Hooded Crow operating panel in hearing test

The crow initiates a single trial by pressing the middle button with the red LED. Then either a tone of a certain level or no tone is played back. The crow must then "answer" whether it thinks there is a tone or not. The crow answers "yes" by pressing the right button and "no" by pressing the left.

The video shows three trials:

1) In the first is a "no tone" trial and the crow answers correctly "no" by pressing the left button. This is called "correct rejection" (CR). Two correct answers in a row is food rewarded. This is the first correct answer and no food pellet is yet given but as a secondary reinforcer the machinery of the food pellet automate runs. If the crow is food rewarded every time the task is too easy and the crow is not as concentrated on listening after the tones (i.e. it is not so much under stimulus control).

2) The second trial is a "tone trial" and you should also be able to hear a tone on the video. The crow answers correctly "yes" by pressing the right button, which is called a "HIT". This is the second correct answer in a row and the crow is rewarded by a food pellet.

3) The third and last trial is also a tone trial but the tone is very faint and the crow doesn't hear it. Thus the crow answers "no" in good faith. This is nevertheless wrong, and called a "MISS", and the crow is "punished" by cage illumination blackout. This punishment is very mild, since the crows are not afraid of the dark, but gets a bit frustrated that they are not able to work for the food.

Category:

Pets & Animals

Tags:

• hooded
• crow
• psychoacoustics
• operant
• conditioning
• hearing
• corvus
• corone
• cornix
• smart