Resultados de Aprendizaje SIMCE, Otros Indicadores de Calidad

The mechanisms proposed to account for RIF can be broadly divided into two kinds, those that evoke a concept of interference and the ones that evoke the concept of inhibition. Starting with the interference-based approach to RIF, a detailed analysis of the blocking hypothesis (Rundus, 1973), a mechanism of this class which is most commonly evoked by researchers, has been presented in the first article introducing the retrieval practice paradigm by Anderson et al., 1994 (see Anderson & Bjork, 1994 for slightly different formulations of interference

mechanisms). In this article a theory of interference-based explanation of RIF was developed by outlining three assumptions necessary to produce RIF by means of interference (p.1063): a) the competition assumption – that memories associated to a common cue compete for access to conscious recall; b) the strength-dependence assumption – that the cued recall of an item will decrease as a function of increases in the strengths of its competitors’ associations to a cue; and c) the retrieval-based learning assumption – that the act of retrieval is a learning event in the sense that it enhances subsequent recall of the retrieved item. The model based on these three assumptions is according to Anderson et al. capable of producing RIF in the basic retrieval practice paradigm by causing a phenomenon of blocking of Rp- items by Rp+ items in a final test.

In the retrieval practice paradigm, retrieval of half of the items from half of the categories is practiced during the second phase of an experiment. The retrieval in this phase is prompted by a category label and two-letter stems of target items.

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According to the retrieval-based learning assumption, such retrieval practice leads to the strengthening of links between Rp+ items and category cues used to prompt their retrieval. The same cues are used in a final test to access all items that were studied with these cues, Rp+, and Rp- items alike. Those items compete for access according to the competition assumption. Based on the strength-dependence assumption and the fact that associations between Rp+ items and their category cues have been strengthened, it can be predicted from the model that access to Rp- items will be impaired relatively to access to Nrp items that are associated to

different category cues which were not used in the retrieval practice phase.

Specifically, during a final test Rp+ items are retrieved by the use of a strengthened associative link and block access to Rp- items which are associated with the same cue. Similar blocking does not occur for Nrp items which are retrieved with the use of a different associative link. Hence, interference-based models can accommodate RIF in the basic retrieval practice paradigm.

The interference-based accounts are contrasted with inhibitory accounts which postulate that changes to representations of Rp- items stored in long-term memory underlie memory impairment observed for these items in a final test (Anderson & Spellman, 1995; Racsmány & Conway, 2006; Norman et al., 2007).

Specifically, inhibitory accounts of RIF borrow the competition assumption from the interference accounts but discard the strength-dependence assumption. These accounts propose that during retrieval practice Rp- items compete for access with to-be-retrieved Rp+ items. This competition is resolved by an inhibitory mechanism which is recruited to dampen activation of competing Rp- items. The consequences of recruiting inhibition against Rp- items in the retrieval practice phase are long-lasting and detectable in the later final memory test in which performance for Rp- items is impaired compared to Nrp items that have never competed for access in the retrieval practice phase. Thus, according to inhibitory accounts, RIF stems not from strengthening of Rp+ items but from direct weakening of Rp- items.

There are several formulations of an inhibitory mechanism that have been proposed in the literature, as described in the previous chapter. The one that is most prominently used in the context of RIF is the pattern-suppression model

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developed by Anderson and Spellman (1995). According to this model the inhibitory mechanism works during retrieval practice to suppress the semantic features of competing Rp- items. These suppressed features make retrieval of Rp- items more difficult in all types of tests that require access to these features. The other

inhibitory accounts of RIF stress its episodic nature. According to the episodic inhibition proposed by Racsmány and Conway (2006), RIF stems from the pattern of activation and inhibition set during retrieval practice and encoded into episodic memory. This pattern is reinstated when an appropriate episode is accessed which results in prolonged RIF on subsequent tests. Somewhat similarly, the model developed by Norman et al. (2007) describes RIF as stemming mostly from an unlearning of episodic associations set at study, although this model allows also for small effects in semantic memory. The present chapter will concentrate mostly on the pattern-suppression model which is commonly equated with an inhibitory approach to RIF, although other models will be described in the section on the cue-independence of RIF as they provide different predictions concerning this main effect of interest for the empirical work described here.

There are several differences between inhibitory and interference-based accounts of RIF besides the issue of whether the effect arises due to the changes in the representations of Rp+ or Rp- items. These differences can be used to formulate contrasting predictions that would allow for resolving the issue of which class of mechanisms is responsible for producing RIF. The first difference is that whereas interference is a passive process in which impairment to Rp- items can be seen as a mere by-product of storing new information or updating already established memory traces of Rp+ items during the retrieval practice phase, the inhibitory mechanism postulate an active process directed against memory representations of Rp- items. Thus, the accounts presumably differ in the postulated involvement of active and hence resource-demanding processes in producing RIF. The second difference lies in the phase of the experiment in which the locus of the effect is assumed to lie. Interference-based mechanisms stress that RIF occurs due to the dynamics of a test phase. The retrieval practice phase serves to implement a strengthening manipulation but the actual impairment to Rp- items occurs only

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during a final test. In contrast, inhibitory theories assume that memory

representations of Rp- items become impaired in the retrieval practice phase and a final test serves only to reveal this impairment. The third difference lies in the role assigned to the retrieval practice phase. The interference-based account assumes that in order to obtain RIF a strengthening of cue-to-Rp+ links needs to occur in this phase but this account is seemingly mute on the way this strengthening should occur. Thus, from this perspective RIF should occur also when strengthening of cue-to-Rp+ associations is induced by additional presentations of intact pairs and not exclusively due to retrieval practice of Rp+ items. In contrast, the inhibitory model assumes that inhibition is triggered during competitive retrieval and thus makes a specific prediction that in order to obtain RIF the competitive retrieval of Rp+ items must occur to trigger inhibitory mechanisms and impair memory for related Rp- items.

Finally, the fourth difference, which is the most crucial from the perspective of the present experiments and results, lies in the breadth of impairment caused by interference and inhibition. The interference-based account makes a specific

prediction that access to Rp- items will be impaired as long as the cues used at retrieval practice to access Rp+ items serve also as cues to access Rp- items in a final test. Only in this case Rp+ items can interfere and block retrieval of Rp- items.

This, however, is not necessarily the case for inhibitory accounts. These accounts assume that representation of Rp- items become disrupted during retrieval practice and thus the generality of this impairment depends crucially on which part of representation of Rp- items actually becomes disrupted. One possibility is that inhibition serves to disrupt an associative link between the cue used at retrieval practice to access Rp+ items and competing Rp- items, the idea commonly referred to as associate unlearning (Melton & Irwin, 1940, as described in Anderson & Neely, 1996). In this case the inhibitory account would make the same prediction as the interference-based account, according to which RIF should be detectable only when the same cues are used during retrieval practice and a final memory test. However, it is also possible that inhibition disrupts not only these particular cue-to-Rp- associations but also other parts of memory representations of Rp- items. In this

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case memory impairment should be more general and detectable also with cues other than the ones employed during retrieval practice. In the most extreme case, a semantic part of representation of Rp- items becomes disrupted by an inhibitory mechanism which leads to a prediction that RIF should be detectable with all kinds of cues that require access to semantic representations of Rp- items. This is the logic of cue-independence which, according to some authors (Anderson &

Spellman, 1995), is the best test for contribution of inhibition to forgetting. It has to be noted, however, that not all formulations of inhibition predict such a property of RIF, which will be apparent in the later discussion on empirical findings concerning cue-independence of RIF.

2.3 Empirical evidence for inhibitory and interference-based accounts of RIF