Limits...
Involvement of the Extrageniculate System in the Perception of Optical Illusions: A Functional Magnetic Resonance Imaging Study.

Tabei K, Satoh M, Kida H, Kizaki M, Sakuma H, Sakuma H, Tomimoto H - PLoS ONE (2015)

Bottom Line: During the word task, participants read aloud the kana letters in the stimuli.A direct comparison between the shape and word tasks showed activation of the right inferior frontal gyrus, left medial frontal gyrus, and right pulvinar.It is well known that there are two visual pathways, the geniculate and extrageniculate systems, which belong to the higher-level and primary visual systems, respectively.

View Article: PubMed Central - PubMed

Affiliation: Department of Dementia Prevention and Therapeutics, Graduate School of Medicine, Mie University, Mie, Japan; Department of Neurology, Graduate School of Medicine, Mie University, Mie, Japan.

ABSTRACT
Research on the neural processing of optical illusions can provide clues for understanding the neural mechanisms underlying visual perception. Previous studies have shown that some visual areas contribute to the perception of optical illusions such as the Kanizsa triangle and Müller-Lyer figure; however, the neural mechanisms underlying the processing of these and other optical illusions have not been clearly identified. Using functional magnetic resonance imaging (fMRI), we determined which brain regions are active during the perception of optical illusions. For our study, we enrolled 18 participants. The illusory optical stimuli consisted of many kana letters, which are Japanese phonograms. During the shape task, participants stated aloud whether they perceived the shapes of two optical illusions as being the same or not. During the word task, participants read aloud the kana letters in the stimuli. A direct comparison between the shape and word tasks showed activation of the right inferior frontal gyrus, left medial frontal gyrus, and right pulvinar. It is well known that there are two visual pathways, the geniculate and extrageniculate systems, which belong to the higher-level and primary visual systems, respectively. The pulvinar belongs to the latter system, and the findings of the present study suggest that the extrageniculate system is involved in the cognitive processing of optical illusions.

No MeSH data available.


Related in: MedlinePlus

Shape task vs. baseline.a: shape > baseline (identified as optical illusions: p < 0.05, family-wise error [FWE] corrected), b: shape > baseline (not identified as optical illusions: p < 0.05, FWE-corrected). IFG = inferior frontal gyrus, MFG = middle frontal gyrus, Th = thalamus, MOG = middle occipital gyrus.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4470923&req=5

pone.0128750.g003: Shape task vs. baseline.a: shape > baseline (identified as optical illusions: p < 0.05, family-wise error [FWE] corrected), b: shape > baseline (not identified as optical illusions: p < 0.05, FWE-corrected). IFG = inferior frontal gyrus, MFG = middle frontal gyrus, Th = thalamus, MOG = middle occipital gyrus.

Mentions: During the shape task, the trials in which stimuli were identified as optical illusions were associated with bilateral activation in the inferior and superior frontal gyrus, precentral gyrus, cingulate gyrus, thalamus (dorsomedial nucleus [dm]), ventral lateral nucleus [vl]), and the pulvinar [p]), cuneus, and occipital area relative to baseline (voxel-level corrected) (Fig 3A, Table 2). During the trials in which the stimuli were not identified as optical illusions, bilateral activation occurred in the inferior and superior frontal gyrus, precentral gyrus, cuneus, and occipital area relative to baseline (voxel-level corrected), but there was no bilateral activation in the thalamus, including the pulvinar (Fig 3B, Table 3).


Involvement of the Extrageniculate System in the Perception of Optical Illusions: A Functional Magnetic Resonance Imaging Study.

Tabei K, Satoh M, Kida H, Kizaki M, Sakuma H, Sakuma H, Tomimoto H - PLoS ONE (2015)

Shape task vs. baseline.a: shape > baseline (identified as optical illusions: p < 0.05, family-wise error [FWE] corrected), b: shape > baseline (not identified as optical illusions: p < 0.05, FWE-corrected). IFG = inferior frontal gyrus, MFG = middle frontal gyrus, Th = thalamus, MOG = middle occipital gyrus.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4470923&req=5

pone.0128750.g003: Shape task vs. baseline.a: shape > baseline (identified as optical illusions: p < 0.05, family-wise error [FWE] corrected), b: shape > baseline (not identified as optical illusions: p < 0.05, FWE-corrected). IFG = inferior frontal gyrus, MFG = middle frontal gyrus, Th = thalamus, MOG = middle occipital gyrus.
Mentions: During the shape task, the trials in which stimuli were identified as optical illusions were associated with bilateral activation in the inferior and superior frontal gyrus, precentral gyrus, cingulate gyrus, thalamus (dorsomedial nucleus [dm]), ventral lateral nucleus [vl]), and the pulvinar [p]), cuneus, and occipital area relative to baseline (voxel-level corrected) (Fig 3A, Table 2). During the trials in which the stimuli were not identified as optical illusions, bilateral activation occurred in the inferior and superior frontal gyrus, precentral gyrus, cuneus, and occipital area relative to baseline (voxel-level corrected), but there was no bilateral activation in the thalamus, including the pulvinar (Fig 3B, Table 3).

Bottom Line: During the word task, participants read aloud the kana letters in the stimuli.A direct comparison between the shape and word tasks showed activation of the right inferior frontal gyrus, left medial frontal gyrus, and right pulvinar.It is well known that there are two visual pathways, the geniculate and extrageniculate systems, which belong to the higher-level and primary visual systems, respectively.

View Article: PubMed Central - PubMed

Affiliation: Department of Dementia Prevention and Therapeutics, Graduate School of Medicine, Mie University, Mie, Japan; Department of Neurology, Graduate School of Medicine, Mie University, Mie, Japan.

ABSTRACT
Research on the neural processing of optical illusions can provide clues for understanding the neural mechanisms underlying visual perception. Previous studies have shown that some visual areas contribute to the perception of optical illusions such as the Kanizsa triangle and Müller-Lyer figure; however, the neural mechanisms underlying the processing of these and other optical illusions have not been clearly identified. Using functional magnetic resonance imaging (fMRI), we determined which brain regions are active during the perception of optical illusions. For our study, we enrolled 18 participants. The illusory optical stimuli consisted of many kana letters, which are Japanese phonograms. During the shape task, participants stated aloud whether they perceived the shapes of two optical illusions as being the same or not. During the word task, participants read aloud the kana letters in the stimuli. A direct comparison between the shape and word tasks showed activation of the right inferior frontal gyrus, left medial frontal gyrus, and right pulvinar. It is well known that there are two visual pathways, the geniculate and extrageniculate systems, which belong to the higher-level and primary visual systems, respectively. The pulvinar belongs to the latter system, and the findings of the present study suggest that the extrageniculate system is involved in the cognitive processing of optical illusions.

No MeSH data available.


Related in: MedlinePlus