Do children profit from looking beyond looks? From similarity-based to cue abstraction processes in multiple-cue judgment.

The authors investigated the ability of 9- to 11-year-olds and of adults to use similarity-based and rule-based processes as a function of task characteristics in a task that can be considered either a categorization task or a multiple-cue judgment task, depending on the nature of the criterion (binary vs. continuous). Both children and adults relied on similarity-based processes in the categorization task. However, adults relied on cue abstraction in the multiple-cue judgment task, whereas the majority of children continued to rely on similarity-based processes. Reliance on cue abstraction resulted in better judgments for adults but not for children in the multiple-cue judgment task. This suggests that 9- to 11-year-olds may have defaulted to similarity-based processes because they were not able to employ a cue abstraction process efficiently. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A developmental study of children's ability to acquire knowledge of spelling patterns.

Studied morphological and orthographic spelling-pattern abstraction by administering 3 multiple-choice tests (one of nonsense words, one of real words, and a dictation test of nonsense words) to 20 good and 20 poor spellers at each grade level from 2 to 5. Results indicate that both groups showed developmental trends in pattern abstraction on all tests. Good spellers were about 2 yrs ahead of poor spellers in pattern acquisition. On the nonsense word tests good spellers performed better on orthographic than on morphological patterns while the reverse was true for poor spellers. Findings indicate that pattern abstraction occurs as part of spelling acquisition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differences in abstraction ability with age.

Three tests of abstraction were administered to 89 optimally healthy subjects aged 30–79. Performance on all 3 tasks showed significant differences with age. This was primarily, although not entirely, the result of deficits in performances by the 70-yr-old subjects. These results do not appear to be related to changes in memory ability or to a differential increase in a particular type of abstraction error. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Constraints on the abstraction of solutions.

Students in college algebra classes attempted to solve a series of three mixture problems and three distance problems and to match concepts between the first two problems in a series. The detailed comparison of two isomorphs did not result in the abstraction of a solution schema, as it was found to do by M. L. Gick and K. J. Holyoak (see record 1983-20819-001) for convergence problems. Attempts to promote abstraction by not allowing students to refer to a specific analogue (Experiment 2) and by providing information about corresponding concepts and principles (Experiment 3) were unsuccessful. These findings suggest that the bottom-up, similarity-based approaches encouraged by mapping concepts may need to be supplemented by top-down, principle-driven instruction. The abstraction of solutions is constrained by (1) the requirement to successfully compare two specific analogues (the bootstrapping constraint) and (2) the existence of superordinate concepts to describe the abstraction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Factor structure of the Wechsler Memory Scale—Revised within a comprehensive neuropsychological battery.

Performed 2 principal factor analyses to examine the construct validity of the Wechsler Memory Scale—Revised (WMS—R) and to determine whether abstraction and memory factors can be extracted from the Halstead-Reitan Neuropsychological Test Battery (HRNB) results. Results from 237 patients support the validity of the verbal memory, delayed recall, and attention and concentration indices of the WMS—R but not the visual memory indices. No separate abstraction factor was found, and none of the HRNB measures loaded substantially on the memory factors defined by WMS—R subtests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unexplained and explained natural deaths among persons above 1 year of age in a series of medico-legal autopsies

We investigated the association of neuropsychological risk indicators in a matched sample of first-degree relatives of schizophrenic patients (n = 54) and normal controls (n = 72). We focussed on three functions previously identified in a smaller, initial sample as putative risk indicators of the schizophrenia genotype: abstraction, verbal memory and auditory attention. The expanded sample of relatives displayed significantly lower scores than controls on abstraction, verbal memory and auditory attention. The relatives demonstrated significant intercorrelations among these three functions. The significant correlations among relatives between attention and verbal memory and between attention and abstraction differed significantly from these correlations among controls. We discuss how the use of multiple risk indicators may help us better identify those relatives that carry the schizophrenia genotype.     

Association, abstraction, and the conceptual organization of recall: Implications for clinical tests.

