Different Patterns Of Performance Research Articles

Daytime and nighttime differences in patterns of performance of primary angioplasty in the treatment of patients with acute myocardial infarction

Background Concern exists regarding the results of primary angioplasty for acute myocardial infarction when the procedure is performed during night hours. Methods and Results Between June 1994 and January 1997, 491 patients with acute myocardial infarction who underwent primary angioplasty procedures were consecutive registered in the Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) study. Three hundred seventy-eight patients (77%) were treated during the day and 113 (23%) at night. Baseline characteristics showed no major differences between the 2 groups. Prehospital delay time was 60 minutes shorter during the night (median value 180 minutes for day, 120 minutes for night, P = .005), and in-hospital time to treatment was 9 minutes longer (median value 85 minutes day, 94 minutes night, P = .037). Patients treated during the night more often received angiotensin-converting enzyme blockers (61.4% day, 76.1% night, P = .004) and the so-called optimal adjunctive therapy (54% day, 64.6% night, P = .045). There were no differences concerning clinical events between the 2 groups. Hospital mortality was 8.7% during the day and 5.3% during the night (univariate analysis P = .238; logistic regression P = .653). Conclusions In a clinical setting, primary angioplasty for acute myocardial infarction can be performed safely during the night with a clinically insignificant prolongation of in-hospital time to reperfusion compared with practice during the day. (Am Heart J 1999;138:1111-7.)

Cluster Subtypes in the Standardization Sample of the California Verbal Learning Test-Children's Version

Representative profile subtypes, based on 5 key z-score variables, were examined in the standardization sample of the California Verbal Learning Test-Children's Version (CVLT-C; Delis, Kramer, Kaplan, & Ober, 1994). Two-stage cluster analysis identified 5 reliable subtypes. Both level and pattern of performance differences contributed to differentiation of the subtypes. The clusters did not differ significantly in age, but educational background of the children and of their parents, as well as level of performance on an independent measure of problem solving (Children's Category Test; Boll, 1993), did covary directly with CVLT-C performance. Guidelines for determining the relative uniqueness of clinically obtained CVLT-C patterns are presented.

Dissociation of attentional processes in patients with focal frontal and posterior lesions

A location-based (‘select-what, respond-where’) priming task was used to examine three measures of selective attention (interference (INT), negative priming (NP), and inhibition of return (IOR)) as a function of focal brain pathology and the complexity of target selection. Control subjects showed different patterns of performance for the three attentional measures as a function of complexity, suggesting some independence among INT, NP, and IOR. Brain-damaged subjects showed significant response slowing, as well as a number of lesion-specific attentional abnormalities. Right frontal (including bifrontal) damage resulted in proportionally increased interference related to task complexity. Left posterior damage increased IOR in the most complex task, while left frontal damage reversed the control pattern of IOR as a function of complexity. Right hemisphere (right posterior and right frontal damage) pathology resulted in a virtual loss of negative priming at all levels of task complexity; left and bifrontal damage resulted in diminished NP only related to increases in the complexity of selection. INT, NP, and IOR are mediated by different brain regions and their expression can be modulated by the complexity of the selection task.

MRI temporal lobe volume measures and neuropsychologic function in Alzheimer's disease.

The authors performed quantitation of the temporal lobes using magnetic resonance imaging in 20 patients with mild-to-moderate Alzheimer's disease, 20 age-matched aged control subjects, and 26 healthy young volunteers. Compared to young subjects, aged controls showed volume reductions in amygdala (17%, p = 0.02), hippocampus (15%, p = 0.0001) and temporal lobe (22%, p = 0.0001). Compared to aged controls, Alzheimer's subjects showed further volume reductions in amygdala (33%, p = 0.0001) and hippocampus (20%, p = 0.006) but not temporal lobe (7%, p = 0.15). In Alzheimer's subjects, left temporal lobe volume correlated strongly with the Mini Mental State (MMSE) score (adjusted r2 = 0.46, p = 0.0006) whereas right amygdala volume correlated inversely with the noncognitive ADAS score (adjusted r2 = 0.46, p = 0.0006). The authors conclude that significant volume changes occur in the temporal lobe in aging and in Alzheimer's disease, with the greatest percentage reductions in the amygdala in Alzheimer's disease. Temporal neocortical atrophy and temporal limbic atrophy might be associated with different patterns of performance and behavior in Alzheimer's patients.

