[Abstract Title]. - Society for Neuroscience

Poster
289. Human Decision Making
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 289.10/RR46
Topic: F.01.g. Decision making and reasoning
Support: NHMRC
Prince of Wales Medical Research Institute
Title: Risk taking and postural control in older people
Authors: *A. A. BUTLER 1,2 , J. L. TAYLOR 1 , S. R. LORD 1 , R. C. FITZPATRICK 1 ;
1 Prince Wales Med., Randwick, Australia; 2 Sch. of Med. Sciences, Univ. of New South Wales,
Sydney, Australia
Abstract: Introduction: It is common sense that taking undue risks causes mishap, falling and
injury for the elderly, just as in youth. Understanding “undue risk” is critical here as risk depends
on ability. Physical ability and sensorimotor performance are the best predictors of falling among
older people. Here, we attempt to identify those subjects who endanger themselves by taking
risks beyond their abilities.
Methods: Subjects (n=294, aged over 70 years) undertook a challenge to walk a plank. They
could choose one of six footpaths to reach the same goal but in each was a plank that had to be
crossed. The shortest path had the narrowest and tallest plank and the longest path had the widest
and lowest plank. Thus, they could walk a shorter but riskier path or take a longer but safer path
to reach their goal as quickly as possible. Tests of physiological performance that predicted the
likelihood of falling from their chosen plank were administered and a questionnaire related to
perceived risk taking behavior was completed.
Results: Subjects were rated on a timid-bold scale based on the probability of falling from their
chosen path. Older people and people with poor physiological performance chose safer planks.
However, despite this they also had the highest probability of falling from their chosen plank.
Men were more likely to choose more difficult planks and had a higher probability of falling
from their chosen plank than women. Overall, subjects with good physiological performance
made appropriate choices while poor performers made either risky choices or overly safe
choices.
Discussion and Conclusions: While older people with poor physiological performance tend to
choose safer plank paths to compensate for their reduced physiological abilities, they do not
adequately compensate and still have a high probability of falling from their chosen plank. Some
subjects adopt a timid or safe strategy whereas others take excessive risks that would be likely to
cause falling over or injury in everyday life. Subjects with the poorest physiological performance
reported risk-avoiding behaviour during daily activities on questionnaire but our test indicates
that this group takes the greatest risks.