Purpose

1
Decreasing Visual Subitising Performance with
Age Maya Kumar1, Roger Li1,2, Dennis Levi1,2,
Sandy Chat1, Manfred MacKeben3 1School of
Optometry 2Helen Wills Neuroscience Institute,
University of California-Berkeley, Berkeley,
California, USA 3The Smith-Kettlewell Eye
Research Institute, San Francisco, California, USA
Poster 890

• Results
• Aging and Subitising

• Purpose
• Visual subitising is the ability to quickly and
  intuitively enumerate small numbers of items, is
  hypothesized to be mediated by parallel
  processing.
• To examine any age-related variations in visual
  subitising performance.
• To understand how optical and neural changes with
  age1 affect visual performance
• Methods
• Visual Stimulus

• Summary Conclusions
• Older people have problems processing multiple
  objects at a time.
• Subitising, the quick assessment of small numbers
  of stimulus elements, is achieved through
  parallel processing. Such mechanisms are
  important where ever speed counts, e.g. in
  mobility and obstacle avoidance..
• Visual subitising performance deteriorates with
  advancing age.
• Mean subitising thresholds Systematically
  decreased from 7.1 (21-30) to 4.8 dots (61-90)
  across the 5 age groups.
• Roughly, 50 of the loss in threshold occurred by
  the age of 62.
• The response latency (61-90) was prolonged an
  average of 30 (the latency curve shifted
  upward for 1 - 7 dots).
• For all age groups, the mean number of dots
  reported was very close to the number of dots
  displayed on the screen.
• The loss in subitising performance cannot be
  explained by the optical changes.
• Subitising threshold (21-40-yr-old) was minimally
  affected by reduced retinal illumination (0.2 log
  unit) and optical blurring (with plus lens
  20/20).