TY - JOUR
T1 - Haptic search with finger movements: using more fingers does not necessarily reduce search times
AU - Overvliet, K.
AU - Smeets, J.
AU - Brenner, E.
PY - 2007
Y1 - 2007
N2 - Two haptic serial search tasks were used to investigate how the separations between items, and the number of fingers used
to scan them, influence the search time and search strategy. In both tasks participants had to search for a target (cross)
between a fixed number of non-targets (circles). The items were placed in a straight line. The target’s position was varied
within blocks, and inter-item separation was varied between blocks. In the first experiment participants used their index
finger to scan the display. As expected, search time depended on target position as well as on item separation. For larger
separations participants’ movements were jerky, resembling ‘saccades’ and ‘fixations’, while for the shortest separation the
movements were smooth. When only considering time in contact with an item, search times were the same for all separation conditions.
Furthermore, participants never continued their movement after they encountered the target. These results suggest that participants
did not use the time during which they were moving between the items to process information about the items. The search times
were a little shorter than those in a static search experiment (Overvliet et al. in Percept Psychophys, 2007a), where multiple items were presented to the fingertips simultaneously. To investigate whether this is because the finger
was moving or because only one finger was stimulated, we conducted a second experiment in which we asked participants to put
three fingers in line and use them together to scan the items. Doing so increased the time in contact with the items for all
separations, so search times were presumably longer in the static search experiment because multiple fingers were involved.
This may be caused by the time that it takes to switch from one finger to the other.
AB - Two haptic serial search tasks were used to investigate how the separations between items, and the number of fingers used
to scan them, influence the search time and search strategy. In both tasks participants had to search for a target (cross)
between a fixed number of non-targets (circles). The items were placed in a straight line. The target’s position was varied
within blocks, and inter-item separation was varied between blocks. In the first experiment participants used their index
finger to scan the display. As expected, search time depended on target position as well as on item separation. For larger
separations participants’ movements were jerky, resembling ‘saccades’ and ‘fixations’, while for the shortest separation the
movements were smooth. When only considering time in contact with an item, search times were the same for all separation conditions.
Furthermore, participants never continued their movement after they encountered the target. These results suggest that participants
did not use the time during which they were moving between the items to process information about the items. The search times
were a little shorter than those in a static search experiment (Overvliet et al. in Percept Psychophys, 2007a), where multiple items were presented to the fingertips simultaneously. To investigate whether this is because the finger
was moving or because only one finger was stimulated, we conducted a second experiment in which we asked participants to put
three fingers in line and use them together to scan the items. Doing so increased the time in contact with the items for all
separations, so search times were presumably longer in the static search experiment because multiple fingers were involved.
This may be caused by the time that it takes to switch from one finger to the other.
U2 - 10.1007/s00221-007-0998-9
DO - 10.1007/s00221-007-0998-9
M3 - Article
SN - 0014-4819
VL - 182
SP - 427
EP - 434
JO - Experimental Brain Research
JF - Experimental Brain Research
IS - 3
ER -