The Effects of Children on Parents: Adoptee Genetic Dispositions and Adoptive Parent Psychopathology

The purposes of this experiment were to investigate the effects of age, item type, and culture on the mental-real distinction made by children. A sample of 42 children (21 affluent and 21 deprived) in three age ranges (3- and 4-year-olds, 5-and 6-year-olds, and 7- and 8-year-olds) participated. Nine items were used. The behavioral-sensory and public-existence criteria (Wellman &; Estes, 1986) were used to gauge the children's ability to make the distinction. Contrary to previous research findings, the 3- and 4-year-olds in this study were unable to make the mental-real distinction. An age-related improvement in making this distinction was observed, and item type affected the mental-real distinction. The affluent children consistently outperformed their deprived counterparts. This finding was partly construed as evidence for the influence of culture on the ability to make this distinction in these age groups.     

Metalinguistic Awareness in Children: A Developmental Progression

The purpose of this study was to determine if a developmental order exists in the metalinguistic ability of children to make judgments about the form of language while simultaneously attending to a meaningful linguistic context. The stimulus material consisted of a short story into which 20 nonsense lexical items had been substituted. The 20 stimuli were comprised of phonotactically illegal and legal sequences of phonemes. In addition, the lexical items had been positioned to replace either structure or content words within the story. The participants were 90 Caucasian children who were divided into nine age groupings from 4;0 to 12;11. Baseline data were obtained from 10 adults. All subjects were required to respond to the audio-recorded stimuli by pressing a button whenever a nonsense item was perceived. The data were analyzed for both number of correct responses and reaction times. Results revealed a major shift in metalanguage ability occurring between 7 and 8 years of age. The 8- to 12-year-olds responded correctly to more items and at significantly faster rates than the 4- to 7-year-olds. The adults outperformed the children on all tasks, showing that metalanguage development continues beyond childhood.     

Developmental differences in intake and storage of visual information

A partial report technique was used to determine how much visual information subjects of four ages (ranging from 5-year-olds to adults) were capable of taking in and what the course of information loss was over a 1-sec time period. Subjects were tachistoscopically presented eight items followed by an indicator at variable intervals after array offset and were required to report that item in the indicated position. No reliable age differences were found at the earliest “memory point,” 50 msec. There were, however, age differences both before and after this point. Results suggested an absence of age differences in visual intake capacity, but important differences in other stages of processing.     

My future self: Young children's ability to anticipate and explain future states

Two experiments examine preschool-aged children's ability to anticipate physiological states of the self. One hundred and eight 3-, 4-, and 5-year-olds were presented with stories and pictorial scenes designed to evoke thought about future states such as thirst, cold, and hunger. They were asked to imagine themselves in these scenarios and to choose one item from a set of three that they would need. Only one of the items could be used to address the future state. In both experiments, developmental differences were obtained for correct item choices and types of verbal explanations. In Experiment 2, the performance of the 3- and 4-year-olds was negatively affected by introducing items that were semantically associated with the scenarios but did not address the future state, whereas the 5-year-olds’ performance was not. Results are discussed with respect to children's understanding of the future, theory of mind, and inhibitory control skills.     

Can Item Format (Multiple Choice vs. Open-Ended) Account for Gender Differences in Mathematics Achievement?

The purpose of this study was to investigate differential performance of boys and girls on open-ended (OE) and multiple-choice (MC) items on the 1988 and 1991 International Assessment of Educational Progress (IAEP) mathematics test. In the 1988 mathematics assessment, a representative sample of approximately 1,000 13-year-olds in each of the six participating countries was assessed. In the 1991 mathematics assessment, a representative sample of 9- and 13-year-olds (approximately 1,650 from each age group) in some 20 participating countries was assessed. Analyses of both assessments yielded results that indicated that boys generally performed better than girls in mathematics. In the 1988 assessment, gender effects were larger on MC items than on OE items, corresponding to results of earlier studies. However, the 1991 IAEP assessment produced contrary results: gender effects tended to be larger for OE items than for MC items. These inconsistent results challenge the assertion that girls perform relatively better on OE test items, and suggest that item format alone cannot account for gender differences in mathematics performance. Further investigation of the data revealed that the inconsistent patterns of gender effects with regard to item format were related to the difficulty level of the items, regardless of item format. Correlations between item difficulty and item gender effect size were computed for age 13 in the 1988 assessment and for ages 9 and 13 in the 1991 assessment. The correlations obtained were 0.26, 0.47, and 0.53, respectively, suggesting that the more difficult the items, the better boys perform relative to girls.     

