In a general way, it informs us that such a reinstatement of the past is determined by the existence of certain connections between the nervous structures concerned in the reviving and revived mental elements.

Thus, it is said that when the sound of a name calls up in the mind a visual image of a person seen some time since, it is because connections have been formed between particular regions and modes of activity of the auditory and the visual centres.

And it is supposed that the existence of such connections is somehow due to the fact that the two regions acted simultaneously in the first instance, when the sight of the person was accompanied by the hearing of his name.
In other words, the centres, as a whole, will tend to act at any future moment in the same complex way in which they have acted in past moments.
All this is valuable hypothesis so far as it goes, though it plainly leaves much unaccounted for.

As to why this reinstatement of a total cerebral pulsation in consequence of the re-excitation of a portion of the same should be accompanied by the specific mode of consciousness which we call recollection of something past, it is perhaps unreasonable to ask of physiology any sort of explanation.[114] Thus far as to the general or essential characteristics of memory on its mental and its bodily side.

But what we commonly mean by memory is, on its psychical side at least, much more than this.