Sentencia de fecha 17 de marzo de 2015, amparo 1776/2014-VI-12, Juzgado Noveno de Distrito en el Estado de Puebla.

Conceptual indirect memory tests, like direct memory tests, are sensitive to encoding manipulations that effect conceptual processing. As discussed earlier, these m anipulations include levels o f processing, read versus generate, and organisation (Hamann, 1990; Rappold & Hashtroudi, 1991; Srinivas & Roediger, 1990). Superficially, the effects o f these variables suggest that conceptual direct and indirect memory tests are mediated by similar processes, which are different from those involved in perceptual indirect m em ory tests (Roediger et al., 1989b). However, conceptual indirect memory tests can themselves be dissociated from direct memory tests using variables such a verbal versus performed-action encoding manipulation (Nyberg & Nilsson, 1995) and amnesia (Moscovitch et al., 1993), which affect conceptual direct mem ory tests, but do not appear to affect conceptual indirect memory tests. In addition, evidence o f stochastic independence between conceptual direct and indirect m em ory tests supports the contention that important differences are

1. Explicit-Implicit M emory and Ageing: Experimental W ork

present between these tests (Cabeza & Ohta, 1993).

The effect o f ageing on conceptual direct and indirect memory tests has been investigated using a variety o f conceptual tasks. Specifically, age-related invariance has been obtained in general knowledge priming (Rastle & Burke, 1996; Small et al., 1995), word association priming (McEnvoy et al., 1995), and category exemplar verification prim ing (Light et al., 1999). Category exemplar verification is distinct from other conceptual m emory tasks, since it involves the re­ presentation o f exemplars at test, which clearly has parallels with perceptual memory tasks, but the task does require access to conceptual or semantic information (Light et al., 1999). The majority o f studies that have investigated the effects o f ageing on conceptual direct and indirect memory tests have employed the category exemplar generation memory task.

For example, Isingrini et al. (1995) examined the difference in direct and indirect category exemplar generation as a function o f age and divided attention. Four age groups were compared: 20-35, 40- 55, 60-75, and 76-90. Both increasing age and divided attention impaired direct category exemplar generation performance. In contrast, category exemplar generation prim ing was unaffected by these two factors. The authors argued that these findings illustrate that the direct and indirect memory tests are mediated by different processes (cf. M ulligan, 1997; M ulligan, 1998; Mulligan & Hartman, 1996; Schmitter-Edgecombe, 1999). Specifically, the absence o f an effect o f divided attention on category exemplar generation, at least in the Isingrini et al. (1995) study, was argued to support the notion that conceptual priming is not dependent on the allocation o f attention.

In contrast, Grober et al. (1992b) reported an age-related impairment in an indirect category free- association task and a direct category cued recall. Unfortunately, G rober et al. (1992b) also reported evidence that young adults engaged in conscious retrieval during the free-association test, although this was not found in older adults. Contamination was to be expected because the cued recall task preceded the free association task and an intentional encoding strategy was employed. These factors may have contributed to the impaired free association performance, because category cued recall was impaired in the older adults; although the source o f the contamination in older adults may have reflected involuntary conscious memory. Jelicic et al. (1996) also reported an age-related impairment in category exemplar generation priming. However, the indirect category exemplar task was also administered after a direct memory test to some participants.

category exemplar generation. In both young and older adults, a standard levels o f processing effect occurred for both tests. Older adults were only impaired in the direct m emory test. However, in the absence o f an independent assessment o f awareness and the fact that the levels o f processing manipulation does not dissociate conceptual direct and indirect memory tests, the extent to which unconscious conceptual processing mediated performance in the indirect test cannot be easily determined. A study by Light and Albertson (1989) is the only other study to have examined category exemplar generation prim ing in older adults. Comparable prim ing effects were obtained for young and older adults in category exemplar generation, when people who explicitly denied attempting to produce list members were excluded from their analysis. However, the samples were small, and consequently the power to detect any age-related differences may have been low.

