Brain-computer interfaces Flashcards
BCI Definition
Artificial interface with the brain that bypasses interface with the brain that bypasses natural mechanisms for output and input, then provides feedback
output: speech, typing, gesturing
input: vision, hearing, touch
Types of sensors used in BCI
Non-invasive, semi-invasive, invasive
Non-invasive sensors
Signal weaker, dispersed by bone, skin, or hair
EEG, fNIRS (functional near-infared spectroscopy), fMRI
Semi-inasive sensors
ECoG (Electrocorticography) electrodes placed outside the dura mater or under the dura mater (epidural/subdural)
Only performed as part of medically necessary procedures
Invasive sensors
Requires craniatomy, but signal and accuracy is much better
Prone to scar tissue build up, signals weaken/fail over time
Types of invasive sensors
cortical implants - well established invasive recording sensor. Utah array: first and most studied, FDA approved implantable sensors
Neuropixels - multi-electrode array with hundreds of sensors along a single thin probe. records hundreds of neurons simultaneously
Sentrodes - wire and electrode implant threaded into brain’s blood vessels
Neural lace - many flexible probes, inserted via surgical robe
Outputs
Controlling an assisitive device, controlling speech synthesizer
Bidirectional BCI
Myoelectric prosthesis: Electordes are implanted in motor and somatosensory cortices. Stimulate the somatosensory cortex as though it is being touched improves the task performance
Deep brain stimulation:
Two intracranial electrodes impanted into basal ganglia, thalamus, or brain stem, with an implantable pulse generator. Stimulates based on predeterimined control, being applied to movement disorders such as parkinsons
Stimulating without reecording
Visual impants (retina/occipital)
Ethical issues relevant to BCI
Corporate accountability, end of use: company dies and patients don’t know where their data goes
User safety: complications from impantation, potential scarring, unknown interactions with plasticity of developing brain, unknown removal effect
Autonomy: incorrect/unwanted actions autonomy?
User burden: user has to deal with difficult parts
Judging agency: who is responsible for BCI outputs?
Cyborgization and personhood: user do not feel that they “melt with technology”, but prefer metaphor like “controlling a tool”
“What is normal”: BCI have potential to bring users closer to “normal”, in alignment with a deficit model of disability. What impact does that have on other individuals who share their condition?
