Your brain lies to you a lot. We’re sorry to have to tell you this but it’s true. Even when your brain is doing important and difficult stuff: you’re not aware of most of what’s going on.

【小题1】For the most part, it’s doing a great job, working hard to help you survive and achieve your goals in a complicated world. Because you often have to react quickly to emergencies and opportunities, your brain usually tries to get a simple answer in a hurry rather than a perfect answer that takes time to work out. But as the world is not simple, this means that your brain has to take shortcuts and make a lot of assumptions.【小题2】

The problem starts when the brain takes in information from the world through the senses. Even if you are sitting quietly in a room, your brain receives far more information than it can hold on to or than you need to decide how to act. You may be aware of the detailed pattern of colors in the rug, the photographs on the wall and the sounds of birds outside.【小题3】

When people look at complicated pictures, they can identify differences if the images remain still. But if the image moves quickly, then they have a lot more trouble.【小题4】To test this, psychologists have tried more interesting ways of getting people to fail to notice things. In one of our favorites, a researcher approaches someone on the street and asks for directions. While the person is replying, workmen carry a large door between the two people, blocking their view of each other. Behind the cover of the door, the person who asked for directions is replaced by another researcher who carries on the conversation as if nothing had happened. Even when the second person looks very different from the first, the person giving the directions has only about a fifty percent chance of noticing the change.【小题5】

Just after hatching, many birds learn to identify and follow the first moving object they encounter—a process called imprinting, which can offer protection in the wild as it helps them stay near a parent. It doesn’t take much visual information for a bird to learn to prefer one object and follow it. Researchers wanted to know whether AI models called transformers could do a similar task with limited inputs.

Transformers are generic learning systems that can be trained to perform a wide variety of tasks, making them useful in both AI chatbots such as ChatGPT and in computer vision applications, such as autonomous car navigation.

“To directly compare learning algorithms (计算程序) to brains, we need to train them on the same experiences,” says Samantha Wood at Indiana University Bloomington. She first raised chicks in a box where the only visual stimulation came from a rotating 3D object presented on a screen. After the first week, she ran each chick through hundreds of test trials that showed that same object on one screen－presented from both familiar and unfamiliar perspectives－and displayed a second unfamiliar object on another screen. The chicks spent more of their time near the first object, suggesting they had imprinted on it.

The researcher then created a virtual simulation (仿造物) of the set-up and used a virtual agent to move through it while looking around and recording a first-person view. That provided tens of thousands of simulated images for training and evaluating four transformer models.

The AI models had just 300 milliseconds to learn from each simulated image－approximating (接近于) how long biological neurons (神经元) fire after being presented with an image. The researcher found that the AIs could learn to recognise a 3D object as quickly and accurately as the chicks.

The study is “a great piece of work” in comparing machine performance with biological brains, says Antone Martinho-Truswell at the University of Sydney. But he also notes, “We might be able to say that the chick ‘saw’its imprinting object, but that will have a component (成分) of experience to it. Particularly as imprinting is to do with identifying its mother, it would be unsurprising if that visual experience were combined with a suite of other components of experience: fear yielding to comfort, for example, as the chick comes to regard the object as its imprinted ‘mother’.”

Chimpanzee culture refers to groups' differing behavioral traditions, which are passed on by learning and imitation rather than genes. For example, some chimps in Uganda have learned to use some plants to soak up water, which they can then drink. Those elsewhere don’t do this.

In 2002, Carel van Schaik at the University of Zurich in Switzerland suggested that human interference could destroy this cultural diversity. Now, a decade-long study has found strong evidence that van Schaik was right. A team co-led by Hjalmar Kühl at the German Centre for Integrative Biodiversity Research in Leipzig, Germany tracked 31 cultural behaviors, such as using tree branches to catch termites, a species of ant, in 144 chimpanzee communities across Africa.

The researchers used camera traps to record behaviors, looked for the remains of tools and studied faeces (排泄物) to see if the chimps had eaten things like termites that can be obtained only by using tools.

The team then placed the different communities on a map and overlaid a measure of human disturbance, which combined factors like the density of human population and the amount of infrastructure (基础建设).

In areas with a greater human footprint, the chimps were found to have fewer cultural behaviors. Each behaviour was 88 per cent less likely to occur in these human-dominated landscapes.

“In those places, we find the chimpanzees have suffered a loss in behavioral or cultural diversity,” says study co-leader Ammie Kalan at the Max Planck Institute for Evolutionary Anthropology in Leipzig.

It is thought that the loss of culture comes from older chimps being killed and there being less interaction between groups, so that if one group dies out, their ideas die with them.

“It is a discouraging finding,” says Jill Pruetz ar Texas State University. “Losing some of the behaviors poses a real risk to the chimps because if they stop fishing for termites or cracking nuts, they can no longer access those foods.”