Episodic memory (情景记忆) allows humans to revisit past personal experiences in their minds, and it was once thought to be a special skill of humans. Although there are still arguments about the extent of this type of memory in non-human animals, scientists have proved that creatures like rats and dogs can pass tests that are developed to assess episodic memory over the past two decades. “Curiously, there is a lack of research investigating dolphins’ episodic memory,” University of Cambridge cognitive (认知的) scientist James Davies says. Therefore, this surprising fact encourages him to fill this gap.
The team used “where” and “who” questions in their research, each on a different test. Each dolphin was first trained to retrieve a ball from the water, and then trained to get a ball by approaching a person holding it in front of them while ignoring an empty-handed person standing at a different spot. During this training, the locations were randomized (使随机化) and the person holding the ball differed each time, so that those details were irrelevant to learning the retrieving behavior. Then, for the tests, the dolphins were asked to retrieve the ball as they had learned to do, but after 10 minutes, something changed-this time, the ball couldn’t be seen, as it was now behind one of the two people’s backs. In the “where” tests, the ball was hidden in the same spot as in the training, but both people had been changed, while in the “who” tests, the locations of the people changed but the ball remained with the person who’d had it previously.
Eight dolphins went through each of the two tests, separated by at least 48 hours. All the dolphins got it right in choosing the correct spot on the “where” experiments, and seven achieved success on the “who” experiments.
Kelly Jaakkola, a psychologist, says that based on their cognitive skills, dolphins are a good candidate for having episodic-like memory, and this study goes really far in showing that. She also says, “The more we look for such capabilities in non-human animals, the more species we’ll likely find them in.” She adds, “An exciting question is therefore ‘Where do we draw that line? Which animals do have it, which animals don’t, and what sort of cognitive or neurological or social characteristics do those animals share? ’ That’s going to be the fun part of the game.”
【小题1】What does the underlined word “retrieve” in Paragraph 2 probably mean?| A．Fetch. | B．Move. | C．Throw. | D．Play. |
| A．The locations of the people involved in the tests. |
| B．The memory tasks that dolphins need to perform. |
| C．The ability of dolphins to communicate with humans. |
| D．The dolphins’ characteristics related to their memory processing. |
| A．Dolphins pass the tests as a result of training. |
| B．It is very likely that dolphins are affected by people during the tests. |
| C．Scientists will probably find episodic memory in all non-human animals. |
| D．The influence of dolphins’ familiarity with a location or a person is avoided. |
| A．Dolphins Are the Most Intelligent Animals |
| B．Dolphins May Remember Personal Experiences |
| C．Episodic Memory Is Important for Humans and Animals |
| D．A Scientific Method Is Used to Study Dolphins’ Memory |
