authors suggested, however, that one possible explanation for the lack of difference in retention between sensory modalities in healthy elders could be the limited sensitivity in their measurement techniques; each story contained 17 story elements to be remembered. In comparison, the Logical Memory subtest of the Wechsler Memory Scales-Fourth Edition (LM-IV) contains 50 story elements (Wechsler, 2009). Another possible limitation to this null finding is the smaller sample size used in the Mahendra et al. study. Morris et al. (2011; 2014) constructed the Morris Revision-IV Alternate Paragraphs (MR-IV) to be linguistically identical to the original paragraphs so they would function as an equivalent form of the LM-IV. A comparison of the logical and linguistic characteristics is presented in Table 1. Standard administration of these tests requires the participant to listen as each paragraph is read, then repeat back verbatim as much of the paragraph as they can remember. Morris and her colleagues (2014) provided the complete stories as well as scoring information, the method of development, and psychometric information. Study Rationale The purpose of this study is to assess whether sensory modality of presentation, be it visual or auditory, influences episodic memory of paragraph-length material. This was accomplished using the LM-IV and the equivalent alternative MR-IV paragraphs. Results from two separate samples established that the MR-IV TABLE 1 Lexical and Linguistic Characteristics of the LM-IV and the MR-IV Paragraphs LM-IV
MR-IV
Index
Anna
Joe
Greg
Rick
Total ‘‘ideas’’ in paragraph Total sentences Total words Total syllables Mean syllables=word Mean sentence length Flesch-Kincaid Index Flesch Reading Ease Index Fog Index
25 3 65 88 1.35 21.67 10 59 10.67
25 5 86 124 1.44 17.20 9 64 10.08
25 3 65 87 1.34 21.67 10 66 10.70
25 5 86 120 1.40 17.20 8 63 10.48
LM-IV ¼ Logical Memory subtest of the Wechsler Memory ScalesFourth Edition; MR-IV ¼ Morris Revision-IV Alternate Paragraphs.
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paragraphs are strongly correlated with the LM-IV paragraphs (Study 1 r ¼ .71; Study 2 r ¼ .61). Consequently, the MR-IV paragraphs can be considered an alternate form to the LM-IV paragraphs. Historically, the correlations between the alternate forms in each of those studies were consistent with the typical correlations found in other instruments accepted as alternate forms. For example, the California Verbal Learning Test-Second Edition (CVLT-II) reports correlations of .61 for Short Delayed Cued Recall, and all other comparisons of the CVLT-II standard and alternate forms have similar correlations, with a high of .69. Further, for the MR-Revised, accepted as an alternate form of the standard WMS-Revised (Morris et al., 1997), showed a similar correlation (r ¼ .73). Further, the LM-Third Edition and MR-Third Edition were similarly correlated (r ¼ .63; Morris, Kopald, Glass, Jackson, & Ryan, 2009). Knowing whether the modality of presentation influences retention will inform clinical judgment, as it will determine if one modality can be substituted for another in testing and in treatment. METHODS Participants A power analysis was conducted to determine the sample size necessary to detect a significant effect (Cohen, 1992). For a large effect size, an alpha set at .05, a power of .80, and the use of a Pearson product–moment correlation, Cohen (1992) suggests a minimum sample size of 28 participants. However, to provide a more rigorous test of the study hypothesis and to allow for the possibility of post-hoc analyses, a larger sample than required was recruited. Participants included 56 individuals from a university student population and 52 other adults from the greater Chicago area. It was intended that broadening participant recruitment outside of the traditional college undergraduate sample would increase the generalizability of the results. Participants with uncorrected sensory deficits in vision or hearing were excluded from the analysis. All exclusions were made by participant self-disclosure. Although no participants were excluded for uncorrected vision, 3 were excluded due to self-reported hearing loss. Participants were also excluded for any self-reported learning disorder or other neurological impairments. Three participants reported a diagnosis of attentiondeficit hyperactivity disorder and were excluded from final analyses. One participant was excluded because English was not his primary language. The final exclusionary criterion was determined using the Wechsler Test of Adult Reading (WTAR; Wechsler, 2001), an
