Visual Imagery in Recognition and Source Memory for ...

Perceptzial and Mofor Skillx, 2001,92,771-776. O Perceptual and Motor Skills 2001

VISUAL IMAGERY IN RECOGNITION AND SOURCE MEMORY FOR AUDIOTAPE AND TEXT ' STUART J. McKELVE AND CAROLIN E B E R i i N Bishop's U ~ z i v e r r i ~ Slimmaw.--80 parricipants heard an audiotape of a crime, read an account with both correct and new information, then took recognition and source memory tests. While listening and reading, parricipants attended carefully, and h a f also formed visual images of the events. Imagery instructions had no effects, bur recocnlrlon memory was better for material from the text only than from the audiotape only. whereas source memory was better for audiotape than for text. These results replicate previous findings €or Eim and audiotape.

Although it is important to remember what we heard, see, or read (item information), we often wish to locate zuhere we encountered it (source information; Jurica & Shimamura, 1999). Various studies have shown that, when item memory is accurate, source memory may not be (Lindsay & Johnson, 1989; Lane & Zaragoza, 1995; Kahan, 1996; Zaragoza & Mitchell, 1996; Koriat, Goldsmith, & Pansky, 2000). Sometimes confusion arises between memory for actual and imagined events (reahty monitoring; Johnson, Raye, Wang, & Taylor, 1979; Markham & Hynes, 1993) or between memory for two external events (source monitoring) (Dobson & Markham, 1993). Why do such errors occur? One account assumes that source memories for external events contain visual information and are particularly likely to be confused if people form vivid images (Dobson & Markham, 1993; Johnson, Hashtroudi, & Lindsay, 1993). To test this, Dobson and Markham conducted a source monitoring study in which they showed people a film then asked them to read an account of it that contained both correct and incorrect information. Recognition memory was better for written statements that came from the text only than from the f h only but source memory was better for film than for text. However, source memory for text was less accurate for people classified as high vivid imagers than low vivid imagers. Dobson and Markham argue that the high imagers formed images of text that were richer in sensory detail than those of low imagers and were consequently more hkely to mistakenly attribute them to the f h , which was already encoded visually. Dobson and Markham wondered whether their results would occur with 'We thank Leo Standing for helpful commenrs. Send correspondence to Stuart J. McKelvie, Department of Psychology, Bishop's University, Lennoxville, Quebec, JIM 127, Canada or e-mail (smckelvi@~~bishops.ca).

other kinds of external source. To examine this, Eberman and McKelvie (in press) presented initial information on an audiotape simulating a radio broadcast. In a parallel result to Dobson and Markham, they found that recognition memory was better for text only than audiotape only whereas source memory was better for audiotape than text. Ln addition, high imagers had poorer source memory for text than low imagers, but only if participants were asked to form visual images while listening and reading. This supports Dobson and Markham's suggestion (1993) that vivid imagery ability increases source confusion if the initial processing is visual (either from the task or from instructions). The present note reports the performance of Eberman and McKelvie's participants (in press) who scored in the moderate range on visual imagery a b h y (the previous paper dealt with those in the extremes). Questions were whether recognition memory is better for text than audiotape, whether source memory is better for a d o t a p e than text, and whether people instructed to form visual images while listening and reading have poorer source memory for text than people instructed only to pay attention. METHOD

Full procedural detads are contained in Eberman and McKelvie (in press).

Participants Participants were 80 undergraduates (18 men, 62 women) who scored in the middle of the distribution of 160 scores on the Vividness of Visual Imagery Questionnaire Revised Version (VVIQRV; Marks, 1995; McKelvie, 1995). They were assigned at random to two experimental conditions (Irnagery, Natural) with matching for gender.

Materials and Procedure Participants were instructed to listen carefully to a 4-min. audotape that described a robbery. Those in the imagery condition were also asked to form clear and vivid visual images of the scene described. After a 5-min. fdler task, everyone read the text version of the crime. This was a 25-statement narrative, with 17 statements referring to the audiotape and eight new statements replacing eight taped events. Participants were again instructed to read it carefully, and those in the imagery condition were also told to generate visual images. After a second 15-min. fdler task, a recognition memory test was given. Each of 32 written statements was judged as old or new (had been encountered before or not) and, if old, as coming from a d o t a p e only, text only, or both audiotape and text. In fact, 8 came from the audiotape, 8 came from the text, 8 came from both, and 8 were new but plausible. Finally, the

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Vividness of Visual Imagery Questionnaire Revised Version was administered. It consists of 32 items, each being rated on a scale from 0 (no image) to 7 (perfect vividness).

