Is Experience Time the same as Experienced Time?

This is mostly a question for Tye. It asks whether the time it takes to have an experience is the same — and if so, is it necessarily the same — as the time it takes for that experience to be had. These might look the same at first glance, but they’re not.

Phillips cites Tye as follows: “Tye holds that the natural explanation is that, our brains collect information a little into the future before an experience is generated, so that what we experience as the present is in reality a little in the past’. The term ‘collecting […] into the future’ is somewhat misleading because processes can only occur in the present. What Tye means is that processing takes place at times beyond which the experience is ‘time-stamped’ by the brain; alternatively, that there is a gap between the objective external time of the event causing the experience and the objective external time at which the perceiver has the experience of that event.

At some level, this must be true, since time is required for perceptual processes to occur. Photons must travel from the external object of which the experience is a perception to the retina; a vanishingly small yet non-zero amount of time. Those photons must impinge on rod and cone receptors which will require a further non-zero amount of time to produce corresponding signals. Those signals must travel to V1 for early processing; subsequent processing takes place in other contiguous but not co-located areas of the visual cortex. It seems to be common ground that all of these steps will sum to a time period of the order of several hundred milliseconds.

Phillips reproduces Tye’s diagram showing how Tye thinks this allows for an explanation of postdictive effects. In these effects, an experience of an event A is modified by a later experience of an event B, providing that event B is within the same several hundred millisecond window. The inter-experience gap must be shorter than the processing window, since otherwise the perceptual system would already have pronounced on event A and the experience of event A would no longer be available for modification by event B. This generates a question, which is also illustrated by the fact that the lines on Tye’s diagram are not parallel: they converge such that there is an experience of zero duration – one might also wonder if that is coherent – which reflects events of non-zero duration viz. the time of event A, the gap between A and B, and the time of event B. The question is: why does the processing of event B take no time or why does it take less time than the processing of event A?

Intuitively, one would expect the processing time to be roughly independent of the event type. The perceptual delay would be constant, in rough analogy with ‘live’ TV broadcasts where it is common to introduce a five second delay above and beyond the ‘processing time’ involving light reception by cameras, signal transmission to broadcast towers etc. to allow broadcast interruption in case of the occurrence of events it is not desired to broadcast. Tye’s model, on the contrary, seems to involve variations in the lag time. Are there implications for Phillips’s interpretation of the Sperling{Sperling \cite{Sperling60}.} data?

Phillips{Phillips \cite[p. 396]{phillips11}.} notes, in fact, that “some aspects of experience, say, contour detection [may be] subject to a smaller delay than, say, surface completion”. The Phillips variation is based, plausibly, on the idea that processing time required for a particular task may be different to the processing time required for a different task, and that the processing times will be similar on each occasion that the particular task is completed. But this is insufficient to rescue the Tye account. That requires that the processing time for a particular task be a function of its postdictive effects such that the former can permit an explanation of the latter. An argument would be required for such a covariance.

Phillips{Phillips \cite[p. 397]{phillips11}.} seeks to support Miller’s PPC — Principle of Presentational Concurrence — which holds that “the time interval occupied by a content which is before the mind is the very same time interval which is occupied by the act of presenting that very content before the mind”. The support is supposed to come from Extensionalism, which is the claim that “our consciousness essentially ‘extends a short distance through time’ ”.\footnote{Phillips \cite[p. 397]{phillips11}.} But \emph{everything} which exists must exist for a non-zero amount of time and so nothing specific may be learned about consciousness from the Extensionalist claim. In addition, the Extensionalist claim only suggests that the ratio (content occupation time) / (content presentation time) is non-zero whereas the PPC requires it to be exactly 1.0. Why?

Bibliography

[1] I. B. Phillips, “Perception and iconic memory: What sperling doesn’t show,” Mind and Language, vol. 26, no. 4, pp. 381–411, 2011.

[2] G. Sperling, “The information available in visual presentations,” Psychological Monographs, vol. 74, pp. 1–29, 1960.

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About timlshort
I am the author of "Simulation Theory" and "The Psychology Of Successful Trading," both published by Routledge. tinyurl.com/oosta11

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