"A great deal is claimed about what young babies know about the world but our findings favour a much more cautious approach," states researcher Professor Gavin Bremner of the University of Lancaster. His research is published today as part of Social Science week.
The study investigated the way in which babies up to six months old perceive objects. "As adults, we perceive a world composed of coherent, segregated objects," explains Professor Bremner. "Also, as objects move we perceive them persisting even if they are temporarily hidden by other objects." These abilities to fill in the gaps in perceptual experience are fundamental to human perception, but are we born with these abilities or do they develop in infancy? Moreover, do babies perceive the world in this way, or is their perception limited very much to what is literally visible at any one moment?
Researchers addressed these questions by testing how young infants perceive an object which moves from left to right but passes behind a screen at the half way point. Do the babies perceive it as a single object moving continuously, or do they see it as two separate movement segments?
"We carried out a series of studies to establish the conditions under which young infants perceived such movement events as continuous," he explains. The first finding is that the width of screen is important: four-month-olds perceive trajectory continuity when the screen the object moves behind is narrow but not when it is wide. There is also a developmental effect: two-month-olds do not perceive trajectory continuity even when the screen is narrow, whereas a baby at six months perceives continuity even when the screen is wide. Further investigation reveals that four-month-olds perceive an object as moving continuously only when it is out of sight for a short distance (ie a narrow screen) or for a short period of time.
"These findings are important because they cast doubt on nativist claims that babies are born with some sort of innate pre-wiring that means awareness of objects is well developed at birth," Professor Bremner points out. "In fact, our results suggest a very different developmental process from that presented by nativists," he adds. Rather than concluding that perception of the identity and permanence of moving objects is present at birth, it seems apparent that babies initially do not see objects that move behind a screen as moving on a continuous path. And by four months they do so only under tightly constrained conditions. "This suggests that babies develop their perceptual abilities with age but are not born with them," he concludes.
For further information, contact:
Professor Gavin Bremner on 152-459-3821 or 44-786-683-9160 (mobile) or e-mail: j.g.bremner@lancaster.ac.uk Or Lesley Lilley or Anna Hinds at ESRC, on 01793-413119/122
NOTES FOR EDITORS
1. Social Science Week 2003, from the 23rd to the 27th June, is about revitalising policy by bringing social scientists and their research together with policy-makers.. Events in various locations will showcase a broad array of ESRC research. Topics will cover a wide spectrum, from the state of UK business to climate change and arms control. For a programme visit www.esrc.ac.uk/socialscienceweek or call David Ridley, External Relations, on 01793 413118.
2. The research report 'Perception of object trajectories by young infants' was based on a three-year project funded by the Economic and Social Research Council (ESRC). Gavin Bremner is Professor of Developmental Psychology, Department of Psychology, University of Lancaster, LA1 4YF.
3. The ESRC is the UK's largest funding agency for research and postgraduate training relating to social and economic issues. It has a track record of providing high-quality, relevant research to business, the public sector and Government. The ESRC invests more than £53 million every year in social science research. At any time, its range of funding schemes may be supporting 2,000 researchers within academic institutions and research policy institutes. It also funds postgraduate training within the social sciences thereby nurturing the researchers of tomorrow. The ESRC website address is http://www.esrc.ac.uk
4. REGARD is the ESRC's database of research. It provides a key source of information on ESRC social science research awards and all associated publications and products. The website can be found at http://www.regard.ac.uk.