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PubMed2002

Returning the tables: language affects spatial reasoning.

Li and Gleitman (Turning the tables: language and spatial reasoning. Cognition, in press) seek to undermine a large-scale cross-cultural comparison of spatial language and cognition which claims to have demonstrated that language and conceptual coding in the spatial domain covary (see, for example, Space in language and cognition: explorations in linguistic diversity. Cambridge: Cambridge University Press, in press; Language 74 (1998) 557): the most plausible interpretation is that different languages induce distinct conceptual codings. Arguing against this, Li and Gleitman attempt to show that in an American student population they can obtain any of the relevant conceptual codings just by varying spatial cues, holding language constant. They then argue that our findings are better interpreted in terms of ecologically-induced distinct cognitive styles reflected in language. Linguistic coding, they argue, has no causal effects on non-linguistic thinking--it simply reflects antecedently existing conceptual distinctions. We here show that Li and Gleitman did not make a crucial distinction between frames of spatial reference relevant to our line of research. We report a series of experiments designed to show that they have, as a consequence, misinterpreted the results of their own experiments, which are in fact in line with our hypothesis. Their attempts to reinterpret the large cross-cultural study, and to enlist support from animal and infant studies, fail for the same reasons. We further try to discern exactly what theory drives their presumption that language can have no cognitive efficacy, and conclude that their position is undermined by a wide range of considerations.

Cognition↗

PubMed1993

Essential hypertension and cognitive function. The role of hyperinsulinemia.

The relation between hypertension and cognitive function is not well established. Therefore, we examined cognitive function in a random sample of 744 nondiabetic elderly inhabitants of Kuopio, East Finland. Five brief neuropsychological tests known to be sensitive to cognitive impairment due to dementia--the Mini-Mental State Examination (MMSE), the Trail Making Test (TMT), the Buschke Selective Reminding Test (BSR), Russell's Adaptation of the Visual Reproduction Test (HVR), and the Verbal Fluency Test (VFT)--were used to evaluate cognitive function. The performance of the hypertensive group (n = 378) was impaired in almost all test items compared with that of the normotensive group (n = 366), but the difference between these two groups was statistically significant in 5 of 19 test items only. Moreover, within the hypertensive group, hyperinsulinemic (fasting plasma insulin > 17.9 mU/L) hypertensive subjects (n = 57) scored worse than normoinsulinemic hypertensive subjects (n = 321) in 16 of 19 test items and worse than the normotensive subjects in the same 16 of 19 test items. The difference between the hyperinsulinemic hypertensive and normotensive groups was significant in 11 test items that reflected complex cognitive function such as calculation, language, semantic memory, and problem solving. This difference in neuropsychological tests among the three study groups (normotensive, normoinsulinemic hypertensive, and hyperinsulinemic hypertensive subjects) persisted after adjustment for fasting plasma glucose, age, sex, and education in 3 test items measuring calculation, copying, and semantic memory. Thus, essential hypertension in the elderly is associated with an impairment in complex cognitive function.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed2006

Identification of factorial structure of MMSE based on elderly cognitive destiny: the Italian Longitudinal Study on Aging.

The Mini-Mental State Examination (MMSE) is one of the most commonly used instruments in the evaluation of global cognitive status, but only few studies have investigated the relationship among its components in terms of factorial structure. We have considered data from the Italian Longitudinal Study on Aging (ILSA), carried out in Italy in 1992 on a sample of 5,632 subjects aged 65-84 years, and followed up in 1996. The aim of our study was to investigate static factorial structure in three groups of elderly (subjects with a diagnosis of dementia at baseline; subjects free of dementia at baseline, but incident cases at follow-up; subjects who never developed dementia during the 4-year follow-up). Considering our results, we could hypothesize that MMSE static structure reflects the cognitive profile of elderly, and is thus influenced by subjects' potential to develop dementia.

Aged↗

PubMedDate not supplied

Working memory, intelligence and knowledge base in adult persons with intellectual disability.

