Spatial tapping interferes with the processing of linguistic spatial relations.

Simple spatial relations may be represented either in a propositional format that is dependent on verbal rehearsal or in a picture-like format that is maintained by visual-spatial rehearsal. In sentence-picture and picture-picture verification tasks, we examined the effect of an articulatory suppression and a spatial tapping dual task on the encoding of simple spatial relations (e.g., triangle left of circle). Articulatory suppression did not interfere, while spatial tapping lowered performance in both tasks. Apparently, both linguistic and perceptual inputs of simple spatial relations engaged the visual-spatial working memory. In the sentence-picture verification experiments, spatial tapping only hampered performance of participants who were classified on the basis of their RT patterns as having used a visual-spatial strategy, while it had no effect for those who were classified as having applied a verbal strategy. Therefore, this study provides converging evidence, using a dual-task methodology, that both separate verbal and visual-spatial strategies exist for the processing of simple spatial sentences.     

Reasoning strategies: the role of working memory and verbal-spatial ability

Evidence increasingly suggests individual differences in strategies adopted on reasoning tasks and that these are either verbal-propositional or visuospatial in nature. However, the cognitive foundations of these strategies remain uncertain. Experiment 1 examined the relationship between the use of working memory resources and strategy selection for syllogistic reasoning. Verbal and spatial strategy users did not differ on working memory capacity, but confirmatory factor analysis indicated that while verbal reasoners draw primarily on verbal working memory, spatial reasoners use both this and spatial resources. Experiment 2 investigated the relationship between strategies and verbal and spatial abilities. Although strategy groups were similar in overall ability, regression analysis showed that performance on a spatial ability measure (Vandenberg mental rotation task) predicted syllogistic reasoning performance, but only for spatial strategy users. The findings provide converging evidence that verbal and spatial strategies are underpinned by related differences in fundamental cognitive factors, drawing differentially on the subcomponents of working memory and on spatial ability.     

Strategic and automatic components in the processing of linguistic spatial relations

The objective of the present study was to determine the extent to which strategies influence the representational format of a linguistic spatial relation. The propositional model assumes that a sentence describing a spatial relation is always represented as a set of propositions, whereas the strategic model claims that a spatial sentence can be represented either as a set of propositions or as a mental image, depending on the strategy (verbal or visual-spatial) an individual follows. Participants read a sentence (spatial or non-spatial) followed by a picture or sentence, which did or did not exemplify the information of the first sentence. In order to examine the involvement of strategic and automatic components the probability (20% or 80%) of the nature (sentence or picture) of the second stimulus was varied. Participants had slower verification RTs for unexpected stimuli than for expected stimuli, but this cost was significantly larger for an unexpected picture than an unexpected sentence. Furthermore, this asymmetric cost for the unexpected visual-spatial stimulus only occurred with spatial sentences and not with non-spatial sentences. Surprisingly, these data do not support a strictly propositional or a strategic model. Instead, we propose a third option: a dual representational model, in which people automatically represent the spatial sentence propositionally. In addition, depending on the context, a pictorial strategy is employed, which results in a supplementary visual-spatial representation.     

Position Location on Topographical Maps: Effects of Task Factors,Training, and Strategies

There is little research on the ways people go about the very common task of extracting information from various forms of maps. In this study, we examined task factors, cognitive processes, and individual differences as determinants of performance differences when locating a position on a topographical map from a given position on the ground. Subjects for the study were 188 Australian Army personnel. Both spatial visualization ability and a visual learning style preference were found to be effective predictors of performance, whereas a form of verbal strategy training produced significantly improved performance. When no effective strategy was supplied, those subjects with a strong visual learning style preference performed dramatically better than their low-preference counterparts, suggesting that this form of processing preference may have a powerful impact on untrained performance. These results indicate that most subjects usually approach the task of map reading in a relatively passive way, without any coherent strategy, and then attempt to encode information using inefficient spatial codes. When a simple and effective verbal strategy was supplied, most subjects were able to adopt it, with uniformly beneficial, results. This suggests that performance on many spatial tasks could be improved by verbal strategy training.     

