The ERP and psychophysical changes related to facial emotion perception by expertise in Japanese hospitality, "OMOTENASHI".

We investigated the emotion perception process based on hospitality expertise. Forty subjects were divided into the OMOTENASHI group working at inns considered to represent the spirit of hospitality, OMOTENASHI in Japan, and CONTROL group without experience in the hospitality industry. We presented neutral, happy, and angry faces to investigate P100 and N170 by these faces, and psychophysical changes by the favor rating test to evaluate emotional perception.

Human Face Perception Using Electroencephalography and Magnetoencephalography.

The face has a large amount of information that is useful for humans in social communication. Recently, non-invasive methods have been used to investigate human brain activity related to perception and cognition processes. Electroencephalography (EEG) and magnetoencephalography (MEG) have excellent temporal resolution and reasonably good spatial resolution.

Differential age-related changes in N170 responses to upright faces, inverted faces, and eyes in Japanese children.

The main objectives of this study were to investigate the development of face perception in Japanese children, focusing on the changes in face processing strategies (holistic and/or configural vs. feature-based) that occur during childhood. To achieve this, we analyzed the face-related N170 component, evoked by upright face, inverted face, and eyes stimuli in 82 Japanese children aged between 8- and 13-years-old.

Magnetoencephalographic study on facial movements.

In this review, we introduced our three studies that focused on facial movements. In the first study, we examined the temporal characteristics of neural responses elicited by viewing mouth movements, and assessed differences between the responses to mouth opening and closing movements and an averting eyes condition. Our results showed that the occipitotemporal area, the human MT/V5 homologue, was active in the perception of both mouth and eye motions.

[Mechanisms of face perception in humans: an MEG study].

In this review article, we summarize our results from magnetoencephalography (MEG) and electroencephalography (EEG) studies on face perception. The primary results were as follows: (1) facial (eye and mouth) movements are processed differently from general motion perception, but eye and mouth movements are likely processed in the same manner. (2) In a study investigating the interaction between auditory and visual stimuli relating to vowel sounds in the auditory cortex, vowel sound perception in the auditory cortex, at least in the primary processing stage, was not affected by simultaneously viewing mouth movements.

Electrophysiological study of face inversion effects in Williams syndrome.

Objective: In order to evaluate whether face perception is intact or not in Williams syndrome (WS), the face inversion effects (FIE) in the event-related potential (ERP) or magnetoencephalography (MEG) were investigated in three teenaged patients with WS.

Methods: Responses to the inverted faces and upright faces were compared using MEG for one 13year old girl with WS (subject A) and ERP for boys with WS at 16 and 14years of age (subjects B and C, respectively).

Results: Although age-matched control children showed FIE in both MEG and ERP studies, two subjects (A and B) with WS showed no FIE at all.

Effects of inverting contour and features on processing for static and dynamic face perception: an MEG study.

We investigated the effects of inverting facial contour (hair and chin) and features (eyes, nose and mouth) on processing for static and dynamic face perception using magnetoencephalography (MEG). We used apparent motion, in which the first stimulus (S1) was replaced by a second stimulus (S2) with no interstimulus interval and subjects perceived visual motion, and presented three conditions as follows: (1) U&U: Upright contour and Upright features, (2) U&I: Upright contour and Inverted features, and (3) I&I: Inverted contour and Inverted features. In static face perception (S1 onset), the peak latency of the fusiform area's activity, which was related to static face perception, was significantly longer for U&I and I&I than for U&U in the right hemisphere and for U&I than for U&U and I&I in the left.

The development of the perception of facial emotional change examined using ERPs.

Objective: The development of the perception of changes in facial emotion was investigated using event-related potentials (ERPs) in children and adults.

Methods: Four different conditions were presented: (1) N-H: a neutral face that suddenly changed to a happy face. (2) H-N: reverse of N-H.

The impact of visual movement on auditory cortical responses: a magnetoencephalographic study.

