Kate Wilmut, John Wann, Janice H. Brown

1
ATTENTION DISENGAGEMENT IN 36 MONTH OLDS
Kate Wilmut, John Wann, Janice H.
Brown University of Reading k.wilmut_at_reading.ac.uk

• Introduction
• Objective
• Many studies have looked at attention
  disengagement, but none have focused on 36
  month-olds.
• At this age children are becoming more active and
  are refining both visual and motor skills.
• This research investigated attention
  disengagement in 36 month-olds for both simple
  eye movements and the integration of a hand
  movement.
• Attention Disengagement
• In order for a eye movement to be made attention
  must be disengaged, shifted and re-engaged at a
  new target location (Posner, 1980).
• The gap paradigm measures attention
  disengagement.
• Gap paradigm
• Gap trials temporal gap between fixation offset
  and target onset.
• Overlap trials fixation offset and target onset
  overlap (see below).
• A shorter saccade latency is seen in gap trials,
  as attention is disengaged prior to target onset.
• This effect has been found in adults (Pratt et
  al., 1999 Bekkering et al., 1996) and newborns
  (Farroni et al., 1999).
• Development of attention disengagement
• Hood and Atkinson (1993) proposed that shifts of
  attention are driven by a dual process.

• Methods
• The gap paradigm was made into an interactive
  game and used to look at attention disengagement
  in 36 month-olds (n18).
• LEDs embedded in a Perspex board
• One central light green
• Six peripheral lights red (decorated with
  pictures of snowmen)
• Children looked at or hit targets (plastic
  hammer) when they lit up.

• Gap effect size
• Gap effect size refers to the difference in
  latency between overlap and gap trials.
• For eye latencies the size of the gap effect was
  much bigger in the look and hit condition (127ms)
  than for the look condition (60ms) (t(17)-3.370
  plt0.01).
• N.B. The gap effect size in adults on the same
  task was similar across the two conditions
  (54ms)
• The gap effect for hand latencies shows a large
  variability.

Display as seen by subjects
Look at the snowman who has the red
tummy or Hit the snowman with the red tummy

• Discussion
• Saccade latencies
• A larger gap effect was found in the look and hit
  response than in the look response (not seen in
  adults).
• When using eye movements alone toddlers display a
  mature pattern of response (similar to that seen
  in adults), this is not the case when a hand
  movement is used.
• This suggests that toddlers are still refining
  their disengagement mechanisms such that the
  process needed for disengagement in overlap
  trials is not fully developed.
• Hand latencies
• The lack of a gap effect in hand latencies (a gap
  effect has been found in the hand latencies of
  adults, Bekkering 1996) may be due to the
  variation in latency.
• The huge variation seen in all aspects of hand
  movements suggests an overall immaturity in the
  combination of visuo-spatial and motor systems.
• Conclusion
• At 36 months children are still refining their
  disengagement mechanisms so when a hand movement
  is added to an eye movement attention
  disengagement is less skilled.
• In addition manual responses are unrefined and
  variable.

• Results
• Saccade latencies
• Significant difference between saccade latencies
  on gap and overlap trials.
• Look, F(1,17)14.986 plt0.01
• Look and hit, F(1,17)47.147 plt0.01

Order of events for gap and overlap trials

• Hand latencies
• No significant difference between gap and overlap
  trials.
• Large variability in hand latencies (ms),
  accuracy error (cm), heading error (o) and in the
  number of adjustments.