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instrument that is often used to estimate IQ (Wechsler, 2001). Participants scoring more than one standard deviation below average (Estimate Full-Scale Intelligence Quotient [EFSIQ] < 85) were excluded from the statistical analysis. This resulted in an additional 4 participants being excluded from the analyses, for a total of 11 excluded participants. After exclusions, 97 participants remained in the sample. This included 50 students and 47 community members. The mean age for students was 22.4 years, and the mean age for community members was 45.5, while the mean years of education were 15.0 years for student and 16.9 years for community members. Demographic data are available in Table 2. Measures Episodic memory was measured using two alternative sets of two paragraphs each. There are 25 scorable units in each paragraph. For the LM-IV, each scorable unit receives 1 point if it meets the criteria given in the WMS-Fourth Edition manual (Wechsler, 2009) and 0 points if it does not meet the criteria. Similarly, for the MR-IV, each scorable unit receives 1 point if it meets the criteria published in the Morris et al. (2014) article. The first set of paragraphs was the LM-IV, while the second set of paragraphs was the MR-IV. Procedure Using a Latin square presentation model, four testing conditions were counterbalanced by order of presentation and by presentation modality. One quarter of the participants read the MR-IV and then listened to the LM-IV, one quarter listened to the MR-IV and then read the LM-IV, one quarter listened to the LM-IV and then read the MR-IV Alternative Paragraphs, and one quarter read the LM-IV and then listened to the MR-IV TABLE 2 Participant Demographics by Sample Student n (Percentage) Community n (Percentage) Gender Male Female Race White Black Asian Latino Multicultural
Age Years of education
6 (12%) 44 (88%)
22 (46.8%) 25 (53.2%)
20 17 2 10 1
38 1 7 1 0
(40%) (34%) (4%) (20%) (2%)
(80.9%) (2.1%) (14.9%) (2.1%) (0%)
Student M (SD)
Community M (SD)
22.4 (5.2) 15.0 (1.9)
45.5 (17.1) 16.9 (2.3)
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Alternative Paragraphs. After exclusions, there were 25, 25, 23, and 25 participants in the four testing conditions, respectively. In the auditory presentation conditions, participants were given instructions from the LM-IV. The same instructions were used for both sets of paragraphs under the auditory conditions, as identical instructions across testing conditions minimize experimenter bias. It was necessary to alter the instructions for the presentation of visual materials, but these instructions were kept as parallel to the auditory instructions as possible. Instead of asking participants to ‘‘listen carefully,’’ as in the auditory instructions, with the visual presentation, the instructions requested that the participant ‘‘read silently through the paragraph’’ to make the visual presentation condition as equivalent to the auditory condition as possible. Presentation of the auditory paragraphs was also standardized by using pre-recorded narrations of the paragraphs. Researchers prepared these recordings for a prior study that standardized the two sets of paragraphs (Morris et al., 2009). Visual materials were presented in the form of standardized typewritten materials. For maximized readability, each paragraph was printed on a separate page in double-spaced, 14-point Times New Roman font. Participants were permitted to read at their own rate. However, it should be noted that self-paced reading typically takes less time than auditory presentation (Taub & Kline, 1976). Visual presentation was not timed to avoid the introduction of demand characteristics, where the participants would form interpretations about the experiment’s purpose and unconsciously alter their behavior based on these assumptions. Participants’ immediate verbal recall of the paragraphs was audio-recorded for scoring purposes. Immediate recall instructions from the LM-IV were used in all four conditions. Recordings of each paragraph were scored in a randomized order to ensure that the scorer was blind to the presentation condition and the identity of all participants. This was accomplished by recording the response onto an iPod and using the ‘‘shuffle’’ feature to randomize the order in which the paragraphs were played back. Participant identification number was the only identifying information on all recordings. Data Analysis Before executing the planned statistical analyses, tests of statistical assumptions were conducted. This included assessment of the normality of the distribution for skew and kurtosis, as well as linearity and homogeneity of variance. All variables were found to be normally distributed except chronological age, which had a bimodal distribution. Within the student and community
subsamples, age was normally distributed. As expected, age was significantly and positively correlated with education (r ¼ .40, p < .01). Missing data were also assessed to determine if such data related to any demographic variables; no such relationships were found. Statistical transformations were not needed to address outliers, as an analysis of the variable distributions and Mahalanobis distances indicated no outliers. As expected, performance on the WTAR was found to be significantly and positively related to age (r ¼ .49), education (r ¼ .39), LM-IV performance (r ¼ .24), and MR-IV performance (r ¼ .32), all at p < .01. A within-subjects comparison of episodic memory performance was conducted using the equivalent forms in the visual and auditory presentations. This comparison was made with a Pearson product-–moment correlation using the total raw scores. For each individual, two paragraphs were presented in each modality (visual and auditory). Thus, the total score measures the total number of elements recalled from the paragraphs and has a maximum possible score of 50 for each of the two modalities.
