Burst and glideUneven, fish-like changes in speed and direction
Motion history → disappearance
→
empty water
→
Retreat and social-offset activityResponses involved visual populations in the optic tectum and thalamus.
Smooth translationAn object follows a regular, non-biological path
Motion history → disappearance
→
empty water
→
No equivalent responseVanishing alone was insufficient; the object first had to resemble a plausible companion.
The useful clue is the combination: “that moved like one of us” followed by “now it is gone.” The study supports this visual computation without implying conscious interpretation or an intentional alarm.