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Dissociable Roles of Dorsolateral Prefrontal Cortex and Frontal Eye Fields During Saccadic Eye Movements.

Cameron IG, Riddle JM, D'Esposito M - Front Hum Neurosci (2015)

Bottom Line: The dorsolateral prefrontal cortex (DLPFC) and the frontal eye fields (FEF) have both been implicated in the executive control of saccades, yet possible dissociable roles of each region have not been established.In contrast, after left DLPFC cTBS, as compared to left S1 cTBS, subjects displayed greater direction errors for contralateral anti-saccades; however, there were no impairments on the number of saccades or the saccade amplitude.These results are consistent with the notion that DLPFC is necessary for executive control of saccades, whereas FEF is necessary for visuo-motor aspects of anti-saccade programming.

View Article: PubMed Central - PubMed

Affiliation: Helen Wills Neuroscience Institute, University of California, Berkeley Berkeley, CA, USA.

ABSTRACT
The dorsolateral prefrontal cortex (DLPFC) and the frontal eye fields (FEF) have both been implicated in the executive control of saccades, yet possible dissociable roles of each region have not been established. Specifically, both establishing a "task set" as well as suppressing an inappropriate response have been linked to DLPFC and FEF activity, with behavioral outcome measures of these mechanisms mainly being the percentage of pro-saccade errors made on anti-saccade trials. We used continuous theta-burst stimulation (cTBS) to disrupt FEF or DLPFC function in humans during an anti-saccade task to assess the causal role of these regions in these executive control processes, and in programming saccades towards (pro-saccade) or away (anti-saccade) from visual targets. After right FEF cTBS, as compared to control cTBS to the right primary somatosensory cortex (rS1), anti-saccade amplitude of the first saccade decreased and the number of anti-saccades to acquire final position increased; however direction errors to the visual target were not different. In contrast, after left DLPFC cTBS, as compared to left S1 cTBS, subjects displayed greater direction errors for contralateral anti-saccades; however, there were no impairments on the number of saccades or the saccade amplitude. These results are consistent with the notion that DLPFC is necessary for executive control of saccades, whereas FEF is necessary for visuo-motor aspects of anti-saccade programming.

No MeSH data available.


Related in: MedlinePlus

(A) Paradigm and stimuli timing, illustrating representative anti-left and anti-left-to-pro-right trials, with the peripheral stimulus on the right. (B) Sample eye traces from FEF study.
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Figure 1: (A) Paradigm and stimuli timing, illustrating representative anti-left and anti-left-to-pro-right trials, with the peripheral stimulus on the right. (B) Sample eye traces from FEF study.

Mentions: Twenty trials were presented in a given run (totaling 7 min) following the basic design of Cameron et al. (2009). Subjects were required to make a saccade to a blue disk located in the periphery of the screen, based on a colored fixation instruction (Figure 1A). The peripheral target stimuli were 15° from fixation in the FEF study and 12° from fixation in the DLPFC study. All stimuli were 0.5° in visual angle and same approximate luminance.


Dissociable Roles of Dorsolateral Prefrontal Cortex and Frontal Eye Fields During Saccadic Eye Movements.

Cameron IG, Riddle JM, D'Esposito M - Front Hum Neurosci (2015)

(A) Paradigm and stimuli timing, illustrating representative anti-left and anti-left-to-pro-right trials, with the peripheral stimulus on the right. (B) Sample eye traces from FEF study.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4644787&req=5

Figure 1: (A) Paradigm and stimuli timing, illustrating representative anti-left and anti-left-to-pro-right trials, with the peripheral stimulus on the right. (B) Sample eye traces from FEF study.
Mentions: Twenty trials were presented in a given run (totaling 7 min) following the basic design of Cameron et al. (2009). Subjects were required to make a saccade to a blue disk located in the periphery of the screen, based on a colored fixation instruction (Figure 1A). The peripheral target stimuli were 15° from fixation in the FEF study and 12° from fixation in the DLPFC study. All stimuli were 0.5° in visual angle and same approximate luminance.

Bottom Line: The dorsolateral prefrontal cortex (DLPFC) and the frontal eye fields (FEF) have both been implicated in the executive control of saccades, yet possible dissociable roles of each region have not been established.In contrast, after left DLPFC cTBS, as compared to left S1 cTBS, subjects displayed greater direction errors for contralateral anti-saccades; however, there were no impairments on the number of saccades or the saccade amplitude.These results are consistent with the notion that DLPFC is necessary for executive control of saccades, whereas FEF is necessary for visuo-motor aspects of anti-saccade programming.

View Article: PubMed Central - PubMed

Affiliation: Helen Wills Neuroscience Institute, University of California, Berkeley Berkeley, CA, USA.

ABSTRACT
The dorsolateral prefrontal cortex (DLPFC) and the frontal eye fields (FEF) have both been implicated in the executive control of saccades, yet possible dissociable roles of each region have not been established. Specifically, both establishing a "task set" as well as suppressing an inappropriate response have been linked to DLPFC and FEF activity, with behavioral outcome measures of these mechanisms mainly being the percentage of pro-saccade errors made on anti-saccade trials. We used continuous theta-burst stimulation (cTBS) to disrupt FEF or DLPFC function in humans during an anti-saccade task to assess the causal role of these regions in these executive control processes, and in programming saccades towards (pro-saccade) or away (anti-saccade) from visual targets. After right FEF cTBS, as compared to control cTBS to the right primary somatosensory cortex (rS1), anti-saccade amplitude of the first saccade decreased and the number of anti-saccades to acquire final position increased; however direction errors to the visual target were not different. In contrast, after left DLPFC cTBS, as compared to left S1 cTBS, subjects displayed greater direction errors for contralateral anti-saccades; however, there were no impairments on the number of saccades or the saccade amplitude. These results are consistent with the notion that DLPFC is necessary for executive control of saccades, whereas FEF is necessary for visuo-motor aspects of anti-saccade programming.

No MeSH data available.


Related in: MedlinePlus