Raffaele Torella has recently identified and edited some large fragments of the previously unedited vivṛti (long gloss) of Utpaladeva on his own Īśvarapratyabhijñākārikā (The Strophes about the Lord's Recognition). The fragment edited in Tantric Studies in Memory of Helène Brunner begins with the following passage (my translations, R.Torella's own one has not been published yet):
The author [of the Strophes] shows that:(smṛtikāle ca pūrvakālāvacchedenārthābhāsasya samarthitasya vārtamānikasmṛtiprakāśād bhedo nopapadyata ity anubhavasmṛtyābhāsayoḥ śarīrībhūta eko ’rthaḥ tayor apy ekatam ākṣipatīti copadarśayan draṣṭāraṃ smartāraṃ caikam upapādayati.)
1. at the time of recollection, there cannot be any difference [between the subject who is recollecting now a certain pot and the one who saw it in the past], because what is manifested in the present memory is the appareance of the object further determined [as having been perceived in] a previous time,
2. the same physical object of both the appearances [of it] in the [past] experience and in the [present] memory implies the unity of both.
By doing that, he proves that the [past] seer and the [present] recollector are one and the same.
In other words, the object of memory is the same that has been experienced before. The only additional feature it displays is the fact that it is recollected as being related to a previous time. Since no one else could have access to that past object, apart from the one who saw it originally, the recollector and the original perceiver must be one and the same person.
The above translation has been modified after a discreet reader pointed out that "congruous" is a rather unusual English word and that the whole passage sounded cumbersome. Thanks!
On memory and the self, see here. On translations, see here.