The grand-mean ERPs of all 42 subjects for the frontal N1 and occipital P1 components.

<p>The scalp topographies were computed at the time interval of 115 to 135 ms. The three white dots in each topography indicate which three electrodes recorded the most prominent electrical activity. F, fearful faces; N, neutral faces.</p

The scatter plots between the behavioral measure d' and the ERSP differences (fearful ERSP – neutral ERSP) at P7 and P8 electrodes in response to 17-ms presentation.

<p>Significant linear correlation is indicated by dashed line in associated color.</p

Schematic diagram of one experimental trial.

<p>Schematic diagram of one experimental trial.</p

The grand-mean ERSPs of all 42 subjects at P7 and P8 electrodes.

<p>Single-participant ERSP was computed for neutral, fearful and fearful-neutral conditions, averaged across 42 subjects. Nongreen areas in the time/frequency plane show significant (<i>p</i><.05) post-stimulus increases (red) or decreases (blue) in log spectral power relative to mean log power the 200-ms pre-stimulus baseline. Vertical dotted lines indicate the N170 latency in response to neutral (magenta line) and fearful faces (black line).</p

The scatter plots between the behavioral measure d' and the amplitude differences between fearful and neutral faces of the N1 (recorded at FCz), P1 (recorded at O1 and O2), and N170 (recorded at P7 and P8) in response to 17-ms presentations.

<p>Significant linear correlation is indicated by dashed line in associated color.</p

Behavioral results of the 42 subjects (data are presented as mean±SD; minimum to maximum).

<p>Behavioral results of the 42 subjects (data are presented as mean±SD; minimum to maximum).</p

Statistical ERSP comparison between fearful and neutral faces in response to 17-ms facial presentations (five or six participants in each group).

<p>The 42 subjects were divided into 8 groups according to d' values at 17 ms. The number of participants and the mean d' value in each group are displayed in the right column. Single-participant ERSP differences were computed by subtracting the ERSP in response to fearful faces by the ERSP in response to neutral faces, averaged across five or six participants.</p

The grand-mean ERP waveforms at the occipito-temporal electrode sites of P7 and P8.

<p>The grand-mean ERP waveforms at the occipito-temporal electrode sites of P7 and P8.</p

Characteristics of low- and high-arousal speech materials.

a<p>Data were from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0076261#pone.0076261-Liu1" target="_blank">[24]</a>.^b Fundamental frequency.</p

Behavioral results of the 22 subjects (data are presented as mean±SD).

<p>Behavioral results of the 22 subjects (data are presented as mean±SD).</p