RESULTS AGE

1. There is no single way of coding space; it all depends on what information is available to the user. Self-referenced spatial coding involves encoding the position of the self while moving. A simple associative self-reference coding system is response learning and a more complex self-reference system is known as dead reckoning or path integration. Externally referencedspatial coding involves spatial relation among objects and locations, such as landmarks. The simpler one is cue learning, where an association is established between a location and a visible landmark, and the more complex type of externally referenced coding is place learning. As the robust findings on infants’ spatial knowledge is that younger infants use the simplier way of spatial coding systems: the response learning and cue-learning. The use of dead reckoning and place learning begin to develop after 16-18 months of old, but fully functional or mature levels of use of the system do not appear until much later than the second year – in fact, not until about the age of seven years. In general, infants under 8-12 months of age tend to code space egocentrically, whereas infants over 8-12 months of age tend to use external allocentric cues. But infants can use allocentric spatial information earlier, in case that their position is not changed during the experiment. With a typical disorientaion task, where infants are moved or rotated a new positions, infants’ coding systems become conflict, and younger infants hesitate and rely on the response learning (egocentric) more often than do slightly older children. Líkely younger infants have insufficient knowledge and experience to drive a determination of which system is more valid, therefore they repeat their earlier successful answer (motor sequence).At this point of the spatial development infants able to learn an action HOW to find a hidden object in their environment, or able to perceive WHAT features of objects to drive spatial searching behavior. But the coordination and integration between this kind of information could not be avaible. After age of 8-12 months there will be a shift in the use of spatial reference frame and information. The shift has been largely perceived as well supported by research. When does this shift appear depend on the type of the task is used to observe the infants knowledge (large or small (table task); near or far space, looking preference or manipulation tasks when they take their conclusions. In near space (within reaching distance, peripersonal space) infants of 8-9 months of age are able to use simple cue (what features of cues e. g. yellow star) information to search (how reach, grasp, look) hidden objects, because the what and how information are coupled, and they determine together the location (where information) of a hidden goal. The shift has been considered to be propelled by the the development of locomotion in the form of crawling (e.g. Acredolo, 1990; Campos et al., 2000). Studies with infants in far space are quite rare under 1.5 year, and the role of motor development on spatial cognition was not investigated as well. But in far space moving infants need to keep desired destination in mind and need to plan a route and be able to navigate around the space. Infants need to use distant cues (WHAT system) to plan their action (HOW system) and update their position to the goal location (WHERE system). To be able to integrate these systems need more locomotor experience and larger visual perspective than the crawling could obtain. A recently published study (Clearfield, 2004) examined the role of locomotor experience and type of locomotor on using of environmental cues to orient in a large space. Interestingly, her results show that without direct locations 8-month-old novice crawlers and 14-month-old novice walkers could not find the goal location, whereas both 11-month-old experienced crawlers and 14-month-old walkers were successful. This findgings suggest that the onset of walking experience results in a disruption in spatial memory set on a new action-perception coupling in the spatial development. The experience of mode of locomotion is the critical factor in the development of spatial cognition. We propose that the walking experience has some critical differences from crawling rather could affect spatial coding system and the integration of what and how systems to determine the where. Walking infants are higher up off the ground and their eye levels are quite different from crawling infants’. Walkers can also see where they are going as they are moving, they can use distal cues, they can fit their action to a distal cues. EXPERIMENT This experiment investigate the spatial behavior in far locomotor space and the role of locomotion on the development of spatial systems. Subjects 34 infants were tested twice on a new locomotor maze, first they were examined when they were 11-12-month-old and the task was repeated 2 months later with each infants (13-14 months). Method To investigate the infants’ spatial behavior we used a four-choiced maze there was arranged in a circle-shaped room, two landmarks were found on the wall: a blue star and a red circle (as cue). There were 2 phases of the task: 1)Training phase Infants were given 5 training trials from one strating position to the goal location. Infants played peekaboo with their mother while they learned a route from the starting point to the goal location where their mother was hidden. The goal location was not changed during the experiment. RESULTS AGE There was no significant difference between the age of 11- and 12-month- old infants and between the age of 13- and 14-month-old as well, therefore two groups of age were made from four. Between these groups were found significant difference (Wilcoxon test, Z=-1,890; p < ,05), infants of 13-14 months are more successful (49%) in use of environmental cues to drive their actions in space than the younger infants (22%). The age effect were analsysed more detailed with logistic regression analysis in each group of age and with Loess smoothing in all of the data. The results show that the successful answers ascended with the increasing age in each groups (11-12 m. group: Wald’s statistic =10,598, df=1, Exp (B) = 2,349, p < ,001; 13-14 m. group: Wald’s statistic = 5,284, df = 1, Exp (B) = ,157, p < ,022). These finding did not support a significant changing point in the development of spatial cognition. LOCOMOTION LOCOMOTOR STATUS To find evidence for the effects of locomotion on the spatial development first we analysed whether the locomotor status predicts the infants’ proportion of successes or not. In both groups of age the locomotor status predicted the spatail orientation, walking infants relied on visually (cues) guided actions more often and were more successful then crawling (11-12 m.: Wald’s statistic = 5,715; df=1, Exp(B) = 2,857, p < ,017; 13-14 ms.: Wald’s statistic = 11,064, df = 1, Exp(B) = 16,999, p < ,001). Not only were they more successful because of olderly age but they had more walking experince as well (logistic regression analysis supported this hypothesis). LOCOMOTOR EXPERIENCE We collected the data of infants’ motor experience in weeks: crawling, upright and walking. As the analysis shows only the walking experience pedicted the successful searching, the upright and crawling experience had not got affect on the spatial orientation in this task. (Logistic regression analysis, Wald’s statistica=4, 669, Df=1, Exp (B)=4,35; p< ,037). ATTENTION Whether the children who did not choose the right location draw any attention to the cues on the wall or not? Did they hesitate before searching location? To answer this question, an independent rater observed and scored the infants’ behavior in the test phases. Infants’ behavior was devided into 4 categories: - good choice without hesitating - good choice with hesitating about which the right location is - bad choice without hesitating (perseverated the earlier successful motor-sequence) - bad choice with hesitating; later this item was devided into two other categories due to which location was looked more often (right or wrong). The results show there was none of them who chose the right location without hesitating about where their mother hid. Successful infants often had sat down on the floor, looked around and paid more attention to the environmental cues before chose the locations. To compare the first and the second occasions (two groups of age) there could be find siginficant changes in the proportion of attentional behavior, instead of the persevereted infants (almost all of them are crawling, (F(1, 35)= 4,948, p < ,033; ). CONCLUSION The findings indicate that the successful spatial oriention in far space appear after 13-month-olds. Although much evidence suggests that the onset of crawling is an important factor in infants’ spatial coding systems, we could not supported this hypothesis. Our results show that the walking experience has a critical role on 3D visual/far space perception. We propose that the walking experience could affect on the attention focus and infants able to use visual cues to drive their action to the goal destination. 1 M M M 22% 49% 64% 44% 14% 7% 2 „What” and „How” system coordination in spatial cognition developmentBeatrix LabadiInstitute of Psychology, University of Pécs, Hungarylabadibea@gmail.com Month Trainig Test 2) Test phase First a baseline trial was taken from the original starting position. Mothers entered the maze, and hid behind the red curtain and remained there at the goal location. Infants were encouraged to find their mother. After a successful baseline trial infants began the test phase. Infants were brouhgt to the one of the two test starting positions by their mothers. Then mothers were instructed to go to the goal location not to move or make any sounds. Infants did not see where their mother went because of the curtain. Infants’ task was to cross the room to find their mothers, the experimenter remained outside of the maze and encouraging them.