Fig 1.
Modified Navon letter oddball paradigm.
A): Twelve composite letters: a global A made of local E’s, S’s, or H’s; a global E made of local A’s, S’s, or H’s; a global H made of local E’s, S’s, or A’s; and a global S made of local E’s, H’s, or A’s. B): In this example (white background used for example), participants were instructed to determine if the target letter E is present (either at the global or local level, 80% and 10% of trials, respectively), or not present (10% of trials). C): Single trial structure of the oddball task. ITI = inter-trial interval.
Fig 2.
Frequency spectral densities and signal waveforms of the auditory stimuli.
Table 1.
Regression with reaction times predicted by trial frequency and sound condition.
Table 2.
Regressions for reaction times for frequent and rare trials predicted by sound condition.
Table 3.
Regression for reaction time predicted by trial frequency, sound condition, and smartphone addiction.
Fig 3.
Interaction analysis for reaction times predicted by sound condition and smartphone addiction.
Plot of reaction times on trials with smartphone sounds (dashed line) vs. control sounds (solid line) as a function of individual differences in the proneness to smartphone addiction. Plotted separately for frequent and rare target trials.
Table 4.
Regressions for reaction times on frequent and rare trials predicted by sound condition and smartphone addiction.
Table 5.
Logistic regression of error rates predicted by trial frequency and sound condition.
Fig 4.
Overall ERP waveforms and scalp maps.
A. Aggregated ERP waveforms for frequent (black lines) and rare trials (red lines). B. Aggregate ERP scalp distribution maps for P2 at 200 ms, N2 at 350 ms, and P3 at 450 ms latencies. Red color reflects activity for P2 and P3. Blue color reflects activity for N2. (Darker colors reflect increased activity).
Table 6.
Paired samples t-tests for ERP amplitudes between trial frequency.
Fig 5.
N2 amplitude on smartphone and control sound trials.
N2 ERP mean amplitudes on trials with smartphone and control sounds. aN2 is a negative going potential, thus smaller values indicate larger ERP amplitudes.
Table 7.
ERP amplitudes between the smartphone and control sound trials.
Fig 6.
N2 ERPs for trial frequency and sound conditions.
N2 ERP amplitudes on rare and frequent trials with smartphone and control sounds. The oddball effect is difference between rare and frequent trials. aN2 is a negative going potential, thus smaller values indicate larger ERP amplitude. A) Bar chart of mean N2 amplitudes. B) ERP waveforms for frequent trials with control sounds (black line), frequent trials with smartphone sounds (red line), rare trials with control sounds (blue line), and rare trials with smartphone sounds (green line). C) Scalp maps of N2 at 300 ms for frequent and rare trials after delivery of the sound stimulus.
Table 8.
ERP oddball effect between the smartphone and control sound trials.
Fig 7.
Correlation between smartphone addiction and P2 ERP.
Correlation between smartphone addiction proneness and the overall P2 mean amplitude (P2 at site Fz within the 150–210 ms time window), indicating that people with higher levels of smartphone addiction show reduced neural activation implicated in early attentional mechanisms.
Table 9.
Overall P2, N2, and P3 as a function of individual differences in smartphone addiction.
Table 10.
Regressions for ERP oddball effect predicted by smartphone addiction.