Researchers who injected goldfish with morphine or saline and then attached small heaters to the fish noted that the placebo-group goldfish experienced cognitive pain—fear, anxiety, and wariness—in addition to reflexive pain, which was also observed in the drugged fish.
Researchers who injected goldfish with morphine or saline and then attached small heaters to the fish noted that the placebo-group goldfish experienced cognitive pain—fear, anxiety, and wariness—in addition to reflexive pain, which was also observed in the drugged fish.