Learn More
What is the best way of assessing the extent to which people are aware of a stimulus? Here, using a masked visual identification task, we compared three measures of subjective awareness: The Perceptual Awareness Scale (PAS), through which participants are asked to rate the clarity of their visual experience; confidence ratings (CR), through which(More)
Recent reports have supported the existence of neural stem cells in the adult mammalian CNS. Important features of such cells are self-renewal and multipotency, i.e., they can give rise to neurons, astrocytes, and oligodendrocytes and thus in principle replace lost cells in the CNS. Observations in several animal models of CNS diseases have shown that by(More)
Dienes and Seth (2010) conclude that confidence ratings and post-decision wagering are two comparable and recommendable measures of conscious experience. In a recently submitted paper, we have however found that both methods are problematic and seem less suited to measure consciousness than a direct introspective measure. Here, we discuss the methodology(More)
The brain has limited capacity, and so selective attention enhances relevant incoming information while suppressing irrelevant information. This process is not always successful, and the frequency of such cognitive failures varies to a large extent between individuals. Here we hypothesised that individual differences in cognitive failures might be reflected(More)
Hemicholinium-3 (HCh-3) is a potent and specific inhibitor of the high-affinity choline transport process (HAChT) localized on cholinergic neurons. In this study, the specific binding of [3H]HCh-3 (120 Ci/mmol) was characterized in crude synaptic membranes prepared from rat brain. The binding of [3H]HCh-3 to forebrain membranes was saturable, reversible and(More)
Two electrophysiological components have been extensively investigated as candidate neural correlates of perceptual consciousness: An early, occipitally realized component occurring 130-320 ms after stimulus onset and a late, frontally realized component occurring 320-510 ms after stimulus onset. Recent studies have suggested that the late component may not(More)
Comparison of behavioural measures of consciousness has attracted much attention recently. In a recent article, Szczepanowski et al. conclude that confidence ratings (CR) predict accuracy better than both the perceptual awareness scale (PAS) and post-decision wagering (PDW) when using stimuli with emotional content (fearful vs. neutral faces). Although we(More)
The selective neurotoxic effects of the aziridinium ion of ethylcholine (AF64A) have been examined after stereotaxic injection into the rat striatum. In a dose-response study (2-26 nmol), 8 nmol caused a 46% decrease in striatal choline acetyltransferase (CAT) activity with minimal effects on the activities of glutamate decarboxylase (GAD) and tyrosine(More)
Significant impairments in the acquisition and retention of a step-down passive avoidance task were found in rats with striatal lesions induced by the cholinergic neurotoxin AF64A. No significant differences between control and AF64A-injected rats were found in sensitivity to electric shock or in various measures of spontaneous locomotor activity. Striatal(More)
Recent findings suggest that cortical gamma aminobutyric acid (GABA) levels may provide a surrogate marker for a number of psychiatric and neurological conditions, as well as behavioural traits. However, the natural variability of GABA levels in the human brain over long periods of time (>8 days) has not yet been studied. The purpose of this work was to(More)