Developmental differences in the use of task goals in a cued version of the stroop task

The ability of children (M= 8.8 years) and adults (M= 25.6 years) to maintain task goals was examined by comparing their performance on a cued version of the Stroop colour‐word task. The experimental task presented a cue on each trial that instructed the participant to either read aloud the forthcoming word or name the colour of the word's lettering. Participants were tested with each of two cue‐stimulus delays (1,000 and 5,000 ms). Analysis of error rates in the colour‐naming condition revealed that children experienced greater interference than adults at each of the cue‐stimulus delays. In an effort to separate the relative contributions of colour‐naming and word‐reading processes, additional analyses were performed based on the process dissociation procedure of Lindsay and Jacoby (1994) . While colour‐naming process estimates did not vary with age group or cue‐stimulus delay, word‐reading process estimates were found to vary with age group and cue‐stimulus delay. Specifically, adults were superior to children in the inhibition of irrelevant word information only during a long cue‐stimulus delay. Collectively, these findings indicate that children have difficulty maintaining task goals in order to suppress stronger, goal‐irrelevant responses.     

Feature binding in children and young adults

The authors measured memory for individual features (objects only or locations only) and the combination of those features (objects and locations) in 9-, 12-, and 21-year-old students with a yes or no recognition task. Analysis of recognition memory performance (d' scores) revealed that although age differences existed in memory for individual features, age differences were greater in the tasks that required memory for combined features (objects and locations). Hierarchical multiple regression analyses indicated that age remained a significant predictor of memory performance in the combination condition even after the authors statistically removed memory performance in object and location conditions and the interaction effects of object and location. These results provide evidence for developmental differences in the binding of features in memory.     

Context processing and cognitive control in children and young adults

T. S. Braver and colleagues (e.g., T. S. Braver, J. D. Cohen, & D. M. Barch, 2002) have provided a theory of cognitive control that focuses on the role of context processing. According to their theory, an underlying context-processing mechanism is responsible for the cognitive control functions of attention, inhibition, and working memory. In the present study, the authors examined whether T. S. Braver et al.'s theory can account for developmental differences in cognitive control. The authors compared the performance of children (M age = 11.9 years, SD = 0.43 years) with that of young adults (M age = 21.7 years, SD = 3.61 years) on a continuous performance task (AX-CPT) that placed demands on context processing. The results suggest that developmental differences in the cognitive control functions of attention, inhibition, and working memory may be based on age-related changes in an underlying context-processing mechanism.     

The dissociation of repetition priming and recognition memory in language/learning-disabled children.

Recent research has found that the performance of learning-disabled and non-disabled children is dissociated on explicit and implicit tests of memory (Lorsbach & Worman, 1989). The current study further examined this phenomenon by comparing language/learning-disabled (L/LD) and nondisabled children (NLD) on tasks measuring primed picture-naming and item recognition. Included within the design of the experiment was the manipulation of both presentation format (pictures or words) and retention interval (immediate or 1 day). Children were initially presented with pictures and words. Performance was measured both immediately and following a 1-day retention interval on a picture naming task, an item recognition task, and a supplementary measure of memory for presentation format. The magnitude of facilitation associated with primed picture-naming was found to be independent of item recognition performance. In addition, the effects of population (L/LD and NLD) and retention interval (immediate test or 1 day) each produced dissociations between the magnitude of naming facilitation and item recognition performance. Results were discussed in terms of their implications for our understanding of the nature of memory difficulties in L/LD children.     

Dual-task performance as a function of adult age and task complexity

A dual-task procedure was used to examine capacity demands of letter-matching in younger and older adults. Older subjects generally were slower on both tasks than were younger adults, but this difference was especially pronounced for the late stages of category matching, suggesting that retrieval and comparison of category information is particularly demanding for older adults.     

