Examining the relationships among attentional resources, working memory, and fluid intelligence

Two experiments are reported which examined the relationships among working memory, fluid intelligence, and attentional resources. In both experiments, sixty subjects performed a working memory and fluid intelligence test, as well as the Enumeration task. The Enumeration task was used to index subjects' processing speed and attentional resources. In the first experiment, the Enumeration task was performed without distractors, while in the second experiment distractors were added to the Enumeration task.Consistent with predictions, in Experiment 1 subjects who scored high and low on the working memory test only differed on the attention demanding trials of the Enumeration task. This finding suggested that working memory capacity is largely determined by attentional resources. Also, results from Experiment 1 demonstrated that attentional resources were more strongly related to fluid intelligence than processing speed.Experiment 2 was performed to replicate and extend the findings from Experiment 1, by adding distractors to the Enumeration task. The results demonstrated that subjects scoring low on the working memory test performed more poorly than subjects who scored high on the working memory test, but again only when the distracting information was attention demanding. The results also indicated that the measure of "processing speed" was related to fluid intelligence to the extent that required attention.Taken together, the results from the experiments performed here suggest that working memory and fluid intelligence are both strongly related to attentional resources. These findings, coupled with the weak relationship between measures of processing speed and fluid intelligence raises serious questions about processing speed theories of general intelligence.