Zoey Isherwood

Commonwealth Bank Of Australia · Behavioural Science Centre of Excellence (CoE)

We introduce HumanBrainAtlas, an initiative to construct a highly detailed, open-access atlas of the living human brain that combines high-resolution in vivo MR imaging and detailed segmentations previously possible only in histological preparations. Here, we present and evaluate the first step of this initiative: a comprehensive dataset of two hea...

Color percepts of anomalous trichromats are often more similar to normal trichromats than predicted from their receptor spectral sensitivities, suggesting that post-receptoral mechanisms can compensate for chromatic losses. The basis for these adjustments and the extent to which they could discount the deficiency are poorly understood. We modeled t...

We introduce HumanBrainAtlas, an initiative to construct a highly detailed, open-access atlas of the living human brain that combines high-resolution in vivo MR imaging and detailed segmentations previously possible only in histological preparations. Here, we present and evaluate the first step of this initiative: a comprehensive dataset of two hea...

Natural scenes contain several statistical regularities despite their superficially diverse appearances (e.g., mountains, rainforests, deserts). First, they exhibit a unique distribution of luminance intensities decreasing across spatial frequency, known as the 1/fα amplitude spectrum (α ≈ 1). Additionally, natural scenes share consistent geometric...

Blur is a fundamental perceptual attribute of images, but the way in which the visual system encodes this attribute remains poorly understood. Previously, we examined the neural correlates of blur by measuring BOLD responses to in-focus images and their blurred or sharpened counterparts, formed by varying the slope of the amplitude spectra but main...

It is well established that natural scenes have a 1/f drop off of spatial and temporal frequencies. The exponent or slope of this drop off has often been reported as being equal to 1. However, more recent work in the spatial domain has revealed that only a few natural scenes conform to this value. Instead, photographs of natural scenes on average h...

A number of studies have found that the suprathreshold color responses of anomalous trichromats are stronger than predicted from the reduced spectral separation of their longer wave cone pigments. These compensatory effects could occur if postreceptoral neurons amplify their gain to discount the weaker difference signal provided by the cones. Howev...

It is well established that natural scenes have a 1/fα drop off of spatial and temporal frequencies. The exponent or slope of this drop off (α) has often been reported as being equal to 1. However, more recent work in the spatial domain has revealed that only a few natural scenes conform to this value. Instead, photographs of natural scenes on aver...

We examined whether perception of color saturation and lightness depends on the three-dimensional (3D) shape and surface gloss of surfaces rendered to have different hues. In Experiment 1, we parametrically varied specular roughness of predominantly planar surfaces with different mesoscopic relief heights. The orientation of surfaces was varied rel...

The 1/fα amplitude spectrum is a statistical property of natural scenes characterising a specific distribution of spatial and temporal frequencies and their associated luminance intensities. This property has been studied extensively in the spatial domain whereby sensitivity and visual preference overlap and peak for slopes within the natural range...

Anomalous trichromacy is a common form of congenital color deficiency resulting from a genetic alteration in the photopigments of the eye’s light receptors. The changes reduce sensitivity to reddish and greenish hues, yet previous work suggests that these observers may experience the world to be more colorful than their altered receptor sensitiviti...

Inherited color vision deficiencies typically result from a loss or alteration of the visual photopigments absorbing light and thus impact the very first step of seeing. There is growing interest in how subsequent steps in the visual pathway might be calibrated to compensate for the altered receptor signals, with the possibility that color coding a...

Despite the large variability that exists across nature (e.g. forests, deserts, mountains), natural scenes share many statistical properties. Firstly, they are similar in their photometric properties since they each contain a unique distribution of luminance intensities across spatial and temporal frequencies known as the 1/fα amplitude spectrum (α...

Anomalous trichromacy is a common form of congenital color-deficiency resulting from a genetic alteration in the photopigments of the eye's light receptors. The changes reduce sensitivity to reddish-greenish hues, yet previous work suggests that these observers may experience the world to be more colorful than their altered receptor sensitivities w...

Functional neuroimaging experiments that employ naturalistic stimuli (natural scenes, films, spoken narratives) provide insights into cognitive function “in the wild”. Natural stimuli typically possess crowded, spectrally dense, dynamic, and multimodal properties within a rich multiscale structure. However, when using natural stimuli, various chall...

Despite the large variability that exists across nature (e.g. forests, deserts, mountains), natural scenes share many statistical properties. Firstly, they are similar in their photometric properties since they each contain a unique distribution of luminance intensities across spatial and temporal frequencies known as the 1/fα amplitude spectrum (α...

This study examined perceptual differentiation of specular from diffuse shading for the recovery of surface color and gloss. In Experiment 1, we parametrically varied the mesoscale relief height of globally planar surfaces, specular sharpness and the orientation of the surface relative to the light source. We obtained psychophysical matches for per...

Many natural phenomena exhibit properties that follow a 1/f fractal-like distribution. In vision, this is most readily observed in the amplitude spectra and edge geometry of natural scenes and visual art. As a result, fractal geometries have been widely considered in the explanation of universal aesthetic experience and beauty. We investigated the...

Despite considerable variability in the visual appearance of natural scenes, they share many statistical regularities. Firstly, natural scenes are similar in their photometric properties as they share a unique distribution of luminance intensity variations known as the 1/f⊠ amplitude spectrum (⊠ ≈ 1). Secondly, natural scenes are similar in their g...

It has long been thought that severe chronic pain conditions, such as complex regional pain syndrome (CRPS), are not only associated with, but even maintained by a reorganization of the somatotopic representation of the affected limb in primary somatosensory cortex (S1). This notion has driven treatments that aim to restore S1 representations in CR...

Natural forms, often characterized by irregularity and roughness, have a unique complexity that exhibit self-similarity across different spatial scales or levels of magnification. Our visual system is remarkably efficient in the processing of natural scenes and tuned to the multi-scale, fractal-like properties they possess. The fractal-like scaling...

Despite general acceptance that the retinotopic organisation of human V4 (hV4) takes the form of a single, uninterrupted ventral hemifield, measured retinotopic maps of this visual area are often incomplete. Here, we test hypotheses that artefact from draining veins close to hV4 cause inverted BOLD responses that may serve to obscure a portion of t...

Despite general acceptance that the retinotopic organisation of human V4 (hV4) takes the form of a single, uninterrupted ventral hemifield, measured retinotopic maps of this visual area are often incomplete. Here, we test hypotheses that artefact from draining veins close to hV4 cause inverted BOLD responses that may serve to obscure a portion of t...

It has long been thought that severe chronic pain conditions, such as Complex Regional Pain Syndrome (CRPS), are not only associated with, but even maintained by a reorganisation of the somatotopic representation of the affected limb in primary somatosensory cortex (S1). This notion has driven treatments that aim to restore S1 representations, such...

Natural scenes vary considerably – forests and canyons for instance do not share obvious perceptual similarities. However, in the statistical properties of visual input that the human brain receives across natural scenes, there exists a common distribution of amplitude variations across both spatial and temporal scales. This is known as the 1/fα am...

The hypothesis that surface draining veins distort measurements in human visual area V4 (hV4) offers an explanation for why retinotopic maps measured in this region often appear to contain only an incomplete hemifield (Winawer et al., 2010). Puckett et al. (2014) indicated that voxels contaminated by venous artefact display inverted responses to vi...

Natural scenes share a consistent distribution of energy across spatial frequencies (SF) known as the 1/fα amplitude spectrum (α ≈ 0.8 – 1.5, mean 1.2). This distribution is scale-invariant, which is a fractal characteristic of natural scenes with statistically similar structure at different spatial scales. While the sensitivity of the visual syste...