| Frontal brain regions undergo significant postnatal change and are the last regions in the brain to reach full maturity. These brain regions have been shown to play important roles in executive abilities in adults. Executive abilities are widely considered to comprise working memory, inhibitory control, and strategic processing. Of these abilities, strategic processing is neither well defined nor well understood, particularly from a developmental perspective. For the purposes of the present study, strategic processing was defined as the spontaneous or cued use of a goal-oriented process in an attempt to facilitate task performance. In an attempt to simplify the complex concept of strategic processing, one specific strategy was studied. A strategy that has been identified to facilitate task performance in the adult literature is semantic categorization, which is the strategy of clustering together items that are similar in meaning and then using clustering of those related items to facilitate task performance on a variety of tasks. From early studies, we know that 2nd grade children use semantic clustering to facilitate memory when instructed to do so, but do not spontaneously use this strategy; high school students, however, spontaneously use semantic clustering to facilitate encoding and retrieval. The present study examined the emergence of semantic categorization in children aged 6 years to 13 years, using four tasks: semantic verbal fluency, card sorting, list learning, and verbal paired associates. Results from the study demonstrated that the use of semantic categorization to facilitate task performance increased with age across all four tasks, sometimes increasing beyond the studied age range. The emergence of semantic categorization, however, did not occur at the same rate across the different tasks. These findings demonstrate that semantic categorization, as measured by the tasks used in the study, is not a single conceptual factor because semantic categorization did not develop in the same manner across all of the tasks. This study provides a starting point for examining the developmental trajectory of one aspect of strategic processing during typical development and revealed important and unique information about how and when this component of executive abilities emerges during childhood. |
