Recognition of Human Emotions from Cerebral Blood Flow Changes in the Frontal Region: A Study with Event-Related Near-Infrared Spectroscopy

Abstract

The aim of this study is to develop a near-infrared spectroscopy (NIRS)-based system that recognizes pleasant and unpleasant human emotions based on cerebral blood flow (CBF) in order to understand the minds of patients whose brain function is severely impaired. The forehead region is easily accessible to NIRS measurements, whereas the role of the anterior prefrontal cortex (PFC) in the processing of emotion remains to be elucidated. METHODSInitially, using event-related NIRS we examined changes in oxygenated hemoglobin (oxyHb) as an indicator of regional CBF changes, which reflect brain activity directly related to emotions, but not to cognitive operations in the anterior frontal regions, during viewing affective pictures. The event-related potentials (ERPs), systemic blood pressure, and pulse rate were also measured simultaneously. RESULTSThe event-related analysis of changes in oxy-Hb for a 6 s-picture presentation period showed that very unpleasant emotion was accompanied by an increase in oxy-Hb in the bilateral ventrolateral PFCs, while very pleasant emotion was accompanied by a decrease in oxy-Hb in the left dorsolateral PFC. There were no significant differences in either ERPs or autonomic nervous system activities between the two emotional states. CONCLUSIONThese findings suggest the possibility of recognizing patients' emotions from CBF changes.

Exploring methodological frameworks for a mental task-based near-infrared spectroscopy brain–computer interface

“…Based on preliminary analysis, 17 s allowed for an adequate amount of time for the haemodynamic activity from the task and ease-of-use selection to subside. In the literature, a variety of rest intervals have been used; including, 12 s (Power et al, 2012a;Schudlo et al, 2013;Schudlo and Chau, 2014), 14 s (Hoshi et al, 2011), 15 s (Coyle et al, 2007;Izzetoglu et al, 2007;Herff et al, 2013aHerff et al, , 2013b, 20 s (Ogata et al, 2007;Tai and Chau, 2009;Hong, 2013a, 2013b;Naseer et al, 2014), and 30 s (Ayaz et al, 2012). Two forms of neurofeedback were provided during all sessions: (1) a trapezoid topographic image showing the real-time changes in blood oxygenation levels over the PFC and (2) a ball that rose and fell with the average change over the entire interrogation area.…”

Using Economic Games to Investigate the Neural Substrates of Cognitive Processes

“…Lesion studies have suggested that the dorsolateral prefrontal cortex is associated with social cognition processes, including the perception of emotional cues [14], while the ventromedial prefrontal cortex is implicated in dysfunctional real-life social behavior [15]. Hoshi et al [7] also found changes in cerebral blood flow in the lateral prefrontal area related to unpleasant emotions. Our results showed a similar pattern in that there was significant change in the right prefrontal cortex and left orbitofrontal cortex in ten subjects in the PD game.…”

“…Irani et al [6] indicated that fNIRS may have considerable potential for neurological or psychiatric applications due to its simplicity, portability, and insensitivity to motion artifacts. Hoshi et al [7] also insisted on the utility of fNIRS in studying the neural substrates of human emotions. They found that some neural pathways related to emotions lie in the prefrontal areas, which are easily accessed by fNIRS.…”

Towards the next generation of near-infrared spectroscopy

“…The significance of the analysis of data for discrete individuals needs to be more appreciated. Similar to MEG data analysis, analytical results for individuals can be organized into grouped data for further statistical analysis of NIRS data [16,20].…”

“…Different from the data analysis in event-related fMRI, which often uses haemodynamic response functions (HRFs), there are no standard HRFs for NIRS data analysis; however, event-related NIRS data can be analysed without using a HRF. For example, we have employed eventrelated NIRS to examine rCBF changes directly related to emotions but not to cognitive operations in the anterior frontal region conducted while the subject viewed pleasant, unpleasant or neutral pictures [20]. Each picture was presented for 6 s, followed by the presentation of a white cross-hair for 14 s. Changes in oxygenated Hb (oxy-Hb), an indicator of changes in rCBF [21], from the value at the stimulus onset during the 6 s stimulation period, which were directly related to emotion generation, were statistically analysed using a two-way ANOVA and the two-tailed Dunnett's method as a post hoc test.…”