Cluster Subtypes in the Children's Category Test Standardization Sample

Representative profile subtypes, based on subtest error scores, were examined in the standardization sample of the Children's Category Test (CCT; Boll, 1993), with separate analyses for the younger subgroup (ages 5–8 years; CCT-1) and the older subgroup (ages 9–16 years; CCT-2). Two-stage cluster analysis identified three reliable subtypes for the CCT-1, and four reliable subtypes for the CCT-2. Both level and pattern of performance differences contributed to the differentiation of subtypes. The clusters that varied in level of performance differed significantly in age and in level of performance on an independent memory measure, but not in gender or educational background. The distinct patterns of CCT subtest performance exhibited by the other clusters could not be reduced to any of these variables, suggesting that such patterns reflect relatively unique variations in specific aspects of problem solving. Guidelines for the consideration of clinically obtained CCT error subtest profiles are provided.

Encoding–Retrieval Interactions in Mild Alzheimer's Disease: The Role of Access to Categorical Information

Normal old adults and patients in an early phase of Alzheimer's disease (AD) were presented with photographs of common objects under two different encoding conditions: naming and naming along with category decisions. Memory was assessed with free recall, category cued recall, and recognition. For both groups, recognition was superior to cued recall which was higher than that for free recall. Most importantly, cue utilization in AD was optimized in the naming + category decision condition, although the normal old showed equivalent gains from cues following both encoding conditions. These results suggest that AD patients require more cognitive support at encoding than normal old adults to make effective use of retrieval cues. Dementia-related deficits in processing categorical information spontaneously may underlie the observed group differences in patterns of performance.

Confabulation and the control of recollection.

It is argued that current models of memory do not adequately account for the confabulations that are found in the recall of certain neurological patients. A model of the relation between control processes and memory involved in recalling autobiographical episodes is put forward. It is based on detailed analysis of the protocols of healthy volunteers' autobiographical recollections of recent everyday events. It is held that damage to different components of the model fits with the different patterns of performance found in confabulators, and examples of the errors that confabulators make are discussed in terms of those made by normal subjects.

Information integration in cross-modal pattern recognition: An argument for acquired modularity

Three experiments addressed the issue of whether modularized operations (Fodor, 1983) in pattern recognition could be acquired. In Experiment 1, blind and sighted individuals were compared in the speech-tactile domain of pattern recognition. The results were inconsistent with the assumptions of the fuzzy logical model of perception (FLMP) (Oden and Massaro, 1978) and with the assumptions of modularized pattern recognition processes, but were consistent with the assumptions of ‘penetrability’ into non-modularized operations. Experiments 2 and 3 compared sighted individuals across speech-visual and speech-tactile domains, revealing fundamentally different patterns of performance that we argue demonstrate modularized and non-modularized FLMP operations in pattern recognition, respectively.

Letter and category fluency in Alzheimer's disease: a prognostic indicator of progression?

This study investigated differential patterns of performance by 40 Alzheimer's disease (AD) patients on standardised letter and category fluency tests. The performance of 24 age and education matched controls was used to classify patients as relatively more letter fluency impaired (L < C, n = 15) or more category fluency impaired (C < L, n = 25), and clinical features distinguishing these patient subgroups were investigated. Category performance was equally impaired in both patient subgroups, whereas the L < C subgroups were particularly impaired on letter fluency. The subgroups differed significantly in duration of illness (24 months for L < C group, 47 months for C < L group; t = 2.69, p = 0.01) but did not differ in global dementia severity, age, education, general language ability, or functional status. Data on annual rate of change (ARC) on the Mini-Mental State Examination were available for 26 patients. While not statistically significant, subgroup ARC differences were suggestive of more rapid decline in the L < C patients, consistent with the finding of shorter duration of illness in this group. Word fluency tests may have potential as early predictors of rate of progression in AD.

