Table 2.

Summary of Variables Tested in Generalizability (G) and Decision (D) Analyses

Variable Label	Precise Operational Definition of Variable
Variables Derived from Psychophysical Measures
Temporal Binding Window for Audiovisual Speech	The difference (in ms) between the points where two psychometric curves fit to data for the proportion of reported synchrony across SOAs cross 0.75 (see Figure 1)
Proportion of Fusions in Response to McGurk Ba/Ga Stimuli	Proportion of “da” and “tha” responses to the number of mismatched audiovisual (i.e., auditory “ba” + visual “ga”) trials
Proportion of Fusions in Response to McGurk Pa/Ka Stimuli	Proportion of “ta” and “ha” responses to the number of mismatched audiovisual (i.e., auditory “pa” + visual “ka”) trials
Audiovisual Word Recognition Identification Accuracy −3dB SNR	Number of whole words correctly identified during the speech-in-noise task in the audiovisual condition with a −3dB SNR
Audiovisual Word Recognition Identification Accuracy −6dB SNR	Number of whole words correctly identified during the speech-in-noise task in the audiovisual condition with a −6dB SNR
Variables Derived from Event Related Potential (ERP) Measure
N1 Amplitude	The average amplitude of the grand-average waveform in response to AO and AV stimuli between 100 ms and 140 ms post-stimulus onset
N1 Latency	Length of time, in ms, for the grand-average waveform in response to AO and AV stimuli to reach the maximum amplitude between 100 ms and 140 ms post-stimulus onset
P2 Amplitude	The average amplitude of the grand-average waveform in response to AO and AV stimuli between 160 ms and 240 ms post-stimulus onset
P2 Latency	Length of time, in ms, for the grand-average waveform in response to AO and AV stimuli to reach the maximum amplitude between 160 ms and 240 ms post-stimulus onset
Variables Derived from Eye Tracking Measure
Proportion of Total Looking Time to the Eyes	Proportion of time looking to the eyes AOI of total time looking to the face AOI in each condition (i.e., English ID, Spanish ID, English AD, Spanish AD)
Proportion of Total Looking Time to the Mouth	Proportion of time looking to the mouth AOI of total time looking to the face AOI during each condition (i.e., English ID, Spanish ID, English AD, Spanish AD)

Note. AD = adult-directed; AO = auditory-only; AV = audiovisual; AOI = area of interest; ID = infant-directed; SNR = signal-to-noise ratio; SOA = stimulus onset asynchrony.