Faces are perceived holistically, a phenomenon best illustrated when the processing of a face feature is affected by the other features. Here, the authors tested the hypothesis that the holistic perception of a face mainly relies on its low spatial frequencies. Holistic face perception was tested in two classical paradigms: the whole-part advantage (Experiment 1) and the composite face effect (Experiments 2-4). Holistic effects were equally large or larger for low-pass filtered faces as compared to full-spectrum faces and significantly larger than for high-pass filtered faces. The disproportionate composite effect found for low-pass filtered faces was not observed when holistic perception was disrupted by inversion (Experiment 3). Experiment 4 showed that the composite face effect was enhanced only for low spatial frequencies, but not for intermediate spatial frequencies known be critical for face recognition. These findings indicate that holistic face perception is largely supported by low spatial frequencies. They also suggest that holistic processing precedes the analysis of local features during face perception.

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Faces Are "Spatial"—Holistic Face Perception Is Supported by Low Spatial Frequencies

Color as a Science

This study shows how advertisers can leverage emotion and attention to engage consumers in watching Internet video advertisements. In a controlled experiment, the authors assessed joy and surprise through automated facial expression detection for a sample of advertisements. They assessed concentration of attention through eye tracking and viewer retention by recording zapping behavior. This allows tests of predictions about the interplay of these emotions and interperson attention differences at each point in time during exposure. Surprise and joy effectively concentrate attention and retain viewers. However, importantly, the level rather than the velocity of surprise affects attention concentration most, whereas the velocity rather than the level of joy affects viewer retention most. The effect of joy is asymmetric, with higher gains for increases than losses for decreases. Using these findings, the authors develop representative emotion trajectories to support ad design and testing.

Emotion-Induced Engagement in Internet Video Advertisements

The role of spatial scales (or spatial frequencies) in the processing of faces, objects, and scenes has recently seen a surge of research activity. In this review, we will critically examine two main theories of scale usage. The fixed theory proposes that spatial scales are used in a fixed, perceptually determined order (coarse to fine). The flexible theory suggests instead that usage of spatial scales is flexible, depending on the requirements of visual information for the categorization task at hand. The implications of the theories are examined for face, object, and scene categorization, attention, perception, and representation.

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Usage of spatial scales for the categorization of faces, objects, and scenes.

PURPOSE To examine the latency of eye movements in three-dimensional space (saccade, vergence, and combined saccade-vergence) in children and adults METHODS Fifteen normal children (45-12 years of age) and 15 normal adults (22-44 years of age) were tested A standard paradigm was used to elicit pure lateral saccades at far and close viewing distance, pure vergence (convergence and divergence), and saccade combined with vergence movements Horizontal eye movements from both eyes were recorded simultaneously by the oculometer, a photoelectric device RESULTS The mean latency in saccades, vergence, and combined eye movements was longer in children than in adults; the variability of such latency values was also larger in children There was a progressive decrease with age in mean latency All latencies approached or reached adult levels at approximately 10 to 12 years of age Latency of saccades at close viewing distance was shorter than that at far in both adults and children Convergence latency was longer than divergence latency in adults and most of the children Latency of components of combined movements was longer than that of corresponding pure movements Children initiated combined movements by triggering the vergence component first, whereas adults did not show a dominant pattern The percentage of synchronous start of the two components was significantly higher in adults CONCLUSIONS Saccade and vergence-triggering mechanisms are distinct and mature progressively and in parallel with age The capacity for synchronization of the two components of combined eye movements develops more slowly and remains below adult level, even at the age of 12 years

The latency of saccades, vergence, and combined eye movements in children and in adults.

On the delay in processing high spatial frequency visual information: reaction time and VEP latency study of the effect of local intensity of stimulation.

Peripheral and central delay in processing high spatial frequencies: reaction time and VEP latency studies.

Spatial summation of S-cone ON and OFF signals: Effects of retinal eccentricity

Contradictory results have been obtained in the studies that compare contour integration abilities in Autism Spectrum Disorders (ASDs) and typically developing individuals. The present study aimed to explore the limiting factors of contour integration ability in ASD and verify the role of the external visual noise by a combination of psychophysical and eye-tracking approaches. To this aim, 24 children and adolescents with ASD and 32 age-matched participants with typical development had to detect the presence of contour embedded among similar Gabor elements in a Yes/No procedure. The results obtained showed that the responses in the group with ASD were not only less accurate but also were significantly slower compared to the control group at all noise levels. The detection performance depended on the group differences in addition to the effect of the intellectual functioning of the participants from both groups. The comparison of the agreement and accuracy of the responses in the double-pass experiment showed that the results of the participants with ASD are more affected by the increase of the external noise. It turned out that the internal noise depends on the level of the added external noise: the difference between the two groups was non-significant at the low external noise and significant at the high external noise. In accordance with the psychophysical results, the eye-tracking data indicated a larger gaze allocation area in the group with autism. These findings may imply higher positional uncertainty in ASD due to the inability to maintain the information of the contour location from previous presentations and interference from noise elements in the contour vicinity. Psychophysical and eye-tracking data suggest lower efficiency in using stimulus information in the ASD group that could be caused by fixation instability and noisy and unstable perceptual template that affects noise filtering.

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Visual Noise Effect on Contour Integration and Gaze Allocation in Autism Spectrum Disorder.

Visually evoked potentials (VEPs) were elicited by Gabor gratings with different lengths and widths at three spatial frequencies (SFs): low, 1.45 c/deg, medium, 2.9 c/deg and high, 5.8 c/deg and at a contrast 3 times above the detection threshold at each SF. An increase of grating length enhanced N1 amplitude at occipital and parietal positions stronger than the increase of grating width at aspect ratios (length : width) above 4:1. The stronger effect of stimulus length than width was reflected also in the amplitude of the later P1 component at central and parietal positions. The larger effect of stimulus length than width on the VEP amplitude was SF specific: it was stronger at 5.8 c/deg, smaller at 2.9 c/deg and vanished at 1.45 c/deg. The results obtained suggest anisotropy in the physiological mechanisms that underlie grating perception and involve bottom- up processes initiated in the occipital cortex.

Milena Mihaylova

Papers

On the delay in processing high spatial frequency visual information: reaction time and VEP latency study of the effect of local intensity of stimulation.

Peripheral and central delay in processing high spatial frequencies: reaction time and VEP latency studies.

Spatial summation of S-cone ON and OFF signals: Effects of retinal eccentricity

Visual Noise Effect on Contour Integration and Gaze Allocation in Autism Spectrum Disorder.

Effect of extending grating length and width on human visually evoked potentials.