Attentional modulation in the human visual cortex: The time-course of the BOLD response and its implications

Smith, Andrew T.; Cotillon-Williams, Nathalie; Williams, AE

doi:10.1016/j.neuroimage.2005.07.003

Cited by 22 publications

(17 citation statements)

References 45 publications

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“…Moreover, processing of a sensory stimulus is enhanced by selective attention to the stimulus. This has been shown in the visual [42], auditory [43], and somatosensory domain [44]. The posterior parietal cortex, however, contains neurons with bilateral receptive fields [45].…”

Section: Discussionmentioning

confidence: 99%

Functional MRI of working memory and selective attention in vibrotactile frequency discrimination

et al. 2007

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Background: Focal lesions of the frontal, parietal and temporal lobe may interfere with tactile working memory and attention. To characterise the neural correlates of intact vibrotactile working memory and attention, functional MRI was conducted in 12 healthy young adults. Participants performed a forced-choice vibrotactile frequency discrimination task, comparing a cue stimulus of fixed frequency to their right thumb with a probe stimulus of identical or higher frequency. To investigate working memory, the time interval between the 2 stimuli was pseudo-randomized (either 2 or 8 s). To investigate selective attention, a distractor stimulus was occasionally presented contralaterally, simultaneous to the probe.

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Section: Discussionmentioning

confidence: 99%

Functional MRI of working memory and selective attention in vibrotactile frequency discrimination

et al. 2007

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“…This area is responsible for visual attention (Smith et al, 2006, Silver et al, 2007). In contrast, the cannabis users demonstrated significantly greater activation of the superior frontal gyrus and brain regions involved in attention (prefrontal and parietal regions, and insula).…”

Section: Methodsmentioning

confidence: 99%

Altered Brain Activation During Visuomotor Integration in Chronic Active Cannabis Users: Relationship to Cortisol Levels

King¹,

Ernst²,

Deng³

et al. 2011

J. Neurosci.

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Cannabis is the most abused illegal substance in the United States. Alterations in brain function and motor behavior have been reported in chronic cannabis users, but the results have been variable. The current study aimed to determine whether chronic active cannabis use in humans may alter psychomotor function, brain activation, and hypothalamic-pituitary-axis (HPA) function in men and women. 30 cannabis users (16 men and 14 women, 18 to 45 years old) and 30 non-drug user controls (16 men and 14 women, 19 to 44 years old) were evaluated with neuropsychological tests designed to assess motor behavior and functional MRI (fMRI), using a 3 Tesla scanner, during a visually paced finger-sequencing task, cued by a flashing checkerboard (at 2 or 4 Hz). Salivary cortisol was measured to assess HPA function. Male, but not female, cannabis users had significantly slower performance on psychomotor speed tests. As a group, cannabis users had greater activation in BA 6 than controls, while controls had greater activation in the visual area BA 17 than cannabis users. Cannabis users also had higher salivary cortisol levels than controls (p = 0.002). Chronic active cannabis use is associated with slower and less efficient psychomotor function, especially in the male users, as indicated by a shift from regions involved with automated visually guided responses to more executive or attentional control areas. These brain activities may be attenuated by the higher cortisol levels in the cannabis users which in turn may lead to less efficient visual-motor function.

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“…A temporal high-pass filter ͑0.017 Hz͒ 19,20 was applied to remove the low frequency noise fluctuations but retain the task-related frequency components. The evoked response of the oxy-Hb signal was estimated by using the general linear model ͑GLM͒ approach with consideration of time series autocorrelation, using the precoloring method.…”

Section: Localizer Task Analysismentioning

confidence: 99%

Detecting resting-state functional connectivity in the language system using functional near-infrared spectroscopy

Zhang

2010

J. Biomed. Opt

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Abstract. Functional connectivity has become one of the important approaches to understanding the functional organization of the human brain. Recently, functional near-infrared spectroscopy ͑fNIRS͒ was demonstrated as a feasible method to study resting-state functional connectivity ͑RSFC͒ in the sensory and motor systems. However, whether such fNIRS-based RSFC can be revealed in high-level and complex functional systems remains unknown. In the present study, the feasibility of such an approach is tested on the language system, of which the neural substrates have been well documented in the literature. After determination of a seed channel by a language localizer task, the correlation strength between the low frequency fluctuations of the fNIRS signal at the seed channel and those at all other channels is used to evaluate the language system RSFC. Our results show a significant RSFC between the left inferior frontal cortex and superior temporal cortex, components both associated with dominant language regions. Moreover, the RSFC map demonstrates left lateralization of the language system. In conclusion, the present study successfully utilized fNIRS-based RSFC to study a complex and highlevel neural system, and provides further evidence for the validity of the fNIRS-based RSFC approach.

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Attentional modulation in the human visual cortex: The time-course of the BOLD response and its implications

Cited by 22 publications

References 45 publications

Functional MRI of working memory and selective attention in vibrotactile frequency discrimination

Functional MRI of working memory and selective attention in vibrotactile frequency discrimination

Altered Brain Activation During Visuomotor Integration in Chronic Active Cannabis Users: Relationship to Cortisol Levels

Detecting resting-state functional connectivity in the language system using functional near-infrared spectroscopy

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