Human beings often share the desire to reach out and connect to others, to feel part of a community, to understand and to be understood. In fact, understanding and empathy underpin a peaceful and productive society, and connecting with others can provide a sense of purpose and meaning. It is this connection of minds that has long been a topic of fascination.
The early-modern philosophers such as Descartes and Wittgenstein introduced the philosophical notion of solipsism, taken from the Latin solus, meaning “alone”, and ipse, meaning “self”. Solipsism can be defined as “the view or theory that the self is all that can be known to exist”. Hence, philosophers of a solipsistic persuasion questioned the very existence of other minds.
This question has been scientifically investigated by psychologists interested in the Theory of Mind (or ToM). The term was coined by Premack and Woodruff (1978), who studied chimpanzees. They inferred from their investigations that chimps could attribute intentions and desires to others (human actors), showing that they understood the concept of another mind. Human research suggests that ToM develops around the age of 5 or earlier, when children can understand that other people have different desires, thoughts, and feelings to their own.
But if the mind can conceive of another mind, how does this occur, and what evidence do we have to challenge the solipsism of Descartes and Wittgenstein?
The answers lie in the advancement of technology and neuroscience. Dr Giacomo Rizzolatti recorded electrical activity from the brain of a monkey whilst they performed a specific action (grasping an object) – so far nothing exceptional. However, the same electrical activity in the monkey’s brain was generated when the animal observed another person performing the same action. This suggested that the monkey understood the action to be the same as its own, demonstrating a kind of ‘sympathy’. The cells responsible for this understanding of another’s actions were termed ‘mirror neurons’, due to the obvious connection with mirroring another’s behaviour.
So far it seems that we can theorise about another’s mind, and that the explanation of understanding another’s actions can be (at least partly) explained by mirror neurons, but the possibility of the connection of minds is yet to be proven.
… Or is it? Earlier this year, a group of scientists from Spain, France and the U.S.A documented what they term ‘conscious brain-to-brain communication’. Grau and colleagues recruited participants in two distant locations, one to be the ‘emitter’ – the person who generated the message to communicate; and one to be the ‘receiver’. The emitter thought of a word, which was represented as a binary code of ‘1’s and ‘0’s. The ‘1’s and ‘0’s were recorded from the brain of the emitter using motor imagery: if the emitter wished to communicate a ‘1’ they imagined an action with their hands, for a ‘0’ they imagined an action with their feet. The electrical activity from the scalp over the brain areas relating to the actions of hands and feet was recorded with electroencephalography. Computers transformed this electrical activity back to binary code for transmission via the internet to the location of the receiver. A computer at this location received the binary code and relayed it to the person designated as the receiver. The receiver experienced the ‘1’s and ‘0’s via a magnetic field applied to the brain through the scalp (transcranial magnetic stimulation or TMS). If the digit of code to be conveyed was a ‘1’ the researchers stimulated the part of the brain responsible for vision, and this made the receiver think they were seeing a light.
If the digit to be conveyed was a ‘0’ the computer positioned the magnetic stimulation over a different part of the brain which resulted in the omission of a light. Therefore, the receiver could communicate the code of ‘1’s and ‘0’s based on the presence and omission of lights. The transmitted word could be deciphered, completing the brain-to-brain communication.
Although perhaps not what Descartes and Wittgenstein had in mind when they questioned the existence of other minds, modern technology has helped us to explore, explain and expand our means of communication with some truly fascinating results.
Post by: Gemma Barnacle
Original article by Grau and colleagues: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0105225
Interview with Rizzolatti on the discovery of mirror neurons: http://www.gocognitive.net/interviews/discovery-mirror-neurons-1