Implicit and rapid conversion of letters into sounds by skilled readers might be reflected in the left lateralization of print-tuned N170 event-related potential. A recent study suggests that the leftward asymmetry of the N170 depends on the attentional selection of letters as perceptual objects (Okumura et al., 2015, Neuropsychologia).The present study tested this possibility by using an experimental paradigm of object-based attention. Stimuli were letters (words, nonwords) or symbol strings that spatially overlapped with random-dot fields. Participants were asked to discriminate the color of either the letter/symbol strings or the dots. Left-lateralized negativity for print was elicited at 200–300 ms post-stimulus only when participants attended to the strings. However, this effect occurred later than the typical N170 latency, which might reflect the time required to resolve competition between overlapping stimuli or perceptual completion of letters. The current study is the first to demonstrate that the leftward asymmetry of print-specific ERP requires selective attention to letter strings.

Color facilitates the processing of information in emotional pictures. Studies have reported that the amplitude of event-related potential’s early posterior negativity (EPN) increases more when processing emotional pictures in color than in grayscale. In contrast, the effect of color on the late positive potential (LPP) amplitude is unclear. Color also facilitates perceiving the global properties of pictures. We investigated the effect of color on subjective and psychophysiological indices (EPN and LPP) under perceptually challenging conditions by manipulating the spatial frequency (low-pass pictures). Participants evaluated the valence of pictures (positive, neutral, or negative),and electroencephalograms were measured during the task. The results indicated that positive and neutral pictures in color were rated as more pleasant than in grayscale. Moreover, the EPN amplitudes increased for color than for grayscale images, regardless of the spatial frequency. However, no effect of color was observed on the LPP amplitude. These results suggest that color influences initial visual information processing of emotional pictures, regardless of the spatial frequency.

We developed a method for estimating people’s emotional states by measuring the pressure exerted on their seats. We focused on approach and avoidance behaviors associated with emotional states and evaluated positive and negative emotions using the movement of a person’s center of gravity by measuring the pressure on their seats when they were watching positive, negative, or neutral film-clips. The results showed that the subjective ratings of the films-clips fit the expected emotions. Moreover, participants’ center of gravity, as measured by the seat pressure, was directed backward when watching negative film-clips. These results suggest that seat pressure could be an alternative measure of negative emotions that does not interrupt a person’s work or require attaching sensors.

High-resolution audio has a higher temporal and/or depth resolution than compact disks (CDs). Several researchers have suggested that inaudible high-frequency components of high-resolution audio might influence listeners’ psychophysiological states. Two types of digital sound sources with the identical frequency structure (<22 kHz) were created at different sampling rates (192 kHz and 44.1 kHz) by filtering out inaudible high-frequency components of an original sound source, which was an excerpt of natural environmental sounds recorded in 192-kHz/24-bit format. Twenty-four university students listened to the three sounds in a random order for five minutes each. Results indicated that the 192-kHz sound source compared to the 44.1-kHz sound source induced higher power in the theta (4.0–8.0 Hz) and slow alpha (8.0–10.5 Hz) bands of the electroencephalogram. However, no apparent differences were found in sound quality or subjective mood. These results suggest that digital sound sources with a higher sampling frequency than CDs influence the physiological state of listeners, although the difference might not be consciously perceived.

The early right anterior negativity (ERAN) is an event-related potential occurring when a chord in Western tonal music deviates from the tonal context, which is considered to reflect syntactic processing of music. A recent study reported that the ERAN was enhanced when pitch deviance occurred in a part of the main melody, rather than other parts. However, it remains unclear whether this effect was caused by deviance in the main melody or the treble voice because only a soprano voice was used as the main melody. We used a bass melody in the current study and compared the ERAN amplitudes between bass-deviant and soprano-deviant chords. The results indicated that a larger ERAN was elicited by a chord with soprano-voice deviance than a chord with bass-voice deviance, suggesting that in syntactic processing of music, the treble voice effect is dominant than the melody effect.