The role of eye movements in subitizing and counting

Previous work has suggested that eye movements may be necessary for accurate enumeration beyond the subitization range of about 4 items. This study determined the frequency of eye movements normally made during enumeration, their relationship to response times, and whether they are required for accurate performance. This was achieved by monitoring eye movements and comparing performance when observers were allowed to saccade and when they were not. The results showed that (a) there was a sharp increase in saccadic frequency beyond about 4 items (from < 0.2 saccades per item to about 1 per item), and (b) enumeration of fewer than 4 items remained rapid and accurate even when eye movements were prevented, whereas enumeration beyond this became less efficient and sometimes less accurate. The results are discussed in relation to the memory and processing requirements of enumeration tasks.     

The role of attention in subitizing: Is the magical number 1?

Subitizing, the fast and accurate enumeration of up to about 3 or 4 objects, has often been thought to be dependent on limited-capacity preattentive mechanisms. We used an attentional blink paradigm to investigate the extent to which subitizing requires attentional resources. On each trial, subjects identified a target letter in an RSVP stream and then enumerated dots presented in the stream that were either simultaneous with the target letter or followed it by up to 400 ms. For numerosities from 2 to 9, evidence of an attentional blink was observed; only enumeration of 0 or 1 elements was independent of lag. Thus, even enumeration of 2–3 objects, which is within the traditional subitizing range, appears to require attentional resources. The relation of this work to studies on the attentional requirements of detecting a unique item among distractors, a supposedly preattentive discrimination, is briefly discussed.     

Integration of weight and distance information in young children: The role of relational complexity

Young children's integration of weight and distance information was examined using a new methodology that combines a single-armed apparatus with functional measurement. Weight and distance values were varied factorially across the item set. Children estimated how far the beam would tilt when different numbers of weights were placed at different distances from the pivot. There was a developmental progression from non-systematic responding (3-year-olds) to responding based on a single variable, usually weight (4-year-olds) to responding based on integration of weight and distance (5-, 6- and 7-year-olds). Individual analyses revealed additive and multiplicative integration rules in children aged from 5 years. Weight–distance strategy complexity increased with age and was associated with better performance on independent measures of relational processing, especially the more complex items. Thus weight–distance integration involves processing of complex relational information. The findings enhance the explanatory power of Relational Complexity theory as a domain-general approach to cognitive development.     

Perceptual integration of motion and form information: evidence of parallel-continuous processing

In three visual search experiments, the processes involved in the efficient detection of motion-form conjunction targets were investigated. Experiment 1 was designed to estimate the relative contributions of stationary and moving nontargets to the search rate. Search rates were primarily determined by the number of moving nontargets; stationary nontargets sharing the target form also exerted a significant effect, but this was only about half as strong as that of moving nontargets; stationary nontargets not sharing the target form had little influence. In Experiments 2 and 3, the effects of display factors influencing the visual (form) quality of moving items (movement speed and item size) were examined. Increasing the speed of the moving items (> 1.5 degrees/sec) facilitated target detection when the task required segregation of the moving from the stationary items. When no segregation was necessary, increasing the movement speed impaired performance: With large display items, motion speed had little effect on target detection, but with small items, search efficiency declined when items moved faster than 1.5 degrees/sec. This pattern indicates that moving nontargets exert a strong effect on the search rate (Experiment 1) because of the loss of visual quality for moving items above a certain movement speed. A parallel-continuous processing account of motion-form conjunction search is proposed, which combines aspects of Guided Search (Wolfe, 1994) and attentional engagement theory (Duncan & Humphreys, 1989).     