The Neural Bases of Strategy and Skill in Sentence–Picture Verification

This experiment used functional Magnetic Resonance Imaging to examine the relation between individual differences in cognitive skill and the amount of cortical activation engendered by two strategies (linguistic vs. visual–spatial) in a sentence–picture verification task. The verbal strategy produced more activation in language-related cortical regions (e.g., Broca's area), whereas the visual–spatial strategy produced more activation in regions that have been implicated in visual–spatial reasoning (e.g., parietal cortex). These relations were also modulated by individual differences in cognitive skill: Individuals with better verbal skills (as measured by the reading span test) had less activation in Broca's area when they used the verbal strategy. Similarly, individuals with better visual–spatial skills (as measured by the Vandenberg, 1971, mental rotation test) had less activation in the left parietal cortex when they used the visual-spatial strategy. These results indicate that language and visual–spatial processing are supported by partially separable networks of cortical regions and suggests one basis for strategy selection: the minimization of cognitive workload.     

Verbal deficits in children with 47, XXY and 47, XXX karyotypes: A descriptive and experimental study

This study examines the intellectual abilities of children with a supernumerary X chromosome complement. In the first part, 33 boys and 13 girls, who were ascertained through a neonatal screening project, were given a WISC-R. Comparisons with siblings revealed a significant deficit in the verbal ability of the extra X children while their nonverbal skills were normal. The second part investigated the specific verbal impairments of these children with a sentence verification task. The results of comparisons with normal children indicated poorer performance by the supernumerary X groups, particularly on the more difficult task items. Correlations between measures indicated that verbal IQ was more strongly related to sentence verification performance than performance IQ. The final section deals with some of the biological factors that may contribute to the verbal deficits in these children. The results indicate that the most verbally impaired children were those with the greatest delays in physical growth, as indicated by bone age and dermatoglyphic measures. These findings are discussed in terms of the influence of chromosomally determined growth rates upon the brain, its maturity, and consequent capacity to develop specific cognitive functions.     

Why does working memory span predict complex cognition? Testing the strategy affordance hypothesis

We introduce and empirically evaluate the strategy affordance hypothesis, which holds that individual differences in strategy use will mediate the relationship between performances on a working memory (WM) span task and another cognitive task only when the same strategies are afforded by both tasks. One hundred forty-eight participants completed basic memory tasks and verbal span tasks that afford the same strategies, such as imagery and sentence generation, and completed reading comprehension tasks that afford different ones, such as self-questioning and summarization. Effective strategy use on WM span tasks accounted for variance in the span-memory relationship, but not for the span-comprehension relationship, supporting the strategy affordance hypothesis. Strategy use mediated the span-cognition relationship only when both tasks afforded the same strategies.     

The activation of representative emotional verbal contexts interacts with vertical spatial axis

Several experimental studies have shown that there exists an association between emotion words and the vertical spatial axis. However, the specific conditions under which this conceptual–physical interaction emerges are still unknown, and no study has been devised to test whether longer linguistic units than words can lead to a mapping of emotions on vertical space. In Experiment 1, Spanish and Colombian participants performed a representative verbal emotional contexts production task (RVEC task) requiring participants to produce RVEC for the emotions of joy, sadness, surprise, anger, fear, and disgust. The results showed gender and cultural differences regarding the average number of RVEC produced. The most representative contexts of joy and sadness obtained in Experiment 1 were used in Experiment 2 in a novel spatial–emotional congruency verification task (SECV task). After reading a sentence, the participants had to judge whether a probe word, displayed in either a high or low position on the screen, was congruent or incongruent with the previous sentence. The question was whether the emotion induced by the sentence could modulate the responses to the probes as a function of their position in a vertical axis by means of a metaphorical conceptual–spatial association. Overall, the results indicate that a mapping of emotions on vertical space can occur for linguistic units larger than words, but only when the task demands an explicit affective evaluation of the target.     

Gender differences in advanced mathematical problem solving

Strategy flexibility in mathematical problem solving was investigated. In Studies 1 and 2, high school juniors and seniors solved Scholastic Assessment Test-Mathematics (SAT-M) problems classified as conventional or unconventional. Algorithmic solution strategies were students' default choice for both types of problems across conditions that manipulated item format and solution time. Use of intuitive strategies on unconventional problems was evident only for high-ability students. Male students were more likely than female students to successfully match strategies to problem characteristics. In Study 3, a revised taxonomy of problems based on cognitive solution demands was predictive of gender differences on Graduate Record Examination-Quantitative (GRE-Q) items. Men outperformed women overall, but the difference was greater on items requiring spatial skills, shortcuts, or multiple solution paths than on problems requiring verbal skills or mastery of classroom-based content. Results suggest that strategy flexibility is a source of gender differences in mathematical ability assessed by SAT-M and GRE-Q problem solving.     

Executive function and children's understanding of false belief: how specific is the relation?