Previous studies have suggested that performance in working memory (WM) tasks is deficient in all etiologies and at all levels of intellectual disability (ID). Knowledge about WM structure, cognitive processes reflected in WM tasks, or the long-term memory contribution to WM capacity in ID is. however, not satisfactory. In the present study, WM capacity, WM task requirements, as well as effects between WM, skills, knowledge base, and intelligence were explored in two groups with matched fluid intelligence: adult persons with ID and normally developing children aged 3-6 years. The ID Group performed equally well as the children in WM tasks based on familiar semantic information and were significantly better on all measures reflecting skills and knowledge base. The Child Group performed better in phonological and visuo-spatial WM tasks including nonsemantic information, respectively. In particular, it appeared that the groups differed in their WM performance although they were matched for fluid intelligence. We hypothesize that the ID Group depended more on knowledge support from long-terrm memory whereas the Child Group could benefit more from efficient online WM processes.

Cognition Disorders↗

PubMed2001

The effect of retrieval cues on post-retrieval monitoring in episodic memory: an electrophysiological study.

The aim of the present experiment was to examine whether episodic retrieval and 'post-retrieval' monitoring are affected by the nature of the cue that guides a search of memory. We recorded event-related brain potentials (ERPs) from young healthy adult participants while they tried to recall studied words (e.g. 'MOTHER') with the aid of word-stem (e.g. 'MOT') and word-fragment (e.g. 'M-TH--') retrieval cues. Analyses of the behavioural data showed that while it was far more difficult to generate completions per se for the fragments, the levels of conscious, or 'explicit', recall obtained with each type of cue were statistically identical. ERP analyses focussed upon differences in neural activity evoked by each type of cue (termed 'old/new' ERP effects) during successful versus unsuccessful retrieval. The stem and fragment old/new ERP effects were remarkably similar in their time course and magnitude, and also in their scalp distribution, which changed over time as multiple neuronal populations, and hence multiple cognitive operations, became activated. These behavioural and ERP findings suggest that the cognitive operations reflected by old/new effects in cued recall tasks may be insensitive to changes in the retrieval strategy, or effort, that participants apply to monitor the episodic status of retrieved information. The findings are discussed in relation to previous ERP and functional imaging studies that have investigated task-specific features of retrieval and post-retrieval processing in episodic memory.

Adolescent↗

PubMed2004

Neural activity in primate parietal area 7a related to spatial analysis of visual mazes.

Cognitive psychological studies of humans and monkeys solving visual mazes have provided evidence that a covert analysis of the maze takes place during periods of eye fixation interspersed between saccades, or when mazes are solved without eye movements. We investigated the neural basis of this process in posterior parietal cortex by recording the activity of single neurons in area 7a during maze solution. Monkeys were required to determine from a single point of fixation whether a critical path through the maze reached an exit or a blind ending. We found that during this process the activity of approximately one in four neurons in area 7a was spatially tuned to maze path direction. We obtained evidence that path tuning did not reflect a covert saccade plan insofar as the majority of neurons active during maze solution were not active on a delayed-saccade control task, and the minority that were active on both tasks did not exhibit congruent spatial tuning in the two conditions. We also obtained evidence that path tuning during maze solution was not due to the locations of visual receptive fields mapped outside the behavioral context of maze solution, in that receptive field centers and preferred path directions were not spatially aligned. Finally, neurons tuned to path direction were not present in area 7a when a naïve animal viewed the same visual maze stimuli but did not solve them. These data support the hypothesis that path tuning in parietal cortex is not due to the lower level visual features of the maze stimulus, but rather is associated with maze solution, and as such, reflects a cognitive process applied to a complex visual stimulus.

Animals↗

PubMed2000

Cognitive style: problem solving by rhesus macaques (Macaca mulatta) reared with living or inanimate substitute mothers.

Cognitive style, reflected in the generation of novel solutions and the use of identifiable response strategies in problem-solving situations, was contrasted in rhesus monkeys (Macaca mulatta) reared individually with either canine companions or inanimate surrogate mothers. Four experiments were conducted over a 5-year period, examining problem solving in relatively unstructured as well as more formal situations. Results indicated that whereas the 2 rearing groups did not differ on most measures of performance, consistent response strategies were identified for the dog-raised monkeys. The results were compared with previously published data from the same monkeys demonstrating rearing group differences in abilities to engage in complex social interaction. The animate nature of the early rearing environment may facilitate-the development of a cognitive style that influences problem-solving abilities in both the social and nonsocial realms.

Animals↗

PubMed2006

Looking for answers: eye movements in non-visual cognitive tasks.

