Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cognitive Reflection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed2004

Reduced Alpha power associated with the recall of mentation from Stage 2 and Stage REM sleep.

Relationships between Alpha (8-12 Hz) activity and cognitive processes during wakefulness raise the possibility of similar relationships between Alpha and cognitive activity during sleep. We hypothesized that Alpha power decreases during both Stage 2 and REM sleep would index the presence of sleep mentation in these stages. Absolute power for six classical EEG bands and three Alpha subbands was calculated for Stage 2 and REM sleep awakenings both with and without mentation recall. In both stages, recall was associated with lower Alpha power, especially with middle Alpha power (9.5-11.5 Hz). Unexpectedly, a similar effect for Delta power (0.5-4.0 Hz) was also observed. The Alpha effect may reflect cognitive elaboration active in the minutes preceding awakening; however, attention and memory processes cannot be excluded. The Delta effect is consistent with prior observations of regular linkages between Alpha and Delta power during sleep.

Alpha Rhythm↗
PubMed2003

Reward anticipation, cognition, and electrodermal activity in the conditioned monkey.

In the present report, we examine electrodermal activity (skin conductance responses, SCRs) in monkeys trained to perform target-selection (TS) tests. In each test, the animal was presented in successive trials with the same two unequally rewarded targets on a touch screen. The probabilistic contingencies of the rewards associated with each target rendered the selection of the best difficult. Our findings revealed SCRs time-locked to the arm movements toward the rewarded targets, occurring after the target touches. Parameters of the SCRs were stable when the uncertainty of the choices and of the outcomes varied. The results support the hypothesis that the physiological processes indexed by the SCRs are the correlate of anticipatory appetitive behavior. In contrast, there is no evidence that the SCRs reflect cognitive processes associated with the detection of the best target.

Animals↗
PubMed2006

Pro-anorexics and recovering anorexics differ in their linguistic Internet self-presentation.

OBJECTIVE: Pro-anorexia has emerged as a new and emotionally charged eating disorder phenomenon. This study explored the linguistic markers of differences in Internet self-presentation of self-identified pro-anorexics who defend anorexia as a lifestyle and self-identified anorexics in recovery. METHOD: One hundred sixty-two Internet message board entries and 56 homepages originating from either pro-anorexics or recovering anorexics were analyzed for linguistic markers of emotional, cognitive, and social functioning, temporal focus, and anorexia-related psychological concerns. RESULTS: Across both text sources, pro-anorexics displayed more positive emotions, less anxiety, a lower degree of cognitive reflection, and lower levels of self-directed attention than did recovering anorexics. Pro-anorexics were also more focused on the present and less on the past. Finally, pro-anorexics were more preoccupied with eating and less with school-related issues and death. CONCLUSION: Linguistically, pro-anorexics and recovering anorexics engage in distinct psychological self-presentation styles. More research is needed to understand the clinical implications of these different linguistic styles.

Adolescent↗
PubMed1999

Measuring phase synchrony in brain signals.

This article presents, for the first time, a practical method for the direct quantification of frequency-specific synchronization (i.e., transient phase-locking) between two neuroelectric signals. The motivation for its development is to be able to examine the role of neural synchronies as a putative mechanism for long-range neural integration during cognitive tasks. The method, called phase-locking statistics (PLS), measures the significance of the phase covariance between two signals with a reasonable time-resolution (<100 ms). Unlike the more traditional method of spectral coherence, PLS separates the phase and amplitude components and can be directly interpreted in the framework of neural integration. To validate synchrony values against background fluctuations, PLS uses surrogate data and thus makes no a priori assumptions on the nature of the experimental data. We also apply PLS to investigate intracortical recordings from an epileptic patient performing a visual discrimination task. We find large-scale synchronies in the gamma band (45 Hz), e.g., between hippocampus and frontal gyrus, and local synchronies, within a limbic region, a few cm apart. We argue that whereas long-scale effects do reflect cognitive processing, short-scale synchronies are likely to be due to volume conduction. We discuss ways to separate such conduction effects from true signal synchrony.

Brain↗
PubMed2004

Correlation between cognitive capacity screening examination and cognitive evoked potential in alcohol-dependent patients.

The aim of this study was to verify the significance of cognitive evoked potentials and the correlation between the auditory event-related potential and the Cognitive Capacity Screening Examination (CCSE) in alcohol dependent patients. The P300 studies using an auditory paradigm were performed on 25 alcohol dependent patients, and then the results were compared with score of the CCSE. 1) The latencies of the P300 were significantly prolonged in the patient group compared with the control group, and the scores of CCSE were significantly reduced in the patient group compared with the control group (p < 0.05). 2) There were significant negative correlation between P300 latency and scores of the CCSE (p < 0.05, r= -0.774). 3) There were no significant correlation between P300 latency and the total amount of ethanol ingestion (p > 0.05). 4) There was significant reliability in P300 latency study (alpha=0.9771). These findings suggest that the latency of P300 may be useful as a clinical electrodiagnostic measurement that can objectively reflect cognitive dysfunction in alcohol dependent patients, and it can be used as a quantitative analysis of cognitive dysfunction even for early asymptomatic alcohol dependent patients.