RESULTS The Pearson product–moment correlation coefficient showed that episodic memory for auditory presentation of paragraph-length linguistic material displayed a moderate positive correlation with episodic memory for visual presentation of equivalent linguistic material, r ¼ .65, p < .001. The strength of the relationship (r2 ¼ .43) falls within an acceptable range for alternate forms of psychological measures and is consistent with the level of correlation previously found for equivalent forms of these paragraphs (Morris et al., 2014). Similarly, the interscorer reliabilities between the two presentation forms were equivalent. A two-tailed student’s t test was used to test for potential differences in performance between the visual and auditory presentation conditions. The mean recall of the visually presented story was significantly higher than the mean recall of the auditory presentation, t(96) ¼ 4.46, p < .001, d ¼ 0.91. On average, participants retained 2.4 more story elements of the 50 possible elements in the visual modality. This suggests that cognitively normal individuals have a slight advantage toward the retention of visually presented linguistic information. A two-tailed student’s t test revealed no significant difference in the mean performance between the two forms of the paragraphs, t(96) ¼ 1.76, p > .05. This study also compared the performance on the memory tests by sample. All analyses were reconducted within the student and community subsamples and by gender. Consistent with previous results, no differences were
SENSORY MODALITY AND EPISODIC MEMORY TABLE 3 Results by Sample Student M (SD) Visual Auditory r t Logical Memory Morris Revision r t
25.14 21.88 .60 3.97 24.44 22.58 .52 2.05
(7.08) (5.58)
(6.93) (6.07)
Community M (SD) 28.38 26.87 .69 2.22 27.70 27.55 .66 0.21
(5.31) (6.29)
(5.30) (6.39)
p < .001.
TABLE 4 Results by Gender
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Male M (SD) Visual Auditory r t Logical Memory Morris Revision r t
27.50 26.00 .66 1.64 26.11 27.39 .65 –1.39
(5.59) (6.10)
(5.63) (6.09)
Female M (SD) 26.39 23.61 .66 4.20 25.99 24.01 .62 2.80
(6.80) (6.45)
(6.70) (6.70)
p < .001.
found in paragraph recall between performance on the alternate paragraphs and the original paragraphs for either sample or gender. Tables 3 and 4 present the descriptive statistics and test results for these more focal analyses.
DISCUSSION Overall, the results of this study supported the hypothesis that in a population of cognitively normal individuals, episodic memory for auditory presentation of paragraph-length linguistic material was strongly correlated with episodic memory for visual presentations of equivalent linguistic material. Historically, the correlations between alternate forms in each of our studies have been consistent with the typical correlations found in other instruments that are accepted as alternate forms, as discussed earlier. This high level of correlation indicates that the alternative administration procedures possess adequate equivalent form reliability to be used when auditory presentation of materials is contraindicated. We can infer that visual presentation of either the LM-IV or the MR-IV can serve as an alternative in cognitively normal individuals with hearing loss. The results showed a very slight preference for retention of material presented in a visual sensory modality.
