The effects of age and uncertainty in the Stroop priming task.

In this study, we tested young and older adults on a spatially separated Stroop priming task in which a neutral word in colored ink (target) randomly appeared on either side of a color word in black ink (prime). Cues that preceded the target-prime word pair either indicated the correct target location (valid), the incorrect location (invalid), or provided no information about the target location (ambiguous). Analyses of proportional response latencies and ex-Gaussian parameters of response latency distributions showed that valid advance cues reduced interference and invalid cues increased interference for both young and older adults. Ambiguous cues were also associated with high levels of interference, but interference was higher for older adults than for younger adults. These findings are consistent with a large body of research showing age-related deficits in the use of the attentional network associated with executive control. However, they also demonstrate that older adults can use the attentional network associated with spatial orienting to reduce response conflict. For instance, we observed facilitation for congruent trials after the presentation of an invalid cue, but very little facilitation for congruent trials after the presentation of an ambiguous cue. As the attentional demands in our world increase, we might use this knowledge to promote optimal functioning in older adults. Our findings challenge the notion of ubiquitous age-related declines in attention and contribute to the discussion of how attentional networks work together as demands for conflict resolution vary. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Aging and associative binding in contingency learning.

Cue competition effects are pervasive in young adults' learning, but evidence for these effects in older adults' learning is mixed. For example, although older adults show strong forward blocking, they do not show recovery from overshadowing. We examined whether this could be due to problems with associative binding using a rapid, streamed trial contingency learning task to minimize long-term memory retrieval demands. In a forward blocking paradigm , target cues gained less predictive value when the competing companion cues had high predictive value and this forward blocking effect was similar for younger and older adults. In a backward blocking paradigm, target cues lost more predictive value when the competing companion cues had high predictive value, but this backward blocking effect was greater for younger than older adults. These findings, together with evidence that within-compound associations for companion and target cues mediate backward, but not forward cue competition effects, suggest that a decline in associative binding may be responsible for the absence of backward cue competition effects in older adults' contingency learning.

Aging and the role of attention in associative learning.

In this study, we investigated whether age-related deficits in cue-outcome associative learning (e.g., Mutter, Atchley, & Plumlee, 2012; Mutter, DeCaro, & Plumlee, 2009; Mutter, Haggbloom, Plumlee, & Schirmer, 2006; Mutter & Williams, 2004) might be due to a decline in older adults' ability to modulate attention to relevant and irrelevant cues. In the first 2 experiments, we used standard blocking and highlighting tasks to indirectly measure the ability to shift attention away from irrelevant stimuli toward relevant, predictive cues (e.g., Kruschke, Kappenman, & Hetrick, 2005). Although there were age differences in prediction accuracy, like young adults, older adults learned to shift attention toward predictive stimuli and ignore irrelevant or less predictive stimuli. This attentional effect was unrelated to either working memory or executive function suggesting that it did not involve voluntary control processes. The third experiment provided further support for this idea. We alternated a category learning task with a dot probe task to more directly assess the development of automatic attentional biases. There were again age differences in category prediction, but young and older adults alike responded more rapidly to the location of a dot probe cued by a stimulus experienced as predictive during the learning task than one cued by a stimulus experienced as nonpredictive. These findings provide converging evidence that even though cue-outcome prediction declines with age, the ability to modulate attention based on the predictive relevance of cues during associative learning remains intact. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Gist and Generalization in Young and Older Adults' Causal Learning.

Objectives: To investigate age differences in gist-based causal learning. Method: Young and older adults learned to predict whether eating foods from each of 6 categories was or was not followed by sickness. Experience with the categories was varied by presenting 5 exemplars of a category in only one of 2 training phases (small categories) or by presenting 5 exemplars of a category in the first phase and an additional 5 exemplars in the second phase (large categories). Trained and novel exemplars from all categories appeared in subsequent causal judgment and recognition tests. Results: There were no age differences in causal judgments for old exemplars or in generalization of causal associations to novel exemplars. For both groups, causal generalization was more successful and recognition was less successful for exemplars from large categories. There was no age difference in recognition for large categories, but older adults performed more poorly than young adults for small categories. Discussion: Older adults resemble young adults in their ability to induce unseen category features from presented exemplars, acquire causal associations for these gist representations, and generalize this knowledge to new exemplars. However, they continue to rely on these gist-based representations for memory discrimination, whereas young adults use both category and individuating features of cues.

