Do noise masks terminate target processing?

Abstract

Much recent research in visual information processing has employed a methodology resting on the assumption that a noise mask following presentation of a target stimulus terminates processing of that target. In the absence of appropriate controls, such a methodology is viable only insofar as an erasure theory of masking is valid. However, the phenomena from which the erasure position has derived its strongest support have been subject to alternative theoretical explanations, the most general of which is that of temporal integration. The experiment reported here tested these alternatives. Twelve subjects served in a tachistoscopic study designed to determine whether the same noise field of dots could either erase a degraded target digit or facilitate target identification through temporal integration, under both forward and backward masking paradigms. This was found to be the case, and the results were interpreted as consistent with an integration theory of masking and as incompatible with an erasure conception. The results suggested that efforts to control target processing time through display of a visual noise pattern subsequent to target presentation are methodologically inadequate when devoid of some basic control operations.

The use of a visual mask may seriously confound your experiment

“…What is not so widely considered, however, is the fact that the same mask will differ in its effectiveness for different form stimuli. The same mask that impairs recognition of one target can actually enhance recognition of a different target (Schultz & Eriksen, 1977). When the possibility of integration of the target and the mask is considered, it is readily apparent that the degree to which target recognition is impaired depends upon which details of the mask are superimposed upon which details of the target.…”

“…Integration theories take as their point of departure the well-documented lack of fine temporal resolution of the visual system (Eriksen & Schultz, 1978;Felsten & Wasserman, in press;Schultz & Eriksen, 1977). When two successive visual stimuli are separated by only a short temporal interval, they are summed together into a composite, resulting in a montage-like effect.…”

The process of perceptual retouch: Nonspecific afferent activation dynamics in explaining visual masking

“…Masking extent with TS-MS with maximal spatial overlap and fewer nonoverlapping features (advantage in the case of luminance summation) was smaller than masking extent with TS-MS with little spatial overlap (advantage in the case of readout from the "montage") within SOAs from 0 to 20 msec, The inverse trend held across SOAs from 20 to 48 msec. Situations in which integration is rather an advantage than a shortcoming for recognition have recently been described by Navon and Purcell (1981) and Schultz & Eriksen (1977).…”

Vibrotactile masking: Temporal integration, persistence, and strengths of representations

“…In the visual literature, two major theoretical explanations of masking have emerged-temporal integration and interruption (Fe1sten & Wasserman, 1980). According to the temporal-integration explanation, two patterns that are presented in close temporal and spatial proximity are integrated by the processing system into a composite form in which the target pattern is obscured (Averbach & Coriell, 1961;Schultz & Eriksen, 1977). The temporal-integration explanation can be applied to both forward-and backward-masking effects.…”