Infants' Prefrontal Hemodynamic Responses and Functional Connectivity During Joint Attention in an Interactive-Live Setting.

The present study examined cerebral hemodynamic responses and functional connectivity during joint attention either initiated by infants (Initiating Joint Attention, IJA condition) or by their partner (Responding to Joint Attention, RJA condition). To capture responses to natural social cues in infants aged 7-12 months using functional near-infrared spectroscopy (fNIRS), we employed an interactive-live paradigm for IJA and RJA. During the measurement, an adult sat facing an infant, and objects, such as small stuffed animals, paired with sound toys were presented to the right or left side of the screen.

Infant word segmentation recruits the cerebral network of phonological short-term memory.

Segmenting word units from running speech is a fundamental skill infants must develop in order to acquire language. Despite ample behavioral evidence of this skill, its neurocognitive basis remains unclear. Using behavioral testing and functional near-infrared spectroscopy, we aimed to uncover the neurocognitive substrates of word segmentation and its development.

Functional hemispheric specialization in processing phonemic and prosodic auditory changes in neonates.

This study focuses on the early cerebral base of speech perception by examining functional lateralization in neonates for processing segmental and suprasegmental features of speech. For this purpose, auditory evoked responses of full-term neonates to phonemic and prosodic contrasts were measured in their temporal area and part of the frontal and parietal areas using near-infrared spectroscopy (NIRS). Stimuli used here were phonemic contrast /itta/ and /itte/ and prosodic contrast of declarative and interrogative forms /itta/ and /itta?/.

Cerebral responses to infant-directed speech and the effect of talker familiarity.

A number of behavioral studies suggest that infant-directed speech (IDS) plays a more important role in facilitating both: a) speech perception, and b) adult-infant social interactions than does adult-directed speech (ADS), and hence that IDS contributes to subsequent social and language development. However neural substrates that may underlie these IDS functions have not been examined. The present study examined cerebral hemodynamic responses to IDS in 48 infants (4-13 months of age) using near-infrared spectroscopy (NIRS).

Neural enhancement and attenuation induced by repetitive recall.

Learning is the process of accumulating information. Repetition can make the process of retrieving information more efficient. The mechanisms by which repetition facilitates the retrieval process, however, are not yet clear.

Neural substrates of implicit cueing effect on prospective memory.

Functional magnetic resonance imaging was used to examine the maintenance of intentions during an ongoing task involving implicit cues. Participants were required to detect target words while engaging in the ongoing task. Cues matched to the target category and cues matched to the action for targets were presented implicitly during the ongoing task.

Magnetoencephalographic study of the neural responses in body perception.

A fundamental trait of human beings is the ability to discern information communicated by others. The human body is one of the important sources of such information. To date, several researchers have reported two body-selective regions in the brain-the extrastriate body area (EBA) and fusiform body area.

How do infants perceive scrambled face?: A near-infrared spectroscopic study.

Using near-infrared spectroscopy (NIRS), we recorded changes of oxy-Hb, deoxy-Hb, and total-Hb in 7- to 8-month-old infants' and adults' brains in response to canonical face and scrambled face stimuli. Using a newly developed probe for NIRS recording, which was light and soft enough to be tolerated by infants, we were able to acquire data from the very young even in the awake state. Total-Hb in response to a canonical face stimulus was greater than for scrambled face stimuli only in the right hemisphere in infants.

Motor activity and imagery modulate the body-selective region in the occipital-temporal area: a near-infrared spectroscopy study.

The extrastriate body area (EBA) lies in the occipital-temporal cortex and has been described as a "body-selective" region that responds when viewing other people's bodies. Recently, several studies have reported that EBA is also modulated when the subject moves or imagines moving their own body, even without visual feedback. The present study involved 3 experiments, wherein the first experiment was conducted to examine whether near-infrared spectroscopy (NIRS) could capture any activity in the EBA when viewing images of bodies.

Cerebral laterality for phonemic and prosodic cue decoding in children with autism.