We developed a visual 3D model of a space module and analyzed whether activity in the auditory cortex is influenced by rotating the image using magnetoencephalography. We presented 1,000 Hz pure tone as an auditory stimulus in four different visual conditions: (1) RR: a virtual image rotated around the center, (2) VR: images rotated vertically, (3) HR: images rotated horizontally and (4) ST: the images did not rotate. We compared the difference in the auditory evoked component among the conditions.

Effect of configural distortion on a face-related ERP evoked by random dots blinking.

Using random dots blinking (RDB), which reflects the activity of the higher visual area related to face perception, the following stimuli were presented. (1) Upright: a schematic face; (2) Inverted: the Upright stimulus inverted; and (3) Scrambled: the same contour and features as in Upright but with the spatial relation distorted. Clear negative components (N-ERP250) were identified at approximately 250 ms after stimulus onset.

Emotional object and scene stimuli modulate subsequent face processing: an event-related potential study.

To understand the processing of facial expressions in terms of social communication, it is important to clarify how they are influenced by environmental stimuli such as natural scenes or objects. We investigated how and when neural responses to facial expressions were modulated by both a natural scene and an object containing emotional information. A facial expression stimulus (fearful/neutral) was presented after a scene or object stimulus (fearful/neutral), and then event-related potentials were recorded from both the onset of scene and facial expression presentation.

Interhemispheric difference for upright and inverted face perception in humans: an event-related potential study.

We recorded event-related potentials (ERPs) to investigate the interhemispheric difference of the N170 component for upright and inverted face perception in detail in fifteen healthy subjects. This is the first ERP study focusing on interhemispheric differences for face perception by showing faces in the hemifield. The face inversion effect, the prolonged latency and enhanced amplitude were found in both hemispheres.

Effects of face contour and features on early occipitotemporal activity when viewing eye movement.

We investigated whether early activity in the occipitotemporal region, corresponding to human MT/V5, is influenced by a face contour and/or features such as the mouth using magnetoencephalography (MEG). We used apparent motion as visual stimuli and compared four conditions as follows: (1) CDL: A schematic face consisting of a face Contour, two Dots and a horizontal Line (2) CD: The Contour and two Dots (3) DL: Two Dots and a horizontal Line and (4) D: Two Dots only. Subjects described a simple movement of dots for D, but eye movement for CDL, DL and CD, though movement modalities were the same through all conditions.

Human MT/V5 activity on viewing eye gaze changes in others: A magnetoencephalographic study.

The present study used magnetoencephalography (MEG) to investigate human MT/V5 activity when observing changes in eye gaze. Subjects viewed a face in which the eyes changed to look either directly at (BACK) or away from (AWAY) the subject in a series of apparent motion conditions. BACK involved 2 directions, from left to center (LC) and from right to center (RC).

Priority of face perception during subliminal stimulation using a new color-opponent flicker stimulation.

We developed a new method of color-opponent flicker (COF) stimulation, and investigated behavioral responses for object discrimination at the around threshold frequency of COF stimulation. Pairs of figures, a face, flower, the letter "G" and a random pattern, were drawn with a red and green checkerboard with a black mesh. COF stimulation was produced by presenting pairs of figures alternately (red-green-red-green-) at various frequencies (30-120 Hz).

Differential priming effects of color-opponent subliminal stimulation on visual magnetic responses.

We investigated the effects of subliminal stimulation on visible stimulation to demonstrate the priority of facial discrimination processing, using a unique, indiscernible, color-opponent subliminal (COS) stimulation. We recorded event-related magnetic cortical fields (ERF) by magnetoencephalography (MEG) after the presentation of a face or flower stimulus with COS conditioning using a face, flower, random pattern, and blank. The COS stimulation enhanced the response to visible stimulation when the figure in the COS stimulation was identical to the target visible stimulus, but more so for the face than for the flower stimulus.

Timing of early activity in the visual cortex as revealed by simultaneous MEG and ERG recordings.

To clarify the latency of the earliest cortical activity in visual processing, electroretinograms (ERGs) and visual evoked magnetic fields (VEFs) following flash stimulation were recorded simultaneously in six human subjects. Flash stimuli were applied to the right eye and ERGs were recorded from a skin electrode placed on the lower lid. ERGs showed two major deflections in all subjects: an eyelid-negativity around 20 ms and a positivity around 60 ms corresponding to an a- and b-waves, respectively.