Effects of distraction on visual enumeration in children and adults

Speeded enumeration of visual stimuli typically produces a bilinear function, with a shallow subitizing rate (<100 ms/item) up to 3-4 items (subitizing span) and a steeper counting rate (~300 ms/item) thereafter. FINST theory (L. M. Trick & Z. W. Pylyshyn, 1993, 1994) suggests that subitizing of targets is possible in the presence of distractors if attention is not required for target detection, but this has not been tested in children. The present study explored enumeration without distractors (Os alone) and with distractors (Os among Xs) in 35 children aged 6-11 years and 17 adults. Subitizing span increased significantly from childhood to adulthood, and counting rate increased significantly with age. Bilinear functions were significantly better than linear fits to the data for most children and adults both without distractors (97% and 100%, respectively) and with distractors (89% and 94%), consistent with their efficient visual search for a single O among multiple Xs. These findings are discussed in comparison with those from new modeling of earlier enumeration data from young and older adults, revealing striking asymmetries in subitizing with distractors between development and aging.     

Novelty and saliency in attentional capture by unannounced motion singletons

The present study examined attentional capture by an unannounced motion singleton in a visual search task. The results showed that a motion singleton only captured attention on its first unannounced occurrence when the observers had not encountered moving items before in the experiment, whereas it failed to capture when observers were familiar with moving items. This indicates that motion can capture attention independently of top-down attentional control settings, but only when motion as a feature is unexpected and new. An additional experiment tested whether salient items can capture attention when all stimuli possess new and unexpected features, and novelty information cannot guide attention. The results showed that attention was shifted to the location of the salient item when all items were new and unexpected, reinforcing the view that salient items receive attentional priority. The implications of these results for current theories of attention are discussed.     

The form of the information and selective counting by ESN(M) pupils

The study springs from views on attentional deficits in retarded performers. Three experiments are reported in which educationally sub-normal (mild) category pupils and average ability pupils matched with them for mental age perform a speeded classification of cards on the basis of an enumeration of a group of items on each card. This group may be the total of the items on the card or a selected part of that total. Interest focuses upon the relationship between performance in the selective situation and the form or structure of the item group. It is argued initially that attentional patterns may be expected to vary in relation to the specific structure of the information available and the way the performer appreciates that structure. The results support this notion. ESN(M) subjects perform in a similar fashion to the matched group, even given selective instructions, when what must be counted is the whole of a vertical linear series of items. However, when what must be counted is in the form of a part of a vertical linear item series, the performance of the ESN(M) group is significantly slower than that of the matched group. In addition the matched group appear more sensitive to discontinuity within the vertical item series while the ESN(M) group may have a less differentiated approach to such information founded mainly on the appreciation of verticality. It is suggested that aspects of information available to performers must be studied in relation to the kind of whole the particular performer takes the information to be. Although retardates do not carry appropriate structural expectations from situation to situation, suitable organisation of information can be appreciated, leading to more successful performance.     

Components of verbal learning in children: Analysis by selective reminding

Free recall verbal learning by 5- and 8-year-old children was analyzed by selectively reminding them only of items not recalled on the preceding trial (instead of continuing to present the entire list before each recall trial) to show learning by retrieval from long-term storage without presentation. Concurrent analysis of long-term storage, consistent and random retrieval from long-term storage, and recall from short-term storage indicates that, while 5-year-olds showed slower acquisition than 8-year-olds, lower recall by 5-year-olds also was due to less effective retrieval from longterm storage. Repeated retrieval, without any further presentation after an item has been recalled just once, indicates that lower recall by 9-year-old children than by adults also reflects retrieval difficulty, since these children showed storage and retention of almost as many items as adults by eventual spontaneous retrieval without further presentation.     

Organization and long-term memory search

A recognition RT paradigm was used to assess a number of plausible search strategies in LTM for categorized lists. List length was determined by factorially combining two, three, or five categories with two, three, or five words per category, and test items could be one of four types: (1) positive, (2) a repeated positive, (3) a related negative, or (4) an unrelated negative. It was found that RT increased linearly with category size for both positive and related negatives (about 30-40 msec/item); whereas the increase was much smaller for the unrelated negatives, especially for three and five categories (about 9 msec/item). With an increase in the number of categories, RT increased at the rate of about 40 msec/category for all three test items. A theory of .high-speed scanning for categorized material was proposed in which a serial and exhaustive search of the categories, is first undertaken. If a positive category match is found, a serial and exhaustive search within the contents of the positive category is initiated; if no category match is found, the search is simply terminated. Some evidence was presented that categories recently probed may provide for a short-circuiting of the category search.     