It is not known why people move their eyes when engaged in non-visual cognition. The current study tested the hypothesis that differences in saccadic eye movement rate (EMR) during non-visual cognitive tasks reflect different requirements for searching long-term memory. Participants performed non-visual tasks requiring relatively low or high long-term memory retrieval while eye movements were recorded. In three experiments, EMR was substantially lower for low-retrieval than for high-retrieval tasks, including in an eyes closed condition in Experiment 3. Neither visual imagery nor between-task difficulty was related to EMR, although there was some evidence for a minor effect of within-task difficulty. Comparison of task-related EMRs to EMR during a no-task waiting period suggests that eye movements may be suppressed or activated depending on task requirements. We discuss a number of possible interpretations of saccadic eye movements during non-visual cognition and propose an evolutionary model that links these eye movements to memory search through an elaboration of circuitry involved in visual perception.

Analysis of Variance↗

PubMed1988

Cognitive enhancing agents: current status in the treatment of Alzheimer's disease.

Extensive recent literature on drugs used to enhance cognitive functioning, reflects the growing social problem of dementia. Many clinical trials have been undertaken with variable success. In most cases the disorder studied has been Alzheimer's disease. The pharmacological approach has been designed to rectify the presumed pathophysiological processes characteristic of the condition. Agents tested include cerebral vasodilators, cerebral metabolic enhancers, nootropics, psychostimulants, neuropeptides and neurotransmitters with a special emphasis on drugs used to enhance cholinergic function. Ethical and practical issues concerning clinical drug trials in dementia will be discussed.

Alzheimer Disease↗

PubMed2006

Brain mechanism of cognitive conflict in a guessing Chinese logogriph task.

To investigate the neural substrates of cognitive conflict in high-level thought processing, we recorded event-related potentials while participants thought about the logogriph answers. We identified three states after the answers were provided: (1) the answer given was just what the participants initially guessed (No-aha answer). (2) Participants could understand the answer given correctly although they had not got the answer themselves (Aha answer). (3) Participants could not understand the correct answer offered (Uncomprehended answer). Results showed that, relative to the No-aha answer, the Aha and Uncomprehended answers elicited more negative event-related potential deflections between 250 and 400 ms. The dipole analysis localized the generator of the difference waves (Aha minus No-aha answer) to the anterior cingulate cortex. Thus, it might reflect the cognitive conflict center between familiar and new ways of processing the logogriphs.

Adult↗

PubMed1998

Performance differences in reaction tasks are reflected in event-related brain potentials (ERPs).

Event-related potentials (ERPs), which can be extracted from the electroencephalogram (EEG), are assumed to reflect distinct cognitive processes in real time. Hence ERP analysis could be used in cognitive ergonomics as a tool to specify, for example, bottlenecks or sources of individual performance differences. Such specific results may be helpful to change the tasks or train the subjects specifically. In the present exploratory study, the authors investigated whether subjects with large spontaneous differences in performance accuracy, as defined by their error rates in a speeded binary choice reaction task, also differ in the structure of their ERPs. The ten subjects were divided post hoc into two groups with relatively low (about 6%) and high (about 20%) error rates. While the reaction times were not significantly different for both groups, the ERPs revealed clear group differences. First, large differences were seen in the late part of the contingent negative variation (late CNV), which is assumed to reflect preparatory processes. Subjects with few errors ('GOOD') had a large late CNV, while subjects with many errors ('POOR') showed virtually no late CNV. Second, the late P300-subcomponent (which is related to response identification) was smaller and delayed for POOR compared to GOOD subjects. Finally, the ERP shows signs of poor movement control in POOR subjects. The high error rate of POOR subjects can hence be explained by: (1) their insufficient preparation for the next trial (small late CNV), which impaired response identification (small and delayed late P300 subcomponent); and (2) their poor movement control. These interpretations have to be regarded as preliminary and should be validated with larger groups of subjects. In conclusion, the main reasons for the profound performance differences between the groups, namely differential preparation and movement control, could be elucidated by ERP analysis. A potential ergonomics application of these results is that they suggest specific strategies (for example, a preparation and motor control training) to improve the performance of POOR subjects in comparable work conditions.

Adult↗

PubMedDate not supplied

Genome survey for loci that influence successful aging: sample characterization, method validation, and initial results for the Y chromosome.

