The extended mind hypothesis was developed by Clark and Chalmers. The central argument of the hypothesis is that cognitive processes assisted by entities external to an inidividual's mind should equally be regarded as cognitive. If an external artefact is used to aid a cognitive process or to expedite a process that can be completed mentally, then that process, too, should be considered cognitive. For example, recording information in a notebook could be considered a source of memory that is external to the individual's physical 'mind'. Traditional accounts of cognition are constrained by an a priori commitment to confining cognition within the physical boundary of the individual. In this respect the extended mind hypothesis is not particularly controversial, people very often use available tools to offload cognitive work.
Where the hypothesis comes under scrutiny is its treatment of cognitive processes. The hypothesis assumes an understanding of cognition that is pre-existing and confirmed. Cognitive processes are processes that are rely on cognition, whatever those might be. It unclear as to where the original boundaries of cognition are drawn before the authors set out to move the goalposts. Moreover, the extended mind hypothesis is more a theory of extended cognition rather than a theory of an extended mind.
A study by Sparrow, Liu and Wegner goes some way in testing the proponents of this hypothesis. This study notes that the development of internet search engines and databases provides easy access to a wealth of information, a very extensive information store much like the notebook mentioned in Clark and Chalmers. Participants were asked to read and then type out a series of trivia statements. Half of the participants operated under the impression that these statements would be stored on the computer. The other half were told that the typed statements would be erased upon completing the task. Both groups were then instructed to write down the trivia statements they could recall. The ‘erased group’ demonstrated better memory for the statements than those who were led to believe that they could still access a record of the statements.
In a further experiment conducted by the group, participants were shown a series of trivia statements which they again read and typed out. Upon typing each statement participants were informed that that statement had been saved in one of six named folders. Participants were then given a recall task and asked to write down as many statements as they could remember. Participants were also asked which folder a statement was saved in using a keyword from the statement as a prompt.
The findings of this experiment demonstrated that participants were more successful at remembering where information was retained as opposed to the information itself. The authors suggest that this implies that while the ‘what’ of information may be easily forgotten that the ‘where’ can be retained. Sparrow, Liu and Wegner compare the internet as a store of information to something akin to transactive memory, a proposed means by which groups store and retrieve information. Transactive memory is essentially a group mind whereby the knowledge of the whole is more intricate and efficient than its individual components.
The proposal of the extended mind hypothesis is more of a revaluation of cognition as opposed to the boundaries of the mind. Its claims are difficult to assess experimentally but Sparrow, Liu and Wegner’s research has produced some interesting results. Potentially the hypothesis could come to embrace transactive memory as a form of extended cognition which would introduce an interesting social cognitive aspect to this theory.