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Age-Related Differences in Spatial Frequency Processing during Scene Categorization.

Ramanoël S, Kauffmann L, Cousin E, Dojat M, Peyrin C - PLoS ONE (2015)

Bottom Line: Behavioral results revealed performance degradation for elderly participants only when categorizing HSF scenes.Elderly participants showed activation only in the anterior part of the occipital lobe for LSF scenes (compared to HSF), but not significant activation for HSF (compared to LSF).Activation of temporo-parietal regions was greater in elderly participants irrespective of spatial frequencies.

View Article: PubMed Central - PubMed

Affiliation: Univ. Grenoble Alpes, LPNC, F-38000 Grenoble, France; CNRS, LPNC, F-38000 Grenoble, France; Univ. Grenoble Alpes, GIN, F-38000 Grenoble, France.

ABSTRACT
Visual analysis of real-life scenes starts with the parallel extraction of different visual elementary features at different spatial frequencies. The global shape of the scene is mainly contained in low spatial frequencies (LSF), and the edges and borders of objects are mainly contained in high spatial frequencies (HSF). The present fMRI study investigates the effect of age on the spatial frequency processing in scenes. Young and elderly participants performed a categorization task (indoor vs. outdoor) on LSF and HSF scenes. Behavioral results revealed performance degradation for elderly participants only when categorizing HSF scenes. At the cortical level, young participants exhibited retinotopic organization of spatial frequency processing, characterized by medial activation in the anterior part of the occipital lobe for LSF scenes (compared to HSF), and the lateral activation in the posterior part of the occipital lobe for HSF scenes (compared to LSF). Elderly participants showed activation only in the anterior part of the occipital lobe for LSF scenes (compared to HSF), but not significant activation for HSF (compared to LSF). Furthermore, a ROI analysis revealed that the parahippocampal place area, a scene-selective region, was less activated for HSF than LSF for elderly participants only. Comparison between groups revealed greater activation of the right inferior occipital gyrus in young participants than in elderly participants for HSF. Activation of temporo-parietal regions was greater in elderly participants irrespective of spatial frequencies. The present findings indicate a specific low-contrasted HSF deficit for normal elderly people, in association with an occipito-temporal cortex dysfunction, and a functional reorganization of the categorization of filtered scenes.

No MeSH data available.


(a) Left and right parahippocampal place area (PPA) activated during the perception of scenes compared to faces and objects ([Scenes > Faces + Objects] contrast) for a young participant and an elderly participant. The ROIs were defined independently for each participant by contrasting scenes to other stimuli: [Scenes > Faces + Objects]. (b) Signal changes were then extracted from the scene-selective ROIs for each participant and each experimental condition (NF, LSF, and HSF).Graphics represent the mean percentage of signal change of the 11 young and 12 elderly participants for each ROI. Error bars correspond to the standard errors.
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pone.0134554.g005: (a) Left and right parahippocampal place area (PPA) activated during the perception of scenes compared to faces and objects ([Scenes > Faces + Objects] contrast) for a young participant and an elderly participant. The ROIs were defined independently for each participant by contrasting scenes to other stimuli: [Scenes > Faces + Objects]. (b) Signal changes were then extracted from the scene-selective ROIs for each participant and each experimental condition (NF, LSF, and HSF).Graphics represent the mean percentage of signal change of the 11 young and 12 elderly participants for each ROI. Error bars correspond to the standard errors.

Mentions: The PPA ROIs were defined in each individual, based on the independent Localizer experiment. This served as the structural constraint for the analysis of the data in the Spatial Frequency experiment. No recordings were obtained in one young participant due to technical problems. The PPA was localized for all other participants (11 young and 12 elderly participants) in the two hemispheres (see Fig 5A for an illustration on representative young and elderly participants) based on the ([Scenes > Faces + Objects] contrast). Parameter estimates (% signal change relative to the global mean intensity of signal) of block responses were extracted from the two sphere ROIs for each participant. The average parameter of activity was calculated for each experimental condition. These values were submitted to a first ANOVA for mixed designs with Groups (young and aged participants) as between-subject factor and Hemisphere (Left and Right) and Spatial frequency (NF, LSF, and HSF) as within-subject factors. The three spatial frequency cut-offs used for LSF and HSF scenes were grouped together for this ANOVA. There was no main effect of Groups (F1,21 < 1) but there was a main effect of Spatial frequencies (F2,42 = 15.83, p < 0.05) and a significant Spatial Frequency × Group interaction (F2,42 = 5.86, p < 0.05; Fig 5B). Planned comparisons showed that for young participants, there was no effect of Spatial frequencies (NF vs. HSF: F1,21 = 1.86, p = 0.19; LSF vs. HSF: F1,21 < 1; NF vs. LSF: F1,21 < 1), whereas for elderly participants, HSF scenes elicited less activation than did NF and LSF scenes (NF vs. HSF: F1,21 = 27.52, p < 0.05; LSF vs. HSF: F1,21 = 26.06, p < 0.05; NF vs. LSF: F1,21 < 1). Hemispheres did not interact with either Groups (F1,21 = 1.42, p = 0.25), Spatial frequencies (F2,42 = 1.85, p = 0.17), or their interaction (F2,42 = 2.77, p = 0.07).


