This paper reports on the effects of LSD on mental time travel during spontaneous mentation. Twenty healthy volunteers participated in a placebo-controlled crossover study, incorporating intravenous administration of LSD (75 μg) and placebo (saline) prior to functional magnetic resonance imaging (fMRI). Six independent, blind judges analysed mentation reports acquired during structured intervie...

Various cognitive theories aim to explain human deductive reasoning: (1) mental logic theories claim syntactic language-based proofs of derivation, (2) the mental model theory proposes cognitive processes of constructing and manipulating spatially organized mental models, and (3) imagery theories postulate that such abilities are based on visual mental images. To explore the neural substrates o...

BACKGROUND Cognitive deficits are frequent in multiple sclerosis (MS) and have been associated with morphologic brain changes. Less information exists on their extent and relation to MRI findings in clinically isolated syndrome (CIS). It is also unclear if structural changes as detected by magnetization transfer (MT) imaging may provide an additional explanation for cognitive dysfunction. OBJ...

The desire to understand complex mental processes using functional MRI drives development of imaging techniques that scan the whole human brain at a high spatial and temporal resolution. In this work, an accelerated multishot three-dimensional echo-planar imaging sequence is proposed to increase the temporal resolution of these studies. A combination of two modern acceleration techniques, UNFOL...

Although some studies showed the efficacy of phosphodiesterase (PDE) inhibitors as neuronal plasticity enhancers, little is known about the effectiveness of these drugs to improve plasticity in cases of mental retardation. Fetal alcohol syndrome (FAS) is the leading cause of mental retardation in the western world. Using a combination of electrophysiological and optical imaging techniques, we s...

Empirical evidence challenges the discriminant validity of the "biologically based mental illness" (BBMI) construct. Data indicate that interventions such as psychotherapy, placebo, and medication yield similar changes in brain function when effective. Drug and brain imaging studies show that psychological and biochemical phenomena can be manipulated reciprocally. Data suggest that mental disor...

Sjögren-Larsson syndrome is a rare autosomal recessive disorder that was originally recognized in the coexistence of congenital ichthyosis, spastic diplegia or quadriplegia and mental retardation. We recently saw two cases with characteristic features of this rare syndrome. Two brothers aged 21 and 25 years presented with triad of congenital ichthyosis, mental retardation and spastic diplegia. ...

Mental visual synthesis is the capacity for experiencing, constructing, or manipulating 'mental imagery'. To investigate brain networks involved in mental visual synthesis, brain activity was measured in right-handed healthy volunteers during mental imagery tasks, in which the subjects were instructed to imagine a novel object, that does not exist in the real world, by composing it from two vis...

conclusion adc, fa, and t2* values may quantitatively reflect the microstructural characteristics of np, therefore they could be used to detect the minimal changes of early ldd. results the adc, fa, and t2* values were different (p < 0.05) among different rois within the same disc or among corresponding rois in different level discs. while the average values of adc increased regularly with the ...

We evaluated the influence of long-term practice on the performance of a mental rotation task in which subjects judged whether two 3-D objects presented in different orientations were identical. Stimuli and experimental conditions were analogous to those used by Shepard and Metzler. Sixteen subjects were selected, to test the influence of aptitude for mental imagery on this learning process. Su...