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Abstract
In three experiments we investigated how one form of learning, that of learning to control complex systems, varies with adult age. We used one version of the Process Control task introduced by Berry and Broadbent (1984), the Sugar Production task, in which participants undertake a role of a manager of a sugar production factory, and are required to reach and maintain a specified sugar output simply by manipulating the number of workers employed. Unbeknownst to them, the output was related to the input by a mathematical equation. People show implicit learning on the Sugar Production task by achieving the target output more frequently across time, despite being unable to answer questions about the system they learned to control. The main goal of this study was to determine whether there are age related differences in learning the Process Control task. Furthermore, we wanted to investigate the two-stage theory of learning, which states that early in training, learning in the Process Control task is implicit, while later on it becomes explicit. We used healthy aging, with its known explicit learning deficits, as a test case to investigate this two-stage theory. A third goal was to examine what kind of knowledge people gain in this task, and whether there are age related differences in the types of knowledge acquired.
The results indicated that first, both age groups were able to learn in the early Process Control task and there were no age-related deficits, suggesting that implicit skill learning of this type, which does not contain the perceptual or motor components typical of many implicit learning tasks, is spared in healthy aging. The results for the late training are mixed in that the second and third experiments examining late training showed different patterns of results: age deficits and age invariance, respectively, calling into question the two-stage theory. However, even though there were age deficits during late training in the Process Control task in Experiment 2, old adults performed as well as young on other measures of task knowledge. This suggested that age deficits observed in the second half of the second experiment might have been due to older people experiencing fatigue or getting discouraged in later training. Overall, the results of all three experiments suggest that learning in the Process Control task is age invariant. Further, the age invariance is also seen in the amount of knowledge the age groups revealed on other tests measuring the task relevant knowledge.
