Learning in multimedia environments can be enhanced when instructional design methods are aligned with human cognitive architecture. This notion was theoretically framed by Mayer (2001; Mayer & Moreno, 2003; Moreno, 2006) and empirically tested with young students. How can older learners benefit from an enhanced multimedia design?

Aging is characterized by a range of cognitive declines. The most influential theories of cognitive aging explain them in terms of: 1) a decreased working memory capacity (Salthouse & Babcock, 1991); 2) reduced processing speed - decrease in the rate at which information is activated, when the time occupied by early memory processes puts limitations on time available for later processes (Salthouse, 1996); 3) reduced source binding and integration: an inability to correctly detect the source of information and to integrate several sources (Chalfonte & Johnson, 1996); 4) decreased processing resources in application to novel complex tasks (Craik, 1986); 5) reduced inhibitory efficiency  - i.e. ability to suppress the activation of nonrelevant information (Hasher & Zacks, 1988). Review of empirical studies including younger and older adults brings several useful points that can be exploited in multimedia design for the elderly (i.e. use of numerical tasks instead of verbal; use of visual modality is preferable to auditory modality; use of auditory modality after visual etc.). Certain techniques (i.e. use of distractors to enhance performance on secondary task) may be beneficial for older learners performance and harmful for their younger counterparts. Cognitive declines are evident on complex novel tasks more than on simple perceptual tasks and are expressed by performance deterioration. How can a multimedia designer use the existing CTML principles to enhance performance of older learners or to promote the learning of both, younger and older students?

Existing principles of multimedia design – multimedia principle, coherence, personalization, pre-training, modality, redundancy, spatial contiguity, temporal contiguity, segmentation, signaling, interactivity, guidance – were based on several assumptions about the human cognitive architecture.  These assumptions included: 1) the human information processing system as two processing channels (an auditory/verbal and visual/pictorial) to process information simultaneously, (dual-coding theory; Pavio, 1986); 2) the amount of information processed at each moment is limited, so the existing channels should not be overloaded; 3) active processing -- elaboration on the presented material, mentally organizing new material into a coherent structure, and integrating the presented material with existing knowledge (Mayer & Moreno, 2003); 4) a long-term memory is seen as a storage for a large number of hierarchically organized schemas (Paas, Renkl, & Sweller, 2003); 5) knowledge representations in a long-term memory may consist of verbal and non-verbal codes (Moreno, 2006). Since all the multimedia learning principles are derived from the general assumptions about human cognitive architecture above, it will be safe to say that they may be effective for different populations (not only for younger adults). However, there are a few studies that have tested these principles with older adults. Looking at cognitive aging theories, it becomes unclear why. For example, empirical studies show that reduced working memory capacity influence performance much less in simple tasks, than complex tasks (Salthouse, Rogan, & Prill, 1984) – which corresponds to the segmentation principle of CTML. Using visual modality and learner-paced tasks are preferable to using auditory modality and experimenter-paced tasks (Hartley, 1986; Wingfield, Stine, Lahar, & Aberdeen, 1988). In this case a reduced working memory capacity may be enhanced by using the interactivity principle (in a sense of learner-paced environment) and redundancy principle: animations presented before a narration and on-screen text are more beneficial for learning than just a narration and on-screen text (Moreno and Mayer, 2002). However, the same redundancy principle in its traditional formulation: several types of presented information shouldn’t share the same channel when both channels are used, may not work with older learners. For them a visual channel being used for a picture (animation) and an on-screen text (i.e. multimedia principle) may be more beneficial than using a narration and on-screen text (traditional non-redundant condition). All implications of CTML for older learners are presented in Figure 1.

Taking a CTML as a framework, one can see that different cognitive aging theories are related to the different cognitive processes. Cognitive theories based on reduced source binding and integration as well as reduced inhibition address more of the process of integrating information from working memory to long-term memory and retrieving information from long-term memory to working memory. On the other hand, cognitive theories based on reduced processing speed, decreased resources and reduced working memory capacity address the process of selecting and organizing information in working memory. Additionally, retrieval of information is an important issue in psychological studies with older population was not covered so extensively in human cognitive architecture theories intended for learning. Finally, a pathway for future research is an empirical testing of coherence, redundancy and segmentation principles as they are supported for most of the cognitive aging theories.