RESULTS AND DISCUSSION Raw scores were converted to proportions before being analyzed. Alpha was set at .05. Recognition Memory Because the main interest is in source memory, these results are presented briefly. For proportion correct, a 2 x 3 (Instructions x Source) mixed-model analysis of variance gave only a significant effect of source (F,,,,,= 23.06). Performance was best for both audiotape and text (M= .88), followed by text only (M= .84) and then by audiotape only ( M = .72). This replicates the previous findings with audiotape (Eberman & McKelvie, in press) and with film (Dobson & Markham, 1993). Proportions of false positives (saying "old" to a new statement) for the imagery and natural conditions were examined with a 2-level analysis of variance. These errors were rare (M=.15), and the effect of instructions was not significant.

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Instrucr~on Audlotaoe

M

SD

Attr~but~on Text

M

Both

SD

False Recognition (Said "Old" to a New Item) Natural .697 .482 .OOO ,000 Imagery ,728 ,457 .OOO .OOO Correct Recognition When Source Was Audiotape Only ,977 ,082 ,003 Natural .063 Imagery ,980 ,089 ,009 .I59 Correct Recognition When Source Was Text Only Natural ,202 ,207 ,462 ,282 Imagery ,134 ,169 ,457 ,303 Correct Recognition When Source Was Both Audiocape and Text ,211 ,187 ,112 ,117 Natural Imagery ,283 ,209 ,002 ,116 Nofe.-1z=40 in each condition for correct recognition; n=24 (Natural), 28 (Imagery) for false recognition (some people did not make false recognitions). Not all rows sum to 1 because of rounding.

The absence of an effect of imagery instructions for correct and incorrect answers agrees with Eberman and McKelvie's results. It is also consistent with Drose and Allen's finding (1993) that recognition memory for sentences was unaffected by imagery instructions and contrasts with positive ef-

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fects of imagery on sentence recall (Drose & Allen, 1993) and word recognition (Bower, 1972; Morris & Reid, 1974). Forming images seems to have a h i t e d effect on recognition of connected verbal material. Source Memory (Table 1) For false positives, a 2 x 3 (Instructions x Source) analysis of variance gave only a significant effect of source (F,,,,, = 30.65). More attributions were made to the audiotape ( M = .69) than to both sources (M= .27) and more to both sources than to text (M= .00). These are the same results found for film (Dobson & Markham, 1993) and for audiotape (Eberman & McKelvie, in press). The absence of an effect of imagery instructions also replicates Eberman and McKelvie's findings. We examined the proportion of attributions to each source from correctly recognized audiotape only, text only, and both audotape and text statements. The 2 x 3 x 3 (Instructions x Imagery Ability x Source x Attribution) analysis of variance gave significant effects of attribution (F,,,,,= 70.00) and of the interaction for source x attribution (F,,,,,=292.63). Generally, most attributions were made to audiotape only (M= .46), followed by both audiotape and text (M= .36), followed by text only (.20). Because this pattern also occurred with false positives, it may mean that people are generally biased towards thinking that recognized information is most likely to have come from audiotape, than from both, then from text only. However, the interaction shows that this pattern did not occur on each source. It arose because a d o t a p e was the most frequent attribution when it was the source (M=.98), text was the most frequent when it was the source (M=.46), and both audiotape and text were the most frequent when they were the source (M= .70). Again, this replicates Eberman and McKelvie's results, includmg the absence of any effects of imagery instructions. In particular, source memory for text was not poorer with imagery (M=.46) than with natural instructions (M= .46). Dobson and Markham did not report their complete set of attributions, but our greater accuracy on a d o t a p e (.98) than on text (.46) is similar to their greater accuracy on f h (.92) than on text (33) and to Eberman and McKelvie's greater accuracy (in press) on audio (.96) than on text (.44). This contrasts with the greater recognition accuracy for text than audiotape (here, Eberman & McKelvie) and for text than f h (Dobson & Markham) and supports the contention that item memory and source memory are governed by different processes (Johnson, et al., 1993). The absence of an effect of imagery instructions for recognition memory and source memory may be related to the fact that people in the natural condition spontaneously generated images. However, Eberman and McKelvie found that source memory was poorer for high than low vivid imagers only in the imagery condition. This implies that processing was different in the imagery and natural conditions.

