Limits...
The mechanisms of feature inheritance as predicted by a systems-level model of visual attention and decision making.

Hamker FH - Adv Cogn Psychol (2008)

Bottom Line: We find that the presence of feedback loops alone is sufficient to account for feature inheritance.Although our simulations do not cover all experimental variations and focus only on the general principle, our result appears of specific interest since the model was designed for a completely different purpose than to explain feature inheritance.We suggest that feedback is an important property in visual perception and provide a description of its mechanism and its role in perception.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Westf.-Wilhelms-Universität Münster, Germany.

ABSTRACT
Feature inheritance provides evidence that properties of an invisible target stimulus can be attached to a following mask. We apply a systemslevel model of attention and decision making to explore the influence of memory and feedback connections in feature inheritance. We find that the presence of feedback loops alone is sufficient to account for feature inheritance. Although our simulations do not cover all experimental variations and focus only on the general principle, our result appears of specific interest since the model was designed for a completely different purpose than to explain feature inheritance. We suggest that feedback is an important property in visual perception and provide a description of its mechanism and its role in perception.

No MeSH data available.


Population activity in IT from target onset to mask offset in three different						model conditions, sensory-driven perception without feedback, sensory driven						perception with feedback and hypothesis-driven feedback with the memorizing						a target template at 180-200 ms after target onset. The numbers on the left						indicate the orientation offset of the target stimulus with respect to the						mask.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2864986&req=5

Figure 5: Population activity in IT from target onset to mask offset in three different model conditions, sensory-driven perception without feedback, sensory driven perception with feedback and hypothesis-driven feedback with the memorizing a target template at 180-200 ms after target onset. The numbers on the left indicate the orientation offset of the target stimulus with respect to the mask.

Mentions: We simulated five different models, (1) sensory-driven without feedback, (2) sensory-driven with feedback (passive hypothesis testing), and three versions of active hypothesis testing (3) hypothesis-driven with memory encoding between 100-120 ms, (4) hypothesis-driven with memory encoding between 140-160 ms, and (5) hypothesis-driven with memory encoding between 180-200 ms. For each model we ran 12 trials with a varying orientation offset between target and mask (0°, 5°, 10°, 15°, 20°, 25°, 30°, 40°, 45°, 50°, 55°, 60°). In the simulation of the model without feedback the cells in IT fire less vigorously (Fig. 5). However, more important appears the general trend that the peak activity is shifted to the orientation of the target when we compare the model without feedback to other models. At an orientation offset of about 45° or more, a second peak in the population response emerges. We did not test if our decision model can detect this peak since the alternative choice is poorly defined, but it appears that in this case the target is either successfully masked or shines through the mask. Without feedback, the information of the target is erased at 100-150 ms depending on the orientation offset, whereas with feedback the information erases between 150-200 ms after target onset. Thus, the memorization of the neural response at different times leads to less target information in memory with increasing time (Fig. 6A). Moreover, for all three models of hypothesis-driven perception, large orientation offsets lead to little or no influence of the target information on the population encoded in memory since only the strongest population enters memory. According to the first approach to the perception of masked visual stimuli, the memory content represents the input of the decision (Smith et al., 2004). Thus, this model predicts the perception of relatively strong tilts (Fig. 6A). In many cases, the perceived tilt is about half of the veridical tilt, which is not consistent with the typical observation (Herzog & Koch, 2001).


The mechanisms of feature inheritance as predicted by a systems-level model of visual attention and decision making.

Hamker FH - Adv Cogn Psychol (2008)

Population activity in IT from target onset to mask offset in three different						model conditions, sensory-driven perception without feedback, sensory driven						perception with feedback and hypothesis-driven feedback with the memorizing						a target template at 180-200 ms after target onset. The numbers on the left						indicate the orientation offset of the target stimulus with respect to the						mask.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2864986&req=5

Figure 5: Population activity in IT from target onset to mask offset in three different model conditions, sensory-driven perception without feedback, sensory driven perception with feedback and hypothesis-driven feedback with the memorizing a target template at 180-200 ms after target onset. The numbers on the left indicate the orientation offset of the target stimulus with respect to the mask.
Mentions: We simulated five different models, (1) sensory-driven without feedback, (2) sensory-driven with feedback (passive hypothesis testing), and three versions of active hypothesis testing (3) hypothesis-driven with memory encoding between 100-120 ms, (4) hypothesis-driven with memory encoding between 140-160 ms, and (5) hypothesis-driven with memory encoding between 180-200 ms. For each model we ran 12 trials with a varying orientation offset between target and mask (0°, 5°, 10°, 15°, 20°, 25°, 30°, 40°, 45°, 50°, 55°, 60°). In the simulation of the model without feedback the cells in IT fire less vigorously (Fig. 5). However, more important appears the general trend that the peak activity is shifted to the orientation of the target when we compare the model without feedback to other models. At an orientation offset of about 45° or more, a second peak in the population response emerges. We did not test if our decision model can detect this peak since the alternative choice is poorly defined, but it appears that in this case the target is either successfully masked or shines through the mask. Without feedback, the information of the target is erased at 100-150 ms depending on the orientation offset, whereas with feedback the information erases between 150-200 ms after target onset. Thus, the memorization of the neural response at different times leads to less target information in memory with increasing time (Fig. 6A). Moreover, for all three models of hypothesis-driven perception, large orientation offsets lead to little or no influence of the target information on the population encoded in memory since only the strongest population enters memory. According to the first approach to the perception of masked visual stimuli, the memory content represents the input of the decision (Smith et al., 2004). Thus, this model predicts the perception of relatively strong tilts (Fig. 6A). In many cases, the perceived tilt is about half of the veridical tilt, which is not consistent with the typical observation (Herzog & Koch, 2001).

Bottom Line: We find that the presence of feedback loops alone is sufficient to account for feature inheritance.Although our simulations do not cover all experimental variations and focus only on the general principle, our result appears of specific interest since the model was designed for a completely different purpose than to explain feature inheritance.We suggest that feedback is an important property in visual perception and provide a description of its mechanism and its role in perception.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, Westf.-Wilhelms-Universität Münster, Germany.

ABSTRACT
Feature inheritance provides evidence that properties of an invisible target stimulus can be attached to a following mask. We apply a systemslevel model of attention and decision making to explore the influence of memory and feedback connections in feature inheritance. We find that the presence of feedback loops alone is sufficient to account for feature inheritance. Although our simulations do not cover all experimental variations and focus only on the general principle, our result appears of specific interest since the model was designed for a completely different purpose than to explain feature inheritance. We suggest that feedback is an important property in visual perception and provide a description of its mechanism and its role in perception.

No MeSH data available.