What at first sounds like a science fiction vision is partly already possible today: intelligent programs can read your thoughts and translate them into spoken words. US researchers have made a breakthrough in this sector.

When people lose all or part of their ability to speak as a result of an accident and the resulting neurological damage, they are in most cases largely cut off from their environment.

Communication with other people is then sometimes only possible through eye movements, as physical signals are often severely restricted by physical limitations.

Electrodes analyse electrical impulses in the brain

For these people in particular, technical progress represents a great opportunity. For example, the neurosurgeon Edward Chang and his team at the US University of California in San Francisco have been working on translating thoughts into language.

But how can we read thoughts if people cannot articulate themselves? The answer: via electrodes in the patients’ cerebral cortex and an artificial intelligence (AI).

And that works in a simplified way like this: The epilepsy patients read several sentences up to 50 times in a row The artificial intelligence then analysed the activities in the brain and brain waves in the background.

In this way, the AI learned to recognise certain patterns and structures in the sentences. In the next step, the technology should then construct the corresponding sentences from brain activity. So it should read thoughts.

Reading thoughts for advanced users: word error rate is three percent

The results of the Californian brain researchers are impressive. According to the german magazine “Welt”, the word error rate in the tests is only three percent. The previous value of artificial intelligence in this sector was around 60 percent.

And even systems for speech recognition – such as Amazon’s Alexa – have an average of five percent.

Before we fall into unbridled euphoria, however, there is one important limitation: the number of words in the test was 250, so we are still a long way from the average adult vocabulary.

Accordingly, the AI’s error rate is likely to deteriorate with a larger number of words. So we can already read thoughts and translate them into words. However, we are still at the beginning.

However, one of the researchers involved told the “Welt”: “We are not yet at the end, but we believe that this could be the basis for a speech prosthesis.