Competition is known to increase cardiovascular response. Previous studies have investigated the effects of the dispositions of opponents, results of matches, and mental activity, but the effects of the competition environment on physiological activities are not yet well-known. In this study, we investigated its effects on autonomic responses during a competitive game task. Twenty undergraduates took part in both face-to-face (FF) and network (NW) competitive conditions. Each condition consisted of four minutes of rest, three minutes of tasks, and three minutes of recovery. Heart rate (HR), finger pulse volume (PV), and skin conductance (SC) were measured. During the rest period, we found lower PV in the FF condition. This can be interpreted as indicating that tension that occurred as a result of non-verbal information from an opponent increased the vasoconstriction of peripheral tissue. Furthermore, we found higher SC during the recovery period in the FF condition, which we consider to also reflect the effects of non-verbal information. These results suggest that the competitive environment is an important factor affecting physiological activity.
Verbal working memory for different orthographic sentences in Japanese was investigated using near-infrared spectroscopy (NIRS). 12 participants were asked to read aloud three sentences presented sequentially on a CRT display in the Reading task. The participants also memorized an underlined target word in each sentence in the Reading Span Test (RST) task. Four conditions were presented to the participants: (1) A sentence with spaces using only Kana characters (Kana-S); (2) A sentence with spaces using Kanji and Kana characters (Kanji-S); (3) A sentence without spaces using only Kana characters (Kana-NS); and (4) A sentence without spaces using Kanji and Kana characters (Kanji-NS). Oxy-Hb waveforms in frontal areas increased significantly when reading the sentences aloud in the RST task, compared to the Reading task. In the RST task, Oxy-Hb waveforms in the right dorsolateral prefrontal cortex during the recall of target words in Kana-NS and Kanji-S (i.e., unfamiliar orthography) increased significantly, compared to Kana-S and Kanji-NS (i.e., familiar orthography). These results suggest that increased attention control is necessary to working memory for orthographically unfamiliar sentences.
Although self-controlled breathing is a widely used relaxation technique, little is known about the mechanisms underlying its clinical effects. Thus, the purpose of this study was to clarify the effect of paced breathing (PB) on the respiratory system. Following a 20-min rest, 10 healthy males and females engaged in slow PB, moving progressively from 12 through 2 cpm. We found the following: 1) subjects progressively reduced their respiration rate (RR) (p<.05); 2) the pressure of the end-tidal CO2 (PetCO2) was maintained under PB conditions, whereas the constant error and coefficient of variation of RR increased markedly under the 2-cpm PB condition (p<.05); 3) minute ventilation (V·E), CO2 output (V·CO2), and CO2 equivalence (V·E/V·CO2) decreased significantly under the 2-cpm condition (p<.05), demonstrating gas-exchange efficiency; and 4) the total power of heart rate variability and baroreflex sensitivity were highest under the 4-cpm breathing condition. These results suggest that PB does not affect the respiratory gas-exchange system but does affect respiratory sensations, such as suffocation.
This study investigated the semantic processing of children with autism spectrum disorder (ASD). Event-related potentials (ERP) with children performing silent reading tasks were analyzed. Furthermore, we used descriptive tests to require participants to answer whether a sentence was correct and to correctly rewrite the incorrect sentences. According to an analysis of ERP, the ASD group demonstrated significantly smaller N400 amplitudes compared with the typically developing (TD) group. However, no significant differences between the groups were observed in the percentage of correct answers on descriptive tests. These results suggest that children with ASD have a peculiarity of neural processing for semantically incongruent words, although they can determine whether sentences are correct or incorrect, which is similar to the TD children.
The correlations between thoracic and abdominal respiratory responses and the effects of these types of breathing on the inhibitory breathing were investigated during 112 concealed information tests (CITs) conducted in the field. The guilty knowledge of all CIT examinees was confirmed by subsequent investigations. Respiratory amplitude (RA), rate (RR), and speed (RS) of thoracic and abdominal respiration were measured every second for 20 seconds following the stimulus onset. The results indicated mostly high positive correlations (r>.7) between thoracic and abdominal RA, RR, and RS. Additionally, thoracic inhibitory breathing had a more significant effect on RA and RS, as well as a significantly longer effect on RA and RR than abdominal breathing. These results suggest the validity of using single channel CIT measurement, and indicate the superiority of thorax respiration measurements in the CIT.
Brain is a complex network, which shows dynamic changes depending on the state and traits of an individual. Graph theory is able to characterize such brain networks by providing neurobiological meaning and easily computable measures. In this article, I have discussed the construction of networks based on data about brain connectivity and described common network measures that can quantify functional segregation and integration, as well as the centrality of brain architecture. Finally, I have introduced software for conducting analyses based on the graph theory.