Emotion can be described by both dimensional and categorical models, exemplified respectively by Peter Lang’s dimensions of valence, salience and arousal and by Paul Ekman’s six basic emotional expressions – happiness, sadness, fear, surprise, anger and disgust. Both models are supported by functional brain imaging. We previously reported increased activity of the anterior insula in response to images evoking disgust, but not to frightening images. Schienle et al. recently published contradictory data showing activation of the anterior insula by both disgust and fear. Since they included pictures of mutilations in their disgust category, we conducted the experiment using three categories: firstly, pictures of contaminants, secondly, pictures of mutilations and thirdly, pictures of imminent threat. The pictures were presented in three 3-minute runs, each consisting of alternating blocks of emotional and neutral pictures. MRI data were acquired using a 3T Siemens Allegra and analyzed using Brain Voyager (Bra...

The specificity of the hemodynamic response function (HRF) is determined spatially by the vascular architecture and temporally by the evolution of hemodynamic changes. The stimulus duration has additional influence on the spatiotemporal evolution of the HRF, as brief stimuli elicit responses that engage only the local vasculature, whereas long stimuli lead to the involvement of remote vascular supply and drainage. Here, we used functional magnetic resonance imaging to investigate the spatiotemporal evolution of the blood oxygenation level-dependent (BOLD), cerebral blood flow (CBF), and cerebral blood volume (CBV) HRF to ultrashort forelimb stimulation in an anesthetized rodent model. The HRFs to a single 333-μs-long stimulus were robustly detected and consisted of a rapid response in both CBF and CBV, with an onset time (OT) of 350 ms and a full width at half-maximum of 1 s. In contrast, longer stimuli elicited a dispersive transit of oxygenated blood across the cortical microvasculature that significantl...

The utilization of stem cells as therapeutic agents is an active area of current research. Although cell-based therapy has been successfully implemented in animal models of stroke or Parkinson’s disease, clinical trials have demonstrated only modest therapeutic effects. Further research is needed to better understand the mechanisms governing cellular migration and differentiation. Magnetic resonance (MR) tracking of stem cells is a new emerging application that aims to obtain a better understanding of the dynamics of cell-tissue interactions, as well as to aid in guiding the development of effective cell therapies. In this study we report on the applicability of MR tracking of magnetically labeled (magnetofected) neural stem cells following transplantation into the dysmyelinated mouse brain. LacZ-transfected C17.2 neural stem cells were Feridex/poly-L-lysine labeled and transplanted into the lateral ventricle of neonatal shiverer mice. In vivo MR imaging was performed at 1, 4, 7 and 14 days after cell tran...

Introduction The prefrontal cortex (PFC) is thought to play an important role especially for our ability to orchestrate thoughts and actions in accordance with internal goals. In experimental psychology, cognitive control has been investigated using the so-called task-switching paradigm. In this paradigm, participants have to selectively adapt their behavior to different situations and tasks. Most importantly, participants are always unequivocally told what to do and cannot deliberately decide which task to perform. This leads to the question whether the task-switching paradigm is suited to investigate active control processes. Methods The present fMRI study aimed at investigating processes which are relevant when participants themselves can decide which task to perform. Four simple discrimination tasks were used. The number of tasks to choose from was varied between a non-choice (1 degree of freedom; DF) and two choice conditions (2 DF or 3 DF). Results The behavioral results revealed a difference for the...

Deep brain stimulation (DBS) is an established therapy for the motor symptoms of Parkinson’s disease (PD). Nevertheless, the underlying circuit mechanisms of DBS are still unclear, and this impedes the continued improvement of DBS therapy. To fill this ...