Age-Related Differences in Spatial Frequency Processing during Scene Categorization.

Ramanoël S, Kauffmann L, Cousin E, Dojat M, Peyrin C - PLoS ONE (2015)

(a) Left and right parahippocampal place area (PPA) activated during the perception of scenes compared to faces and objects ([Scenes > Faces + Objects] contrast) for a young participant and an elderly participant. The ROIs were defined independently for each participant by contrasting scenes to other stimuli: [Scenes > Faces + Objects]. (b) Signal changes were then extracted from the scene-selective ROIs for each participant and each experimental condition (NF, LSF, and HSF).Graphics represent the mean percentage of signal change of the 11 young and 12 elderly participants for each ROI. Error bars correspond to the standard errors.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4543582&req=5

pone.0134554.g005: (a) Left and right parahippocampal place area (PPA) activated during the perception of scenes compared to faces and objects ([Scenes > Faces + Objects] contrast) for a young participant and an elderly participant. The ROIs were defined independently for each participant by contrasting scenes to other stimuli: [Scenes > Faces + Objects]. (b) Signal changes were then extracted from the scene-selective ROIs for each participant and each experimental condition (NF, LSF, and HSF).Graphics represent the mean percentage of signal change of the 11 young and 12 elderly participants for each ROI. Error bars correspond to the standard errors.
Mentions: The PPA ROIs were defined in each individual, based on the independent Localizer experiment. This served as the structural constraint for the analysis of the data in the Spatial Frequency experiment. No recordings were obtained in one young participant due to technical problems. The PPA was localized for all other participants (11 young and 12 elderly participants) in the two hemispheres (see Fig 5A for an illustration on representative young and elderly participants) based on the ([Scenes > Faces + Objects] contrast). Parameter estimates (% signal change relative to the global mean intensity of signal) of block responses were extracted from the two sphere ROIs for each participant. The average parameter of activity was calculated for each experimental condition. These values were submitted to a first ANOVA for mixed designs with Groups (young and aged participants) as between-subject factor and Hemisphere (Left and Right) and Spatial frequency (NF, LSF, and HSF) as within-subject factors. The three spatial frequency cut-offs used for LSF and HSF scenes were grouped together for this ANOVA. There was no main effect of Groups (F1,21 < 1) but there was a main effect of Spatial frequencies (F2,42 = 15.83, p < 0.05) and a significant Spatial Frequency × Group interaction (F2,42 = 5.86, p < 0.05; Fig 5B). Planned comparisons showed that for young participants, there was no effect of Spatial frequencies (NF vs. HSF: F1,21 = 1.86, p = 0.19; LSF vs. HSF: F1,21 < 1; NF vs. LSF: F1,21 < 1), whereas for elderly participants, HSF scenes elicited less activation than did NF and LSF scenes (NF vs. HSF: F1,21 = 27.52, p < 0.05; LSF vs. HSF: F1,21 = 26.06, p < 0.05; NF vs. LSF: F1,21 < 1). Hemispheres did not interact with either Groups (F1,21 = 1.42, p = 0.25), Spatial frequencies (F2,42 = 1.85, p = 0.17), or their interaction (F2,42 = 2.77, p = 0.07).

Bottom Line: Behavioral results revealed performance degradation for elderly participants only when categorizing HSF scenes.Elderly participants showed activation only in the anterior part of the occipital lobe for LSF scenes (compared to HSF), but not significant activation for HSF (compared to LSF).Activation of temporo-parietal regions was greater in elderly participants irrespective of spatial frequencies.

View Article: PubMed Central - PubMed

Affiliation: Univ. Grenoble Alpes, LPNC, F-38000 Grenoble, France; CNRS, LPNC, F-38000 Grenoble, France; Univ. Grenoble Alpes, GIN, F-38000 Grenoble, France.

ABSTRACT
Visual analysis of real-life scenes starts with the parallel extraction of different visual elementary features at different spatial frequencies. The global shape of the scene is mainly contained in low spatial frequencies (LSF), and the edges and borders of objects are mainly contained in high spatial frequencies (HSF). The present fMRI study investigates the effect of age on the spatial frequency processing in scenes. Young and elderly participants performed a categorization task (indoor vs. outdoor) on LSF and HSF scenes. Behavioral results revealed performance degradation for elderly participants only when categorizing HSF scenes. At the cortical level, young participants exhibited retinotopic organization of spatial frequency processing, characterized by medial activation in the anterior part of the occipital lobe for LSF scenes (compared to HSF), and the lateral activation in the posterior part of the occipital lobe for HSF scenes (compared to LSF). Elderly participants showed activation only in the anterior part of the occipital lobe for LSF scenes (compared to HSF), but not significant activation for HSF (compared to LSF). Furthermore, a ROI analysis revealed that the parahippocampal place area, a scene-selective region, was less activated for HSF than LSF for elderly participants only. Comparison between groups revealed greater activation of the right inferior occipital gyrus in young participants than in elderly participants for HSF. Activation of temporo-parietal regions was greater in elderly participants irrespective of spatial frequencies. The present findings indicate a specific low-contrasted HSF deficit for normal elderly people, in association with an occipito-temporal cortex dysfunction, and a functional reorganization of the categorization of filtered scenes.

No MeSH data available.