By I. Edwards HealthDay Reporter<\/b>
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FRIDAY, Aug. 15, 2025 (HealthDay News) \u2014 For the first time, scientists have created a brain implant that can \u201chear\u201d and vocalize words a person is only imagining in their head.<\/p>\n
The device, developed at Stanford University<\/a> in California, could help people with severe paralysis communicate more easily, even if they can\u2019t move their mouth to try to speak.<\/p>\n \u201cThis is the first time we\u2019ve managed to understand what brain activity looks like when you just think about speaking,\u201d Erin Kunz<\/a>, lead author of the study, published Aug. 14 in the journal Cell<\/a><\/em>, told the Financial Times.<\/em><\/p>\n \u201cFor people with severe speech and motor impairments, brain-computer interfaces [BCIs] capable of decoding inner speech could help them communicate much more easily and more naturally,\u201d said Kunz, a postdoctoral scholar in neurosurgery.<\/p>\n Four people with paralysis from amyotrophic lateral sclerosis (ALS) or brainstem stroke volunteered for the study. One participant could only communicate by moving his eyes up and down for \u201cyes\u201d and side to side for \u201cno.\u201d<\/p>\n Electrode arrays from the BrainGate brain-computer interface (BCI) were implanted in the brain area that controls speech, called the motor cortex.<\/p>\n Participants were then asked to try speaking or to silently imagine certain words.<\/p>\n The device picked up brain activity linked to phonemes, the small units that make up speech patterns, and artificial intelligence (AI) software stitched them into sentences.<\/p>\n Imagined speech signals were weaker than attempted speech but still accurate enough to reach up to 74% recognition in real time, the research shows.<\/p>\n Senior author Frank Willett<\/a>, an assistant professor of neurosurgery at Stanford, told the Financial Times<\/em> the results show that \u201cfuture systems could restore fluent, rapid and comfortable speech via inner speech alone,\u201d with better implants and decoding software.<\/p>\n \u201cFor people with paralysis attempting to speak can be slow and fatiguing and, if the paralysis is partial, it can produce distracting sounds and breath control difficulties,\u201d Willett said.<\/p>\n The team also addressed privacy concerns. In one surprising finding, the BCI sometimes picked up words participants weren\u2019t told to imagine \u2014 such as numbers they were silently counting.<\/p>\n To protect privacy, researchers created a \u201cpassword\u201d system that blocks the device from decoding unless the user unlocks it. In the study, imagining the phrase \u201cchitty chitty bang bang\u201d worked 98% of the time to prevent unintended decoding.<\/p>\n \u201cThis work gives real hope that speech BCIs can one day restore communication that is as fluent, natural and comfortable as conversational speech,\u201d Willett said.<\/p>\n More information<\/strong><\/p>\n Learn more about the technology by reading the full study in the journal Cell<\/a>.<\/em><\/p>\n