Magic provides an ecologically valid means of examining ... attentional
misdirection (AM) paradigms, citing four important differences between protocols
within ...
Using magic to reconcile inattentional blindness and attentional misdirection
ECEM 2011
Anthony S. Barnhart Arizona State University Abstract Recently, Memmert [2010, Consciousness & Cognition, 19, 1097-1101] argued for an empirical dissociation between inattentional blindness (IB) and attentional misdirection (AM) paradigms, citing four important differences between protocols within each field of study. Following the lead of Kuhn and Tatler [2005, Perception, 34, 1153-1161], we have developed a magic trick for use in eye-tracking experimentation that has properties which make it ideal for reconciling the differences highlighted in Memmert’s critique, while maintaining the ecological validity that many experiments in IB lack. In the magic trick, a coin placed beneath a napkin disappears, reappearing under a different napkin. Depending upon the condition, in some instances participants were also required to identify a briefly presented visual stimulus. Careful attention during the trial would allow a participant to detect the “secret” event that underlies the illusion, as the event happens in full view. The magic trick has been used to successfully replicate results across the IB and AM literatures, including the common finding that IB cannot be predicted by the locus of fixation, relative to the IB stimulus. We will show how the magic trick can be manipulated to address each of Memmert’s points.
Attention & Magic
Results: IB Rates
Kuhn & colleagues (2005; 2008; 2010) developed a unique magic trick for use in IB experimentation wherein a cigarette and lighter disappear. Although the method used to vanish the cigarette happened in full view, few participants detected it. The method replicated and extended findings from the IB (and change blindness) literature. Fixation location during critical period was not predictive of IB, suggesting differences in covert attentional deployment.
In its pure form (C1), the illusion produces rates of IB similar to those of Kuhn et al. (2008) and Simons & Chabris (1999).
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IB Rate
Magic provides an ecologically valid means of examining inattentional blindness (IB).
Rates of IB differed significantly between conditions. 80% 60% 40% 20%
Reduction of IB rate in C2 runs counter to predictions from magic theory.
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Results: IB Predictors In a replication of Kuhn et al. (2008), IB could not be predicted by fixations during the critical period. At midpoint of critical period, fixation distances did not differ between IB and not-IB participants . Condition 1 Heat Maps: Critical Period.
Kuhn, Tatler, Findlay, & Cole (2008)
Eye movements following the critical period were predictive of IB.
1) Definition of unexpected object: In AM, the identity of the IB stimulus is foreshadowed; In IB, it is not. 2) Control task: IB experiments typically employ a fullattention control trial; AM experiments do not consistently. 3) Attention workload of the task: IB experiments employ a distractor task; AM experiments do not. 4) Functionality of the unexpected object: IB stimuli are irrelevant to the task while AM stimuli are integral to it.
Current Experiment We adapted an illusion from Regal (1999) for use in IB experimentation. A coin placed beneath a napkin disappears from its location and reappears beneath a second napkin. The method behind the illusion happens in full view, but is often missed due to social cues and attentional workload. Method: Three between-subject experimental conditions: 1) Experimental Trial & Free-Viewing Trial (6 participants) 2) Three Control Trials (no movement), Experimental Trial, & Free-Viewing Trial (12 participants) 3) Condition 2 with Distractor Task (8 participants) Participants were queried on the location of the coin after each trial to gauge blindness, with follow-up questions after the free-viewing trial.
not blind
Across conditions, not-IB participants fixated the endpoint of the coin movement earlier than IB participants (p = .001). Same was true for C2 comparison of Control to Experimental trials (p = .008). Participants could be differentiated based on first two post-move fixations, but not the third. 12
Fixation Frequency
IB vs. Attentional Misdirection Memmert (2010) highlighted four dissociations between IB and attentional misdirection (AM).
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All reliable predictors occurred after the critical period.
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Start End Napkin Napkin
Coin Area
Face
Start End Napkin Napkin
1st Fixation
Coin Area
2nd Fixation
blind
Face
Start End Napkin Napkin
Coin Area
Face
3rd Fixation
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Left→Right
Right→Left
Initial post-movement fixations: Condition 1
Future Directions Method can be manipulated to examine each of Memmert’s (2010) dissociations. Method provides control over more variables than method employed by Kuhn and colleagues, allowing for extension of early work by Mack & Rock (1998). Support provided by NIH / NIDCD Grant #DC04535 to Stephen D. Goldinger. References provided on accompanying handout.
References Kuhn, G. & Findlay, J. M. (2010). Misdirection, attention, and awareness: Inattentional blindness reveals temporal relationship between eye movements and visual awareness. The Quarterly Journal of Experimental Psychology, 63, 136-146. Kuhn, G. & Tatler, B. W. (2005). Magic and fixation: Now you don’t see it, now you do. Perception, 34, 1155-1161. Kuhn, G., Tatler, B. W., Findlay, J. M., & Cole, G. G. (2008). Misdirection in magic: Implications for the relationship between eye gaze and attention. Visual Cognition, 16, 391-405. Mack, A. & Rock, I. (1998). Inattentional Blindness. Cambridge, MA: MIT Press. Memmert, D. (2010). The gap between inattentional blindness and attentional misdirection. Consciousness and Cognition, 19, 1097-1101. Regal, D. (1999). Close-up & Personal. Seattle, WA: Hermetic Press. Simons, D. J. & Chabris, C. F. (1999). Gorillas in our midst: Sustained inattentional blindness for dynamic events. Perception, 28, 1059-1074.
Please send correspondence to: Anthony Barnhart email:
[email protected] webpage: http://www.AnthonyBarnhart.com