Mechanisms of face perception in humans: a magneto- and electro-encephalographic study.

We have been studying the underlying mechanisms of face perception in humans using magneto- (MEG) and electro-encephalography (EEG) including (1) perception by viewing the static face, (2) differences in perception by viewing the eyes and whole face, (3) the face inversion effect, (4) the effect of gaze direction, (5) perception of eye motion, (6) perception of mouth motion, and (7) the interaction between auditory and visual stimuli related to the vowel sounds. In this review article, we mainly summarize our results obtained on 3, 5, and 6 above. With the presentation of both upright and inverted unfamiliar faces, the inferior temporal cortex (IT) centered on the fusiform gyrus, and the lateral temporal cortex (LT) near the superior temporal sulcus were activated simultaneously, but independently, between 140 and 200 ms post-stimulus.

Serial and parallel processing in the human auditory cortex: a magnetoencephalographic study.

Although anatomical, histochemical and electrophysiological findings in both animals and humans have suggested a parallel and serial mode of auditory processing, precise activation timings of each cortical area are not well known, especially in humans. We investigated the timing of arrival of signals to multiple cortical areas using magnetoencephalography in humans. Following click stimuli applied to the left ear, activations were found in six cortical areas in the right hemisphere: the posteromedial part of Heschl's gyrus (HG) corresponding to the primary auditory cortex (PAC), the anterolateral part of the HG region on or posterior to the transverse sulcus, the posterior parietal cortex (PPC), posterior and anterior parts of the superior temporal gyrus (STG), and the planum temporale (PT).

Magnetoencephalographic study of occipitotemporal activity elicited by viewing mouth movements.

Objective: We studied the temporal and spatial characteristics of neural responses elicited by viewing mouth movements using magnetoencephalography.

Methods: We focused on differences in responses to mouth opening and closing movements by apparent motion, using an averting eyes condition as a control.

Results: A large clear MEG component, 1 M (mean peak latency of approximately 160 ms), was elicited by both mouth movements.

Interaction between auditory and visual stimulus relating to the vowel sounds in the auditory cortex in humans: a magnetoencephalographic study.

We investigated the interaction between auditory and visual stimulus relating to the vowel sounds in the auditory cortex in humans, using magnetoencephalography. We compared the difference in the main component, M100 generated in the auditory cortex, in terms of peak latency, amplitude, dipole location and moment, following the vowel sound_/a/_between two conditions: (1) showing a face with closed mouth; and (2) showing the same face with mouth movement appearing to pronounce/a/using an apparent motion method. We found no significant difference in the M100 component between the two conditions within or between the right and left hemispheres.

Sensory perception during sleep in humans: a magnetoencephalograhic study.

We reported the changes of brain responses during sleep following auditory, visual, somatosensory and painful somatosensory stimulation by using magnetoencephalography (MEG). Surprisingly, very large changes were found under all conditions, although the changes in each were not the same. However, there are some common findings.

Brain responses for the subconscious recognition of faces.

We investigated the event-related responses following subthreshold and suprathreshold stimulation with facial and non-facial figures using magnetoencephalography (MEG) and EEG recordings to clarify the physiological nature of subconscious perception. Event-related magnetic fields and potentials were recorded from the right hemisphere in eight healthy subjects. Three types of stimulus, i.

Gaze direction affects face perception in humans.

We recorded event-related potentials (ERP) in response to images of faces with a straight gaze (straight eyes) and eyes averted (averted eyes). Peak latencies of ERP components showed no significant change between straight eyes and averted eyes, but amplitude for averted eyes, particularly when averted to the right, was significantly larger than that for straight eyes at the lateral temporal electrode of the right hemisphere. Single-unit recordings in monkeys and neuroimaging studies in humans have revealed activity in the lateral temporal region, mainly the superior temporal sulcus, and a clinical study demonstrated the importance of the right hemisphere when viewing gaze direction.