Domains Of Human Cognition Research Articles

Effects of X-ray radiation on complex visual discrimination learning and social recognition memory in rats.

The present report describes an animal model for examining the effects of radiation on a range of neurocognitive functions in rodents that are similar to a number of basic human cognitive functions. Fourteen male Long-Evans rats were trained to perform an automated intra-dimensional set shifting task that consisted of their learning a basic discrimination between two stimulus shapes followed by more complex discrimination stages (e.g., a discrimination reversal, a compound discrimination, a compound reversal, a new shape discrimination, and an intra-dimensional stimulus discrimination reversal). One group of rats was exposed to head-only X-ray radiation (2.3 Gy at a dose rate of 1.9 Gy/min), while a second group received a sham-radiation exposure using the same anesthesia protocol. The irradiated group responded less, had elevated numbers of omitted trials, increased errors, and greater response latencies compared to the sham-irradiated control group. Additionally, social odor recognition memory was tested after radiation exposure by assessing the degree to which rats explored wooden beads impregnated with either their own odors or with the odors of novel, unfamiliar rats; however, no significant effects of radiation on social odor recognition memory were observed. These data suggest that rodent tasks assessing higher-level human cognitive domains are useful in examining the effects of radiation on the CNS, and may be applicable in approximating CNS risks from radiation exposure in clinical populations receiving whole brain irradiation.

Binding of intrinsic and extrinsic features in working memory.

There is ongoing debate concerning the mechanisms of feature binding in working memory. In particular, there is controversy regarding the extent to which these binding processes are automatic. The present article demonstrates that binding mechanisms differ depending on whether the to-be-integrated features are perceived as forming a coherent object. We presented a series of experiments that investigated the binding of color and shape, whereby color was either an intrinsic feature of the shape or an extrinsic feature of the shape's background. Results show that intrinsic color affected shape recognition, even when it was incidentally studied and irrelevant for the recognition task. In contrast, extrinsic color did not affect shape recognition, even when the association of color and shape was encoded and retrievable on demand. This strongly suggests that binding of intrinsic intra-item information but not extrinsic contextual information is obligatory in visual working memory. We highlight links to perception as well as implicit and explicit long-term memory, which suggest that the intrinsic-extrinsic dimension is a principle relevant to multiple domains of human cognition.

Ideational fluency as a domain of human cognition.

Many disorders are characterized by impoverished ideational fluency. Tests of letter word, category word, and design fluency likely invoke different cognitive processes, but they might depend on overlapping cortical circuits. Despite differences in the tasks used to assess it, we hypothesized that ideational fluency represents a dissociable dimension of human cognition. Altogether, 317 healthy adults and 280 adults with medical or psychiatric illnesses completed a cognitive test battery that included three measures of ideational fluency. Principal component analyses assessed the factor loadings of these fluency measures along with 10 other cognitive test scores. A series of hierarchical multiple regressions determined the relative contribution of the other fluency measures to the fluency variable of interest after accounting for demographic factors and other cognitive abilities. In both participant groups all three measures of word and design fluency loaded on a single factor. An ideational fluency composite score was also normally distributed among healthy adults. After accounting for demographic characteristics, intelligence, processing speed, memory, and executive functioning, adding terms for letter- and category-cued word fluency improved multiple regression models predicting design fluency and vice versa. Despite differences among them, the three fluency measures emerged as clearly distinct from other cognitive abilities. Alternate fluency measures also accounted for significant incremental variability in both word and design fluency, even after accounting for other cognitive abilities. Thus, word and design fluency appear to involve a distinct and dissociable, material-independent dimension of cognitive processing, namely ideational fluency.

Number meaning and number grammar in English and Spanish

Grammatical agreement makes different demands on speakers of different languages. Being widespread in the languages of the world, the features of agreement systems offer valuable tests of how language affects deep-seated domains of human cognition and categorization. Number agreement is one such domain, with intriguing evidence that typological characteristics of number morphology are associated with differences in sensitivity to number distinctions. The evidence comes from research on language production that points to the morphological richness of languages as enhancing the expression of number distinctions. To critically test this hypothesis, native speakers of a sparse-morphology language (English) were compared with native speakers of a rich-morphology language (Spanish) in their use of semantically and grammatically motivated number agreement. With meaning-matched materials, speakers of both languages displayed significant variations in number agreement due to implicit nuances of number semantics, and the patterns and magnitudes of interaction with grammatical number were the same for both groups. In this important respect, speakers of English and Spanish appear to construe numerosity in similar ways, despite the substantial morphological and syntactic differences in their languages. The results challenge arguments that language variations can shape the apprehension of nonlinguistic number or promote differential expression of number meaning during the production of grammatical agreement.

A Study on the Semantics of Preposition Of: Based on Prototype Theory and Cognitive Categorization

Traditionally, with its inherent property as an unmarked grammatical entity, the preposition of has been classified as a category of function words. However, cognitive grammarians claim that the preposition of has its own meanings. From a cognitive-semantic perspective, this study aims to examine how the diverse and apparently different meanings of the preposition of are related in a cognitively-oriented way. In this study, it is proposed that based on the historical origin of of, the concept of 'separation' is considered as a prototypical meaning, since it is the most easily depictive and conceptualized in the spatial-physical domain of human cognition. As for the cognitive-semantic factors that categorize the multiple meanings of the preposition of, it is claimed that the semantic properties, such as the degree of prototypicality, concreteness, and lexicality, play a decisive role in determining the fuzziness in its meaning. Finally, it is suggested that a cognitive-semantic approach to the diverse meanings of the preposition of provides us with a relevant perspective to understand its multiple functions.

