the user must gaze at one of the flashing or iterating symbols in order to interact with the system. it is, therefore, likely that the symbols could become irritating and uncomfortable to use during longer play sessions, which can often last more than an hour which may not be an ideal gameplay. another type of vep used with applications is the p300 potential. the p300 event-related potential is a positive peak in the eeg that occurs at roughly 300 ms after the appearance of a target stimulus (a stimulus for which the user is waiting or seeking) or oddball stimuli. the p300 amplitude decreases as the target stimuli and the ignored stimuli grow more similar.the p300 is thought to be related to a higher level attention process or an orienting response using p300 as a control scheme has the advantage of the participant only having to attend limited training sessions. the first application to use the p300 model was the p300 matrix. within this system, a subject would choose a letter from a grid of 6 by 6 letters and numbers. the rows and columns of the grid flashed sequentially and every time the selected "choice letter" was illuminated the user's p300 was (potentially) elicited. however, the communication process, at approximately 17 characters per minute, was quite slow. the p300 is a bci that offers a discrete selection rather than a continuous control mechanism. the advantage of p300 use within games is that the player does not have to teach himself/herself how to use a completely new control system and so only has to undertake short training instances, to learn the gameplay mechanics and basic use of the bci paradigm. synthetic telepathy/silent communication in a $6.3 million us army initiative to invent devices for telepathic communication, gerwin schalk, underwritten in a $2.2 million grant, found the use of ecog signals can discriminate the vowels and consonants embedded in spoken and imagined words, shedding light on the distinct mechanisms associated with production of vowels and consonants, and could provide the basis for brain-based communication using imagined speech. in 2002 kevin warwick had an array of 100 electrodes fired into his nervous system in order to link his nervous system into the internet to investigate enhancement possibilities. with this in place warwick successfully carried out a series of experiments. with electrodes also implanted into his wife's nervous system, they conducted the first direct electronic communication experiment between the nervous systems of two humans. another group of researchers was able to achieve conscious brain-to-brain communication between two people separated by a distance using non-invasive technology that was in contact with the scalp of the participants. the words were encoded by binary streams using the sequences of 0's and 1's by the imaginary motor input of the person "emitting" the information. as the result of this experiment, pseudo-random bits of the information carried encoded words "hola" ("hi" in spanish) and "ciao" ("goodbye" in italian) and were transmitted mind-to-mind between humans separated by a distance, with blocked motor and sensory systems, which has low to no probability of this happening by chance.conscious brain-to-brain communication in humans using non-invasive technologies in the 1960s a researcher was successful after some training in using eeg to create morse code using their brain alpha waves. research funded by the us army is being conducted with the goal of allowing users to compose a message in their head, then transfer that message with just the power of thought to a particular individual. on 27 february 2013 the group with miguel nicolelis at duke university and iinn-els successfully connected the brains of two rats with electronic interfaces that allowed them to directly share information, in the first-ever direct brain-to-brain interface. cell-culture bcis researchers have built devices to interface with neural cells and entire neural networks in cultures outside animals. as well as furthering research on animal implantable devices, experiments on cultured neural tissue have focused on building problem-solving networks, constructing basic computers and manipulating robotic devices. research into techniques for stimulating and recording from individual neurons grown on semiconductor chips is sometimes referred to as neuroelectronics or neurochips. the world's first neurochip, developed by caltech researchers jerome pine and michael maher development of the first working neurochip was claimed by a caltech team led by jerome pine and michael maher in 1997. the caltech chip had room for 16 neurons. in 2003 a team led by theodore berger, at the university of southern california, started work on a neurochip designed to function as an artificial or prosthetic hippocampus. the neurochip was designed to function in rat brains and was intended as a prototype for the eventual development of higher-brain prosthesis. the hippocampus was chosen because it is thought to be the most ordered and structured part of the brain and is the most studied area. its function is to encode experiences for storage as long-term memories elsewhere in the brain. in 2004 thomas demarse at the university of florida used a culture of 25,000 neurons taken from a rat's brain to fly a f-22 fighter jet aircraft simulator. after collection, the cortical neurons were cultured in a petri dish and rapidly began to reconnect themselves to form a living neural network. the cells were arranged over a grid of 60 electrodes and used to control the pitch and yaw functions of the simulator. the study's focus was on understanding how the human brain performs and learns computational tasks at a cellular level. collaborative bcis the idea of combining/integrating brain signals from multiple individuals was introduced at humanity+ @caltech, in december 2010, by a caltech researcher at jpl, adrian stoica; stoica referred to the concept as multi-brain aggregation. a provisional patent application was filed on january 19, 2011, with the non-provisional patent following one year later. in may 2011, yijun wang and tzyy-ping jung published, "a collaborative brain-computer interface for improving human performance", and in january 2012 miguel eckstein published, "neural decoding of collective wisdom with multi-brain computing". stoica's first paper on the topic appeared in 2012, after the publication of his patent application. given the timing of the publications between the patent and papers, stoica, wang & jung, and eckstein independently pioneered the concept, and are all considered as founders of the field. later, stoica