Cortical implant
Their initial implant was based on the surface of the visual cortex and it did not provide as clear of images that it could, with an added downside of damage to surrounding tissues.
More recent models, such as the "Utah" Electrode Array use deeper cortical stimulation that would hypothetically provide higher resolution images with less power needed, thus causing less damage.
The visual cortex is much more complex and difficult to deal with than the other areas where artificial vision are possible, such as the retina or optic nerve.
In addition, each areas of the cortex is specialized to deal with different aspects of vision, so simple direct stimulation will not provide complete images to patients.
Lastly, surgical operations dealing with brain implants are extremely high-risk for patients, so the research needs to be further improved.
However, cortical visual prostheses are important to people who have a completely damaged retina, optic nerve or lateral geniculate body, as they are one of the only ways they would be able to have their vision restored, so further developments will need to be sought out.
Despite the complications these prostheses may cause, their purpose is to enhance the transmission of sound vibrations into the inner ear and, consequently, improve hearing abilities.
Implants in the prefrontal cortex help restore attention, decision-making and movement selection by duplicating the minicolumnar organization of neural firings.
By mimicking the natural coding of the brain with electrical stimulation, researchers look to replace compromised hippocampal regions and restore function.
[11] Treatment for several conditions that impact cognition such as stroke, Alzheimer's disease and head trauma can benefit from the development of a hippocampal prosthetic.
[12] A Brain-computer interface (BCI) is a type of implant that allows for a direct connection between a patient's brain and some form of external hardware.
A majority of research focuses on the sensorimotor region of the brain, using imagined motor actions to drive the devices, while some studies have sought to determine if the cognitive control network would be a suitable location for implantations.
Some innovative studies used a technique called "classical conditioning with functional magnetic resonance imaging (fMRI) and BCIs.".
Research using local field potentials from deep brain stimulation (DBS) electrodes has shown improvements in motor functions.
BCIs with EEG feedback primarily aim to specifically detect intentional movements, with the goal of reducing neurological tremors when combined with technologies like functional electrical stimulation (FES).
Some studies with SMA patients have explored integrating BCIs into control systems to enable remote devices such as TVs and telephones.
Other studies have focused on enabling SMA individuals to manipulate a robotic arm using surface electromyography (sEMG).
With a full understanding of the neural code, more progress can be made in developing a hippocampal prosthetic that can more effectively enhance memory.
In addition, the nature of a microelectrode array intended effect is limited due to the stated variance's presented in association with individual cortex uniqueness i.e. differences.
Present day microelectrode arrays are also constrained due their physical size, and achievable data processing/capability rates; which continue to be governed in relation to the characteristics dictated in accordance with Moore's Law.
The goal with the development of new implants is "to avoid the hydrolytic, oxidative and enzymatic degradation due to the harsh environment of the human body or at least to slow it down to a minimum which enables the interface to work over a long time period, before it finally has to be exchanged.
