Chapter 1 Video information

1.1 Overview on video-level

Of my 260 videos (in which at least 65% of the fish are trackable), I have 74 video with at least one responding fish, and 186 where none of the fish respond. Within these videos, I vary the speed of the stimulus, as well as the location of the setup and the repetition of that location. Within one setup, I show the stimulus multiple times, and the group size of the fish differs between the videos.

1.1.1 Influence of speed of the stimulus

When the slowest speeds are presented, none of the fish respond. Only speeds larger than 20 m/s resulted in responses in the fish.

Fraction of videos with at least one responding fish, per speed of the looming stimulus

Figure 1.1: Fraction of videos with at least one responding fish, per speed of the looming stimulus

THIS IS AN IMPORTANT REMARK

1.2 Types of fish

For the fish that can see the stimulus, we have 4 types:

  • First responders (FR): first-responding fish and fish that respond withing 4 frames (… seconds) after the first-responding fish (due to the sensory-motor delay they can’t respond to other fish that respond).
  • Secondary responders (SRL): all responding fish that respond at least 4 frames after the first-responding fish. They have access to both the stimulus as well as other fish that respond (which is at least one, the first-responding fish).
  • Non-responders in a response video (NRL-r): all non-responding fish that don’t respond in a video where there is at least one fish that responds, and that can see the stimulus.
  • Non-responders in a non-response video (NRL-nr): all non-responding fish that don’t respond in a video where none of the fish respond, and that can see the stimulus.

For the fish that don’t see the stimulus, we have 3 types:

  • Secondary responders (SRNL): all responding fish that respond at least 4 frames after the first-responding fish, and cannot see the stimulus.
  • Non-responders in a response video (NRNL-r): all fish that don’t respond in a video where there is at least one responding fish, and cannot see the stimulus.
  • Non-responders in a non-response video (NRNL-nr): all fish that don’t respond in a video where none of the fish respond, and cannot see the stimulus.
Number of fish in each category, excluding the unusable fish

Figure 1.2: Number of fish in each category, excluding the unusable fish