In addition to differences in the extent to which task contamination compromised conceptual priming, the inconsistent findings may be due to the differences in the experimental protocols that were employed and the age o f the older adults (the implications o f task related factors for the functional demands associated with the category exemplar generation task are considered in Chapter 9). First, both the Light and Albertson (1989) and Isingrini et al. (1995) studies measured priming by taking the number o f targets that appeared in the first eight category members produced, whereas in the category free association test used by Grober et al. (1992), only the first word produced was taken into account. Both o f these procedures have been used in studies that have investigated conceptual priming in young adults (Rappold & Hashtroudi, 1991; Schmitter- Edgecombe, 1999; Srinivas & Roediger, 1990). The unique category exemplar approach is probably less susceptible to effects associated with organisational strategies at retrieval. Under these conditions, deficiencies in the ability o f older adults to invoke greater semantic processing and cognitive resources needed for strategic retrieval may bias task performance in favour o f young adults (but see. Chapter 9). Second, the difference in the mean ages o f the older adults across the studies suggests that a decline in conceptual priming may occur in late adulthood. Specifically, the mean ages o f the older adults in the Light and Albertson (1989) and Grober et al. (1992) study were 69 and 78 years, respectively; however, the findings from the Isingrini et al (1995) study did not support the notion o f a progressive decline with age, since there was still no reliable deficit in category exemplar generation prim ing even for the oldest age groups that had a mean age o f 81 years. However, the absence o f an effect o f divided attention on conceptual prim ing does suggest that their dependent measure was not particularly resource demanding.

1. Explicit-Implicit M emory and Ageing: Experimental Work

1.4,2,2 Summary

The difficulties associated with the studies that have investigated the effects o f age on conceptual direct and indirect memory tests underscores the need to replicate and extend this research to establish the reliability, and evaluate the validity, o f any age effects that may be present. The majority o f studies that reported age invariance in conceptual priming employed the category exemplar generation task (Isingrini et al., 1995; Light & Albertson, 1989; Light et al., 1999; Maki & Knopman, 1996; Monti et al., 1996), whereas when evidence o f age-related decline in priming in category exemplar generation has been obtained (Grober et al., 1992b; Jelicic et al., 1996), contamination by conscious processes, which can produce effects in the same direction as conceptual unconscious processes, could not be excluded. Indeed, M ulligan and Hartman (1996) reported that the percentage o f test-aware participants in indirect category exemplar generation was 93%, whereas Jaciw and M cAndrews (1993) reported that the category exemplar generation task was primarily mediated by conscious processes (see also, Schmitter-Edgecombe, 1999).

As discussed earlier, ageing appears to reduce attentional resource capacity (Craik, 1986; Hasher & Zacks, 1988; Plude & Hoyer, 1985), thus if conceptual unconscious processes are demonstrated to be attention demanding under certain experimental conditions, age-related deficits may appear in both conceptual conscious and unconscious processes. Therefore, in addition to obtaining a veridical measure o f conceptual unconscious processes, examining the effect o f changes in the availability o f attention at encoding on the estimates o f unconscious processes in a category exemplar generation task will inform the conclusions that have been made with regard to the demands that these processes place on cognitive resources. The following section reviews studies that have applied a manipulation o f divided attention at encoding to conceptual direct and indirect memory tests.

Given that a particular memorial state o f awareness is unlikely to be associated uniquely with a particular retrieval strategy or mem ory content (Gardiner & Java, 1993b), an evaluation o f the proposition that ageing does not affect performance on indirect mem ory tests (Light & La Voie, 1993a) and that unconscious m em ory processes are largely age invariant (Jennings & Jacoby, 1993) requires that the distinction between perceptual and conceptual processing is crossed with the distinction between item- and association-specific retrieval. M ore specifically, given the component processes that contribute to conceptual item-specific and perceptual associative-specific memory tasks (Craik, 1986), an overall research strategy that compares these two forms o f mem ory under a

variety o f equivalent encoding conditions represents a powerful method for investigating the nature o f age-related differences in the processes, and for determining the extent to which conscious and unconscious processes in these tasks represent independent bases for responding.