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For Dobson and Markham, source memory for text was poorer than for film for high than for low vivid imagers. For Eberrnan and McKelvie, source memory was poorer for text than for audotape for high than for low vivid imagers if visual images were generated while listening and reading. Although this supports Dobson and Markham's contention that confusion for the text source occurs with initial visual processing, there were two h d s : film and high vivid imagers (Dobson & Markham), or imagery instructions with audiotape and high vivid imagers (Eberman & McKelvie). In the present study, there was only one lund of initial visual processing: imagery instructions with audiotape. This was also true in one condition in Eberman and McKelvie's study: natural listening to an audiotape and high vivid imagers. Ln neither of these two situations was source memory for text poorer with imagery instructions alone or vivid imagers alone. For confusion to arise between two external sources, it appears that there have to be two h d s of visual processing. This supports the theoretical position that confusion between external sources occurs if there is sensory and spatial processing (Johnson, et al., 1993), but it shows that the visual processing must be extensive. Research might investigate whether it matters what the external sources are. Would the confusion occur with two f i sources, two text sources, or with f h and audiotape? REFERENCES BOWER.G. H. (1972) Mental image and associative learning. In L. Gregg (Ed.), Cognilion in Wiley. P p . 51-88. learning and memory. New doe so^, M., & ARKHA HAM. R. (1993) Ima ery ability and source monitoring: implications for eyewitness memory. Briiish Journal oB~sYchologv,32, 111118. DROSE,G. S., &ALLEN,G. L. (1993) The role of visual imagery in the retention of information from sentences. The Jorrrnal of General Psychology, 121, 37-60. EBERMAN,C., &MCKELVIE,S. J. (in press) Vividness of visual imagery and source memory for audio and text. Applied Memory and Cognition. JOHNSON,M. K., ~ S H T R O U D I , S., & LINDSAY.D. S. (1993) Dreams and reality monitoring. Psychological Bulletin, 114, 3-28. JOHNSON,M. K., RAYE, C. L., WANC.A. Y., &TAYLOR,T. H. (1979) Fact and fantasy: the roles of accuracy and variability in confusing imagination with perceptual experiences. Journal of Experimental P.Fychology:Hrrman Learrtlrtg and Memory, 5, 229-210. J U R I C AI? , J., &SHIMAMURA, A. I? (1999) Monitoring item and source information: evidence for a negative generation effect in memory. Memory €7 Cognifiort. 27. 648-656. KAHAN.T. L. (1996) Memor source confus~ons:effects of character rotation and sensory mo~ ~ ~43 , 1-448. dality. American ]otirna~ofP s y c l , o ~ 109, KORIAT,A,, GOLDSMITH. M., &PANSKI..A 12000) Towards a psychology of memory accuracy. An~zzmlReview o/Psychology, 51, 481-537. LANE,S. M., &ZARACOZA, M. S. (1995) T h e collective experience of cross-modality confusion errors. Memory €7 Cognitiotz, 23, 607-610. LINDSAY, D. S., &JOHNSON.M. K. (1989) The eyewitness suggcs~ibhcyeffect and memory for source. Memory €7 Cognitio~z,17, 349-358. MARKHAM, R., &HYNES.L. (1993) The effect of vividness of visual imagery on reality monicoring. Jozrrnal of Menfal Imagery, 17, 159-170. MARKS,D. F. (1995) New directions for mencal imagery research. Jorrrrlal of Mental Imagery, 19, 153-166.

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Vividness of virzial imagery: measzrmnent, nafzrre, fzmction & dynamics. New York: Brandon House. MORRIS,I? E., &REID, R. L. (1974) Imagery and recognition. Bn'tish Jozirnal of Psychology, 65, 7-12.

Lw\cou\, M. S., &MITCHELL, K. J. (1996) Repeaced exposure to suggestion and the crearion of false memories. Psychological Science, 7, 294-300. Accepted April 17, 2001.