Time estimation and concurrent nontemporal processing: Specific interference from short-term-memory demands

Abstract

Previous studies have shown that the effect of concurrent nontemporal processing on time estimation may vary depending on the level of difficulty ofthe nontemporal task. This is commonly interpreted within the context of so-called distraction/interruption models of temporal processing, which propose that as concurrent task difficulty or complexity is increased, temporal processing receives less attention. We hypothesize that the effect of nontemporal processing does not depend on the level of difficulty as such, but rather on the extent to which the concurrent nontemporal task specifically involves processing in short-term memory. Four experiments were run in which the short-term memory requirements of concurrent tasks were systematically varied, although all of the tasks were of comparable levels of difficulty. In the first experiment, the effect of memory search on simultaneous temporal productions was proportional to the number of items to search. As with reaction time, produced intervals were shown to increase linearly with the number of items in the memorized set. In Experiment 2, a visual search involving some load on short-term memory interfered in the same way with time production, although to a lesser extent. The last two experiments showed that performing attention-demanding visual search tasks that did not involve short-term memory did not lengthen simultaneously produced time intervals. This suggests that interference of nontemporal processing on time processing may not be a matter of nonspecific general purpose attentional resources, but rather of concurrent shortterm-memory processing demands.Prospective timing occurs when one is required to estimate the duration of a temporal interval that is to be presented. In such a situation, it is often reported that estimated duration decreases as a result of increasing concurrent nontemporal processing demands. This is commonly interpreted within the context of so-called distraction/interruption models of temporal processing, which propose that as concurrent task difficulty or complexity is increased, temporal processing receives less attention (Block, 1990;Brown, 1985;Fortin & Rousseau, 1987;Fraisse, 1984;Hicks, Miller, & Kinsbourne, 1976;McClain, 1983; Rousseau, Fortin, & Kirouac, in press;Thomas & Cantor, 1978;Vroon, 1970). The reduction of attention to temporal processing is assumed to result in less temporal information and, consequently, to shorter perceived duration. In spite of the accumulation of evidence, the distraction models still remain quite informal, which led Block to state that "Terms like attention to time and temporal information processing are unacceptedly vague" (p. 22).We believe that two basic questions should be addressed for some progress to be achieved. First, temporal-

Temporal order in memory and interval timing: An interference analysis

“…This conclusion is supported by Brown's data showing that visual search and spatial pursuit were not affected by concurrent temporal production. It may is also be interesting to note that in previous experiments, increasing the load in a visual search task did not lengthen simultaneous time productions whereas a lengthening was observed with corresponding manipulations in equally difficult item recognition tasks (Fortin, Rousseau, Bourque, & Kirouac, 1993). Taken together with the results of Experiment 1, these findings suggest that time production does not rely heavily on the use of visuospatial resources.…”

Duration judgements in patients with schizophrenia

“…Moreover, a number of studies of human timing (Fortin et al 1993 ;Zakay & Block, 1996Fortin, 1999) have indicated that accurate estimation of intervals in the order of several seconds requires sustained focusing of attention, and furthermore strategies such as counting can be recruited in making such judgements. The involvement of attentional and strategic processes in these tasks is also potentially problematical, given the well-documented attentional impairments in patients with schizophrenia (e.g.…”

Temporal interval production and processing in working memory

“…These data suggest that some nontemporal activities may interrupt pulse accumulation; in fact, such data have been used to assume attentional control in time estimation, thus forming the category of attentional models of time estimation (Block, 1990). However, using a concurrent processing methodology in which they interpolated nontemporal processing in a temporal interval produced by a subject, Fortin, Rousseau, Bourque, and Kirouac (1993) showed that attention-demanding search tasks did not interfere with time estimation if these This research was supported by Grant OGP0046422 from the Natural Science and Engineering Research Council of Canada to the first author. The second experiment of this study was run as part of a master's thesis by the second author.…”