Buildup of proactive inhibition as a function of temporal spacing and adult age

Glenberg's theory of temporal distinctiveness (Glenberg, 1987; Glenberg & Swanson, 1986) was used to examine whether the buildup of proactive inhibition (PI) may be interpreted as an overloading of temporal retrieval cues. The Brown-Peterson task was selected on the basis of the assumption that successful performance on such a task requires the use of a recency rule where the subject must use temporal cues to retrieve the contents of the most recent study list. Two variables were manipulated that were presumed to affect the utilization of temporal cues: length of intertrial interval (ITI) (0 or 90 s) and adult age (young or elderly). Glenberg's theory suggests that temporal spacing improves memory by enhancing the distinctiveness of temporal retrieval cues. Thus, it was predicted that PI buildup should be less in the 90-s condition than in the 0-s condition. Assuming that older adults are more sensitive to the overloading of temporal cues, it was anticipated that older adults would experience a greater buildup of PI than younger adults at the 0-s condition. Results showed that although PI buildup varied with length of ITI, it did not vary with adult age. Analysis of delayed measures of recall, recognition, and temporal memory suggested that a retrieval interpretation based on Glenberg's theory is insufficient as an explanation of the current results; encoding difficulties also appear to contribute to the buildup of PI.     

Encoding and contextual components of word recognition in good and poor readers

Good and poor readers from the third and sixth grades (9- and 12-year-olds, respectively), named visually presented words as rapidly as possible. Words were in clear or degraded form, and were preceded by related or unrelated words. Poor readers were hurt more by degradation than were good readers, and showed greater benefit from context. In general, the contextual benefit was greater with degraded words than with intact, and this interaction was especially pronounced in the poor readers. The results are consistent with an interactive-compensatory model of word recognition. Under conditions in which stimulus encoding is slow, contextual factors may compensate for this encoding deficit.     

Developmental Differences in Cognitive Control: Goal Representation and Maintenance During a Continuous Performance Task

The present study examined whether younger and older children differ in the use of the goal-related information in a continuous performance task (AX-CPT), and if so, whether those age differences are due to the ability to represent and/or maintain goal information. Experiment 1 compared third- and sixth-grade children in their ability to transform the identity of letter cues into goal representations, as well as to sustain those goal representations during a long (5,500 ms) cue-probe delay in the AX-CPT. Experiment 2 used a short cue-probe delay (1,000 ms) and thereby eliminated the demands of maintaining goal representations in working memory. In addition, Experiment 2 varied the level of demand that was placed on the ability to represent context information by varying the features of letter cues. The combined results of these experiments indicated that sixth graders were superior to third graders in cognitive control under conditions that placed demands on either the ability to represent or maintain goal-related information.     

Automatic semantic feedback during visual word recognition

Four experiments were conducted to determine whether semantic feedback spreads to orthographic and/or phonological representations during visual word recognition and whether such feedback occurs automatically. Three types of prime-target word pairs were used within the mediated-priming paradigm: (1) homophonically mediated (e.g., frog-[toad]-towed), (2) orthographically mediated (e.g., frog-[toad]-told), and (3) associatively related (e.g., frog-toad). Using both brief (53 msec; Experiment 1) and long (413 msec; Experiment 3) prime exposure durations, significant facilitatory-priming effects were found in the response time data with orthographically, but not homophonically, mediated prime-target word pairs. When the prime exposure duration was shortened to 33 msec in Experiment 4, however, facilitatory priming was absent with both orthographically and homophonically mediated word pairs. In addition, with a brief (53-msec) prime exposure duration, direct-priming effects were found with associatively (e.g., frog-toad), orthographically (e.g., toad-told), and homophonically (e.g., toad-towed) related word pairs in Experiment 2. Taken together, these results indicate that following the initial activation of semantic representations, activation automatically feeds back to orthographic, but not phonological, representations during the early stages of word processing. These findings were discussed in the context of current accounts of visual word recognition.     

Orthographically mediated inhibition effects: evidence of activational feedback during visual word recognition

Models of visual word recognition that have adopted an interactive activation framework (e.g., Coltheart, Curtis, Atkins, & Haller, 1993; Grainger & Jacobs, 1996) assume that activation can spread from semantic to orthographic representations via a feedback mechanism during visual word recognition. The present study used a mediated priming paradigm to test whether such feedback exists and, if so, under what conditions. Participants named aloud targets that were preceded either by a semantically related prime (e.g., dog-cat) or by a prime that was related to the target via a mediating word (e.g., cat-[dog]-bog). Direct evidence of activational feedback was obtained in the form of orthographically mediated inhibition effects. These mediated inhibition effects are consistent with activational feedback and support models of visual word recognition that have adopted an interactive activation framework.