OBJECTIVE: A systematic genome survey was initiated to identify loci that affect the likelihood of reaching age 90 with preserved cognition. This communication describes the clinical characterization and comparison of the experimental groups, validation of the experimental method, and results for the Y chromosome. METHODS: The genome survey was conducted at 10 cM resolution for simple sequence tandem repeat polymorphisms (SSTRPs) that identify genes for successful aging by virtue of linkage disequilibrium. Efficiency was enhanced by genotyping pools of DNA from 100 cognitively intact elders (50 men/50 women) and 100 young (age 18-25 years) adults matched for sex, race, ethnicity, and geographic location. RESULTS: Elders (94 nonagenarians, 6 centenarians) manifested preserved cognition, as reflected by clinical and psychometric assessments; "good" average capacity to carry out their activities of daily living; and the majority were living independently despite multiple medical conditions. None had a history of mental disorders in early or middle adulthood, only one was a current smoker, and 80% consumed alcohol less than once each month. The genome survey method detected the expected elevation of the APOE epsilon2 allele frequency, and reciprocal reduction in the epsilon4 frequency, among the elders, compared with the young adults. It also detected significant differences in the allelic distributions of DYS389 and DYS390, which are separated by only 2.6 Mb near the centromere of Yq. CONCLUSIONS: These results suggest that several behavioral and genetic factors may contribute to the likelihood of achieving exceptional longevity with preserved cognition.

Adolescent↗

PubMed1997

Differential relationships between positive and negative symptoms and neuropsychological deficits in schizophrenia.

UNLABELLED: This study assessed the relationships between positive and negative clinical symptoms and specific neuropsychological deficits in a group of stable schizophrenic patients. METHOD: Thirty patients were assessed using the Positive and Negative Syndrome Scale (PANSS) for schizophrenia and a battery of cognitive tests. The PANSS assessments were done by a group of raters blind to the results of cognitive tests, while the cognitive tests were conducted by a different group of raters who remained blind to the PANSS scores. RESULTS: We found that, although positive and negative symptoms showed a trend toward direct correlation with each other, they correlated with distinct cognitive deficits. Patients with higher negative scores had more perseverative responses, perservative errors, and completed fewer categories on the Wisconsin Card Sorting Test; they also experienced more difficulties on trail making and verbal fluency tests. On the other hand, positive symptoms were associated with poor performance on the Digit Span, particularly the Digit Span Forward. CONCLUSIONS: Our findings are in agreement with previous reports that negative symptoms may be associated with poor performance on cognitive tests reflecting particularly frontal function. Positive symptoms, on the other hand, seem to be associated with poor attention, specifically of auditory type, and thus, possibly with dysfunction within the more widespread neural networks underlying attention. Our findings support the hypothesis that positive and negative symptoms may be associated with distinct neuropsychological deficits and thus with distinct neurological substrates and point to the need to address both positive and negative dimensions when studying schizophrenia.

Adult↗

PubMed2005

Neural basis of aging: the penetration of cognition into action control.

Although functional imaging studies have frequently examined age-related changes in neural recruitment during cognitive tasks, much less is known about such changes during motor performance. In the present study, we used functional magnetic resonance imaging to investigate age-related changes in cyclical hand and/or foot movements across different degrees of complexity. Right-handed volunteers (11 young, 10 old) were scanned while performing isolated flexion-extension movements of the right wrist and foot as well as their coordination, according to the "easy" isodirectional and "difficult" nonisodirectional mode. Findings revealed activation of a typical motor network in both age groups, but several additional brain areas were involved in the elderly. Regardless of the performed motor task, the elderly exhibited additional activation in areas involved in sensory processing and integration, such as contralateral anterior insula, frontal operculum, superior temporal gyrus, supramarginal gyrus, secondary somatosensory area, and ipsilateral precuneus. Age-related activation differences during coordination of both segments were additionally observed in areas reflecting increased cognitive monitoring of motor performance, such as the pre-supplementary motor area, pre-dorsal premotor area, rostral cingulate, and prefrontal cortex. In the most complex coordination task, the elderly exhibited additional activation in anterior rostral cingulate and dorsolateral prefrontal cortex, known to be involved in suppression of prepotent response tendencies and inhibitory cognitive control. Overall, these findings are indicative of an age-related shift along the continuum from automatic to more controlled processing of movement. This increased cognitive monitoring of movement refers to enhanced attentional deployment, more pronounced processing of sensory information, and intersensory integration.

Adult↗

PubMed2006

Switch and maintenance of task set in schizophrenia.

