A Global Geomorphologic Map of Saturn's Moon Titan.

Titan has an active methane-based hydrologic cycle1 that has shaped a complex geologic landscape2, making its surface one of most geologically diverse in the solar system. Despite the different materials, temperatures, and gravity fields between Earth and Titan, many surface features are similar between the two worlds and can be interpreted as products of the same geologic processes3. However, Titan's thick and hazy atmosphere has hindered the identification of geologic features at visible wavelengths and the study of surface composition4. Here we identify and map the major geologic units on Titan's surface using radar and infrared data from the Cassini orbiter spacecraft. Correlations between datasets enabled us to produce a global map even where data sets were incomplete. The spatial and superposition relations between major geologic units reveals the likely temporal evolution of the landscape and gives insight into the interacting processes driving its evolution. We extract the relative dating of the various geological units by observing their spatial superposition in order to get information on the temporal evolution of the landscape. Dunes and lakes are relatively young, while hummocky/mountainous terrains are the oldest on Titan. Our results also show that Titan's surface is dominated by sedimentary/depositional processes with significant latitudinal variation, with dunes at the equator, plains at mid-latitudes and labyrinth terrains and lakes at the poles.

Spatio-temporal correlates of taste processing in the human primary gustatory cortex.

In humans the identification of the primary gustatory cortex (PGC) is still under debate. Neuroimaging studies indicate insula and overlying opercula as the best candidates but the exact position of the PGC within this region is not entirely clear. Moreover, inconsistencies appear when comparing results from studies using functional magnetic resonance imaging (fMRI), and gustatory event-related potentials (gERP), or gustatory event-related magnetic fields (gERMF). fMRI indicates activations in the anterior part of the insula and frontal operculum, while gERP and/or gERMF indicate activations at the transition between the parietal operculum and insula in its posterior part. Here it is important to note that for gERP and gERMF temporal and spatial characteristics of the stimulus must be well controlled to evoke a useful brain response. In the present study gERMF and gERP were recorded simultaneously using a whole-head system with 249 magnetometers and 32 electrodes, respectively; taste stimuli were applied using a stimulator providing excellent temporal and spatial control of the stimulus. Separate ERP and ERMF averaged waveforms were derived time-locked to the onset of the taste stimuli. The source analysis for the early time range revealed activity in the left and right anterior and mid part of the insula, where in the later time range the sources were located more in the posterior part of the insula.

How does attention attenuate target-distractor interference in vision?. Evidence from magnetoencephalographic recordings.

This study used magnetoencephalographic and electroencephalographic recordings to investigate the neural mechanisms that underlie the attentional resolution of ambiguous feature coding in visual search. We addressed this issue by comparing neural activity related to target discrimination under conditions of more versus less feature overlap between the target and distractor items. The results show that increasing feature overlap leads to a focal enhancement of neural activity in ventral occipito-temporal areas, consistent with the larger need to attenuate distractor interference. Furthermore, the results suggest that distractor attenuation proceeds as a stepwise operation, with different spatial locations containing interfering features being suppressed successively. These findings support theories of visual search that emphasize location-based attentional selection as a key mechanism in resolving ambiguous feature coding in vision.

Teratogenic effects of alcohol on brain and behavior.

Children prenatally exposed to alcohol can suffer from serious cognitive deficits and behavioral problems as well as from alcohol-related changes in brain structure. Neuropsychological studies have identified deficits in learning and memory as well as in executive functioning both in children with fetal alcohol syndrome and in children with less severe impairments. Both groups of children also exhibit problem behaviors, such as alcohol and drug use, hyperactivity, impulsivity, and poor socialization and communication skills. Brain imaging studies have identified structural changes in various brain regions of these children--including the basal ganglia, corpus callosum, cerebellum, and hippocampus--that may account for the cognitive deficits. Functional brain imaging studies also have detected changes in alcohol-exposed children indicative of deficits in information processing and memory tasks.