Adult↗
PubMed2003

Ibuprofen for Alzheimer's disease.

BACKGROUND: Non-steroidal antiinflammatory drugs such as ibuprofen may have a role in the treatment of conditions characterized by inflammatory processes. Ibuprofen may attenuate the effects of modulators of inflammation that have been implicated in the pathogenesis of Alzheimer's disease. OBJECTIVES: To investigate the efficacy of ibuprofen treatment for people with Alzheimer's disease. SEARCH STRATEGY: The trials were identified from a search of the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group on 10 December 2002 using the (many) terms listed in the main text of the review. The CDCIG Register is updated regularly and contains records from all major health care databases and many ongoing trials databases. In addition computerized databases and Internet sites pertaining to ibuprofen and Alzheimer's disease were systematically examined by two reviewers independently. Data on ongoing trials of ibuprofen for the treatment of people with AD were also sought. SELECTION CRITERIA: Eligibility for this review included all single or multi centre placebo-controlled randomized trials examining the efficacy of ibuprofen in the treatment of people diagnosed with Alzheimer's disease according to internationally accepted criteria. Inclusion and exclusion criteria were specified to ensure lack of bias in selection and methodological quality of selected trials. DATA COLLECTION AND ANALYSIS: The aim was for the two reviewers NT and HF to collect data independently. The data selected would reflect cognitive, behavioural, physical and psychological domains of AD. MAIN RESULTS: A systematic search of all available databases and other sources failed to identify any completed randomized, double-blind and placebo-controlled trials, assessing the efficacy of ibuprofen in AD eligible for inclusion in the review. One double-blind placebo-controlled trial investigating ibuprofen treatment for age-associated memory impairment has been identified, but is yet unfinished and no data are yet available. Other trials assessing the effect of ibuprofen on CSF beta amyloid in cognitively unimpaired individuals and the effect of other NSAIDs such as naproxen and rofecoxib for people with AD are currently under way. REVIEWER'S CONCLUSIONS: No evidence yet exists from randomized double-blind and placebo-controlled trials on whether ibuprofen is efficacious for patients diagnosed as having Alzheimer's disease. Ibuprofen, like other NSAIDs, has an identifiable and in some instances a significant side-effect profile which may include gastrointestinal bleeding. Therefore, it needs to be shown that the benefits of such a treatment outweighs the risk of side effects before ibuprofen can be recommended for people with Alzheimer's disease.

Alzheimer Disease↗
PubMed2000

Microinfusion of the non-competitive N-methyl-D-aspartate receptor antagonist MK-801 (dizocilpine) into the dorsal hippocampus of wistar rats does not affect latent inhibition and prepulse inhibition, but increases startle reaction and locomotor activity.

Latent inhibition (the retarded conditioning to a stimulus following its repeated non-reinforced pre-exposure) and prepulse inhibition (the reduction in the startle response to an intense acoustic stimulus when this stimulus is immediately preceded by a prepulse) reflect cognitive and sensorimotor gating processes, respectively, and are deficient in schizophrenic patients. The disruption of latent inhibition and prepulse inhibition in the rat is used as an animal model for the attentional deficits associated with schizophrenia. The present study tested the extent to which latent inhibition and prepulse inhibition, startle reaction and locomotor activity in the open field were affected by infusing the non-competitive N-methyl-D-aspartate receptor antagonist MK-801 (dizocilpine) into the dorsal hippocampus of Wistar rats. We used the same dose of MK-801 (6.25microg/0.5microl per side) previously found to be effective in the disruption of prepulse inhibition when infused into the dorsal hippocampus of Sprague-Dawley rats [Bakshi V. P. and Geyer M. A. (1998) J. Neurosci. 18, 8394-8401; Bakshi V. P. and Geyer M. A. (1999) Neuroscience 92, 113-121]. Bilateral infusion of MK-801 into the dorsal hippocampus did not disrupt latent inhibition. Furthermore, in contrast to previous studies, we failed to find a significant disruption of prepulse inhibition after MK-801 infusion into the dorsal hippocampus, although MK-801 infusion was effective in increasing the startle amplitude as well as locomotor activity in an open field. From our results, we suggest that N-methyl-D-aspartate receptor-mediated processes within the dorsal hippocampus are not necessary for the normal maintenance of the attentional processes reflected by latent inhibition and prepulse inhibition.

Animals↗
PubMed2002

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗
PubMed1978

Behavioral sequelae of closed head injury. A quantitative study.