Are there representational shifts during category learning?

Early theories of categorization assumed that either rules, or prototypes, or exemplars were exclusively used to mentally represent categories of objects. More recently, hybrid theories of categorization have been proposed that variously combine these different forms of category representation. Our research addressed the question of whether there are representational shifts during category learning. We report a series of experiments that tracked how individual subjects generalized their acquired category knowledge to classifying new critical transfer items as a function of learning. Individual differences were observed in the generalization patterns exhibited by subjects, and those generalizations changed systematically with experience. Early in learning, subjects generalized on the basis of single diagnostic dimensions, consistent with the use of simple categorization rules. Later in learning, subjects generalized in a manner consistent with the use of similarity-based exemplar retrieval, attending to multiple stimulus dimensions. Theoretical modeling was used to formally corroborate these empirical observations by comparing fits of rule, prototype, and exemplar models to the observed categorization data. Although we provide strong evidence for shifts in the kind of information used to classify objects as a function of categorization experience, interpreting these results in terms of shifts in representational systems underlying perceptual categorization is a far thornier issue. We provide a discussion of the challenges of making claims about category representation, making reference to a wide body of literature suggesting different kinds of representational systems in perceptual categorization and related domains of human cognition.

Structural extensions of a hierarchical view on human cognitive abilities

During the 1990s, research within the Individual Differences Unit at the University of Sydney was oriented towards expanding knowledge of poorly understood domains of human cognition. Using the theory of fluid and crystallized intelligence (Gf/Gc) served as the overarching framework. This research has led to an improved understanding of the nature of complexity and the role of working memory in Gf. Another outcome has been the charting of factors underlying of mental speed, tactile/kinesthetic performance, and olfactory memory. Recently, there has been exploration of the “borderline area” between abilities and personality. Our work on self-confidence and self-monitoring of cognitive performance has demonstrated excellent measurement properties of scores based on confidence ratings. We have also established a clear separation of a broad self-confidence factor from traditional intelligence and personality factors. Our research in these borderline areas has also explored the status of emotional intelligence. Results from several studies raise questions regarding the measurement of this construct.

How far does a construction grammar approach to argument structure take us in understanding children's language development?

Tomasello's stimulating review of Goldberg's (1995) book, Constructions: a construction grammar approach to argument structure, raises several themes worthy of discussion. Tomasello suggests numerous reasons why functional and cognitive linguistic approaches in general, and Goldberg's approach in particular, are central to current work in child language. In my commentary I will summarize Tomasello's central claims about what he sees as significant about Goldberg's book, and I will raise the question of whether construction grammar – rather than any other cognitive or functional approach – is worth pursuing. While generally sympathetic to Goldberg's approach, I will discuss two issues that I think are worthy of further consideration in future research.Tomasello highlights three very important reasons why he believes Goldberg's approach makes a significant contribution to child language research. First, he states that construction grammar provides a way of understanding language development as a whole, and not just particular aspects of language development, such as core grammar. Second, Tomasello characterizes Goldberg's approach as noteworthy because it provides a way of relating language development to other domains of human cognition. A third advantage, Tomasello claims, is that construction grammar allows for the view of language development as protracted (e.g. not instantaneous), something Tomasello suggests fits well with his own research findings (see Tomasello, 1992).

What We Know About Spreadsheet Errors

Although some spreadsheets are small “scratch pad” applications, many are large and complex, and many missioncritical decisions depend on spreadsheet analyses. In recent years, we have learned a good deal about the errors that people make when they develop spreadsheets. In general, errors seem to occur in a few percent of all cells, meaning that for large spreadsheets, the issue is how many errors there are, not whether an error exists. These error rates, although troubling, are in line with error rates in programming and other human cognitive domains. In programming, we have learned to follow strict development disciplines to eliminate most errors. Surveys of spreadsheet developers indicate that spreadsheet creation, in contrast, is informal, and that few organizations have comprehensive policies for spreadsheet development. Although prescriptive articles have focused on such disciplines as modularization and having assumptions sections, these may be far less important than postdevelopment testing.Request access from your librarian to read this article's full text.

Intuition and information processing in mathematical activity

In the first part of the chapter, the basic characteristics of intuitive knowledge are outlined. Using examples from history and from experiments with children and adults, it is argued that at every level of mathematical reasoning, besides the formal and algorithmic aspects, the intuitive aspect must be considered. In the second part of the chapter, it is considered whether a formulation of information processing that encompasses intuitive cognition is possible. The conclusion is that if information processing is to cover the entire domain of human cognition, then it must span the intuitive as well as the logical aspects. Within such a formulation, the computer metaphor, which fails to capture the intuitive aspects of cognition, loses its central role, while still making an important contribution.

Chemicals, Exercise and Hyperactivity: A Short Report

PSYCHOACTIVE DRUGS have been shown to enhance children's short‐term performance on a number of cognitive and social interaction measures and there are encouraging indications that physical exertion can mimic these effects. Although the health benefits of aerobic exercise have been acknowledged for some time, other parameters of physical exertion are less well‐known, particularly in the domain of human cognition. The data presented, and briefly reviewed, are supportive of the hypothesis that physical activity can enhance problem‐solving performance and for so‐called hyperactive children, their ability to attend to the task at hand. Indeed, aerobic exercise may offer an alternative to traditional chemical treatments.