In the last post in the series (see Appendix) I looked at the concept of ‘replicability’ of a word. If two people use the same word and are independently able to convincingly verify the word through measurement in the external world then this word will have a replicability of 1. I gave the example of a ‘centimetre’. I also discussed the limits of words and suggested that our inner experiences highlight the limitations of words. Ironically the words that we use are a product of our inner experiences. In order for language to be useful we assume a shared understanding of the words we use. Even within the last sentence, I have used a number of words such as ‘understanding’ and ‘assume’ in the assumption that the reader will readily understand these words in the same way that I do. Without these assumptions, this shared understanding language would be reduced to an unambiguous structure such as symbolic notation (e.g mathematics).
Programming languages are an excellent example. With such a language, the programmer will not use any ambiguity. The computer having no consciousness, no shared understanding – it must be instructed explicitly at each and every step. As time progresses computer languages become more sophisticated and these small explicit steps are nested inside words or structures being thus one step removed from the programmer but still present and implied in the usage of the new terms. We may also infer that in natural language usage, circumstantiality may be a similar attempt to make the meaning of words explicit. In such cases of natural language usage however it may give us useful clues into theory of mind. When there are difficulties with theory of mind perhaps in some cases there is a tendency to make explicit the meaning of words which may be seen as circumstantiality. The formal use of language may be an additional example of natural language usage where steps are taken to reduce perceived ambiguity in shared understanding. In this case, strict adherence to grammatical rules in all situations may be meant as an attempt to reduce ambiguity even when others would use informal language.
In recent studies by Gallant and Kasanti the researchers convincingly interpreted the neurophysiological correlates of inner experiences in a way which causes us to redefine ‘replicability’. Some might ask why Gallant et al’s study is any different from recording of retinal activity. However when the researchers in Gallant’s study recorded from areas V1-V3 in the Occipital Cortex they were recording from the brain, the location of conscious experience. By so doing they were in a way similar to the work of Penfield beginning to localise distinct phenomenological experiences. However their work was extremely elegant, allowing them to reverse engineer video footage that was seen by the research participants. By looking at the video below, the reader will i’m sure be convinced that they had achieved this result. I remarked at the time that the researchers had done away with the need for statistical analyses of the results as the audience could confirm their results by simply inspecting the footage.
Reconstruction of Video Images in Gallant’s Lab
Video Reconstructions of Clips Presented to 3 Subjects. The average of the best-fit clips is on the left, while those on the right are the best fit clips. Each row represents a single subject.
Gallant’s study makes the concept of the reproducibility of a word redundant. The researchers and participants knowing the methodology beforehand would not have to speak a single word to each other from the start to the end. The participants watch the footage, the brain activity is recorded, the software analyses the results and incorporates the data into a sophisticated model which is then used to reverse engineer the final footage that is presented. The study can be language independent. In this case the researchers and the subjects know that they are examining inner experiences. The researchers are able to use sensory experience – their vision – to visually inspect the final footage viewed by the research subjects and the reconstructed footage.
We can therefore return to the original question posed in the previous post ‘how can two people be certain that they are sharing the same meaning of a word’. For the word centimetre it just involves measuring and drawing a centimetre and comparing the results. For visual phenomenon when confined to words we are in a little bit of a difficult situation. This can be circumnavigated with the use of visual field testing and other similar methods. With Gallant’s study however two people may have a means to verify part of their visual experience of watching a movie. More importantly however those people can describe part of each other’s neurophysiology by means of a language independent comparison of video clips. The replicability is therefore the use of an external aid in conjunction with sensory processing of that external aid to enable two people to independently confirm the same fact relating to the neurophysiology of the brain.
Unfortunately there is a twist at the end as what I would like to say is that they could independently confirm the same fact relating to the conscious experience of the other person. After all that is what is effectively happening when we use language. Alas there is a final obstacle thrown in the way. The predictive value of the brain recording in Gallant’s study still does not tell us if it is conscious experience. The conversion of inner phenomenological experience into a physical correlate that is reproducible is still beyond our grasp. The mind/brain dichotomy remains.