Metacontrast masking with texture-defined second-order stimuli

Tapia, Evelina; Breitmeyer, Bruno G.; Jacob, Jane

doi:10.1016/j.visres.2011.10.010

Cited by 6 publications

(2 citation statements)

References 65 publications

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“…For example, the classical Yerkes-Dodson law describes a U-shaped relationship between arousal levels and performance in a task [86]. Other, more recent examples of U-shaped relationships are found in psychophysical experiments with visual [26; 72], olfactory [17], or tactile stimuli [9]. A few imaging studies employing a combination of innocuous and noxious stimuli have reported U-shaped S-R curves, e.g., in the prefrontal cortex [8; 16].…”

Section: Methodsmentioning

confidence: 99%

Disentangling linear and nonlinear brain responses to evoked deep tissue pain

Loggia

Edwards

Kim

et al. 2012

Pain

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Pain stimuli evoke widespread responses in the brain. However, our understanding of the physiological significance underlying heterogeneous response within different pain-activated and -deactivated regions is still limited. Using functional MRI, we evaluated brain responses to a wide range of stimulus intensity levels (1 innocuous, 7 painful) in order to estimate region-specific stimulus-response functions, which we hypothesized could illuminate that region’s functional relationship to pain. Linear and nonlinear brain responses to pain were estimated through independent Legendre polynomial transformations of pain ratings within a general linear model. This approach identified at least five different, regionally-specific activity profiles in the brain. Linearly increasing (e.g., primary somatosensory/motor cortex, insulae) and intensity-independent (e.g., secondary somatosensory cortex) activation was noted in traditional pain processing areas, potentially reflecting sensory encoding and all-or-none salience responses, respectively. Multiple activity profiles were seen in areas of the default mode network (DMN): intensity-independent deactivation (e.g., posterior cingulate cortex), linearly decreasing (e.g., contralateral inferior parietal lobule), and quadratic (U-shaped; e.g., medial prefrontal cortex). The latter observation suggests that: 1) different DMN subregions exhibit functional heterogeneity and 2) some DMN subregions respond in a percept-related manner to pain, suggesting closer linkage between the DMN and pain processing than previously thought. Future studies should apply a similar approach using innocuous stimuli of multiple intensities in order to evaluate whether the response profiles reported here can also be generalized to nonpainful somatosensory processing.

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Section: Methodsmentioning

confidence: 99%

Disentangling linear and nonlinear brain responses to evoked deep tissue pain

Loggia

Edwards

Kim

et al. 2012

Pain

View full text Add to dashboard Cite

show abstract

“…Further experiments using our stimuli may investigate the transition from "type A" to "type B" metacontrast as the size of the square mask annulus is progressively diminished. Finally, following and Tapia et al (2010aTapia et al ( , 2010b, it might also be important to distinguish tasks that require a judgment on the surface appearance of the target as opposed to tasks requiring contour discriminations, as these might imply different time courses and, consequently, may have yield different metacontrast functions.…”

Section: Discussionmentioning

confidence: 99%

Dynamics of visual masking revealed by second-order metacontrast

Sackur

2011

Journal of Vision

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Metacontrast is a powerful visual illusion by which the visibility of a brief stimulus is drastically reduced when it is followed by a snugly fitting second, masking stimulus. There have been longstanding debates about the levels at which metacontrast mechanisms operate and about the temporal unfolding of the masking effect. Here, we use second-order features (texture and movement) in order to set a lower bound to the level at which metacontrast may be found. First, we show that interactions of two second-order stimuli readily produce typical metacontrast masking. We then create second-order single-transient stimuli that induce visual percepts when a random uniform texture is locally replaced by a similar random uniform texture. We show that these ultra-brief stimuli can be used both as target and mask. Using these single-transient stimuli, we seek to disentangle the relative contributions of mask onset and offset. Results suggest that, at least in the context of second-order masking, nearly all of the mask's effectiveness is due to the very first visual event that follows the target.

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Visual Masking

Bachmann

Francis

2014

Visual Masking

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Metacontrast masking with texture-defined second-order stimuli

Cited by 6 publications

References 65 publications

Disentangling linear and nonlinear brain responses to evoked deep tissue pain

Disentangling linear and nonlinear brain responses to evoked deep tissue pain

Dynamics of visual masking revealed by second-order metacontrast

Visual Masking

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