Jessie Bullens prof. dr. Albert Postma http://wayfinding.fss.uu.nl The processing of categorical and coordinate spatial changes in children Jessie Bullens prof. dr. Albert Postma http://wayfinding.fss.uu.nl

Spatial Relations (Kosslyn, 1987) Categorical: the position of an object in relation to another object (LH) Coordinate: the exact metric distance between (parts of an) object(s) (RH)

Imagery Memory Development? Perception Imagery Memory (Submitted by Postma et al., 2005) ‘Bar-and-Dot’ task (Hellige & Michimata, 1989) Image Generation Task (Kosslyn et al., 1995) Development?

Questions Does spatial relation processing develop with age? What is the developmental pattern of functional lateralization?

Method ‘Memory’ Task 120 participants: 6-8 years (7.3; 1.15)

Within Between Sample picture Categorical change Coordinate change

WITHIN / BETWEEN SAME DIFFERENT CATEGORICAL COORDINATE

Signal Detection Theory Response Stimulus Same Different Same HIT MISS Different FA CR

[ 1 - % Hits + % False Alarms] Sensitivity (Pr): % Hits – % False Alarms Bias (Br): % False Alarms [ 1 - % Hits + % False Alarms]

Results : Sensitivity

Results : Bias No age differences: all groups tended to respond ‘same’ more than ‘different’ (liberal response bias) Hemisphere effect: LH > RH

Results : FA’s

Surprisingly, a RH advantage was found for categorical spatial changes: this effect might depend on intrinsic difficulty of the task LH RH

Conclusion Discrimination sensitivity improves with age (not bias) and is higher in the RH Lateralization in processing spatial relations might be a relatively late appearing phenomenon

Questions?