Scene analysis with saccadic eye movements: Top-down and bottom-up modeling

2001 ◽  
Vol 10 (1) ◽  
pp. 152 ◽  
Author(s):  
Kerstin Schill
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Scene Analysis ◽  
Top Down ◽  
Bottom Up

Top-Down versus Bottom-up Control of Saccades in Texture Perception

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 162-162 ◽  
Author(s):  
R Groner ◽  
A von Mühlenen ◽  
M Groner
Keyword(s):  
Eye Movements ◽  
Spatial Frequency ◽  
Target Stimulus ◽  
Saccadic Eye Movements ◽  
Landing Site ◽  
Luminance Contrast ◽  
Eye Tracker ◽  
Top Down ◽  
Bottom Up ◽  
Low Pass

An experiment was conducted to examine the influence of luminance, contrast, and spatial frequency content on saccadic eye movements. 112 pictures of natural textures from Brodatz were low-pass filtered (0.04 – 0.76 cycles deg−1) and high-pass filtered (1.91 – 19.56 cycles deg−1) and varied in luminance (low and high) and contrast (low and high), resulting in eight images per texture. Circular clippings of the central parts of the images (approximately 15% of the whole image) were used as stimuli. In the condition of bottom - up processing, the eight stimuli derived from one texture were presented for 1500 ms in a circular arrangement around the fixation cross. They were followed by a briefly presented target stimulus in the centre, which in half the trials was identical to one of the eight test stimuli. Participants had to decide whether the target stimulus was identical to any of the preceding stimuli. During a trial, their eye movements were recorded by means of a Dual-Purkinje-Image eye tracker. In the top - down condition, the target stimulus was presented in each trial prior to the display of the test stimulus. It was assumed that the priming with a target produced a top - down processing of the test stimuli. The latency and landing site of the first saccade were computed and compared between the top - down and bottom - up conditions. It is hypothesised that stimulus characteristics (luminance, contrast, and spatial frequency) play a more prominent role in bottom - up processing, while top - down processing is adjusted to the particular characteristics of the prime.

Knowledge-based scene analysis with saccadic eye movements

1999 ◽  
Author(s):  
Kerstin Schill ◽  
Elisabeth Umkehrer ◽  
Stephan Beinlich ◽  
Gerhard Krieger ◽  
Christoph Zetzsche
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Scene Analysis ◽  
Knowledge Based

Style-Dependency of Melodic Expectation

2015 ◽  
Vol 33 (1) ◽  
pp. 110-128 ◽  
Author(s):  
Zuzana Cenkerová ◽  
Richard Parncutt
Keyword(s):  
Learning Process ◽  
Auditory Scene Analysis ◽  
Scene Analysis ◽  
Top Down ◽  
Bottom Up ◽  
Gestalt Principles ◽  
Auditory Scene ◽  
Similar Organization ◽  
Melodic Expectation

In theories of auditory scene analysis and melodic implication/realization, melodic expectation results from an interaction between top-down processes (assumed to be learned and schema-based) and bottom-up processes (assumed innate, based on Gestalt principles). If principles of melodic expectation are partly acquired, it should be possible to manipulate them – to condition listeners' expectations. In this study, the resistance of three bottom-up expectation principles to learning was tested experimentally. In Experiment 1, expectations for stepwise motion (pitch proximity) were manipulated by conditioning listeners to large melodic leaps; preference for small intervals was reduced after a brief exposure. In Experiment 2, expectations for leaps to rise and steps to fall (step declination) were manipulated by exposing listeners to melodies comprising rising steps and falling leaps; this reduced preferences for descending seconds and thirds. Experiment 3 did not find and hence failed to alter the expectation for small intervals to be followed by an interval in the same direction (step inertia). The results support the theory that bottom-up principles of melodic perception are partly learned from exposure to pitch patterns in music. The long-term learning process could be reinforced by exposure to speech based on similar organization principles.

scholarly journals Cat and mouse search: the influence of scene and object analysis on eye movements when targets change locations during search

2017 ◽  
Vol 372 (1714) ◽  
pp. 20160106 ◽  
Author(s):  
Anne P. Hillstrom ◽  
Joice D. Segabinazi ◽  
Hayward J. Godwin ◽  
Simon P. Liversedge ◽  
Valerie Benson
Keyword(s):  
Eye Movements ◽  
Target Location ◽  
Saccadic Eye Movements ◽  
Movement Planning ◽  
Scene Analysis ◽  
Object Properties ◽  
Visual Mask ◽  
Visible Object ◽  
Scene Gist ◽  
Trial Participants

We explored the influence of early scene analysis and visible object characteristics on eye movements when searching for objects in photographs of scenes. On each trial, participants were shown sequentially either a scene preview or a uniform grey screen (250 ms), a visual mask, the name of the target and the scene, now including the target at a likely location. During the participant's first saccade during search, the target location was changed to: (i) a different likely location, (ii) an unlikely but possible location or (iii) a very implausible location. The results showed that the first saccade landed more often on the likely location in which the target re-appeared than on unlikely or implausible locations, and overall the first saccade landed nearer the first target location with a preview than without. Hence, rapid scene analysis influenced initial eye movement planning, but availability of the target rapidly modified that plan. After the target moved, it was found more quickly when it appeared in a likely location than when it appeared in an unlikely or implausible location. The findings show that both scene gist and object properties are extracted rapidly, and are used in conjunction to guide saccadic eye movements during visual search. This article is part of the themed issue ‘Auditory and visual scene analysis’.

scholarly journals Pictorial balance is a bottom-up aesthetic property mediated by eye movements

2020 ◽  
Author(s):  
David M Corwin
Keyword(s):  
Eye Movements ◽  
Peripheral Vision ◽  
Evolutionary Development ◽  
Complex Object ◽  
Top Down ◽  
Visual Stream ◽  
Aesthetic Property ◽  
Bottom Up ◽  
The Aesthetic ◽  
Visual Percept

Pictures evoke both a top down and a bottom-up visual percept of balance. Through its effect on eye movements, balance is a bottom-up conveyor of aesthetic feeling. Eye movements are predominantly influenced by the large effects of saliency and top-down priorities; it is difficult to separate out the much smaller effect of balance. Given that balance is associated with a unified and harmonious picture and that there is a pictorial effect known to painters and historically documented that does just that, it was thought that such pictures are perfectly balanced. Computer models of these pictures were created by the author and were found to have bilateral quadrant luminance symmetry with a lower half lighter by a factor of ~1.07 +/- ~0.03. A top weighted center of quadrant luminance calculation is proposed to measure balance. To show that this effect exists, two studies were done that compared identical pictures in two different frames with respect to whether they appeared different given that the sole difference is balance. Results show that with observers, mostly painters, there was a significant correlation between average pair imbalance and observations that two identical pictures appeared different indicating at a minimum that the equation for calculating balance was correct. A conventional study of preference could not be done because of the necessity of using LED pictures that increase overall salience, and so decrease the aesthetic effect while retaining the effects on eye movements. The effect is the result of the absence of balancing forces on eye movements. With painters who can disregard salience, the effect results from the absence of forces drawing attention to any part of the image. All parts of the picture including that in peripheral vision receive attention, and the eye seems to slide through rather than to jump from objet to object. The effect is being called pictorial coherency. Large tonally contrasting forms, geometric forms or many different forms that cannot be visually combined prevent the effect from being seen. Pictorial balance, an unaccustomed visual force, explains why viewing pictures cause fatigue. That pictures can evoke such a low level percept based on luminance would indicate that it belongs to a much earlier evolutionary development of the visual stream where it was possibly used to follow movement by defining a complex object as a simple vector.

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