Can time-based decay explain temporal distinctiveness effects in task switching?

Abstract

In task switching, extending the response-cue interval (RCI) reduces the switch cost-the detriment to performance when switching compared to repeating tasks. This reduction has been used as evidence for the existence of task-set decay processes. Recently, this has been challenged by the observation of sequential dependencies on the RCI effect: switch cost is only reduced at longer RCIs when the previous trial had a short RCI. This trialwise variation of RCI is thought to affect the temporal distinctiveness (TD) of a previous task's episodic trace, affecting the probability of its automatic retrieval on the current trial; importantly, TD is thought to be independent of the current trial's RCI. The present study highlights a dependency between the current RCI and TD, and demonstrates that a decay model can reproduce some patterns of data attributed to TD. Further, the decay account makes a strong prediction when TD is held constant: repetition response times should slow as RCI increases, and switch response times should be facilitated. This prediction was tested via re-analysis of extant data and three experiments. The re-analysis provided some evidence for the decay account, but Experiments 1 and 2 report slowing for task repetition and switch trials, which cannot be explained by a task-set decay process. Experiment 3, which utilised tasks requiring perceptual judgements, showed small evidence for decay. We conclude that the data are largely consistent with the TD account and that the evidence for decay of higher-level task-sets is not convincing.

Time manages interference in visual short-term memory

“…In comparison to the consolidation account, temporal distinctiveness states that successful memory retrieval is determined by the ratio between the TIME MANAGES INTERFERENCE 24 inter-item intervals between successive to be remembered items and the retention interval between initial encoding and subsequent retrieval (Ecker, Tay, et al, 2015;Souza & Oberauer, 2014). It has been argued that this ratio is critical for successful memory recall because when memory traces are maintained longer in short term memory they are compressed in psychological space (Grange & Cross, 2015) and by reducing the inter-item interval, it produces confusion between those items within their spatial and temporal context Ecker & Lewandowsky, 2012).…”

Temporal Distinctiveness in Task Switching: Assessing the Mixture-Distribution Assumption

“…Given this importance, Grange and Cross (2015) developed a basic mathematical model of TD effects using SIMPLE (Brown et al, 2007) to calculate the TD for a range of RCI-ratios, and in turn to predict mean RT for a range of RCI-ratios.…”

“…In the first, I use a statistical test-the fixed-point property test-to assess the presence/absence of evidence for intermediate RCI-ratios being a mixture of a fast and a slow distribution. Then, in a next step I extend the model of Grange and Cross (2015) to predict whole RT-distributions, which allows a direct test of the mixturedistribution assumption.…”

“…Second, the temporal distinctiveness account of Horoufchin et al (2011a) mostly considers task repetition performance because the RCIratio did not influence switch trials. As such, the formal model of Grange and Cross (2015) only modeled repetition RTs. As the purpose of the present paper is to test further the main assumptions of the account of Horoufchin et al (2011a) and the formal model of Grange and Cross (2015), the current work continues to focus on repetition RT.…”

“…As such, the formal model of Grange and Cross (2015) only modeled repetition RTs. As the purpose of the present paper is to test further the main assumptions of the account of Horoufchin et al (2011a) and the formal model of Grange and Cross (2015), the current work continues to focus on repetition RT. A complete model would of course have to account for switch trial performance, too, but as these trials appear unaffected by temporal distinctiveness they are less interesting for the aims of the current paper.…”