Navigation
3 Core Navigation Processes
1. Path Intergration
- Desert ants
- Compute home vestor while moving with natural geometry
2. Scene Recognition
- view dependent mental snapshot
- learn routes between landmarks
- Rats, bees, ants
3. Reorientation
- Geometric module
- Domain specific, task specific, encapsulated
2 Uniquely Human Navigational Abilities
1. Flexible reorientation
2. Use of picture, models, maps
Desert Ants Study
- Wandering outward to get food, straight line homeward
- 3 hypothesis when testing ants:
- The energy hypothesis - when added weight, ants still found home
- Optic flow hypothesis - when covered eyes, ants still found home
- *Pedometer hypothesis - step counting, use of stumps and stilts affects ant’s
navigation home
- Represent distance (count of steps) and direction of nest (sun as compass) at each steps to
compute current displacement and home vector using geometry
- Use of sun: internal clock compute movement of sun to correct for sun’s shift
Bees Study
- Compute distance from nest to food, uses optic flow as one of the cues to assess distance
traveled (use dead reckoning/path intergration in the dark)
- Unchanged in wind, change with texture in the ground
- The waggle dance: communication about where they travelled (length = how far, fly =
direction)
- View dependent scene representations
Limits of Path Intergration
- Cumulative error (farther = more error)
- Requires continuous memory (can forget, ant = 2 days)
3 Core Navigation Processes
1. Path Intergration
- Desert ants
- Compute home vestor while moving with natural geometry
2. Scene Recognition
- view dependent mental snapshot
- learn routes between landmarks
- Rats, bees, ants
3. Reorientation
- Geometric module
- Domain specific, task specific, encapsulated
2 Uniquely Human Navigational Abilities
1. Flexible reorientation
2. Use of picture, models, maps
Desert Ants Study
- Wandering outward to get food, straight line homeward
- 3 hypothesis when testing ants:
- The energy hypothesis - when added weight, ants still found home
- Optic flow hypothesis - when covered eyes, ants still found home
- *Pedometer hypothesis - step counting, use of stumps and stilts affects ant’s
navigation home
- Represent distance (count of steps) and direction of nest (sun as compass) at each steps to
compute current displacement and home vector using geometry
- Use of sun: internal clock compute movement of sun to correct for sun’s shift
Bees Study
- Compute distance from nest to food, uses optic flow as one of the cues to assess distance
traveled (use dead reckoning/path intergration in the dark)
- Unchanged in wind, change with texture in the ground
- The waggle dance: communication about where they travelled (length = how far, fly =
direction)
- View dependent scene representations
Limits of Path Intergration
- Cumulative error (farther = more error)
- Requires continuous memory (can forget, ant = 2 days)