Recent discoveries about associative meaning were hypothesized to have important implications for the problem of assessment of abstraction by clinical tests. The major hypothesis was that association functions in abstraction tests by eliciting both (1) the concept required for the abstraction item, and (2) the associative neighborhood containing the required concept. A series of 4 experiments investigated this hypothesis for both the WAIS Similarities and BRL (Bolles, Rosen, and Landis) Object Sorting tests. In a 5th experiment, an abstraction test (the BRL) was administered as a memory task in order to investigate the role of association in the conceptual organization of recall. All experiments provided strong support for the major hypothesis and have implications for construction of abstraction tests of enhanced clinical sensitivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hydrogen atom abstraction of 3,5-disubstituted analogues of paracetamol by horseradish peroxidase and cytochrome P450

1. The formation of free radicals during enzyme catalysed oxidation of eight 3,5-disubstituted analogues of paracetamol (PAR) has been studied. A simple peroxidase system as well as cytochrome P450-containing systems were used. Radicals were detected by electron spin resonance (ESR) on incubation of PAR and 3,5-diCH3-, 3,5-diC2H5-, 3,5-ditC4H9-, 3,5-diOCH3-, 3,5-diSCH3-, 3,5-diF-, 3,5-diCl- and 3,5-diBr-substituted analogues of PAR with horseradish peroxidase in the presence of hydrogen peroxide (H2O2). Initial analysis of the observed ESR spectra revealed all radical species to be phenoxy radicals, based on the absence of dominant nitrogen hyperfine splittings. No radicals were detected in rat liver cytochrome P450-containing microsomal or reconstituted systems. 2. To rationalize the observed ESR spectra, hydrogen atom abstraction of PAR and four of the 3,5-disubstituted analogues (3,5-diCH3-, 3,5-diOCH3-, 3,5-diF- and 3,5-diCl-PAR) was calculated using ab initio calculations, and a singlet oxygen atom was used as the oxidizing species. The calculations indicated that for all compounds studied an initial hydrogen atom abstraction from the phenolic hydroxyl group is favoured by approximately 125 kJ/mol over an initial hydrogen atom abstraction from the acetylamino nitrogen atom, and that after hydrogen abstraction from the phenolic hydroxyl group, the unpaired electron remains predominantly localised at the phenoxy oxygen atom (+/-85%). 3. The experimental finding of phenoxy radicals in horseradish peroxidase/H2O2 incubations paralleled these theoretical findings. The failure to detect experimentally phenoxy radicals in cytochrome P450-catalysed oxidation of any of the eight 3,5-disubstituted PAR analogues is more likely due to the reducing effects that agents like NADPH and protein thiol groups have on phenoxy radicals rather than on the physical instability of the respective substrate radicals.     

Impairment of executive function induced by hypertension in the Rhesus monkey (Macaca mulatta).

The effects of chronic, untreated hypertension on executive function were investigated in a nonhuman primate model of hypertensive cerebrovascular disease. Executive function was assessed with the Conceptual Set-Shifting Task (CSST), a task adapted from the human Wisconsin Card Sorting Test (WCST). Like the WCST, the CSST requires abstraction of a stimulus set, followed by a series of set shifts. Performance on the CSST by 7 young adult monkeys (Macaca mulatta) with surgically induced hypertension was compared with that of 6 normotensive monkeys. The hypertensive group was significantly impaired relative to the normotensive group in abstraction and set shifting. Although the neural basis of this impairment is unclear, evidence from studies with humans and monkeys suggests that the prefrontal cortex may be the locus for this effect of hypertension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thirty-day mortality and long-term survival following surgery for prosthetic endocarditis: a study from the UK heart valve registry

Age of onset of schizophrenia (AOS) may be largely determined by neurobiological factors. We examined in a diverse sample of schizophrenia out-patients the relationships of AOS with neuropsychological abilities and structural brain abnormalities as measured on cerebral magnetic resonance imaging (MRI). A total of 82 out-patients meeting DSM-III-R criteria for schizophrenia were evaluated with a comprehensive neuropsychological battery and semi-automated quantitatively analysed cerebral MRI. Earlier AOS correlated with poorer performance in learning and abstraction/cognitive flexibility, and with larger volumes of caudate and lenticular nuclei, and smaller volume of thalamus on MRI. A model for predicting AOS consisting of abstraction and thalamic and caudate volumes remained significant after controlling for duration of illness, current age and daily neuroleptic dose. In conclusion, AOS may be related to specific rather than general measures of cognitive performance and structural brain abnormalities.     