The effects of age on associative and rule-based causal learning and generalization.

We assessed how age influences associative and rule-based processes in causal learning using the Shanks and Darby (1998) concurrent patterning discrimination task. In Experiment 1, participants were divided into groups based on their learning performance after 6 blocks of training trials. High discrimination mastery young adults learned the patterning discrimination more rapidly and accurately than moderate mastery young adults. They were also more likely to induce the patterning rule and use this rule to generate predictions for novel cues, whereas moderate mastery young adults were more likely to use cue similarity as the basis for their predictions. Like moderate mastery young adults, older adults used similarity-based generalization for novel cues, but they did not achieve the same level of patterning discrimination. In Experiment 2, young and older adults were trained to the same learning criterion. Older adults again showed deficits in patterning discrimination and, in contrast to young adults, even when they reported awareness of the patterning rule, they used only similarity-based generalization in their predictions for novel cues. These findings suggest that it is important to consider how the ability to code or use cue representations interacts with the requirements of the causal learning task. In particular, age differences in causal learning seem to be greatest for tasks that require rapid coding of configural representations to control associative interference between similar cues. Configural coding may also be related to the success of rule-based processes in these types of learning tasks.

Aging and retrospective revaluation of causal learning.

In a 2-stage causal learning task, young and older participants first learned which foods presented in compound were followed by an allergic reaction (e.g., STEAK-BEANS→ REACTION) and then the causal efficacy of 1 food from these compounds was revalued (e.g., BEANS→ NO REACTION). In Experiment 1, unrelated food pairs were used, and although there were no age differences in compound- or single-cue-outcome learning, older adults did not retrospectively revalue the causal efficacy of the absent target cues (e.g., STEAK). However, they had weaker within-compound associations for the unrelated foods, and this may have prevented them from retrieving the representations of these cues. In Experiment 2, older adults still showed no retrospective revaluation of absent cues even though compound food cues with pre-existing associations were used (e.g., STEAK-POTATO), and they received additional learning trials. Finally, in Experiment 3, older adults revalued the causal efficacy of the target cues when small, unobtrusive icons of these cues were present during single-cue revaluation. These findings suggest that age-related deficits in causal learning for absent cues are due to ineffective associative binding and reactivation processes.

Aging and integration of contingency evidence in causal judgment.

Age differences in causal judgment are consistently greater for preventative/negative relationships than for generative/positive relationships. In this study, a feature analytic procedure (Mandel & Lehman, 1998) was used to determine whether this effect might be due to differences in young and older adults' integration of contingency evidence during causal induction. To reduce the impact of age-related changes in learning/memory, the authors presented contingency evidence for preventative, noncontingent, and generative relationships in summary form; the meaningfulness of causal context was varied to induce participants to integrate greater or lesser amounts of this evidence. Young adults showed greater flexibility in their integration processes than did older adults. In an abstract causal context, there were no age differences in causal judgment or integration, but in meaningful contexts, young adults' judgments for preventative relationships were more accurate than older adults' and young adults assigned more weight to the contingency evidence confirming these relationships. These differences were mediated by age-related changes in processing speed. The decline in this basic cognitive resource may place boundaries on the amount or type of evidence that older adults can integrate for causal judgment.

The role of contingency and contiguity in young and older adults' causal learning.

