Differential effects of task difficulty on target-type switching in haptic foraging: Evidence for increased switching with extreme task demands.

This study investigated how varying difficulty levels modulate haptic foraging performance and search behavior. Thirty-three blindfolded participants had to locate and remove 20 target objects within three conditions - easy feature, conjunction, and hard feature - defined by target-distractor similarity. Response times and target-type switching were measured, and errors were recorded but remained very low across all conditions. Results revealed that higher task difficulty was associated with longer response times. Although participants switched between target types frequently in both the easy and the hard feature conditions, they switched significantly less often in the conjunction condition. This suggests that tasks requiring multiple feature dimensions to distinguish targets from distractors elicit more top-down-driven sequential searching, whereas distinctly defined targets permit more frequent shifts driven by salient cues. Practice effects emerged as participants performed each condition faster when they had already practiced different search conditions. These findings show that haptic search behavior, like visual foraging, is shaped by the interplay of top-down and bottom-up processes. They further highlight that tactile and visual systems may share common representational pathways and that practical considerations, such as target similarity and prior experience, play a crucial role in task efficiency.