Symmetry Detection in Visual Impairment: Behavioral Evidence and Neural Correlates

Cattaneo, Zaira; Bona, Silvia; Bauer, Corinna M.; Silvanto, Juha; Herbert, Andrew M.; Vecchi, Tomaso; Merabet, Lotfi B.

doi:10.3390/sym6020427

Cited by 13 publications

(12 citation statements)

References 74 publications

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“…When assessed in terms of brain processing, these topics would add to the list of open questions on the subject revised by Bertamini and Makin [101]. We know that the detection of visual and haptic symmetry appears to rely on common brain areas such as the lateral occipital complex in sighted individuals and that in both early blind and sighted (but blindfolded) control subjects, the detection of tactile symmetry is associated with a network implicating frontal and parietal cortical areas (i.e., the medial frontal and superior parietal cortices) [95]. However, in the case of early blind individuals, a significant activation in the retinotopic (i.e., primary visual cortex) and object-selective areas (i.e., lateral occipital and fusiform cortices) was also observed.…”

Section: Discussionmentioning

confidence: 99%

“…This might be further extended to embodied experiences of mirror symmetry related to the proprioception of one's own body structure or of specific body movements as well as to haptic symmetry perception (e.g., [91][92][93][94]). We might also ask about the relationship between the proprioceptive and tactile perception of symmetry and the acoustic processing of symmetry in congenitally blind people whose visual experiences of symmetry are lacking [60,[95][96][97][98][99][100]. When assessed in terms of brain processing, these topics would add to the list of open questions on the subject revised by Bertamini and Makin [101].…”

Section: Discussionmentioning

confidence: 99%

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Matching Visual and Acoustic Mirror Forms

Bianchi

Burro

Pezzola³

et al. 2017

Symmetry

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This paper presents a comparative analysis of the ability to recognize three mirror forms in visual and acoustic tasks: inversion (reflection on a horizontal axis), retrograde (reflection on a vertical axis) and retrograde inversion (reflection on both horizontal and vertical axes). Dynamic patterns consisting of five tones in succession in the acoustic condition and five square dots in succession in the visual condition were presented to 180 non-musically expert participants. In a yes/no task, they were asked to ascertain whether a comparison stimulus represented the "target" transformation (i.e., inversion, retrograde or retrograde inversion). Three main results emerged. Firstly, the fact that symmetry pertaining to a vertical axis is the most easily perceived does not only apply to static visual configurations (as found in previous literature) but also applies to dynamic visual configurations and acoustic stimuli where it is in fact even more marked. Secondly, however, differences emerged between the facility with which the three mirror forms were recognized in the acoustic and visual tasks. Thirdly, when the five elements in the stimulus were not of the same duration and therefore a rhythmic structure emerged, performance improved not only in the acoustic but also (even more significantly) in the visual task.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Matching Visual and Acoustic Mirror Forms

Bianchi

Burro

Pezzola³

et al. 2017

Symmetry

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“…Mirror (reflective) symmetry is an important cue in visual perception for both animals and humans and it is extracted fast and pre-attentively from visual scenes (e.g., Barlow and Reeves, 1979;Wagemans et al, 1991; for reviews, see Bertamini and Makin, 2014;Cattaneo et al, 2014;Treder, 2010). The salience of vertical symmetry is likely to have emerged to facilitate recognition of animals (mostly symmetric along the vertical axis) and of human bodies and faces (e.g., Treder, 2010).…”

Section: Introductionmentioning

confidence: 99%

Not all visual symmetry is equal: Partially distinct neural bases for vertical and horizontal symmetry

2017

Self Cite

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Visual mirror symmetry plays an important role in visual perception in both human and animal vision; its importance is reflected in the fact that it can be extracted automatically during early stages of visual processing. However, how this extraction is implemented at the cortical level remains an open question. Given the importance of symmetry in visual perception, one possibility is that there is a network which extracts all types of symmetry irrespective of axis of orientation; alternatively, symmetry along different axes might be encoded by different brain regions, implying that there is no single neural mechanism for symmetry processing. Here we used fMRI-guided transcranial magnetic stimulation (TMS) to compare the neural basis of the two main types of symmetry found in the natural world, vertical and horizontal symmetry. TMS was applied over either right Lateral Occipital Cortex (LO), right Occipital Face Area (OFA) or Vertex while participants were asked to detect symmetry in low-level dot configurations. Whereas detection of vertical symmetry was impaired by TMS over both LO and OFA, detection of horizontal symmetry was delayed by stimulation of LO only. Thus, different types of visual symmetry rely on partially distinct cortical networks.

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“…However, if effects on regularity detection are modality specific, this would indicate that these effects reflect stimulus exploration and information extraction and storage. Compared with research on visual regularity detection, there has been relatively little research investigating the haptic perception of symmetry (for a recent review, see Cattaneo et al, 2014 ). It is well established that haptics can detect symmetry but, as far as we are aware, we are the only researchers to have established that haptics can also detect repetition (Cecchetto & Lawson, 2017 ; Lawson et al, 2016 ).…”

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confidence: 99%

The role of contour polarity, objectness, and regularities in haptic and visual perception

Cecchetto

Lawson

2018

Atten Percept Psychophys

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Regularities like symmetry (mirror reflection) and repetition (translation) play an important role in both visual and haptic (active touch) shape perception. Altering figure-ground factors to change what is perceived as an object influences regularity detection. For vision, symmetry is usually easier to detect within one object, whereas repetition is easier to detect across two objects. For haptics, we have not found this interaction between regularity type and objectness (Cecchetto & Lawson, Journal of Experimental Psychology: Human Perception and Performance, 43, 103–125, 2017; Lawson, Ajvani, & Cecchetto, Experimental Psychology, 63, 197–214, 2016). However, our studies used repetition stimuli with mismatched concavities, convexities, and luminance, and so had mismatched contour polarities. Such stimuli may be processed differently to stimuli with matching contour polarities. We investigated this possibility. For haptics, speeded symmetry and repetition detection for novel, planar shapes was similar. Performance deteriorated strikingly if contour polarity mismatched (keeping objectness constant), whilst there was a modest disadvantage for between-2objects:facing-sides compared to within-1object:outer-sides comparisons (keeping contour polarity constant). For the same task for vision, symmetry detection was similar to haptics (strong costs for mismatched contour polarity, weaker costs for between-2objects:facing-sides comparisons), but repetition detection was very different (weak costs for mismatched contour polarity, strong benefits for between-2objects:facing-sides comparisons). Thus, objectness was less influential than contour polarity for both haptic and visual symmetry detection, and for haptic repetition detection. However, for visual repetition detection, objectness effects reversed direction (within-1object:outer-sides comparisons were harder) and were stronger than contour polarity effects. This pattern of results suggests that regularity detection reflects information extraction as well as regularity distributions in the physical world.

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Symmetry Detection in Visual Impairment: Behavioral Evidence and Neural Correlates

Cited by 13 publications

References 74 publications

Matching Visual and Acoustic Mirror Forms

Matching Visual and Acoustic Mirror Forms

Not all visual symmetry is equal: Partially distinct neural bases for vertical and horizontal symmetry

The role of contour polarity, objectness, and regularities in haptic and visual perception

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