Processing of indexical information requires time: Evidence from change deafness

Abstract

Studies of change detection have increased our understanding of attention, perception, and memory. In two innovative experiments we showed that the change detection phenomenon can be used to examine other areas of cognition—specifically, the processing of linguistic and indexical information in spoken words. One hypothesis suggests that cognitive resources must be used to process indexical information, whereas an alternative suggests that it is processed more slowly than linguistic information. Participants performed a lexical decision task and were asked whether the voice presenting the stimuli changed. Nonwords varying in their likeness to real words were used in the lexical decision task to encourage participants to vary the amount of cognitive resources/processing time. More cognitive resources/processing time are required to make a lexical decision with word-like nonwords. Participants who heard word-like nonwords were more likely to detect the change when it occurred (Experiment 1) and were more confident that the voice was the same when it did not change (Experiment 2). These results suggest that indexical information is processed more slowly than linguistic information and demonstrate how change detection can provide insight to other areas of cognition.

Keywords:

• Change deafness
• Indexical information
• Lexical information

Acknowledgments

This research was supported by a grant from the National Institutes of Health (NIH) to the University of Kansas through the Schiefelbusch Institute for Life Span Studies (NIDCD R01 DC 006472). The experiments in this report partially fulfilled the requirements for a Master's degree in Psychology awarded to A.D. We thank the members of the committee (Andrea Greenhoot and Joan Sereno) for their comments and suggestions.

Notes

¹ For the sake of completeness we report that for the real words, participants correctly indicated that the speaker was the same at a rate of 98.77%. For the word-like nonwords, participants correctly indicated that the speaker was the same at a rate of 97.44%. For the less word-like nonwords, participants correctly indicated that the speaker was the same at a rate of 97.50%.

² Only for completeness do we report the speed and accuracy with which the nonwords in each condition were responded to. Word-like nonwords were correctly responded to with a mean = 1,247.36 ms (SD  = 384.65) and a mean accuracy = 81.2% (SD = 6.3). The less word-like nonwords were correctly responded to with a mean = 1,086.78 ms (SD = 389.73) and a mean accuracy = 90.4% (SD = 5.1).

³ Only for completeness do we report the speed and accuracy with which the nonwords in each condition were responded to. Word-like nonwords were correctly responded to with a mean = 1,328.95 ms (SD = 704.11) and a mean accuracy = 81.6% (SD = 10.2). The less word-like nonwords were correctly responded to with a mean = 1,089.29 ms (SD = 388.25) and a mean accuracy = 92.3% (SD = 7.8).

⁴ For an interesting application of the change detection paradigm to objectively evaluate the prominence of various elements of package labels, see Bix, Kosugi, Bello, Sundar, and Becker (2010).