How do we communicate stereotypes? Linguistic bases and inferential consequences.

The linguistic expectancy bias is defined as the tendency to describe expectancy-consistent information at a higher level of abstraction than expectancy-inconsistent information. The communicative consequences of this bias were examined in 3 experiments. Analyses of judgments that recipients made on the basis of linguistically biased information generated by transmitters indicated that behavior in expectancy-consistent messages was attributed more to dispositional and less to situational factors than behavior in expectancy-inconsistent messages. Moreover, this effect was mediated by the level of linguistic abstraction of the messages. These findings provide direct evidence for the hypothesis that recipients are sensitive to variations in linguistic abstraction in spontaneous language use because of stereotypes. Results are discussed with respect to the interpersonal aspects of stereotyping. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Levels of Abstraction in Orangutan (Pongo abelii) Categorization.

Levels of abstraction have rarely been manipulated in studies of natural concept formation in nonhumans. Isolated examples have indicated that animals, relative to humans, may learn concepts at varying levels of abstraction with differential ease. The ability of 6 orangutans (Pongo abelii) of various ages to make natural concept discriminations at 3 levels of abstraction was therefore investigated. The orangutans were rewarded for selecting photos of orangutans instead of humans and other primates (concrete level), primates instead of other animals (intermediate level), and animals instead of nonanimals (abstract level) in a 2-choice touch screen procedure. The results suggest that, like a gorilla (Gorilla gorilla gorilla) tested previously (Vonk & MacDonald, 2002), orangutans can learn concepts at each level of abstraction, and unlike other nonhumans, most of these subjects rapidly learned the intermediate level discrimination. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cue abstraction and exemplar memory in categorization.

In this article, the authors compare 3 generic models of the cognitive processes in a categorization task. The cue abstraction model implies abstraction in training of explicit cue-criterion relations that are mentally integrated to form a judgment, the lexicographic heuristic uses only the most valid cue, and the exemplar-based model relies on retrieval of exemplars. The results from 2 experiments showed that, in lieu of the lexicographic heuristic, most participants spontaneously integrate cues. In contrast to single-system views, exemplar memory appeared to dominate when the feedback was poor, but when the feedback was rich enough to allow the participants to discern the task structure, it was exploited for abstraction of explicit cue-criterion relations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A simplified formula for measuring abstraction in writing.

Based on an analysis of the separate categories making up Flesch's count of "definite words," a formula for estimating abstraction in writing, derived in part from the Flesch abstraction formula, was devised. The multiple R between the Flesch formula score and the elements of the new formula is .82. Abstraction score ranges are given. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Go with the flow: How to master a nonlinear multiple-cue judgment task.

The authors examined the cognitive processes that participants use in linear and nonlinear multiple-cue judgment tasks, hypothesizing that people are unable to use explicit cue abstraction in a nonlinear task, instead turning to exemplar memory. Experiment 1 confirmed that people are unable to use cue abstraction in nonlinear tasks but failed to confirm the hypothesized, spontaneous shift to exemplar memory. Instead, the participants appeared to be trapped in persistent and futile attempts to abstract the cue-criterion relations. Only after being instructed to rely on exemplar memory in Experiment 2 did they master the nonlinear task. The results suggest that adaptive shifts of representation need not occur spontaneously and that analytical thought may sometimes harm performance in nonlinear tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The psychology of 1975: An extrapolation.

In 1975 "our motive in studying psychology will continue to be primarily the fact that we have cognitive needs… . The creativity excitement of today will be geometrically expanded… because even the creativity abstraction is itself an exciting abstraction." The "new realm of knowledge to which Freud above all, has led… . [and] the huge legacy of Ivan Pavlov and our Soviet colleagues" will be utilized. Outrageous hypotheses are desirable tools. Advances in 4 fields will "make major impacts upon psychology: genetics, neurophysiology, perception theory, and ecology… . It is perfectly plain that among all the behavioral sciences psychology is central." Major sections are: Prediction Models, Radar into the Future, The "Specious Present," Biological Vistas, Outrageous Hypotheses, and New Psychologies? (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual abstraction processes in young and old adults.