This study examined the cerebral functional lateralization, from a phonological perspective, in children with autism spectrum disorder (ASD) and typically developing children (TDC). With near infrared spectroscopy, we measured auditory evoked-responses in the temporal areas to phonemic and prosodic contrasts in word contexts. The results of TDC showed stronger left-dominant and right-dominant responses to phonemic and prosodic differences, respectively.

Temporal dissociation of global and local features by hierarchy of vision.

Most objects in our environment are organized hierarchically with a global whole embedding its local parts, but the way we recognize these features remains unclear. Using a visual masking paradigm, we examined the temporal dissociation between global and local feature as proposed in Reverse Hierarchy Theory, RHT (Ahissar & Hochstein, 2000), where global and local information are assumed to be processed, respectively, by feed-forward and feedback systems. We found that in a long Stimulus Onset Asynchrony (SOA) condition, both global and local information were recognized adequately.

Configurational factors in the perception of faces and non-facial objects: an ERP study.

During the viewing of human faces, it is easier to recognize detailed features if the face is presented in an unusual configuration; for example, a split face. The present study used electroencephalography to investigate the brain activity elicited in response to a neutral, inverted, and split face and compared this to the activity produced in response to a non-facial stimulus (a clock). Results showed that the N170 response amplitude was larger and its latency longer during recognition of split and inverted faces as compared to a normal face, whereas no amplitude change was seen for the different clock configurations.

Prefrontal activation associated with social attachment: facial-emotion recognition in mothers and infants.

Attachment between mothers and infants is the most primitive and primary form of human social relationship. Many reports have suggested that the orbitofrontal cortex (OFC) plays a significant role in this attachment; however, only a select few provide experimental neurophysiological evidence. In the present study, to determine the neural substrates underlying the social and emotional attachment between mothers and infants, we measured their prefrontal activation by using near-infrared spectroscopy.

The neural mechanism associated with the processing of onomatopoeic sounds.

This event-related fMRI study was conducted to examine the blood-oxygen-level-dependent responses to the processing of auditory onomatopoeic sounds. We used a sound categorization task in which the participants heard four types of stimuli: onomatopoeic sounds, nouns (verbal), animal (nonverbal) sounds, and pure tone/noise (control). By discriminating between the categories of target sounds (birds/nonbirds), the nouns resulted in activations in the left anterior superior temporal gyrus (STG), whereas the animal sounds resulted in activations in the bilateral superior temporal sulcus (STS) and the left inferior frontal gyrus (IFG).

Motion illusion activates the visual motion area of the brain: a near-infrared spectroscopy (NIRS) study.

Near-infrared spectroscopy (NIRS) enables noninvasive measurement of concentration changes of oxy- and deoxy-hemoglobin. The present study investigated cerebral representations of motion illusion by NIRS and examined several experimental procedures to determine an efficient procedure that can shorten the experimental time. We compared hemodynamic responses to figures with and without motion illusion.

Matching vocalizations to vocalizing faces in a chimpanzee (Pan troglodytes).

Auditory-visual processing of species-specific vocalizations was investigated in a female chimpanzee named Pan. The basic task was auditory-visual matching-to-sample, where Pan was required to choose the vocalizer from two test movies in response to a chimpanzee's vocalization. In experiment 1, movies of vocalizing and silent faces were paired as the test movies.

Identification of vocalizers by pant hoots, pant grunts and screams in a chimpanzee.

Identification of vocalizers was examined using an auditory-visual matching-to-sample task with a female chimpanzee. She succeeded in selecting the picture of the vocalizer in response to various types of vocalizations: pant hoots, pant grunts, and screams. When pant hoots by two chimpanzees were presented as a "duet", she could identify both of the vocalizers.

Position reversal learning in aged Japanese macaques.

We examined aged and young monkeys using a multiple position reversal task to investigate declines in cognitive functions with aging. The task consisted of an original learning task (simple position discrimination task) and a reversal learning task. While the performance of the aged monkeys was not different from that of the young monkeys in the original learning task, the aged monkeys showed a poorer performance than the young monkeys in the reversal learning task.