Is time to scan visual images due to demand characteristics?

Abstract

The time to scan across an object in a mental image increases with the distance scanned. Does this finding reflect the operation of underlying mechanisms or the effects of demand characteristics? Two types of demand characteristics were considered here. First, the scanning effects were shown to persist even when they conflicted with the experimenters' expectations. Experimenters were led to expect different rates of scanning and different effects of distance on scan times, but the results in all cases showed no hint of experimenter effects, instead displaying the usual increase in time with distance scanned. Second, the scanning effects were shown to persist in the absence of implicit task demands. Effects of distance were observed in an experiment in which subjects were never asked to scan the image; furthermore, such effects were observed only for items that should require spontaneous scanning even though they were randomly intermixed with items that should not, and this distinction was never mentioned nor alluded to in the instructions. Thus, experimenter effects and task demands are not sufficient explanations for the increase in the time to scan across an image as distance is increased.

Analog properties of cognitive maps constructed from verbal descriptions

“…The analysis of chronometric data shows that the greater the distances separating two points, the longer the corresponding scanning times. This finding is generally considered to be support for the assumption of structural isomorphism of visual images with the spatial entities they represent (e. g., Finke & Pinker, 1982Jolicoeur & Kosslyn, 1985;Kosslyn, Ball, & Reiser, 1978;Pinker, Choate, & Finke, 1984). A time-distance relationship in mental scanning across text-based representations would strengthen the claim that cognitive maps constructed from verbal descriptions possess emergent properties that confer on them structural isomorphism as regards the described configurations.…”

Eye scanpaths during visual imagery reenact those of perception of the same visual scene

“…Many responses have been given in the past to this type of criticism (e.g., Finke & Pinker, 1982Jolicoeur & Kosslyn, 1985). In the specific case of the present study, we are skeptical that such explanation can account for both the character and the complexity of the findings.…”

Structural properties of visual images constructed from poorly or well-structured verbal descriptions

“…Goldston, Hinrichs, & Richman, 1985;Intons-Peterson & McDaniel, 1991). This seems unlikely, because mental scanning has been shown to resist empirical efforts to reduce it to a pure consequence of tacit knowledge effects or task demands (see Denis & Carfantan, 1985;Finke & Pinker, 1982, 1983Jolicoeur & Kosslyn, 1985;Pinker, Choate, & Finke, 1984;Reed, Hock, & Lockhead, 1983). Denis and Cocude's (1989) results suggest that similar linear time-distance relations occur in mental scanning of representations formed from verbal descriptions and from those formed perceptually.…”