1. Kazuo Moria & Hiroshi Itob
SARMAC XII, January 4, 2017
Sydney, Australia
Research proposal: Assessment of the international index of conformity ratio of co-witness pairs by utilizing the Garry-Mori experimental procedure
Kazuo Moria & Hiroshi Itob
Good afternoon, everyone.
I am Hiroshi Ito from Aichi University in Japan.
In this presentation, on behalf of myself and my partner,
I will report on “The effect of post-event conversation on eyewitness memory: Using the MORI technique with an East Asian sample.”
a Division of Advanced Health Science, Institute of Engineering,
Tokyo University of Agriculture and Technology
b Department of Psychology, Faculty of Letters, Aichi University, Japan
This research was supported by a Grant-in-Aid from the JSPS (Grant No ) to the first author.

2. For most cases, there were many witnesses who observed the event.
What if do they report the same event differently in details?
Can we trust the recalled points that were reported uniformly?
How do we treat the items being reported differently by co-witnesses?
We need a basic research on how and when co-witnesses conform on the details they observed differently.

3. Kanematsu, Mori, & Mori (1996)
Memory conformity of co-witness pairs
Kanematsu, Mori, and Mori (1996) examined memory conformity of co-witnesses who observed the event differently by utilizing a presentation trick.
The experimenters presented two different versions of the same simulated criminal event with three differing details to pairs of participants without their noticing the duality by utilizing two pairs of polarizing filters.
The co-witness pairs tended to conform to their partners even on the items they had observed differently.
The conformity occurred more frequently among the pairs who discussed the event after presentation than the pairs who did not.
Yes, it was an apple.
Many researchers studying memory conformity have made significant advances in our understanding of the phenomenon.
Previous studies have reported the effects of memory conformity on eyewitness memory, suggesting that people can easily incorporate new and inaccurate information into their own eyewitness memory during discussion with another person.
Figure 1 shows a sample of memory conformity during discussion.
They are undergraduate students in my laboratory. For example, one person says “I saw Eric tried on a red cap.”
And then, the other person think “Not black? He might have tried on a red cup.”
Finally, she agree with her partner.
A pineapple
An apple
I saw an apple.
Fig. 1 Having observed differently but conforming to the partner afterward

4. Garry, French, Kinzett, & Mori (2008)
A replication of the Kanematsu et al. study
Garry et al. (2008) replicated Kanematsu et al. (1996) with participants from New Zealand.
They also elaborated the experimental procedure by having created a set of digital video clips with eight differing details and utilizing a within-subject design.
The results were basically the same as the Kanematsu et al. study.
For example, Garry et al. (2008) showed that participants from New Zealand were more likely to give a correct answer concerning non-discussed critical details than discussed critical details in a movie.
They used a technique called the Manipulation of Overlapping Rivalrous Images, —that is, the MORI technique. In the MORI technique (which I’ll detail in the Method section), people can sit side by side watching different movies, and believe that they have seen exactly the same thing.
Fig. 2 Diagram of the experimental procedure of Garry et al. (2008)

5. Differences between the two studies
Too many differences between the two studies
Both studies showed that co-witnesses tended to conform to their partners even on the points they had observed differently.
The discussion worked to produce more conforming responses.
However, it was not possible to assess the cultural differences, Japanese and New Zealanders, of conforming tendencies because too many intervening factors were different in these studies.
Table 1 The major differences of the Kanematsu et al. and Garry et al. studies
Parti-cipants
Experi-mental design
MORI equipment
Video clip
Witnessed events
Kanematsu et al. (1996)
60 Japanese
Between subjects
LCD projectors
Analog
1 minute
Theft by a car driver
Garry et al. (2008)
40 New Zealanders
Within subjects
DLP projectors
Digital
6 minutes
Theft by an electrician
Forty Japanese students at Aichi University in Japan participated in our study. The present study was based on a within-subject design (non-discussed vs. discussed), and the critical target items for recognition were fully counterbalanced, such that each served equally as a control and a discussion item.

6. The research proposal
Assessment of the conformity ratios among different cultures
To examine the ratios of conformity on discussed and non-discussed items among participants from different cultural backgrounds by utilizing strictly the same experimental procedure.
We will obtain the international index of conformity ratio of co-witness pairs with the 95% confidence interval.
Preregistered replication study
All the details of the experimental procedure are pre-determined.
The research doubles as the preregistered replication study of Garry et al. (2008).
We will re-examine the reliabilities of the findings of Garry et al. (2008).
However, though the phenomenon has been observed in Western culture, there is a lack of consensus on whether the effect of post-event conversation is also observable in East Asian culture (for example, Japan).
Thus, using the MORI technique and an experimental paradigm similar to that of Garry et al. (2008), we examined the effect of post-event conversation on East Asian population.
“Personally, I aim never again to submit for publication a report of a study that was not preregistered.” (Lindsay, 2015)

7. Preregistered method Participants Design Video materials
Forty university students to form 20 co-witness pairs
Design
A within-subject (between-items) design used in Garry et al. (2008)
The critical items being counterbalanced so that each serves equally as a discussed and a non-discussed item
Video materials
The Takarangi Video Clips (Takarangi et al. 2006)
The clips depicted a simulated criminal event carried out by an electrician working in an absent house, wherein he slipped away from his task and stole some items.
The two versions of the movie were identical except for eight critical items.
Forty Japanese students at Aichi University in Japan participated in our study. The present study was based on a within-subject design (non-discussed vs. discussed), and the critical target items for recognition were fully counterbalanced, such that each served equally as a control and a discussion item.
Version 1
Version 2
Fig. 3 Examples of the differing items inserted in the Takarangi movie

