Visual Cues, Landmarks and Time and How They Aid Object Permanence

November 28th, 2006
Cognitive Psychology (PSYO 3390)

As infants developed the ability to move around and become more active in relation to their surroundings, they become able to learn more by experience than they have been simply by watching and listening. With this new ability, they can expand their knowledge and with that, memory. How quickly can long-term memory develop in infants and how does it apply to object permanence? For how long can an infant remember the existence of an object after it has been removed from their immediate presence? Moore & Melzoff (2004) designed a study that tested infants and object permanence and whether infants could remember the location of a previously hidden object after a period of 24 hours. Different conditions were made to test the infants in different settings to determine under what situations the object sought-after would be found after 24 hours.

In this experiment, Moore & Melzoff (2004) had three different groups of infants aged 14-months in a laboratory setting. Two of the groups participated for a period that covered two days. They were the experimental (object hidden) and occluder-manipulation control group in which the object was not hidden. The remaining group was the baseline group that only partook in the second day.

Day one consisted of familiarizing the infant with the experimenter and the room by playing interactive games and explicitly presenting visual cues that included a mobile, a poster of a frog and a colourful lamp. Then the experimenter presented a silver hand bell to the infants to play with for a short time. For the experimental group, the experimenter hid the hand bell inside a container while the infants were watching and repeating the motion three times. For the occluder-manipulation group, the experimenter did all of the same actions except the bell was placed in front of the container instead.

On the second day, before the infants were brought in, the hand bell was removed from the location it had been last seen in the day before. Otherwise, all of the activities for the second day were the same as the day before for all three groups. When the interactive games and presentations of the visual cues were complete, the experimenter had the parent and infant sit with their back to the experimenter as he retrieved the bell and made it ring before hiding it behind his back. The infants were then allowed to search for the bell. The results showed that in the experimental group, more than half of the infants were successful in finding the bell by going to the correct location and averting their gaze to where the bell should have been as they opened the container. The infants were held as the bell was placed on the floor in front of them and then released to do an object-visible test where 2/3 looked in the container even as the hand bell was already present. This suggested that infants search by numerical identity, which means that the location an object was last seen is more important than its physical features. It may look the same but if not located where expected, it may not be the desired object. Numerical identity is also the guide that adults use when searching for objects.

Moore & Melzoff (2004) also had a second experiment which took into account room changes that eliminated visual cues between day 1 and day 2. Everything was the same as in the first experiment except the overall apparent shape of the room and visual cues were different between the two days while the hiding container was in the same location. Due to the assumption that the room was different, the infants did not search for the object.

In the first experiment of the present study, the experimenter had an object recall for all of the groups in which he had the infant turned back-on as he provided auditory stimulation of the object sought-after. Had the entire session for day 2 been the same, except the object recall, would the visual cues be enough for the infant to remember the existence of the object and search for it?

A point-of-interest in the present experiment was that there was only one hiding place and thus only one place to expect to find the object sought-after. Would infants be as accurate in finding the object if there was a choice between places to look? The use of visual cues in the present experiment was used more for the infants to ensure the room was the same for both days then as landmarks. What if they were used for both purposes at the same time to determine that (a) they were in the same room as before and (b) to use as landmarks when searching the room?

A final question to ask is the length of time an infant can maintain object permanence. In the present experiment, the time allotted was 24 hours. This time has been deemed a successful length of time so it is a logical step to extend it.

With these points in mind, a follow-up experiment would be conducted using infants aged 14 months, as in the Moore & Melzoff (2004) study. They will be selected for four groups: a control group, a landmark rotation group, a no-object recall group and an extended delay group. The experiment will take place in a rectangular shaped room with visual-stimulating cues throughout, such as colourful posters on the walls, mobiles hanging from the ceiling, two chairs placed in one end, two feet from each other at a 45º from the wall and two containers at the other end of the room, one in each corner. The containers will serve as the hiding spot for the object sought-after with it being placed in the right container for half of the infants and the left container for half of the infants. All groups will be brought into the room and be brought around by the experimenter as in the Moore & Melzoff (2004) study. The visual cues will be pointed out and described by the experimenter. Infants in all groups will then be presented with an attractive toy (i.e., a bell) on day 1. The infant will have a short time to play with the bell before it is hidden in either one of the two containers while the infant is watching. Then the infant will be taken out of the room by the parent.

Group 1, the control group, will return the next day with all of the previous day’s activities repeated. Except the infant and the parent will turn back-on as the experimenter makes a sound with the bell and places it back in the hiding spot. Then the infant is allowed to search for it.

Group 2, the landmark rotation group, will have all of the same conditions as the first group, except everything in the room, aside from the two containers, will be moved clockwise along one wall. So instead of the two chairs being located directly across the room from the two containers, they will now be adjacent to them on the left side, and so on. Assuming the infants think they are in the same room, this will determine whether they rely on landmarks to find the bell or whether remembering the left or right side was enough.

Group 3, the no-object recall group, will have the same conditions as the first group except there will be no object recall. The infant will be brought around the room and given the same tour as in the previous day except there will be no auditory sign of the bell. This will help verify whether the visual cues presented will be enough to remind the infant of the existence of the bell and thus if a search will occur once they are allowed to.

Group 4, the extended delay group, will have all of the same conditions as the first group except instead of coming back the next day, the infants will return 7 days after the initial introduction. This will establish whether object permanence lasts for as long as 7 days, given that Moore & Melzoff (2004) were successful in their findings after 24 hours.

With this design, the results should provide the answers needed to conclude what is being asked. Are infants able to search for an object if visual landmarks have been altered, are visual cues enough to remind an infant of an object’s existence and can object permanence last for significantly longer than 24 hours? The answers to these questions should provide necessary framework for future studies.

References

Moore, M.K. & Melzoff, A.N. (2004). Object permanence after a 24-hr delay and leaving the locale of disappearance: The role of memory, space and identity. Developmental Psychology. 40(4). 606-620.