City Research Online

Abstract

Methods of measuring visual persistance are discussed with particular reference to partial report (PR) and temporal integration techniques. The current categorization of information persistence as exemplified by PR methods and visible persistence, which is purportedly demonstrated by "direct" methods of investigation, is critically examined. A survery is conducted of various "direct" investigations and it is pointed our that differing techniques do not always generate concordant results. Moreover, certain anomalies that are exposed by TI techniques are difficult to explain with conventional notions about visible persistence.

Two variations of the Eriksen and Collins paradigm are used to test a proposal that lexical and pattern-only collages would give rise to differential temporal effects. This idea was not supported but effects due to following field duration (Sd2), wich have been largely overlooked in recent TI literature, were found to be robust.

A visual masking investigation as well as further TI studies are used to investigate the Sd2 function in greater depth. A tentative hypothesis for TI operations, which involved perceptual segregation of iconically stored information, was proposed. This idea included the possibility that perceptual integration is limited by two processes, one of these being the gradual loss of persisting visual information.

Predictions from this hypothesis are validated in studies which compare the effects of the Sd2 parameter on backward masking and integration. The other process that limited integration was tentaively identified to be a tendency towards perceptual dissociation (as distinct from perceptual segregation).

It is argued that a consequence of this hypothesis could be that the differences between PR and TI might become reconciled. A PR approach is used to investigate this. Temporal effects not usually associated with this paradigm, were obtained under certain circumstances. Moreover, two types of transposition error, which are predicted by the dissociation hypothesis, were identified.

A tentative model of temporal integration and its consequences for immediate short term visual memory is outlined and critically discussed.

Publication Type:	Thesis (Doctoral)
Departments:	School of Health & Medical Sciences > Optometry & Visual Sciences School of Health & Medical Sciences > Psychology Doctoral Theses School of Health & Medical Sciences > School of Health & Medical Sciences Doctoral Theses

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