The present study examined developmental relations among understanding false belief, understanding “false” photographs, performance on the Dimensional Change Card Sort (DCCS), and performance on a picture–sentence verification task in 69 3–5-year-old children. Results showed that performance on the DCCS predicted performance on false belief questions even after controlling for children's age and verbal ability. However, neither performance on the picture–sentence verification task, nor performance on the “false” photograph task predicted false belief understanding. Implications of these findings are discussed in the context of suggestions that understanding false belief reflects a general understanding of representation, propositional negation, and the ability to use higher order rules.     

Flexibility of working memory encoding in a sentence–picture–sound verification task

Dual-process accounts of working memory have suggested distinct encoding processes for verbal and visual information in working memory, but encoding for nonspeech sounds (e.g., tones) is not well understood. This experiment modified the sentence–picture verification task to include nonspeech sounds with a complete factorial examination of all possible stimulus pairings. Participants studied simple stimuli–pictures, sentences, or sounds–and encoded the stimuli verbally, as visual images, or as auditory images. Participants then compared their encoded representations to verification stimuli–again pictures, sentences, or sounds–in a two-choice reaction time task. With some caveats, the encoding strategy appeared to be as important or more important than the external format of the initial stimulus in determining the speed of verification decisions. Findings suggested that: (1) auditory imagery may be distinct from verbal and visuospatial processing in working memory; (2) visual perception but not visual imagery may automatically activate concurrent verbal codes; and (3) the effects of hearing a sound may linger for some time despite recoding in working memory. We discuss the role of auditory imagery in dual-process theories of working memory.     

Optimal learning strategies and their spontaneous use: The importance of task-appropriate processing

College students were given three verbal learning tasks to perform, with some subjects instructed to use a particular verbal or imaginal encoding strategy for all three tasks and other subjects not instructed to use any particular strategy. It was found that the relative effectiveness of the assigned encoding strategies varied as a function of the learning task. In addition, “uninstructed” subjects, for the most part, spontaneously employed strategies that produced recall comparable to that observed for subjects assigned the most effective strategy for a particular learning task. In Experiment 2, subjects were instructed to perform a different encoding strategy for each learning task. Subjects who were assigned the strategies in a “task-appropriate” fashion recalled more, in general, than subjects who were assigned the same strategies paired with the learning tasks in a haphazard fashion. Subjects not instructed to use a particular strategy again demonstrated relatively high recall and were found to vary processing across learning tasks. It was concluded that optimal learning for a range of tasks can require deployment of several semantic/elaborative strategies in a task-appropriate fashion. Furthermore, mature learners seem to spontaneously utilize semantic and imaginal strategies and do so task appropriately.     

Girls who use "masculine" problem-solving strategies on a spatial task: proposed genetic and environmental factors.

This study investigated strategy and performance differences between right-handed boys and girls on a mental rotation task. Based on predictions from Casey and Brabeck's (1990) theory of sex differences, the study was also designed to identify a target group of right-handed girls with the optimal combination of genetic and environmental factors (high math/science achievers with nonright-handed immediate relatives). They were predicted to show strategies and performance more similar to those of the boys than to those of both the low math/science achieving girls and the high math/science girls with all right-handed immediate relatives (predicted to have the nonoptimal genotype). Strategy preference was measured using selective interference, whereby subjects solved mental rotation items concurrently with either verbal or visual-spatial interference tasks. Group comparisons were made on the amount of decrement in mental rotation performance as a result of the two types of interference tasks. This provided a basis for comparing the groups on the use of visual-spatial or verbal strategies on the mental rotation task. The boys: (1) did not show a significant advantage over the girls on the mental rotation items, but (2) did depend more on visual-spatial strategies than the girls, and (3) depended less on verbal strategies than the girls. The target girls: (1) outperformed the low math/science achieving girls on the mental rotation items and did not show a significant advantage over the other high math/science group, (2) depended more on visual-spatial strategies than both the other two groups of girls, and (3) depended less on verbal strategies than the low math/science girls, while showing no significant difference compared to the nonoptimal high math/science girls. Examining within-group differences, the boys preferred visual-spatial strategies, while the girls in both the nontarget groups preferred verbal ones. However, for the target girls, no within-subject strategy differences were found. The present findings support the theory that, like the boys, the target girls depend more on visual-spatial strategies than do other girls. It is possible that the target girls use a combination of visual-spatial and verbal strategies when solving mental rotation tasks.     

