Search results for "NEUROSCIENCE"

Is It Easy to Synchronize Our Minds When We Are Forced to Cooperate?

2019

There is increasing scientific interest in elucidating the biological mechanisms underlying cooperative behaviors. Humans have developed a high degree of complexity in their cooperativity, which has been defined as hyper-cooperativity. An interesting biological marker to study how two individuals are emotionally linked when they cooperate is their psychophysiological synchronization (the overlapping of signals as indicators of Autonomous Nervous System activation). Hence, the main aim of this study was to explore participants&rsquo

Object Localization Does Not Imply Awareness of Object Category at the Break of Continuous Flash Suppression

2017

In continuous flash suppression (CFS), a dynamic noise masker, presented to one eye, suppresses conscious perception of a test stimulus, presented to the other eye, until the suppressed stimulus comes to awareness after few seconds. But what do we see breaking the dominance of the masker in the transition period? We addressed this question with a dual-task in which observers indicated (i) whether the test object was left or right of the fixation mark (localization) and (ii) whether it was a face or a house (categorization). As done recently Stein et al. (2011a), we used two experimental varieties to rule out confounds with decisional strategy. In the terminated mode, stimulus and masker wer…

Emotional modulation of the attentional blink and the relation to interpersonal reactivity

2013

The extent of the attentional blink effect on detection rates in rapid serial visual presentations is modulated by the emotionality of the stimuli. Emotionally salient stimuli are detected more often, even if presented in the attentional blink period, and elicit an enlarged P3 response, which has been interpreted as enhanced consolidation. This effect correlates with individual differences in trait affectivity such as anxiety or dysphoria. Here, we ask if it is also related to the capacity to detect emotions in others, i.e., to interpersonal social traits. We therefore presented emotional and neutral images depicting social scenes as targets in an attentional blink design and measured detec…

Orosensory Perception of Dietary Lipids in Mammals

2008

Obesity constitutes a major public health problem for the twenty-first century, with its epidemic spread worldwide, particularly in children. The overconsumption of fatty foods greatly contributes to this phenomenon. Rodents and humans display a spontaneous preference for lipid-rich foods. However, the molecular mechanisms underlying this pattern of eating behaviour in mammals remain unclear. The orosensory perception of dietary lipids was long thought to involve only textural and olfactory cues. Recent findings challenge this limited viewpoint, strongly suggesting that the sense of taste also plays a significant role in dietary lipid perception and might therefore be involved in the prefer…

100 Years of Benham's Top in Colour Science

1995

For 100 years Benham's top has been a popular device demonstrating pattern-induced flicker colours (PIFCs). Results of early and recent investigations on PIFCs are reported and show that the phenomenon originates in phase-sensitive lateral interactions of modulated neural activity in the retina followed by additional spatial interactions in the visual cortex behind the locus of binocular fusion. Colour matches with normal colour stimuli indicate that S/(M + L) opponent neurons are involved. Dichromats do not find matching stimuli for all PIFCs. PIFCs may become useful in medical diagnosis. The phenomenon is interpreted as a side effect of a neural mechanism providing colour constancy under…

2017

Prismatic adaption (PA) has been proposed as a tool to induce neural plasticity and is used to help neglect rehabilitation. It leads to a recalibration of visuomotor coordination during pointing as well as to aftereffects on a number of sensorimotor and attention tasks, but whether these effects originate at a motor or attentional level remains a matter of debate. Our aim was to further characterize PA aftereffects by using an approach that allows distinguishing between effects on attentional and motor processes. We recorded EEG in healthy human participants (9 females and 7 males) while performing a new double step, anticipatory attention/motor preparation paradigm before and after adaptat…

Evoked local field potentials can explain temporal variation in blood oxygenation level-dependent responses in rat somatosensory cortex

2010

The aim of this study was to explain the temporal variations between subjects in the blood oxygenation level-dependent (BOLD) response. Somatosensory responses were elicited with the electrical forepaw stimulus at a frequency of 10 Hz in urethane-anesthetized rats, and functional magnetic resonance imaging (fMRI) with BOLD contrast and local field potential (LFP) measurements were performed simultaneously. BOLD fMRI activation was evaluated by two different models, one based on the stimulus paradigm (the block model) and the other on the simultaneously measured evoked LFP responses. In the initial analysis, the LFP model captured the BOLD activation in the primary somatosensory cortex in al…

"Awake Surgery" of Slow-Growing Tumors and Cortical Excitability Measured by EEG Recordings. Preliminary Results

2012

International audience; To investigate interhemispheric imbalance following "awake surgeries" of slow-growing tumors we recorded EEG in a visuo-manual RT paradigm. Increase of cortical excitability within the ipsilesional hemisphere was signed by increased ERPs amplitude for two patients. The cortical excitability in the lesioned hemisphere may be increased to maintain performances and cerebral plasticity.

Penetration of 2% cyclosporin eyedrops into human aqueous humour.

1989

The penetration into the eye and the systemic absorption of 2% cyclosporin eye drops were determined by polarisation immunofluorescent assay of cyclosporin in the aqueous humour and plasma of 30 patients at the time of cataract surgery. The results were then compared with the corresponding results after oral administration at a dosage of 5 mg/kg/day to three further patients. The maximum intraocular concentration (24 (SD 9) mg/l) was achieved four hours after topical administration. This level was slightly less than that found in aqueous humour (28 (SD 10) mg/l) 12 hours after systemic administration of the drug at a dosage of 5 mg/kg/day. Both these levels are below the minimum therapeutic…

Magnetic stimulation in the definition of eloquent cortical areas

2003

Publisher Summary This chapter discusses the physiological principles of transcranial magnetic stimulation (TMS) and focus on detailing the techniques used in TMS mapping of the motor cortex relating it to the use of TMS in the presurgical assessment of patients with epilepsy. Since the main measure of TMS is the motor potential evoked in muscles, fine delineation of the functional topography of cortex is limited mainly to the primary sensorimotor cortex. In addition, TMS might be helpful to identify language dominance. The characterization of eloquent cortical areas is important in epilepsy surgery for the planning of the resection. TMS is not routinely employed for this purpose and TMS ma…