would collaborate with university of essex researchers, riccardo poli and caterina cinel. the work was continued by poli and cinel, and their students: ana matran-fernandez, davide valeriani, and saugat bhattacharyya. ethical considerations sources: user-centric issues long-term effects to the user remain largely unknown. obtaining informed consent from people who have difficulty communicating. the consequences of bci technology for the quality of life of patients and their families. health-related side-effects (e.g. neurofeedback of sensorimotor rhythm training is reported to affect sleep quality). therapeutic applications and their potential misuse. safety risks non-convertibility of some of the changes made to the brain legal and social issues of accountability and responsibility: claims that the influence of bcis overrides free will and control over sensory-motor actions, claims that cognitive intention was inaccurately translated due to a bci malfunction. personality changes involved caused by deep-brain stimulation. concerns regarding the state of becoming a "cyborg" - having parts of the body that are living and parts that are mechanical. questions personality: what does it mean to be a human? blurring of the division between human and machine and inability to distinguish between human vs. machine-controlled actions. use of the technology in advanced interrogation techniques by governmental authorities. selective enhancement and social stratification. questions of research ethics regarding animal experimentation questions of research ethics that arise when progressing from animal experimentation to application in human subjects. moral questions mind reading and privacy. tracking and "tagging system" mind control. movement control emotion control in their current form, most bcis are far removed from the ethical issues considered above. they are actually similar to corrective therapies in function. clausen stated in 2009 that "bcis pose ethical challenges, but these are conceptually similar to those that bioethicists have addressed for other realms of therapy". moreover, he suggests that bioethics is well-prepared to deal with the issues that arise with bci technologies. haselager and colleagues pointed out that expectations of bci efficacy and value play a great role in ethical analysis and the way bci scientists should approach media. furthermore, standard protocols can be implemented to ensure ethically sound informed-consent procedures with locked-in patients. the case of bcis today has parallels in medicine, as will its evolution. similar to how pharmaceutical science began as a balance for impairments and is now used to increase focus and reduce need for sleep, bcis will likely transform gradually from therapies to enhancements. efforts are made inside the bci community to create consensus on ethical guidelines for bci research, development and dissemination. as innovation continues, ensuring equitable access to bcis will be crucial, failing which generational inequalities can arise which can adversely affect the right to human flourishing. the ethical considerations of bcis are essential to the development of future implanted devices. end-users, ethicists, researchers, funding agencies, physicians, corporations, and all others involved in bci use should consider the anticipated, and unanticipated, changes that bcis will have on human autonomy, identity, privacy, and more. low-cost bci-based interfaces recently a number of companies have scaled back medical grade eeg technology to create inexpensive bcis for research as well as entertainment purposes. for example, toys such as the neurosky and mattel mindflex have seen some commercial success. in 2006 sony patented a neural interface system allowing radio waves to affect signals in the neural cortex. in 2007 neurosky released the first affordable consumer based eeg along with the game neuroboy. this was also the first large scale eeg device to use dry sensor technology. in 2008 ocz technology developed a device for use in video games relying primarily on electromyography. in 2008 final fantasy developer square enix announced that it was partnering with neurosky to create a game, judecca. in 2009 mattel partnered with neurosky to release the mindflex, a game that used an eeg to steer a ball through an obstacle course. it is by far the best selling consumer based eeg to date. in 2009 uncle milton industries partnered with neurosky to release the star wars force trainer, a game designed to create the illusion of possessing the force. in 2009 emotiv released the epoc, a 14 channel eeg device that can read 4 mental states, 13 conscious states, facial expressions, and head movements. the epoc is the first commercial bci to use dry sensor technology, which can be dampened with a saline solution for a better connection. in november 2011 time magazine selected "necomimi" produced by neurowear as one of the best inventions of the year. the company announced that it expected to launch a consumer version of the garment, consisting of catlike ears controlled by a brain-wave reader produced by neurosky, in spring 2012. in february 2014 they shall walk (a nonprofit organization fixed on constructing exoskeletons, dubbed lifesuits, for paraplegics and quadriplegics) began a partnership with james w. shakarji on the development of a wireless bci. in 2016, a group of hobbyists developed an open-source bci board that sends neural signals to the audio jack of a smartphone, dropping the cost of entry-level bci to £20. basic diagnostic software is available for android devices, as well as a text entry app for unity. in 2020, nextmind released a dev kit including an eeg headset with dry electrodes at $399. the device can be played with some demo applications or developers can create their own use cases using the provided software development kit. future directions brain-computer interface a consortium consisting of 12 european partners has completed a roadmap to support the european commission in their funding decisions for the new framework program horizon 2020. the project, which was funded by the european commission, started in november 2013 and published a roadmap in april 2015. a 2015 publication led by dr. clemens brunner describes some of the analyses and achievements of this project, as well as the emerging brain-computer interface society. for example, this article reviewed work within this project that further defined bcis and applications, explored recent trends, discussed ethical issues, and evaluated different directions for new bcis. other recent publications too have explored future bci directions for