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As the difference was only 2.4 raw score points, this statistical difference has little clinical relevance. Similarly, Mahendra et al. (2005) found a slight preference for immediate recall of visually presented stories among a sample of patients with Alzheimer’s disease but were unable to find such a difference in a group of healthy elders. In the current study, it is possible, though unlikely, that some participants may have re-read some or all of the paragraph, though they were instructed to read it once only and the examiner observed them as they were doing it. The population of the current student was largely female, perhaps limiting generalizability of the study findings. It also used adults who, on average, had at least some college education, another potential limiting factor. Thus, this study has taken the first step and established that with regard to immediate memory for paragraph-length material, there is essentially no clinical difference between written and oral presentations in normal individuals. Next, it would be important to investigate whether or not this relationship holds true for specific patient populations. If individuals with specific disorders (e.g., individuals with traumatic brain injury, those who are HIV-positive, and those with multiple sclerosis) show the same pattern in which there is no difference between modality of administration, then it would permit us to test them in either format with the confidence of obtaining valid results. Alternatively, if these future studies in clinical populations demonstrate differences or more variability than in normal individuals, then individuals with neurological disorders could be tested in both modalities. By that means, we would discover whether that particular individual learns best from hearing information or reading it and could determine which modality to use in rehabilitation or other settings when teaching that person. REFERENCES Cohen, J. (1992). A power primer. Psychological Bulletin, 112, 155–159. doi:10.1037=0033–2909.112.1.155 Kramer, D., Rosenberg, L., & Thompson, S. (2009). The neural correlates of visual and verbal cognitive styles. Journal of Neuroscience, 29, 3792–3798. Litzinger, T., Lee, S., Wise, J., & Felder, R. (2007). A psychometric study of the Index of Learning Styles. Journal of Engineering Education, 96, 309–319. Mahendra, N., Bayles, K., & Harris, F. (2005). Effect of presentation modality on immediate and delayed recall in individuals with Alzheimer’s disease. American Journal of Speech-Language Pathology, 14, 144–155. doi:10.1044=1058-0360(2005=015) Morris, J., Glass, L., Ryan, J., Czipri, S., Herst, S., Jackson, A., & Kopald, B. (2011, August). Development of alternate paragraphs for the Logical Memory subtest of the Wechsler Memory Scale-IV. Paper presented at the 119th annual convention of the American Psychological Association, Washington, DC.
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Morris, J., Kopald, B., Glass, L., Jackson, I., & Ryan, J. J. (2009, February). Alternate paragraphs for the Logical Memory subtest of the Wechsler Memory Scale-IV. Poster session presented at the 37th annual meeting of the International Neuropsychological Society, Atlanta, GA. Morris, J., Kunka, J., & Rossini, E. (1997). Development of alternate paragraphs for the Logical Memory subtest of the Wechsler Memory Scale-Revised. Clinical Neuropsychologist, 11, 370–374. doi:10.1080=13854049708400465 Morris, J., Swier-Vosnos, A., Woodworth, C., Umfleet, L. G., Czipri, S., & Kopald, B. (2014). Development of alternate paragraphs for the Logical Memory subtest of the Wechsler Memory Scale-IV.
Applied Neuropsychology: Adult, 21, 143–147. doi:10.1080= 09084282.2013.780172 Pashler, H., McDaniel, M., Rohrer, D., & Bjork, R. (2008). Learning styles: Concepts and evidence. Psychological Science in the Public Interest, 9, 105–119. doi:10.1111=j.1539-6053.2009. 01038.x Taub, H., & Kline, G. (1976). Modality effects and memory in the aged. Educational Gerontology, 1, 53–60. Wechsler, D. (2001). Wechsler Test of Adult Reading. San Antonio, TX: Psychological Corporation. Wechsler, D. (2009). Wechsler Memory Scale-Fourth Edition. San Antonio, TX: Psychological Corporation.