We determined the profile of behavioral disturbance in relation to closed head injury of graded severity. Patients with severe injuries, as defined by duration of coma and the presence of neurological deficit, were differentiated from a group of mildly injured patients by behavioral ratings that reflected cognitive disorganization, emotional withdrawal, and motor retardation. Neurologic measurements of injury related to the severity of behavioral disturbance included hemiparesis, aphasia, and abnormalities on computerized axial tomography. Agitation during the acute phase of injury was also predictive of residual behavioral disturbance. Hemispheric lateralization of the site of greatest injury had no discernible effect on behavioral sequelae.

Adult↗
PubMed2000

Deferred imitation of object-related actions in human-reared juvenile chimpanzees and orangutans.

Deferred imitation of object-related actions (e.g., picking up a cloth with a set of tongs) was assessed in 3 enculturated juvenile orangutans (Pongo pygmaeus) and 3 enculturated juvenile chimpanzees (Pan troglodytes). For each task, animals were given 4 min to explore the objects (baseline), followed by a demonstration of the target behavior, and 10 min later, were re-presented the objects (deferred phase). Each animal displayed deferred imitation on at least one trial, with each species demonstrating deferred imitation on approximately half of all possible trials. The findings were interpreted as reflecting cognitive abilities in juvenile great apes that permit deferred imitation under humanlike rearing conditions.

Age Factors↗
PubMed2007

Regulation of emotional responses elicited by threat-related stimuli.

The capacity to voluntarily regulate emotions is critical for mental health, especially when coping with aversive events. Several neuroimaging studies of emotion regulation found the amygdala to be a target for downregulation and prefrontal regions to be associated with downregulation. To characterize the role of prefrontal regions in bidirectional emotion regulation and to investigate regulatory influences on amygdala activity and peripheral physiological measures, a functional magnetic resonance imaging (fMRI) study with simultaneous recording of self-report, startle eyeblink, and skin conductance responses was carried out. Subjects viewed threat-related pictures and were asked to up- and downregulate their emotional responses using reappraisal strategies. While startle eyeblink responses (in successful regulators) and skin conductance responses were amplified during upregulation, but showed no consistent effect during downregulation, amygdala activity was increased and decreased according to the regulation instructions. Trial-by-trial ratings of regulation success correlated positively with activity in amygdala during upregulation and orbitofrontal cortex during downregulation. Downregulation was characterized by left-hemispheric activation peaks in anterior cingulate cortex, dorsolateral prefrontal cortex, and orbitofrontal cortex and upregulation was characterized by a pattern of prefrontal activation not restricted to the left hemisphere. Further analyses showed significant overlap of prefrontal activation across both regulation conditions, possibly reflecting cognitive processes underlying both up- and downregulation, but also showed distinct activations in each condition. The present study demonstrates that amygdala responses to threat-related stimuli can be controlled through the use of cognitive strategies depending on recruitment of prefrontal areas, thereby changing the subject's affective state.

Adolescent↗
PubMed1993

Assessment of central, peripheral, and autonomic nervous system functions in lead workers: neuroelectrophysiological studies.

To assess the effects of lead on central, peripheral, and autonomic nervous systems, the visual-, short-latency somatosensory-, and brainstem auditory-evoked potentials (VEP, SSEP, and BAEP), event-related potential (P300), distribution of nerve conduction velocities (DCV), and electrocardiographic R-R interval variability (CVRR), together with conventional median and radial nerve conduction velocities (NCV), were measured in the lead workers. The lead workers consisted of 22 gun metal foundry workers occupationally exposed to lead, zinc, and copper. In the lead workers with blood lead concentrations below 65 micrograms/dl, the latencies of the VEP (from the retina to the visual cortex), SSEP (from the brachial plexus to the brainstem), and P300 (which reflects cognitive function) were significantly prolonged when compared with the sex- and age-matched controls. All these latencies and the BAEP latencies (from the cochlear nerve to the brainstem) were significantly correlated with the indicators of lead absorption among these workers. The CVRR (especially, a component of parasympathetic activity) was significantly depressed in the lead workers. The slower (V10) velocity of the DCV, the motor, and sensory NCVs were also significantly slowed. These findings suggest that lead affects not only peripheral nerve but also the central and autonomic nervous functions at a subclinical level; zinc may antagonize the neurotoxic effects of lead.

Adult↗
PubMed1990

Inter-relationships among anticipatory EMG activity, Hoffmann reflex amplitude and EMG reaction time during voluntary standing movement.

