Coincidence and Cause: A Discussion on Correlations Between Activity in Primary Afferents and Perceptive Experience in Cutaneous Sensibility

Abstract

The method of recording naturally occurring activity from peripheral nerves in waking human subjects was first presented in 1966 (Vallbo and Hagbarth, 1967). This recording technique allows the afferent activity in the single units to be assessed with an extreme accuracy while, at the same time, the subject’s experience of the stimuli may be explored with psychophysical methods. This approach opens the possibility (a) to define exactly the functional properties of primary afferent units in man and (b) to assess directly whether a correlation exists between a defined property of the afferent activity, and an element of the perceptive experience. It seems that these kinds of studies may narrow the gap, so far inconceivable, between biophysical events in the nervous system and perceptive phenomena within the mind, and thereby contribute to an understanding of the mechanisms by which the human brain brings into existence the product which we introspectively experience as consciousness.