Three experiments with young adults (18–20 yrs) and old adults (64–77 yrs) examined the conceptual skills of the 2 age groups. Using the visual abstraction procedure of J. J. Franks and J. D. Bransford (see record 1972-02149-001) allowed the study of concept abstraction independent of problem-solving skills. In Exps I (16 Ss in each age group) and II (12 Ss each), young and old Ss did not differ in their ability to abstract central tendency information from a class of nonmeaningful stimuli. Both groups classified novel stimuli in terms of transformational distance from a central representation (or prototype) of these patterns. Both groups also abstracted information regarding relations into which attributes could enter, and discriminated between test patterns reflecting acceptable and unacceptable transformations. It is suggested that visual abstraction performance may reflect the encoding of frequency information, which is presumed to be an automatic process founded on innate structures and which remains stable with age. Exp III (14 Ss in each age group) found that older Ss experienced greater interference in acquisition when the new concept was based on a reorganization of attributes associated with an established conceptual structure. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fragmentary knowledge and the processing-specific control of structural sensitivity.

P. Perruchet (see record 1994-24296-001) suggested that "neither a specific-item retrieval process nor abstractive capacity" is required to explain J. R. Vokey and L. R. Brooks's (see record 1992-18658-001) results, which instead can be accounted for in terms of knowledge of item fragments. The literature contains 2 definitions of abstractive. Rejecting abstractive in the sense of nonliteral units requires rejecting the results of studies on changed-letter transfer, some of which do not need the control group Perruchet claims and thus stand, confirming nonliteral (relational) abstraction. However, the rejection of pooled across items abstraction even in the form of the proposed retrieval-time pooling is feasible, which was not previously appreciated. Perruchet's rejection of item retrieval ignores Vokey and Brooks's coding and retrieval variations. Coding and retrieval results cannot be ignored simply because they are nonstandard, however. Integrating this literature with known memory phenomena requires incorporating these processing factors, rather than assuming fixed, literal fragments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cellular and molecular mechanisms of radiation inhibition of restenosis. Part I: role of the macrophage and platelet-derived growth factor

BACKGROUND: Desflurane, enflurane and isoflurane can be degraded to carbon monoxide (CO) by carbon dioxide absorbents, whereas sevoflurane and halothane form negligible amounts of CO. Carbon monoxide formation is greater with drier absorbent, and with barium hydroxide, than with soda lime. The mechanism, role of absorbent composition and water, and anesthetic structures determining CO formation are unknown. This investigation examined sequential steps in anesthetic degradation to CO. METHODS: Carbon monoxide formation from anesthetics and desiccated barium hydroxide lime or soda lime was determined at equimole and equiMAC concentrations. Carbon monoxide formation from deuterium-substituted anesthetics was also quantified. Proton abstraction from anesthetics by strong base was determined by deuterium isotope exchange. A reactive chemical intermediate was trapped and identified by gas chromatography-mass spectrometry. The source of the oxygen in CO was identified by 18O incorporation. RESULTS: Desflurane,enflurane,andisoflurane(difluoromethylethyl ethers), but not sevoflurane (monofluoromethyl ether), methoxyflurane (methy-ethyl ether), or halothane (alkane) were degraded to CO. The amount of CO formed was desflurane > or = enflurane > isoflurane at equiMAC and enflurane > desflurane > isoflurane at equimole concentrations. Proton abstraction from the difluoromethoxy carbon was greater with potassium than with sodium hydroxide, but unmeasurable with barium hydroxide. Carbon monoxide formation was correlated (r = 0.95-1.00) with difluoromethoxy (enflurane > desflurane > isoflurane > or = methoxyflurane = sevoflurane = 0) but not ethyl carbon proton abstraction. Deuterium substitution on enflurane and desflurane diminished CO formation. Chemical trapping showed formation of a difluorocarbene intermediate from enflurane and desflurane. Incorporation of H2(18)O in barium hydroxide lime resulted in C18O formation from unlabeled enflurane and desflurane. CONCLUSIONS: A difluoromethoxy group is a structural requirement for haloether degradation to CO. Results are consistent with initial base-catalyzed difluoromethoxy proton abstraction (potassium > sodium hydroxide, thus greater CO formation with barium hydroxide lime vs. soda lime) forming a carbanion (reprotonated by water to regenerate the anesthetic, hence requirements for relatively dry absorbent), carbanion decomposition to a difluorocarbene, and subsequent difluorocarbene reaction to form CO.