Walking through doorways: An analysis of navigation skills in patients with neglect

Abstract Neglect can cause problems in navigation in the environment, for instance because patients tend to bump into objects such as doorposts. The aim of this study was to analyse the extent to which neglect affected navigation skills. Nine stroke patients with adequate walking abilities, of whom five had visual neglect, were observed while they walked through an aperture. The width of the passage was varied, and in some trials a coloured strip was attached to either the left or the right side of the aperture in order to increase the salience of that side. Patients with neglect bumped into the sides of the aperture much more often than the patients without neglect or the controls (N = 18). The coloured cue had no effect on the number of collisions. The number of collisions correlated highly with paper and pencil tests of neglect. The results showed that there are differential patterns of performance. Three patients with mild neglect bumped into the left side, and two others with more severe neglect bumped predominantly into the right side. An important indicator of the coupling between perception and action is rotation of the shoulders while passing a narrow aperture. Although the patients were able to do so, they often failed to rotate their shoulders when this was required for a smooth passage, thus indicating an impairment at the level of perception-action coupling. This is even more interesting because patients were very well able to estimate the width of the aperture at the verbal level. The main findings are discussed in terms of contralateral attentional deficit and an ipsilateral release of “intentional” processes. Implications for future research are discussed.

Converging evidence for the interaction of semantic and sublexical phonological information in accessing lexical representations for spoken output

Abstract Detailed studies of naming, reading, and comprehension by three braindamaged patients are reported. The three subjects had different patterns of performance across lexical tasks, which are best explicated by proposing, for each case, separate loci of damage to one or more components of the lexical system. Nevertheless, all three patients showed better oral reading than would be expected on the basis of either their demonstrated abilities in lexical-semantic processing or their demonstrated abilities in sublexical orthography-to-phonology conversion. The disproportionately intact oral reading in each of these subjects can be explained either by proposing a nonsemantic “direct route” of reading and/or by proposing that at least partial semantic information interacts with at least partial sublexical phonological information to access lexico-phonological representations for output in the task of oral reading. Evidence favouring the latter hypothesis was provided by studies of the subjects' performance on a variety of tasks in which partial semantic information and/or partial or complete sublexical phonological information were presented to facilitate oral production. Also, further analyses of the patients' oral reading as a function of complete vs. incomplete vs. abolished comprehension of printed words, and as a function of orthographic regularity, were consistent with specific predictions that follow from the hypothesis that (even partial) semantic information and (even partial) sublexical phonological information interact to access lexicophonological representations for output.

Do differences in visuospatial ability between senile dementias of the alzheimer and lewy body types reflect differences solely in mnemonic function?

Visuospatial memory was investigated in two groups of patients suffering from senile dementias of the Alzheimer (SDAT) or Lewy body (SDLT) types; a, third, age-matched, healthy control group was also included. The two patient groups were mildly demented and could not be distinguished from each other by traditional tests of cognitive function. A different pattern of performance emerged in the two groups on a computerised test of spatial working memory, which is a self-ordered pointing task requiring the subject to search for hidden tokens. An analysis of the pattern of errors revealed that the SDLT group made more of both possible types of error ("Within Search" and "Between Search") than the SDAT group. Neither patient groups' performance differed from each other when assessed on a computerised Corsi spatial span task. A measure of planning ability was obtained by examining search strategies. Although an index previously developed to measure the subject's use of a particular strategy in the spatial working memory task failed to detect any differences between the three groups, a novel index was calculated which focuses on performance within a search, and this revealed deficits in both demented groups. Since the two patient groups differed from each other in the spatial working memory, but not the Corsi spatial span, task, it is suggested that the differences between the two demented groups are not due to a specific mnemonic impairment, but reflect dysfunctions in non-mnemonic processes mediated by fronto-subcortical circuits, which are more severely damaged in SDLT.

