Limits...
Effects of broken affordance on visual extinction.

Wulff M, Humphreys GW - Front Hum Neurosci (2015)

Bottom Line: In line with previous research (e.g., Riddoch et al., 2006), extinction was reduced when action-related object pairs and when unrelated tool pairs were presented compared to unrelated object pairs.In addition, performance with action-related objects decreased when the tool appeared on the ipsilesional side compared to when it was on the contralesional side, but only when the tool handle was intact.This attentional capture effect is mediated by the affordance to the intact tool.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, University of Birmingham Birmingham, UK.

ABSTRACT
Previous studies have shown that visual extinction can be reduced if two objects are positioned to "afford" an action. Here we tested if this affordance effect was disrupted by "breaking" the affordance, i.e., if one of the objects actively used in the action had a broken handle. We assessed the effects of broken affordance on recovery from extinction in eight patients with right hemisphere lesions and left-sided extinction. Patients viewed object pairs that were or were not commonly used together and that were positioned for left- or right-hand actions. In the unrelated pair conditions, either two tools or two objects were presented. In line with previous research (e.g., Riddoch et al., 2006), extinction was reduced when action-related object pairs and when unrelated tool pairs were presented compared to unrelated object pairs. There was no significant difference in recovery rate between action-related (object-tool) and unrelated tool pairs. In addition, performance with action-related objects decreased when the tool appeared on the ipsilesional side compared to when it was on the contralesional side, but only when the tool handle was intact. There were minimal effects of breaking the handle of an object rather than a tool, and there was no effect of breaking the handle on either tools or objects on single item trials. The data suggest that breaking the handle of a tool lessens the degree to which it captures attention, with this attentional capture being strongest when the tool appears on the ipsilesional side. The capture of attention by the ipsilesional item then reduces the chance of detecting the contralesional stimulus. This attentional capture effect is mediated by the affordance to the intact tool.

No MeSH data available.


Data for one-item and two-item trials in the Intact (unbroken handles) condition and in the broken handle condition as a function of side of stimulus. Mean accuracy of performance (A,C) and mean patient accuracies (B,D) with error bars indicating standard error (SE).
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4585295&req=5

Figure 2: Data for one-item and two-item trials in the Intact (unbroken handles) condition and in the broken handle condition as a function of side of stimulus. Mean accuracy of performance (A,C) and mean patient accuracies (B,D) with error bars indicating standard error (SE).

Mentions: Performance on one-item trials was significantly better than performance on two-item trials, confirming that visual extinction was present, F(1,16) = 674.86, p < 0.001, = 0.977. The main effects of side, F(1,16) = 55.10, p < 0.001, = 0.775 (ipsilesional > contralesional stimuli) and patient, F(7,16) = 9.33, p < 0.001, = 0.803, were significant. The number of objects by side interaction, F(1,16) = 6.64, p = 0.020, = 0.293, reached significance. The side effect was slightly larger in the two-item trial conditions compared to the one-item trial conditions, though it was reliable for both, t(23) = 4.96, t(23) = 4.63, both p < 0.001, respectively (see Figure 2A). There were also significant interactions between the number of objects and patient, F(7,16) = 3.70, p = 0.014, = 0.618, between side and patient, F(7,16) = 3.44, p = 0.019, = 0.601, and between number of objects, side and patient, F(7,16) = 14.87, p < 0.001, = 0.867 (Figure 2B). These interactions indicate that the extinction effect was larger for some patients than for others, though all patients showed extinction and patients’ performance varied as a function of the side of stimulus.


Effects of broken affordance on visual extinction.

Wulff M, Humphreys GW - Front Hum Neurosci (2015)

Data for one-item and two-item trials in the Intact (unbroken handles) condition and in the broken handle condition as a function of side of stimulus. Mean accuracy of performance (A,C) and mean patient accuracies (B,D) with error bars indicating standard error (SE).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4585295&req=5

Figure 2: Data for one-item and two-item trials in the Intact (unbroken handles) condition and in the broken handle condition as a function of side of stimulus. Mean accuracy of performance (A,C) and mean patient accuracies (B,D) with error bars indicating standard error (SE).
Mentions: Performance on one-item trials was significantly better than performance on two-item trials, confirming that visual extinction was present, F(1,16) = 674.86, p < 0.001, = 0.977. The main effects of side, F(1,16) = 55.10, p < 0.001, = 0.775 (ipsilesional > contralesional stimuli) and patient, F(7,16) = 9.33, p < 0.001, = 0.803, were significant. The number of objects by side interaction, F(1,16) = 6.64, p = 0.020, = 0.293, reached significance. The side effect was slightly larger in the two-item trial conditions compared to the one-item trial conditions, though it was reliable for both, t(23) = 4.96, t(23) = 4.63, both p < 0.001, respectively (see Figure 2A). There were also significant interactions between the number of objects and patient, F(7,16) = 3.70, p = 0.014, = 0.618, between side and patient, F(7,16) = 3.44, p = 0.019, = 0.601, and between number of objects, side and patient, F(7,16) = 14.87, p < 0.001, = 0.867 (Figure 2B). These interactions indicate that the extinction effect was larger for some patients than for others, though all patients showed extinction and patients’ performance varied as a function of the side of stimulus.

Bottom Line: In line with previous research (e.g., Riddoch et al., 2006), extinction was reduced when action-related object pairs and when unrelated tool pairs were presented compared to unrelated object pairs.In addition, performance with action-related objects decreased when the tool appeared on the ipsilesional side compared to when it was on the contralesional side, but only when the tool handle was intact.This attentional capture effect is mediated by the affordance to the intact tool.

View Article: PubMed Central - PubMed

Affiliation: School of Psychology, University of Birmingham Birmingham, UK.

ABSTRACT
Previous studies have shown that visual extinction can be reduced if two objects are positioned to "afford" an action. Here we tested if this affordance effect was disrupted by "breaking" the affordance, i.e., if one of the objects actively used in the action had a broken handle. We assessed the effects of broken affordance on recovery from extinction in eight patients with right hemisphere lesions and left-sided extinction. Patients viewed object pairs that were or were not commonly used together and that were positioned for left- or right-hand actions. In the unrelated pair conditions, either two tools or two objects were presented. In line with previous research (e.g., Riddoch et al., 2006), extinction was reduced when action-related object pairs and when unrelated tool pairs were presented compared to unrelated object pairs. There was no significant difference in recovery rate between action-related (object-tool) and unrelated tool pairs. In addition, performance with action-related objects decreased when the tool appeared on the ipsilesional side compared to when it was on the contralesional side, but only when the tool handle was intact. There were minimal effects of breaking the handle of an object rather than a tool, and there was no effect of breaking the handle on either tools or objects on single item trials. The data suggest that breaking the handle of a tool lessens the degree to which it captures attention, with this attentional capture being strongest when the tool appears on the ipsilesional side. The capture of attention by the ipsilesional item then reduces the chance of detecting the contralesional stimulus. This attentional capture effect is mediated by the affordance to the intact tool.

No MeSH data available.