Oleaje y viento

The stove paradigm utilised by Van den Hout and Kindt (2003a; 2003b; 2004) in their original series of five experiments, consisted of participants being trained to ‘turn-on’, ‘turn-off’ and ‘check’ the six knobs of a virtual gas stove, as well as perform a similar sequence with virtual light bulbs. Following this training phase, participants completed a pre-checking trial, where they were asked to ‘turn- on’, ‘turn-off’ and ‘check’ a set of three knobs on the stove. Participants were then either asked to perform 20 further checking trials using the virtual stove, in the ‘relevant checking’ condition, or of the virtual light bulbs, in the ‘irrelevant

checking’ condition, before completing one further post-checking trial of the stove. These experiments showed that non-clinical participants who engaged in repeated ‘relevant checking’ of the virtual gas stove, as opposed to ‘irrelevant checking’ of virtual light bulbs, had significantly decreased memory confidence, vividness and detail for a subsequent check of the virtual stove. Memory accuracy and confidence

in outcome for this final check was unaffected by the repeated ‘relevant checking’ trials.

Radomsky, Gilchrist & Dussault (2006) attempted to replicate and extend this finding in a laboratory based experiment using a working electric stove and sink in place of the virtual stove and lights. They hypothesised that the use of virtual stimuli presented only a limited sense of perceived threat or responsibility for the prevention of harm and therefore reduced the affect that would be generated in more ecologically valid situations. Consistent with the findings of van den Hout & Kindt (2003a; 2003b; 2004), reduced memory confidence, vividness and detail were

observed following ‘relevant checking’ in the post-checking trial. Unlike the van den Hout and Kindt (2003a; 2003b; 2004) experiments, there was also a slight but

significant decrease in memory accuracy following the post-checking trial in the ‘relevant checking’ condition. However as there was no manipulation check of threat or responsibility it is unclear if this inconsistency in memory accuracy between the studies is due to the improved ecological validity of the paradigm resulting in higher perceived responsibility or increased probability and severity of harm as had been proposed by Radomsky et al. (2006). Additionally the stove task in this study utilised a single removable plastic knob to operate all six hobs while the burner lights were covered (Radomsky et al., 2006). These alterations were made to the stove paradigm to prevent participants from engaging in visual checking to determine the status of the stove between trials, however may have also have artificially increased the difficulty of this task which may explain the observed differences in memory accuracy.

Despite consistent findings of reductions in metamemory, the ecological validity and extent to which either paradigm truly represents the difficulties faced by

individuals who engage in repeated checking is questionable. Due to the

methodological challenges of testing the effects of repeated checking, this paradigm utilises a complex procedure with multiple checks being given over a short period of time to provide an approximation of an individual’s experience of repeated checking. The stove paradigm requires participants to remember which 3 of the 6 stoves they checked on the post-test trial following multiple trials with different outcomes, rather than simply if the stove is off or if they checked the stove. Additionally although both van den Hout & Kindt (2004) and Radomsky et al. (2006) include a ‘check’ step, this is limited in its scope, meaning it is unclear whether these effects are due specifically to ‘checking’ or ‘repetition’. Nevertheless these studies provide support to the hypothesis that doubt is a normal phenomenon following repeated checking, providing an insight into why compulsive checkers continue to distrust their memory despite repeated checking.

While the effects on memory accuracy remain unclear, reductions in memory confidence, vividness and detail following repeated checking are well established and have been replicated in studies utilising both virtual (Boschen & Vuksanovic, 2007; Dek et al., 2010; Medway & Jones, 2013) and functional stimuli (Coles, Radomsky & Horng, 2006; Radomsky & Alcolado, 2010; Radomsky et al., 2014). A number of studies have begun to test the limits of the repeated checking effect. Coles, Radomsky and Horng (2006) using a functional stove showed that varying the number of checking trials resulted in significant reductions in metamemory

occurring after as few as 5-10 relevant checks. Additional trend analyses for this study revealed that such effects were detectable even after only two checks. At present no studies have reviewed the impact of increased checking trials on memory accuracy above the 20 trials used in the original paradigm. However a recent study

has suggested that physically ‘checking’ itself may not be necessary for these effects to occur and simply repeatedly using an object can have the same effects on

metamemory. Medway & Jones (2013) adapted the virtual stove paradigm to compare repeated checking with repeated stimuli use, where the ‘check’ step was removed, and found significant reductions in memory confidence, vividness and detail as well as slight reductions in memory accuracy. This provides support for the hypothesis that reductions in metamemory may be the result of increased familiarity rather than something unique to checking and suggests that alongside other factors proposed by Rachman (2002) that repeated object use may serve as a precursor to repeated checking.

Van den Hout & Kindt (2003a; 2003b; 2004) proposed that reductions in metamemory as a result of repeated checking may be explained by coding shifting from perceptual processing to more semantic processing. This was explored in their series of experiments utilising the virtual stove paradigm, where participants who were in the relevant checking condition were more likely to report only ‘knowing’ which knobs they had checked rather than being able to ‘remember’ in comparison to participants in the irrelevant checking condition. This finding has since been replicated (Coles, Radomsky & Horng, 2006; Radomsky, Gilchrist & Dussault, 2006) providing further support for this hypothesis. Boschen, Wilson & Farrell (2011) attempted to build on this finding utilising a computerised virtual stove task where the stimulus would change colour every 5 checks, the aim of this was to test if memory distrust can be ameliorated through the use of novel stimuli. In line with this hypothesis, participants in the relevant checking condition did not experience the decrease in memory confidence, vividness and detail seen in other studies. The results of this study suggest the potential for interventions aimed at increasing the

novelty of checks may limit the effects of repeated checking or object use. However a factor that may limit their generalisability is that while distinctiveness and novelty can be easily achieved within a computerised task they may be more challenging to replicate in real life settings.