Systematic Movements in Haptic Search: Spirals, Zigzags, and Parallel Sweeps.

Area of Science:

• * Cognitive Psychology
• * Human-Computer Interaction
• * Haptics and Tactile Perception

Background:

• * Understanding human movement strategies in tactile exploration is crucial for designing effective interfaces and assistive technologies.
• * Previous research suggests systematic search patterns, but their modulation by sensory input size is less understood.

Purpose of the Study:

• * To investigate how the number of fingers used affects movement strategies during a one-handed haptic search task.
• * To determine if participants adapt their search behavior based on the detection radius provided by one versus five fingers.

Main Methods:

• * Blindfolded sighted participants performed a landmark search on an unstructured tactile map.
• * Two conditions were tested: using one finger versus five fingers for exploration.
• * Movement strategies (e.g., systematic vs. random) were analyzed based on the number of fingers employed.

Main Results:

• * Systematic search strategies (spirals, zigzags, parallel sweeps) were significantly more prevalent in the one-finger condition compared to the five-finger condition.
• * Participants utilized the larger detection radius with five fingers to find targets more broadly, employing more systematic patterns with a single finger.
• * During five-finger search, fingers moved cohesively, expanding and contracting to adapt search speed, with primary examination by the index and middle fingers.

Conclusions:

• * Untrained sighted individuals naturally adopt optimal, systematic strategies during haptic search.
• * Haptic search behavior is effectively modulated by the available detection radius, demonstrating adaptive exploration.
• * The findings provide insights into the sensorimotor control of tactile exploration and its strategic adaptation.