Biomedical subjects

G Pagnoni

Publications and source records attributed to G Pagnoni.

3 recordsLinked to original sources

PubMed2001

Predictability modulates human brain response to reward.

Certain classes of stimuli, such as food and drugs, are highly effective in activating reward regions. We show in humans that activity in these regions can be modulated by the predictability of the sequenced delivery of two mildly pleasurable stimuli, orally delivered fruit juice and water. Using functional magnetic resonance imaging, the activity for rewarding stimuli in both the nucleus accumbens and medial orbitofrontal cortex was greatest when the stimuli were unpredictable. Moreover, the subjects' stated preference for either juice or water was not directly correlated with activity in reward regions but instead was correlated with activity in sensorimotor cortex. For pleasurable stimuli, these findings suggest that predictability modulates the response of human reward regions, and subjective preference can be dissociated from this response.

Adolescent↗

PubMed2001

Explicit and incidental facial expression processing: an fMRI study.

Considerable evidence indicates that processing facial expression involves both subcortical (amygdala and basal ganglia) and cortical (occipito-temporal, orbitofrontal, and prefrontal cortex) structures. However, the specificity of these regions for single types of emotions and for the cognitive demands of expression processing, is still unclear. This functional magnetic resonance imaging (fMRI) study investigated the neural correlates of incidental and explicit processing of the emotional content of faces expressing either disgust or happiness. Subjects were examined while they were viewing neutral, disgusted, or happy faces. The incidental task required subjects to decide about face gender, the explicit task to decide about face expression. In the control task subjects were requested to detect a white square in a greyscale mosaic stimulus. Results showed that the left inferior frontal cortex and the bilateral occipito-temporal junction responded equally to all face conditions. Several cortical and subcortical regions were modulated by task type, and by facial expression. Right neostriatum and left amygdala were activated when subjects made explicit judgements of disgust, bilateral orbitofrontal cortex when they made judgement of happiness, and right frontal and insular cortex when they made judgements about any emotion.

Adult↗

PubMed1999

Bilateral representation of sequential finger movements in human cortical areas.

The spatial distribution of cortical neural clusters activated during movement of either hand ('bilateral' population), or only of one hand, was investigated in healthy right-handed volunteers performing a sequential finger opposition task, using echo-planar functional magnetic resonance imaging. 'Bilateral' clusters were found in the mesial premotor, perirolandic and adjacent lateral premotor cortex of the two hemispheres, and in the left superior parietal lobule. In the precentral gyrus, their spatial extent was larger on the left hemisphere. Clusters activated exclusively during contralateral finger movements were equally distributed in the left and right perirolandic cortex. No cluster activated exclusively during ipsilateral finger movements was detected. These findings support a role of the motor/lateral premotor cortex of the dominant hemisphere in bilateral motor control.

Adult↗