Task set maintenance and switching deficits are robust in schizophrenia. However, little is known about how these constructs are related to one another. The development of an improved understanding of set switching and maintenance deficits in schizophrenia requires that these constructs be explicated in terms of elementary cognitive processes rather than grouped into broad psychological concepts like executive functioning. A relevant dichotomy has been proposed in which sensory and perceptual ("attentional") processes are distinguished from decisional ("intentional") processes in task maintenance and switching; however, the contributions these processes make to performance deficits in schizophrenia is not known. In the present study, 30 participants with schizophrenia and 27 healthy comparisons completed a cued attentional set switching task. In addition to analyses of mean response times, the contributions of attentional and intentional processes to task performance were estimated using an ex-Gaussian distributional analysis. Schizophrenia was associated with a set maintenance deficit that was accounted for by an attentional, rather than intentional, dysfunction. Both groups showed significant switch costs that could be attributed to attentional processes, but there was no evidence for an attentional set switching deficit in schizophrenia. The findings suggest that set switching and set maintenance may reflect distinct cognitive deficits in schizophrenia and that they may be associated with unique information processing mechanisms.

Adolescent↗

PubMed1995

[Reverse-tolerance phenomenon in methamphetamine-induced behavioral stereotypy and impairment of cliff avoidance reaction after subchronic methamphetamine administration in rats].

Clinical evidence of methamphetamine (MAP)-induced reverse-tolerance phenomenon is available in studies of methamphetamine psychosis. To examine the clinical relevance of the reverse-tolerance phenomenon as a model of this psychosis, two experiments were conducted using rats. In the first experiment, we examined the relationship of MAP (4 mg/kg/day)-induced reverse tolerance in behavioral stereotypy to impairment of the cliff avoidance reaction (CAR). The stereotypy scores by the method of Creese and Iversen reached a maximum at day 14, and were unchanged thereafter. Impairment of CAR appeared in 3 of 6 rats at day 21 or 28 without motor ataxia, as rated by the scoring system of Hiramatsu et al. This suggested that cognitive dysfunction reflected by CAR impairment may develop after MAP-induced reverse-tolerance phenomenon, as evaluated by the behavioral stereotyping rating scale. In the second experiment, the effect of PCP (1 mg/kg) on CAR was examined in rats pretreated with MAP (4 mg/kg/day) for 30 days. No behavioral stereotypy or CAR impairment was found in these rats for 1 hour after PCP challenge. This showed that MAP-induced reverse-tolerance did not alter sensitivity to PCP in producing behavioral stereotypy or CAR impairment.

Animals↗

PubMed1982

A developmental study of proverb comprehension.

Growth in proverb comprehension was hypothesized to result from the gradual emergence of cognitive abilities reflected in a sequence of increasingly complex abilities: story matching, transfer of relations, desymbolization, proverb matching, and paraphrase. Items for these abilities for each of 10 proverbs of two structural types were administered in three test sessions to 438 students in grades three to seven. An analogy subtest was used to measure general intelligence. ANOVA yielded significant main effects for grade, tasks, and proverbs (all p's less than .01). A significant task x proverb interaction (p less than .01) revealed the difficulty of precise control over the language of the items. Proverb structure had no measurable impact on difficulty. Analogy score was a significant factor in performance (p less than .01) but not as potent as age (p less than .01). The sequential order of abilities received only weak confirmation, though tasks did correlate among themselves with medium strength (r's = .50-.70). Individual interviews added a qualitative dimension to the findings. The suitability of cognitive hierarchical models for proverb comprehension was questioned.

Aphorisms and Proverbs as Topic↗

PubMed1991

Clock drawing in acute stroke.

We studied 118 elderly subjects with first-ever stroke free of severe cognitive impairment and able to write. Within 14 days of stroke we measured clock drawing, ability to copy drawings of dual pentagons and a house, line bisection, Mini-Mental State score, homonymous hemianopia and visual and tactile extinction. Thirty subjects had impaired clock drawing. When compared with the remaining 88 subjects with normal clock drawing the impaired group had similar pre-stroke characteristics but had significantly more severe stroke deficits. Hospital stay was significantly longer in the impaired group and a much greater proportion of subjects were discharged to long-term hospitals rather than home. Barthel ADL scores at days 7, 30, 60 and maximal recovery were significantly lower. Using a multivariate generalized linear model, clock drawing was a significant independent predictor of maximal Barthel ADL after accounting for other significant predictors such as Barthel score at day 7, limb power, visual extinction, line bisection error and Mini-Mental State score. Impaired clock drawing can reflect either cognitive impairment or spatial neglect.

Acute Disease↗