Visuospatial working memory and mental representation of spatial descriptions

The purpose of the present research is to investigate whether different components of working memory (WM) are involved in processing spatial and nonspatial texts. The interference effects of two concurrent tasks on comprehension and recall of two kinds of text were investigated in two experiments. Each participant listened to a spatial and a nonspatial text, with one of two concurrent tasks: articulatory suppression or spatial tapping. The dependent variables in Experiment 1 were accuracy of recall and verification of information inferred from the texts. In Experiment 2 response times in the verification task were also considered. Results support the hypothesis that verbal and spatial components of working memory are differentially involved in the comprehension and memory of spatial and nonspatial texts, with a selective interference effect of the spatial concurrent task on the spatial text and an interference effect of the verbal concurrent task on both the spatial and nonspatial texts. These effects emerged for recall, sentence verification, and response times. Our findings confirm previous results showing that the verbal component of working memory is involved in the process of text comprehension and memory. In addition, they show that visuospatial working memory is involved, in so far as the text conveys visuospatial information.     

Presentation format and its effect on working memory

In three experiments, we examined the separate cognitive demands of processing and storage in working memory and looked at how effective the coordination was when items for storage varied in format/modality. A sentence verification task involving arithmetic facts was combined with a span task involving two to six items presented in picture, printed word, or spoken word format. The first two experiments were the same, except for the added requirement of articulation of the math sentence in Experiment 2. Experiment 3 varied the length of the span item and compared recall with recognition performance. The results showed that both spoken words and picture produced superior recall and recognition, as compared with printed words, and are consistent with Baddeley and Logie's (1999) and Mayer's (2001) models of working memory. Also, the differences in processing performance across spans varied with the difficulty of the task but showed the strongest support for the resource allocation model (Foos 1995).     

Strategy choice for arithmetic verification: effects of numerical surface form

Canadian university students (n=48) solved simple addition problems in a true/false verification task with equations in digit format (3+4=8) or written English format (three+four=eight). Participants reported their solution strategy (e.g. retrieval or calculation) after each trial. Reported use of calculation strategies was much greater with word (41%) than digit stimuli (26%), and this difference was exaggerated for numerically larger problems. Word-format costs on reaction time (RT) were correspondingly greater for large than for small problems, but this Format×Size RT effect was bigger for true than for false equations. The results demonstrate that surface format affects central, rather than only peripheral, stages of cognitive arithmetic.     

The Measurement of Verbal Working Memory Capacity and Its Relation to Reading Comprehension

Ninety-four subjects were tested on the Daneman and Carpenter (1980) reading span task, four versions of a related sentence span task in which reaction times and accuracy on sentence processing were measured along with sentence-final word recall, two number generation tasks designed to test working memory, digit span, and two shape-generation tasks designed to measure visual-spatial working memory. Forty-four subjects were retested on a subset of these measures at a 3-month interval. All subjects were tested on standard vocabulary and reading tests. Correlational analyses showed better internal consistency and test-retest reliability of the sentence span tasks than of the Daneman-Carpenter reading span task. Factor analysis showed no factor that could be related to a central verbal working memory; rotated factors suggested groupings of tests into factors that correspond to digitrelated tasks, spatial tasks, sentence processing in sentence span tasks, and recall in sentence span tasks. Correlational analyses and regression analyses showed that the sentence processing component of the sentence span tasks was the best predictor of performance on the reading test, with a small independent contribution of the recall component. The results suggest that sentence span tasks are unreliable unless measurements are made of both their sentence processing and recall components, and that the predictive value of these tasks for reading comprehension abilities lies in the overlap of operations rather than in limitations in verbal working memory that apply to both.     

The neural bases of strategy and skill in sentence-picture verification

This experiment used functional Magnetic Resonance Imaging to examine the relation between individual differences in cognitive skill and the amount of cortical activation engendered by two strategies (linguistic vs. visual-spatial) in a sentence-picture verification task. The verbal strategy produced more activation in language-related cortical regions (e.g., Broca's area), whereas the visual-spatial strategy produced more activation in regions that have been implicated in visual-spatial reasoning (e.g., parietal cortex). These relations were also modulated by individual differences in cognitive skill: Individuals with better verbal skills (as measured by the reading span test) had less activation in Broca's area when they used the verbal strategy. Similarly, individuals with better visual-spatial skills (as measured by the Vandenberg, 1971, mental rotation test) had less activation in the left parietal cortex when they used the visual-spatial strategy. These results indicate that language and visual-spatial processing are supported by partially separable networks of cortical regions and suggests one basis for strategy selection: the minimization of cognitive workload.