In order to understand the process of executing a voluntary standing movement, the parameters latency (AEA-LT), duration (AEA-DUR) and amplitude (AEA-AMP) of the anticipatory electromyographic (EMG) activity (AEA) in the tibialis anterior muscle, Hoffmann (H) reflex amplitude in the soleus muscle (Sol) prior to the onset of EMG activity in that muscle, and EMG reaction time (EMG-RT) were measured during heel raising from the standing position. The following results were obtained: the three parameters of AEA correlated with EMG-RT in each subject; the average values for all nine normal subjects were r = 0.856 for AEA-DUR, r = 0.448 for AEA-LT and r = -0.215 for AEA-AMP; for the group the mean value of AEA-DUR correlated significantly with that of EMG-RT (r = 0.983, P less than 0.01), while no such significant correlation was observed for AEA-LT; the average value of the AEA-DUR in three slower EMG-RT performers (SLOW-PFM) was significantly longer (P less than 0.05) than that in three faster ones (FAST-PFM), while no significant difference in the AEA-LT was observed; and lastly the total area of the anticipatory suppression of the Sol H reflex amplitude in the SLOW-PFM was greater than that in the FAST-PFM. These results suggest that AEA-DUR, representing postural responses, rather than AEA-LT, reflecting cognitive processes, may have had a close link with EMG-RT, and that the increased suppression in Sol H reflex amplitude originated from the increased anticipatory postural requirement, thus bringing about the EMG-RT delay.

Adult↗
PubMed1977

The functional independence of response latency and accuracy: implications for the concept of conceptual tempo.

Kagan (1965a) developed the concepts of impulsive and reflective cognitive styles (conceptual tempo) to add a new dimension to the understanding and assessment of human intelligence. Although latency (the principal component of conceptual tempo) is negatively correlated with academic performance, it may not be necessary to modify latency in order to modify accuracy.. With 40 disadvantaged preschool children, it was found that reinforcing long latencies in choice tasks did not increase accuracy and vice versa, and that reinforcing both long latencies and accuracy was no more effective than reinforcing accuracy alone. These data were used to question the usefulness of the construct of conceptual tempo.

Achievement↗
PubMed1986

Learning is improved by a soybean oil diet in rats.

A semi-synthetic diet containing 20% polyunsaturated fat (soybean) oil was fed to young male hooded rats for 21 days. These animals exhibited improved performance on an environmentally-cued testing paradigm which is thought to reflect cognitive learning skills (i.e., Place Navigation Water Task). Other rats fed the same base diet but containing 20% saturated fat (lard) showed no such improvement compared to chow-fed (4.5% mixed fat) controls. The animals fed soybean oil also exhibited a transient resistance to extinguish this learning. This improved learning could not be explained by changes in general motor activity, basal body temperature, energy consumption, body weight, or in the brain activity of choline acetyltransferase, the marker enzyme for cholinergic neurons. These findings constitute the first evidence that short-term variations in the quality of dietary fat can enhance mammalian learning.

Animals↗
PubMed1988

Dichotic listening asymmetries and psychotic symptoms in schizophrenia: a preliminary report.

Schizophrenic subjects were compared with both psychiatric control and normal control groups on two verbal measures of functional hemispheric asymmetry on a dichotic listening task. One measure of language perception showed little variation in ear differences across groups. However, the task that contained both attentional and language-processing components showed variations in asymmetry according to symptomatology. Subjects with high scores on scales of hallucinations and delusions showed a pattern of ear differences that was not found in those with low scores on these symptom dimensions. The results may reflect cognitive factors in a dysfunctional information-processing system and, in particular, attentional disturbance rather than anomalies in the lateralization of language.

Adolescent↗
PubMed1986

Latency variability and temporal interrelationships of the auditory event-related potentials (N1, P2, N2, and P3) in normal subjects.

Peak latency variation and the temporal interrelationships of the auditory event-related potential were investigated in 12 normal adults (ages 28-42). Measures of variation were based on both conventional averages and single trials. Estimates of N1, P2, N2 and P3 latencies were made on a trial-by-trial basis to target stimuli recorded from Fz, Cz and Pz scalp locations. Results showed that single-trial latency variability of the auditory ERP differed both among the various components and between subjects. Larger standard deviations were measured for the later N2 and P3 components than the earlier N1 and P2 components. Regression analyses between various component latencies indicated a strong covarying relationship between N2 and P3, with N2 accounting for up to 61% of the variance of P3 latency at Pz. Earlier N1 and P2 components added little to the overall prediction of either P3 or N2. For the other components, P2 accounted for 9-16% of the variance of N2, while N1 accounted for approximately 1% of the variance of N2; N1 accounted for 8-10% of the latency variation of P2. The correlations between single-trial peak latencies and RTs were positive but of low magnitude. The highest correlations between peak latency and RT were found for N2 (r = 0.33) and P3 (r = 0.24). The low correlations between the single-trial latencies of N1 and P3 suggest that the processes reflected by these components are independent and support a distinction between the earlier and the later components of the ERP. The close temporal coupling between N2 and P3 suggests that N2 may reflect cognitive properties in common to P3 in stimulus evaluation processes.

Adult↗