8. Presentation by MORI technique
Apparatus
A set of two DLP projectors (TAXAN, KG-PL021X) and polarizing filters used in Ito and Mori (2015)
The image from each of the projectors is perpendicularly polarized so that it can be observed by only one of the participants wearing an appropriate pair of polarizing sunglasses.
Polarizing filters
Viewer (A)
Here you can see the MORI technique. Each version of the movie was projected onto the back of the same half-transparent projection screen. The two projectors were mounted on a stand, one above the other, with one tilted slightly upward and the other slightly downward, so that the two images overlapped.
Polarizing filters were attached to the stand, in front of the lens of each projector, one placed vertically and the other horizontally. For each pair of participants, one set of glasses allowed the wearer to view the vertically polarized image while blocking the horizontally polarized one, and the other set of glasses did the opposite.
Viewer (B)
Video clips
DLP projectors
Half-transparent screen
Fig. 4 Diagram of the MORI presentation trick technique

9. Experimental procedure
The experimental procedure is the same as Garry et al. (2008).
An individual recognition test
(up to 10 min)
A filler multiplication test
(5 min)
354
✖︎ 821
Time
A collaborative recognition test with discussion on selected items
(up to 12 min)
We used a three-phase procedure. First, participants watched a movie, after which they worked on a filler logic puzzle for 15 minutes, and then the second phase began. In the second phase, participants took part in the collaborative recognition test, after which they worked on long multiplication problems (3-digit by 3-digit) for five minutes, and then the third phase began. In the third phase, participants completed the individual recognition test. Finally, participants were debriefed.
A filler logic puzzle (15 min)
Watching a movie
(6:34)
Fig. 5 Diagram of the preregistered experimental procedure (Ito & Mori, 2015)

10. The 1st round of the international project
Results of the 1st round of the project: Five countries
The basic findings were replicated across the five countries.
For materials, we used the Takarangi Video Clips, which depicted a simulated criminal event carried out by an electrician (“Eric”) working in an unoccupied house, wherein he slipped away from his task and stole a number of items.
The two versions of the movie were identical except for eight critical details. Here you can see an example of a critical detail: Eric tried on a black baseball cap in one version and a red cap in the other. The video ran for 6 minutes 34 seconds, without audio.
Fig. 6 Results of the the 1st round of the project along with the original results

11. Call for participation in the 2nd round
We would like to invite you to participate in the 2nd round of the project.
Researchers from varieties of cultural backgrounds are welcome.
The MORI equipment, a set of DLP projectors and polarizing sunglasses, will be sent to the participating investigators.
All the experimental materials, including the video clips, the filler puzzles, the recognition test items, etc. will be provided.
All you need are the lab space, a transparent screen, and 20 pairs of participants.
It is suitable for a training of grad students for conducting an eye-witness experiment.
In this study, we conducted two recognition tests: a collaborative recognition test with discussion, and an individual recognition test.
In the former test, a set of 12 questions appeared on the screen, one at a time, and participants were asked to discuss and answer the questions together. Each question asked about a detail of the movie, and offered five possible responses. For example, with respect to the aforementioned example, “Eric tried on a [blank]_____ cap.: Blue; Black; Green; Red; Grey”.
Of the 12 questions, 4 targeted four of the eight critical details in the movie, with both correct answers being included among the possible responses; and the remaining 8 targeted filler details. The other four critical items from the movie were not discussed, and thus served as controls in the individual recognition test.
Fig. 7 The MORI equipment: a set of two DLP projectors and polarizing sunglasses

12. The Turkish Results Please visit Poster #13 later this afternoon.
Ceren Gurdere & Sami Gulgoz
Investigating memory conformity using the MORI technique with a central Asian-Turkish sample
In conclusion, we replicated, in an East Asian context, the findings of Garry et al. (2008). Whether people experience actual memory distortion or simply believe their partner to be correct, our results show that people will tend to incorporate elements of each other’s memory reports into their own memory report, even when that information contradicts what they themselves have seen.

13. References
Garry, M., French, L., Kinzett, T., & Mori, K. (2008). Eyewitness memory following discussion: Using the MORI technique with a Western sample. Applied Cognitive Psychology, 22,
Ito, H. & Mori, K. (2015). The effect of post event conversation on eyewitness memory: Using the MORI technique with an East Asian sample. Paper presented at the SARMAC XI, Victoria, Canada. (June, 2015).
Kanematsu, H., Mori, K., & Mori, H. (1996). Memory distortion in eyewitness pairs who observed nonconforming events and discussed them. Ninchi Kagaku (Cognitive Studies: Bulletin of the Japanese Cognitive Science Society), 3,
Lindsay, D. S. (2015). Replication in psychological science. Psychological Science, 26,
Mori, K. (2007). A revised method for projecting two different movies to two groups of viewers without their noticing the duality. Behavior Research Methods, 39,
Takarangi, M. K. T., Parker, S. L., & Garry, M. (2006). Modernizing the misinformation effect: The development of a new stimulus set. Applied Cognitive Psychology, 20, 1-8.
In conclusion, we replicated, in an East Asian context, the findings of Garry et al. (2008). Whether people experience actual memory distortion or simply believe their partner to be correct, our results show that people will tend to incorporate elements of each other’s memory reports into their own memory report, even when that information contradicts what they themselves have seen.