Aging and enumeration: a selective deficit for the subitization of targets among distractors

The term subitization has been used to refer to the fast and accurate enumeration of up to about 4 items. Beyond 4 items, enumeration becomes more serial and less accurate, with each additional item adding to the total enumeration time. The effects of aging on visual enumeration of targets (Os) were assessed with and without the presence of distractors (Xs). Young participants (n = 30; 18-27 years) showed the usual subitization-counting enumeration function, both with and without the presence of distractors. In contrast, for older participants (n = 35; 65-79 years), evidence for subitization was found only when distractors were absent. This occurred even though they could detect an individual target among distractors in parallel across the field. The results are discussed in relation to recent theories of visual selection and enumeration.     

False memories in children. Evidence for a shift from phonological to semantic associations

Memory illusions in children of three age groups (5-, 8-, and 11-year-olds) were investigated using a modified version of the Deese-Roediger-McDermott (DRM) procedure. Children from each age group falsely recalled nonpresented items related to the study lists. However, the nature of the intrusions varied across the different groups. The 5-year-olds were more likely to falsely recall words that rhymed with the studied items than to recall unrelated items, whereas the 11-year-olds were more likely to falsely recall words that were semantically related to the list theme than to produce either rhyming or unrelated intrusions. Intrusions made by the 8-year-olds were equally likely to be semantic, rhyming, or unrelated to study items. The results are consistent with the notion of a developmental shift from phonological to semantic associations, leading to qualitatively different memory distortions in children of different ages.     

The ontogeny of serial-order behavior in humans (Homo sapiens): representation of a list

The authors trained 3-, 4-, 7-, and 10-year-old children and adults (Homo sapiens) on a nonverbal serial-order task to respond to 5 items in a specific order. Knowledge of each item's sequential position was then examined using pairwise and triplet tests. Adults and 7- and 10-year-olds performed at high levels on both tests, whereas 3- and 4-year-olds did not. The latency to respond to the first item of a test pair or triplet was linearly related to that item's position in the training series for the 7- and 10-year-olds and adults, but not for the 3- and 4-year-olds. These data suggest that older children and adults, but not younger children, developed a well-integrated internal representation of the serial list.     

More than superstition: differential effects of featural heterogeneity and change on subitizing and counting

This study investigates the effects of item heterogeneity (differences in color and shape) and moment-to-moment feature change as it relates to the issue of whether subitizing and counting involve different processes. Participants enumerated displays of up to eight items that were either homogeneous or heterogeneous. In situations where the heterogeneous displays always had approximately half of the items of one type and half of the other, heterogeneity significantly sped enumeration in the counting range (6-8 items) and significantly slowed enumeration in the subitizing range (1-3 items), a dissociation that suggests that subitizing and counting involve different operations. Moment-to-moment feature change had no effect on subitizing. However, feature change slowed counting, but only when participants were enumerating heterogeneous items that were half of one type and half of the other, as might be expected if participants were using differences in features to select items by type.     

Prioritization within visual working memory reflects a flexible focus of attention

When motivated, people can keep nonrecent items in a list active during the presentation of new items, facilitating fast and accurate recall of the earlier items. It has been proposed that this occurs by flexibly orienting attention to a single prioritized list item, thus increasing the amount of attention-based maintenance directed toward this item at the expense of other items. This is manipulated experimentally by associating a single distinct feature with a higher reward value, such as a single red item in a list of black items. These findings may be more parsimoniously explained under a distinctiveness of encoding framework rather than a flexible attention allocation framework. The retrieval advantage for the prioritized list position may be because the incongruent feature stands out in the list perceptually and causes it to become better encoded. Across three visual working memory experiments, we contrast a flexible attention theory against a distinctiveness of encoding theory by manipulating the reward value associated with the incongruent feature. Findings from all three experiments show strong support in favor of the flexible attention theory and no support for the distinctiveness of encoding theory. We also evaluate and find no evidence that strategy use, motivation, or tiredness/fatigue associated with reward value can adequately explain flexible prioritization of attention. Flexible attentional prioritization effects may be best understood under the context of an online attentional refreshing mechanism.