Amphetamine-like psychostimulants, including methylphenidate, have been shown to produce two opposing effects on dopamine (DA) neurons: a DA receptor-mediated feedback inhibition and a non-DA receptor-mediated excitation. To test whether the latter effect is mediated through the prefrontal cortex (PFC), we made dual-site recordings from the PFC and ventral tegmental area (VTA). Consistent with ...

The Bereitschaftspotential (BP) is a slow negative cortical potential preceding voluntary movement. Since movement preparation is dependent upon the synchronous activity of a variety of neurons, BP may develop through the exchange of information among motor-related neurons. However, the relationship between BP and information flow is not yet well-known. In the present study, we aimed to investi...

Changes in memory function in elderly individuals are often attributed to dysfunction of the prefrontal cortex (PFC). One mechanism for this dysfunction may be disruption of white matter tracts that connect the PFC with its anatomical targets. Here, we tested the hypothesis that white matter degeneration is associated with reduced prefrontal activation. We used white matter hyperintensities (WM...

The prefrontal cortex (PFC) plays a fundamental role in internally guided behavior. Although it is generally accepted that PFC subserves working memory and executive control operations, it remains unclear whether the subregions within lateral PFC support distinct executive control processes. An event-related fMRI study was implemented to test the hypothesis that ventrolateral and dorsolateral P...

Several neuroimaging studies of cognitive ageing have found that age-related deficits in working memory (WM) and episodic memory abilities are related to changes in prefrontal cortex (PFC) function. Reviews of these neuroimaging studies have generally concluded that with age there is a reduction in the hemispheric specialization of cognitive function in the frontal lobes that may either be due ...

Several current models propose an important role of the prefrontal cortex (PFC) in attention. To test the effects of attention in PFC, we recorded from PFC neurons in monkeys performing a task in which they had to attend to one hemifield and wait for a single stimulus that matched a previously presented cue. Neurons exhibited a slight decrease in their initial response and an enhanced activity ...

BACKGROUND The purpose of this study was to investigate prefrontal cortex (PFC) volumes in youth with posttraumatic stress symptoms (PTSS) and explore the relationship between cortisol secretion and PFC volumes. METHODS Total brain tissue volumes, segmented areas of the PFC, and diurnal cortisol secretion were examined in a sample of 33 youth aged 10 to 16 years. Cerebral volumes were availab...

This is the first study to use fNIRS to explore anaesthetic depth and awakening during surgery with general anaesthesia. A 16 channel continuous wave (CW) functional near-infrared system (fNIRS) was used to monitor PFC activity. These outcomes were compared to BIS measures. The results indicate that deoxyHb concentration in the PFC varies during the suppression and emergence of consciousness. D...

Many brain circuits control behavior by integrating information arising from separate inputs onto a common target neuron. Neurons in the ventral striatum (VS) receive converging excitatory afferents from the prefrontal cortex (PFC), hippocampus (HP), and thalamus, among other structures, and the integration of these inputs is critical for goal-directed behaviors. Although HP inputs have been de...

We investigated the role of prefrontal cortex (PFC) in local contextual processing using a combined event-related potentials and lesion approach. Local context was defined as the occurrence of a short predictive series of visual stimuli occurring before delivery of a target event. Targets were preceded by either randomized sequences of standards or by sequences including a three-stimulus predic...