Prefrontal cortex and basal ganglia control access to working memory.

Our capacity to store information in working memory might be determined by the degree to which only relevant information is remembered. The question remains as to how this selection of relevant items to be remembered is accomplished. Here we show that activity in the prefrontal cortex and basal ganglia preceded the filtering of irrelevant information and that activity, particularly in the globus pallidus, predicted the extent to which only relevant information is stored.

Male-to-female transsexuals show sex-atypical hypothalamus activation when smelling odorous steroids.

One working hypothesis behind transsexuality is that the normal sex differentiation of certain hypothalamic networks is altered. We tested this hypothesis by investigating the pattern of cerebral activation in 12 nonhomosexual male-to-female transsexuals (MFTRs) when smelling 4,16-androstadien-3-one (AND) and estra-1,3,5(10),16-tetraen-3-ol (EST). These steroids are reported to activate the hypothalamic networks in a sex-differentiated way.

Do delay aversion and executive function deficits make distinct contributions to the functional impact of ADHD symptoms? A study of early academic skill deficits.

Background: The present study examined the distinct properties of executive functioning in relation to ADHD symptoms, as well as functional outcomes associated with ADHD. In line with the dual-pathway model of ADHD, executive functioning and delay aversion were expected to show independent effects on ADHD symptoms. Furthermore, relations to early academic skills were examined, and it was hypothesized that the two processes of the dual-pathway model can be differentiated in terms of their effect on academic skill deficits, such that EF deficits, but not delay aversion, mediate the link between ADHD and academic functioning.

Resting-state networks in the infant brain.

In the absence of any overt task performance, it has been shown that spontaneous, intrinsic brain activity is expressed as systemwide, resting-state networks in the adult brain. However, the route to adult patterns of resting-state activity through neuronal development in the human brain is currently unknown. Therefore, we used functional MRI to map patterns of resting-state activity in infants during sleep.

Independent neural control of rhythmic sequences--behavioral and fMRI evidence.

Can the temporal structure of movement sequences can be represented and learned independently of their ordinal structure? Are some brain regions particularly important for temporal sequence performance? We addressed these questions in behavioral and functional magnetic resonance imaging (fMRI) experiments. Using a learning transfer design, we found evidence for independent temporal representations: learning a spatiotemporal sequence facilitated learning its temporal and ordinal structure alone; learning a temporal and an ordinal structure facilitated learning of a sequence where the two were coupled. Secondly, learning of temporal structures was found during reproduction of sequential stimuli with random ordinal structure, suggesting independent mechanisms for temporal learning.

Tectal control of locomotion, steering, and eye movements in lamprey.

The intrinsic function of the brain stem-spinal cord networks eliciting the locomotor synergy is well described in the lamprey-a vertebrate model system. This study addresses the role of tectum in integrating eye, body orientation, and locomotor movements as in steering and goal-directed behavior. Electrical stimuli were applied to different areas within the optic tectum in head-restrained semi-intact lampreys (n = 40).

Brain response to putative pheromones in lesbian women.

The progesterone derivative 4,16-androstadien-3-one (AND) and the estrogen-like steroid estra-1,3,5(10),16-tetraen-3-ol (EST) are candidate compounds for human pheromones. In previous positron emission tomography studies, we found that smelling AND and EST activated regions primarily incorporating the sexually dimorphic nuclei of the anterior hypothalamus, that this activation was differentiated with respect to sex and compound, and that homosexual men processed AND congruently with heterosexual women rather than heterosexual men. These observations indicate involvement of the anterior hypothalamus in physiological processes related to sexual orientation in humans.