ET-seminar 2012-01-27: Ignace Hooge about search of small objects near borders
Today Ignace Hooge talked about visual search for specific, known targets - such as searching for a contact lens on the floor, a particular village in a map, or a tumor in a mammography image. It is known that the border of the object may masked by neighbouring borders, degrading the perceived contrast around the object so it becomes effectively invisible. According to the literature on visual crowding and focal and ambient search, this should make fixation durations longer and saccade amplitudes shorter when participants search close to the a border, but Ignaces data show the opposite. We had a long discussion why participants search so inefficiently in these tasks.
This is one of the studies Ignace will be working with here. The three others are: 1) a systematic table of under what noise and sampling frequencies event detection algorithms break down, 2) investigating whether the small glissade at the end of saccades are real eye movements or artifacts of the measurement equipment, and 3) study the effect on data quality of using another luminosity during calibration compared to the actual recording.
Next Friday, we will discuss Kerstin Gidlöfs paper about phases in the decision process, and how that can be measured using eye movements. The full program for the eye-tracking seminar can be found at http://wiki.humlab.lu.se/dokuwiki/doku.php?id=public:eyetracking_seminar