The role of figural context attention in masking
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the role of figural context & attention in masking. identification task. A. Williams and Weisstein 1978. identification task. A. Williams and Weisstein 1978. identification task. A. Williams and Weisstein 1978. « Consequently, as well as relying on bottom-up activation,

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The role of figural context attention in masking

the role offigural context & attentionin masking


Identification task

identification task

A. Williams and Weisstein 1978


Identification task1

identification task

A. Williams and Weisstein 1978


Identification task2

identification task

A. Williams and Weisstein 1978

« Consequently, as well as relying on bottom-up activation,

the perceptual process may also incorporate a top-down feedback

activity or a same-level horizontal modulation between the

representations of context and local features. »

Breitmeyer and ögmen 2006


Target mask integration

depth connectedness

target-mask integration

A. Williams and Weisstein 1981


Target mask integration1

depth connectedness

target-mask integration

A. Williams and Weisstein 1981


Target mask integration2

depth connectedness

target-mask integration

other gestalt factors also modulating masking

- collinearity (decreased masking)

- symmetry (increased masking)

- similarity (increased masking)

A. Williams and Weisstein 1981


Target only integration

target-only integration

Ramachandran and Cobb 1995, experiment 1


Target only integration1

target-only integration

Ramachandran and Cobb 1995, experiment 1


Target only integration2

target-only integration

Constant SOA = 116 ms

Subjective rating of visibility:

Attending squares: 1.17

Attending circles: 4.08

Ramachandran and Cobb 1995, experiment 2


Conclusion

conclusion (?)

figural context modulates the masking function ...

... but !

some researchers may have combined selective attention and grouping

others have confounded space- or location-based attention with object- or configuration-based attention


Conclusion1

conclusion (?)

figural context modulates the masking function ...

... but !

some researchers may have combined selective attention and grouping

others have confounded space- or location-based attention with object- or configuration-based attention ...

... therefore

unclear if modulation of masking is due to grouping or space/object-based attention


Space based attentional effects

space-based attentional effects

Enns and DiLollo 1997, experiment 1


Space based attentional effects1

space-based attentional effects

  • masking with four-dot mask not only

  • due to low-level contour interactions

Enns and DiLollo 1997, experiment 1


Space based attentional effects2

space-based attentional effects

  • masking insensitive to contour

  • proximity at parafoveal locations

Enns and DiLollo 1997, experiment 2


Space based attentional effects3

space-based attentional effects

  • four-dot masking increased with number of targets

Enns and DiLollo 1997, experiment 3


Space based attentional effects4

  • conclusions

  • four-dot masking cannot be explained by contour-based mechanisms commonly used to explain meta-contrast.

  • one explanation might be incomplete focusing of spatial attention

space-based attentional effects

Enns and DiLollo 1997


Space based attentional effects5

  • conclusions

  • four-dot masking cannot be explained by contour-based mechanisms commonly used to explain meta-contrast.

  • one explanation might be incomplete focusing of spatial attention

space-based attentional effects

« ... these data suggest that the need for observers to distribute their attention over all three targets, prior to the onset of the four dots, resulted in masking of even the foveated target shape. »

Enns and DiLollo 1997


Space based attentional effects6

space-based attentional effects

masking increased with number of targets

Tata 2002, experiment 1


Space based attentional effects7

space-based attentional effects

correct attentional cue decreased masking

Tata 2002, experiment 2


Space based attentional effects8

space-based attentional effects

pop-out effect reduced masking

Tata 2002, experiment 3


Space based attentional effects9

space-based attentional effects

  • conclusions

  • results suggest that theories based on low-level processes early in visual system is insufficient to explain metacontrast masking.

  • visual selective attention plays an important role in metacontrast masking

Tata 2002


Object feature based attentional effects

inattentional blindness, is an observed phenomenon of the inability to perceive features in a visual scene when the observer is not attending to them.

object/feature-based attentional effects


Object feature based attentional effects1

inattentional blindness, is an observed phenomenon of the inability to perceive features in a visual scene when the observer is not attending to them.

object/feature-based attentional effects


Object feature based attentional effects2

inattentional blindness, is an observed phenomenon of the inability to perceive features in a visual scene when the observer is not attending to them.

object/feature-based attentional effects

more familiar, typical, or salient visual objects have higher probability of resisting IB, which leads to less masking compared to items less resistant to IB.


Central attentional effects

  • mechanisms of masking:

  • integration through common synthesis

  • interchannel inhibition

  • replacement principle

central attentional effects

Michaels and Turvey 1979


Central attentional effects1

  • mechanisms of masking:

  • camouflage masking

  • interruption

central attentional effects

another role of attention:

increase spatiotemporal resolution of objects presented to nonfoveal regions

  • masking by four dots possible because:

  • unattended targets are coded with low spatiotemporal resolution

  • attended four-dot mask have an advantage when competing for higher level mechanisms involved in object recognition

Enns and DiLollo 1997


Central attentional effects2

  • mechanisms of masking:

  • camouflage masking

  • interruption

central attentional effects

another role of attention:

increase spatiotemporal resolution of objects presented to nonfoveal regions

  • masking by four dots possible because:

  • unattended targets are coded with low spatiotemporal resolution

  • attended four-dot mask have an advantage when competing for higher level mechanisms involved in object recognition

Object substitution masking

Enns and DiLollo 1997


Conclusions

conclusions

  • figural context and masking

  • gestalt factors influence masking

  • target integrated in an object (2D/3D) is less masked

  • different temporal properties governs operation of different gestalt factors of figural organization

  • target being part of larger gestalt is masked less than when being part of a meaningless arrangement

Breitmeyer and ögmen 2006


Conclusions1

conclusions

  • figural context and masking

  • gestalt factors influence masking

  • target integrated in an object (2D/3D) is less masked

  • different temporal properties governs operation of different gestalt factors of figural organization

  • target being part of larger gestalt is masked less than when being part of a meaningless arrangement

  • attention and masking

  • attending features or location of targets enhances visibility of the target

  • centrally controlled attention processes mediate transfer of information from iconic levels to post-iconic levels predicts level of performance

Breitmeyer and ögmen 2006


Conclusions2

conclusions

both figural context and attention affects visibility of a target, but this is a general feature of attention/figural context when studied in a variety of other experimental paradigms

Breitmeyer and ögmen 2006


Conclusions3

conclusions

both figural context and attention affects visibility of a target, but this is a general feature of attention/figural context when studied in a variety of other experimental paradigms

« Thus both top-down influences on backward masking can be viewed simply as modulators of masking analogous to the bottom-up modulatory effects produced by varying certain physical parameters of the target and mask stimuli »

Breitmeyer and ögmen 2006


Thank you for your attention at the lecture

thank youfor your attentionat the lecture


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