Absence seizures are 5–10 s episodes of impaired consciousness accompanied by 3–4 Hz generalized spike-and-wave discharge on electroencephalography (EEG). The time course of functional magnetic resonance imaging (fMRI) changes in absence seizures in relation to EEG and behavior is not known. We acquired simultaneous EEG–fMRI in 88 typical childhood absence seizures from nine pediatric patients. We investigated behavior concurrently using a continuous performance task or simpler repetitive tapping task. EEG time–frequency analysis revealed abrupt onset and end of 3–4 Hz spike-wave discharges with a mean duration of 6.6 s. Behavioral analysis also showed rapid onset and end of deficits associated with electrographic seizure start and end. In contrast, we observed small early fMRI increases in the orbital/medial frontal and medial/lateral parietal cortex >5 s before seizure onset, followed by profound fMRI decreases continuing >20 s after seizure end. This time course differed markedly from the hemodynamic re...

Directing attention to some acoustic features of a sound has been shown repeatedly to modulate the stimulus-induced neural responses. On the contrary, little is known about the neurophysiological impact of auditory attention when the auditory scene remains empty. We performed an experiment in which subjects had to detect a sound emerging from silence (the sound was detectable after different durations of silence). Two frontal activations (right dorsolateral prefrontal and inferior frontal) were found, regardless of the side where sound was searched for, consistent with the well established role of these regions in attentional control. The main result was that the superior temporal cortex showed activations contralateral to the side where sound was expected to be present. The area extended from the vicinity of Heschl's gyrus to the surrounding areas (planum temporale/anterior lateral areas). The effect consisted of both an increase in the response to a sound delivered after attention was directed to detect ...

Objectives: The purpose of the present study is to investigate the cortical changes in pain perception when applying different kind of conditioning sensory stimuli, namely acupuncture (Meridian) and acupuncture-like (Sham) stimuli and to show that these stimuli are essentially those of the stress-inducing stimuli and the results are the consequence of the HPA axis reflexes. Methods: Brain activation was observed with functional magnetic resonance imaging (fMRI) using a set of thermal stimuli as pain stimulus which induced by immersing the index finger into a hot water bath, approximately 51~52°C for 30 seconds. The experiment is performed by applying the pain following Meridian acupuncture and Sham acupuncture which applying needling to the traditionally known acupuncture points and points nearby but not those. These stimuli were manually twirling or rotating of a needle with approximately 1 Hz for a period of 30 seconds and rest period of 30 seconds with repetition of 5 times. Results: The results were co...

Languages differ depending on the set of basic sounds they use (the inventory of consonants and vowels) and on the way in which these sounds can be combined to make up words and phrases (phonological grammar). Previous research has shown that our inventory of consonants and vowels affects the way in which our brains decode foreign sounds ([Goto, 1971][1]; [Näätänen et al., 1997][2]; [Kuhl, 2000][3]). Here, we show that phonological grammar has an equally potent effect. We build on previous research, which shows that stimuli that are phonologically ungrammatical are assimilated to the closest grammatical form in the language ([Dupoux et al., 1999][4]). In a cross-linguistic design using French and Japanese participants and a fast event-related functional magnetic resonance imaging (fMRI) paradigm, we show that phonological grammar involves the left superior temporal and the left anterior supramarginal gyri, two regions previously associated with the processing of human vocal sounds. [1]: #ref-22 [2]: #re...

Purpose: Patients with non-lesional temporal lobe epilepsy (NLTLE) commonly show prominent imaging abnormalities on magnetic resonance imaging (MRI) in the ipsilateral temporal lobe in the absence of hippocampal atrophy. The rat amygdala kindling model shows many of the characteristics of NLTLE, including a relative lack of cell loss in the hippocampus. It is unknown if the imaging changes seen in NLTLE also are present in this model. The present study aimed to determine whether imaging changes seen on MRI in NLTLE are also detectable in the hippocampus in the rat amygdala kindling model, and then utilise this model to investigate the processes underlying these changes. Methods: MRI compatible were developed to enable imaging without the induction of ‘artefacts’. Surgeries were performed according to well-established methods. Following one week recovery, T2 and diffusion weighted images were acquired every two weeks for six weeks on a 4.7T MRI. Electrical stimulations began the day following the first imag...