Memory loads have an impact on reasoning, problem solving or comprehension and reciprocally, performing these tasks has a detrimental effect on short-term storage. The time-based resource-sharing (TBRS) model is based on four main assumptions. Thus, contrary to Engle and Kane who suggested, for example, that working memory capacity is not required in all circumstances for supposedly complex tasks such as reading, we assume that the goal-directed identification of material as simple as letters or digits necessarily requires working memory This resource is shared on a temporal basis because, and this is the second assumption, there is some bottleneck at the central level of cognition constraining the cognitive operations involved in both storage and processing to take place one at a time. Working memory would consist of representations that are created and actively maintained in an accessible state for further processing, whereas long-term memory is better described as the dormant information used to build transient working memory representations.