Developmental Dyslexia: Contrasting Patterns of Performance on a Diagnostic Psycholinguistic Assessment

Models of the stages by which the acquisition of reading skills normally proceeds have been proposed by Frith (1985) and Seymour (1987). Based on these developmental models, a battery of psycholinguistic tests appropriate for English-speaking South African children was devised to identify the processing strategies which a child has and has not acquired. The procedure yields both qualitative and quantitative information and allows comparison of dyslexic children with average readers of similar Reading Age. Two cases of developmental dyslexia are discussed to illustrate different patterns of performance on the assessment. These patterns of performance are interpreted in the context of current models of the development of reading skills.

Amino acid composition of phloem sap and the relation to intraspecific variation in pea aphid ( Acyrthosiphon pisum) performance

The performance of five clones of the pea aphid, Acyrthosiphon pisum, was evaluated on red clover, Trifolium pratense, alfalfa, Medicago sativa, broad bean, Vicia faba and five genotypes of pea, Pisum sativum. Phloem sap samples were collected from excised aphid stylets on plants of each species and analysed for amino acids. The pea aphid clones displayed large differences in performance patterns on the plant species, but more uniform patterns on the pea genotypes. Performance patterns of the aphid clones were related to the host plant species from which they had been collected originally. The total concentration of amino acids varied considerably between phloem samples, but there were no significant differences in the means between plant species or pea genotypes. Plant species differed distinctly in their amino acid composition, whereas pea genotypes did not. Several of the amino acids were present in similar compositions in all plant species and pea genotypes. The total concentration of amino acids in the phloem sap could not explain the differences in the performance of pea aphid clones on pea genotypes. However, differences in the performance of two out of five of the pea aphid clones could be explained by a part of the amino acid composition.

Verbal learning patterns in moderate and severe traumatic. brain injury

Previous studies that have examined performances on the California Verbal Learning Test (CVLT) among individuals with traumatic brain injury (TBI) have found differing levels of performance. Differential patterns of performance, however, have only been inferred. The present investigation sought to determine empirically if differential patterns of performance could be discerned in a TBI sample of 65 subjects with CVLT variables. The CVLT variables were selected based on the instrument's factor structure. Cluster analysis yielded four distinct subtypes of brain-injured individuals. The Active subtype demonstrated impaired unassisted retrieval, but used active encoding strategies and showed relatively intact ability to store novel information. The Disorganized subtype demonstrated an inconsistent, haphazard learning style along with deficits in encoding. The Passive subtype was marked by an overreliance on a serial clustering strategy as well as impaired encoding and/or consolidation. The Deficient subtype was the most impaired of all groups, exhibiting a slowed rate of acquisition, passive learning style, and significant impairment in encoding. Implications for rehabilitation are discussed.

Memory champions

The seven contestants at the first World Memory Championships and three other subjects showing outstanding memory performance were administered a battery of memory tasks used in previous studies of superior memory performance. Evidence for both all‐round and more specific patterns of superior performance was found. The role of mnemonic techniques in relation to different types of task is discussed but evidence was also found for ‘natural’ superior memory, indicated by superior performance without the use of techniques, good incidental long‐term retention, and reported superior memory ability in close relatives. An attempt to distinguish ‘natural’ from strategic memorizers was explored, based on these criteria and on differential patterns of performance on tasks suited and unsuited to the application of mnemonic techniques.