Contingency and temporal contiguity are important "cues to causality." In this study, we examined how aging influences the use of this information in response-outcome causal learning. Young and older adults judged a generative causal contingency (i.e., outcome is more likely when a response is made) to be stronger when response and outcome were contiguous than when the outcome was delayed. Contiguity had a similar beneficial effect on young adults' preventative causal learning (i.e., outcome is less likely when a response is made). However, older adults did not judge the preventative relationship to be stronger when the response and outcome were separated by a short delay or when the outcome immediately followed their response. These findings point to a fundamental age-related decline in the acquisition of preventative causal contingencies that may be due to changes in the utilization of cues for the retrieval of absent events.

The role of age and prior beliefs in contingency judgment.

This experiment investigated how prior beliefs affect young and older adults' ability to detect differences in objective contingency. Participants received new evidence that the objective contingency between two events was positive, negative, or zero when they believed that there was a positive or negative relationship between events, when they believed that the events were unrelated, and when they had no knowledge of the relationship between the events. They were then asked to estimate the objective contingency and recall the contingency evidence. Beliefs that events were or could be related improved young adults' contingency discrimination. Moreover, these beliefs did not produce biases in young adults' memory for the contingency evidence, but rather affected how they weighted this evidence at judgment. In contrast, these same beliefs did not improve older adults' contingency discrimination, but did produce biases in their memory for the evidence that were similar to those seen in their judgment. These findings are discussed in terms of age-related changes in working memory executive processes that impair older adults' ability to fully evaluate both belief-confirming and disconfirming contingency evidence and update their beliefs with this information.

Aging, working memory, and discrimination learning.

Older adults easily learn probabilistic relationships between cues and outcomes when the predictive event is the occurrence of a cue, but have greater difficulty when the predictive event is the nonoccurrence of a cue (Mutter & Pliske, 1996; Mutter & Plumlee, 2004; Mutter & Williams, 2004). This study explored whether this age-related deficit occurs in a simpler learning context and whether it might be related to working memory (WM) decline. We gave younger and older adults simultaneous discrimination tasks that allowed us to compare their ability to learn deterministic relationships when either the occurrence (feature positive; FP) or the nonoccurrence (feature negative; FN) of a distinctive feature predicted reinforcement. We also included a group of younger adults who performed the discrimination tasks under a concurrent WM load. Both age and WM load had a detrimental effect on initial FP and FN discrimination; however, these effects persisted only in FN discrimination after additional learning experience. Learning predictive relationships requires inductive reasoning processes that apparently do not operate as efficiently in individuals with reduced WM capacity. The impact of WM decline may ultimately be greater for negative cue-outcome relationships because learning these relationships requires more difficult inductive reasoning processes, which place greater demands on WM.

The effects of age and task context on Stroop task performance.

In this study, we investigated the impact of age and task context on Stroop task performance, using error scores, response latencies, and process dissociation estimates (e.g., Lindsay & Jacoby, 1994). Across three experiments, the findings showed that although older adults were able to evaluate Stroop task demands and modify their representations of task context in response to this knowledge, they were less able to maintain and update these representations on a trial-by-trial basis in tasks with high stimulus uncertainty or ambiguity. Moreover, although there was no age-related decline in the ability to modulate print color information, older adults were consistently less able to control the activation of conflicting word information. Together, these findings suggest that whereas age differences in the Stroop task may be magnified under conditions that promote transient failures to maintain task context, the primary source of these differences seems to be a more enduring decline in the efficiency of processes that are responsible for suppressing the activation of irrelevant lexical information.

Aging and the detection of contingency in causal learning.

Young and older participants' ability to detect negative, random, and positive response-outcome contingencies was evaluated using both contingency estimation and response rate adaptation tasks. Age differences in contingency estimation were consistently greater for negative than positive contingencies, and these differences, though still present, were smaller when response rate adaptation was used as the measure of contingency learning. Detecting causal contingency apparently becomes more difficult with age, especially when an oven numerical estimate of contingency must be provided and when the relationship between a causal event and an outcome is negative. A model that incorporates features of both associative and rule-based approaches to contingency learning (e.g., P. C. Price & J. F. Yates, 1995; D. R. Shanks, 1995) provides the best explanation for this pattern of findings.