Introduction 2005 1998 2003 2001 1998 2003 2001 2001 2003 1999 1999 1998 1998 2001 2001 Methods Participants 1997 1994 1 t 2 Table 1 ADI scores on the four domains for individual PDD subjects ADI scores individual subjects Social interaction (cutoff 10) Communication (cutoff 8) Stereotypy (cutoff 3) Age of onset (cutoff 1) 1 22 18 2 0 2 18 13 9 0 3 24 16 3 5 4 26 16 8 5 5 24 24 10 3 6 21 20 4 3 7 28 17 5 2 Table 2 Mean age and IQ characteristics of the control and PDD group  Control PDD Age 21.2 22.1 TIQ 115.3 121.9 VIQ 119.1 124.0 PIQ 106.7 114.0 Set up and Data Analysis 1997 1997 2002 1995 Stimulus and Task 2001 Procedure The order in which the two conditions were presented was counterbalanced. Prior to each task participants were given 10 practice trials. Participants were instructed to respond as quickly and accurate as possible by pressing the five key on the numeric pad when the target was present and the four key when the target was absent. Thereafter, the eye link camera was attached to the head and calibrated. On each trial the sequence of events was as follows: a fixation cross was presented. The participant had to fixate at the cross and press the space bar subsequently. Fixation of the fixation cross was used for on-line drift correction of the eye tracker. Then, the search display appeared and remained visible until the participant responded. After the response the next trial started. Results t condition 1 condition 2 1996 p RT Analysis F p F p F p p F F p 1 Fig. 1 left panel right panel  Eye Movement Analysis F p F p p p F p p p 2 Fig. 2 left panel right panel  No significant group differences were found for fixation times at either the first fixation or the remaining fixations. Discussion 2001 2001 1998 2001 1994 2002 2006 Concluding, the measurement of eye movements during search tasks shows that the superior behavior of subjects with PDD in these tasks cannot be attributed to strategy difference, but point indeed to increased stimulus discriminability in this group.