Selective attention contributes to global processing in vision

Dickinson, J. Edwin; Broderick, Carol; Badcock, David R.

doi:10.1167/9.2.6

Cited by 16 publications

(18 citation statements)

References 29 publications

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“…The same ratio was obtained from the much more extensive data set of Dickinson et al (2009). The model also predicts a larger number of coherently placed dot pairs at threshold for the 72 dot-pair stimulus, assuming a constant proportional change in response from that obtained with 0% coherence is required for threshold, since both the response to 0% coherence increases and the slope of the increase in model response is shallower for the 72 dot-pair stimuli.…”

Section: Glass Pattern Experimentsmentioning

confidence: 60%

“…They were presented on the center of the screen within a 1.7° radius circular region to ensure linear summation of signal over the patterns (Wilson et al, 1997; Dickinson et al, 2009). Although no fixation point was given, observers were informed that the stimuli would always appear toward the center of the screen.…”

Section: Methodsmentioning

confidence: 99%

“…Prior work with Glass patterns composed of a small number of pairs yields a threshold of approximately 20% for concentric Glass pattern detection (Wilson et al, 1997; Wilson and Wilkinson, 1998; Badcock et al, 2005; Dickinson et al, 2009). This was used to estimate a threshold of 7 dot-pairs in the 36 pair stimulus.…”

Section: Glass Pattern Experimentsmentioning

confidence: 99%

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Detecting global form: separate processes required for Glass and radial frequency patterns

Badcock¹,

Almeida²,

Dickinson³

2013

Front. Comput. Neurosci.

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Global processing of form information has been studied extensively using both Glass and radial frequency (RF) patterns. Models, with common early stages, have been proposed for the detection of properties of both pattern types but human performance has not been examined to determine whether the two pattern types interact in the manner this would suggest. The experiments here investigated whether low RF patterns and concentric Glass patterns, which are thought to tap the same level of processing in form-vision, are detected by a common mechanism. Six observers participated in two series of masking experiments. First: sensitivity to the presence of either coherent structure, or contour deformation, was assessed. The computational model predicted that detection of one pattern would be masked by the other. Second: a further experiment examined position coding. The model predicted that localizing the center of form in a Glass pattern would be affected by the presence of an RF pattern: sensitivity to a change of location should be reduced and the apparent location should be drawn toward the center of the masking pattern. However, the results observed in all experiments were inconsistent with the interaction predicted by the models, suggesting that separate neural mechanisms for global processing of signal are required to process these two patterns, and also indicating that the models need to be altered to preclude the interactions that were predicted but not obtained.

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Section: Glass Pattern Experimentsmentioning

confidence: 60%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Detecting global form: separate processes required for Glass and radial frequency patterns

Badcock¹,

Almeida²,

Dickinson³

2013

Front. Comput. Neurosci.

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“…In this example, the global motion direction is clockwise, which is opposite the perceived direction of motion for a single element but is consistent with motion energy predictions. patterns (Badcock, Clifford, & Khuu, 2005;Dickinson, Broderick, & Badcock, 2009;Wilson & Wilkinson, 1998). It is likely that some of this disparity arises because global dot motion thresholds are derived from a series (typically eight) of stimulus frames.…”

Section: Resultsmentioning

confidence: 99%

The shape of motion perception: Global pooling of transformational apparent motion

et al. 2013

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Transformational apparent motion (TAM) is a visual phenomenon highlighting the utility of form information in motion processing. In TAM, smooth apparent motion is perceived when shapes in certain spatiotemporal arrangements change. It has been argued that TAM relies on a separate high-level form-motion system. Few studies have, however, systematically examined how TAM relates to conventional low-level motion-energy systems. To this end, we report a series of experiments showing that, like conventional motion stimuli, multiple TAM signals can combine into a global motion percept. We show that, contrary to previous claims, TAM does not require selective attention, and instead, multiple TAM signals can be simultaneously combined with coherence thresholds reflecting integration across the entire stimulus area. This system is relatively weak, less tolerant to noise, and easily overridden when motion energy cues are sufficiently strong. We conclude that TAM arises from high-level form-motion information that enters the motion system by, at least, the stage of global motion pooling.

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“…Glass patterns were presented within an annular aperture with an outer diameter of 14.4° visual angle, an inner diameter of 1.5° visual angle, and with reduced contrast in the 0.75° visual angle before the inner and outer edges following a raised cosine profile. While this stimulus extent is larger than necessary to perceive coherent polar form, spatial integration can proceed over considerable regions of the visual field (Dickinson et al, 2009) and fMRI response estimation reliability for a given visual area is enhanced by the capacity to measure from units with receptive field locations tiling the visual field. Digits relating to a concomitant behavioral task were drawn in the center of the stimulus annulus.…”

Section: Methodsmentioning

confidence: 99%

Consequences of polar form coherence for fMRI responses in human visual cortex

2013

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Relevant features in the visual image are often spatially extensive and have complex orientation structure. Our perceptual sensitivity to such spatial form is demonstrated by polar Glass patterns, in which an array of randomly-positioned dot pairs that are each aligned with a particular polar displacement (rotation, for example) yield a salient impression of spatial structure. Such patterns are typically considered to be processed in two main stages: local spatial filtering in low-level visual cortex followed by spatial pooling and complex form selectivity in mid-level visual cortex. However, it remains unclear both whether reciprocal interactions within the cortical hierarchy are involved in polar Glass pattern processing and which mid-level areas identify and communicate polar Glass pattern structure. Here, we used functional magnetic resonance imaging (fMRI) at 7T to infer the magnitude of neural response within human low-level and mid-level visual cortex to polar Glass patterns of varying coherence (proportion of signal elements). The activity within low-level visual areas V1 and V2 was not significantly modulated by polar Glass pattern coherence, while the low-level area V3, dorsal and ventral mid-level areas, and the human MT complex each showed a positive linear coherence response functions. The cortical processing of polar Glass patterns thus appears to involve primarily feedforward communication of local signals from V1 and V2, with initial polar form selectivity reached in V3 and distributed to multiple pathways in mid-level visual cortex.

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Selective attention contributes to global processing in vision

Cited by 16 publications

References 29 publications

Detecting global form: separate processes required for Glass and radial frequency patterns

Detecting global form: separate processes required for Glass and radial frequency patterns

The shape of motion perception: Global pooling of transformational apparent motion

Consequences of polar form coherence for fMRI responses in human visual cortex

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