The response of low-input agricultural systems to environmental variability. A theoretical approach

The aims of this paper are: (a) to analyze the response of low-input agricultural systems to environmental variability; and (b) to suggest a theoretical framework to explain such behavior. Available evidence suggests that low-input systems are, in general, more sensitive than high-input systems to changes in the climatic environment. However, on the one hand this is not necessarily the case with respect to the economic environment, but, on the other hand, low-input systems of any region can differ in their response to similar environmental changes. Thus, when different levels of productivity and degrees of environmental sensitivity are combined, different patterns of performance can arise. A theoretical approach is presented in which the variations in system performance are related to system structure. It is suggested that a key feature is the degree of linkage between the system components. The ‘articulation hypothesis’ proposed here associates different patterns of articulation among essential components of the system with its performance. It is argued that, sensitivity in systems shows a negative relationship with the degree of internal articulations among different farming activities. The hypothesis also suggests that, the higher the internal articulation, the higher the maintenance cost, and hence, the lower the productivity of the system. Articulation appears to be a powerful risk-dissipative structural feature, reducing sensitivity at the price of lower productivity. In principle, the hypothesis could be successfully tested in marginal environments, but not in non-limiting or very extreme conditions.

Verbal working memory and sentence comprehension: A multiple-components view.

Semantic and syntactic aspects of sentence comprehension were investigated for 3 patients who showed different patterns of performance on short-term memory tasks. On a sentence anomaly judgment task assessing the retention of semantic information, only patient A.B. showed a detrimental effect on comprehension with increases in the number of words to be held in an unintegrated fashion. On judgments of grammatical acceptability, only patient M.W. demonstrated a detrimental effect of increasing the number of words intervening between the words signaling that a sentence was ungrammatical. The results suggest that semantic and syntactic components must be postulated in addition to the phonological and articulatory components of A. D. Baddeley's (1986, 1990) working memory model. Although the phonological, semantic, and syntactic components may be differentiall y affected by brain damage, the components interact and support each other in normal comprehension. The working memory model initially proposed by Baddeley and Hitch (1974) has played an important role in neuropsychological studies of brain-damaged patients with language disorders. The essential insight of their model was that working memory should not be seen as a unitary store, but rather as consisting of different components with separate storage capacities. It differed in this respect from the so-called modal model of memory (Murdock, 1974), which posited a single store in which information of all types was maintained prior to transfer to long-term memory (e.g., Atkinson & Shiffrin, 1968; Waugh & Norman, 1965). Baddeley and Hitch's now well-known model separated a central executive component of working memory from peripheral storage devices dedicated to the maintenance of different types of information. The central executive was seen as an attention-controlling system with storage space of its own, which directed the processes involved in cognitive functions and which drew on the information stored in the peripheral stores. The peripheral storage devices included a phonemically based rehearsal buffer, currently termed the phonological loop, and a visual buffer, currently termed the visuospatial sketchpad (Baddeley, 1986, 1990). The phonological loop itself may be broken down into two components, a phonological storage component and an articulatory rehearsal component (Salame & Baddeley, 1982; Vallar & Baddeley, 1984a).

Reasoning with three Types of Conditional: Biases and Mental Models

Two experiments are reported which compare conditional reasoning with three types of rule. These consist of two types of rule that have been widely studied previously, if p then q and p only if q, together with a third type, q if p. In both experiments, the p only if q type of rule yields a different pattern of performance from the two other types of rule. Experiment 1 is an abstract rule-evaluation task and demonstrates differential effects of temporal order and of suppositional bias. Experiment 2 investigates rule generation, rephrasing, and comparison, and demonstrates differential effects of temporal order and of thematic content. An analysis of the results is offered in terms of biases and mental models. Effects of rule form and context can be explained as reflecting the different sequences in which mental models are created for each rule form. However, it is necessary to consider the internal structure of individual mental models to account for effects arising from temporal ordering of rules.

WISC-R subtest patterns in children with traumatic brain injury

Abstract Subtypes of WISC-R subtest patterns were explored statistically in a sample of 96 children with traumatic brain injury. Four subtypes were identified by cluster analysis. Differences in level of performance as well as differences in pattern of performance contributed to the clustering process. Level of performance was meaningfully related to both premorbid variables and to length of coma. Several subtest patterns were found that did not resemble any of the subtypes known to be prevalent in the WISC-R standardization sample, suggesting that these patterns may be clinically significant in children with traumatic brain injury. Support for the reliability and validity of the clusters, as well as clinical and research implications, are discussed.