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Neural substrates of positive emotion induced in hypnosis
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International Journal of Psychophysiology 94 (2014) 120–261
Neural substrates of positive emotion induced in hypnosis Chihiro Hasegawa, Nobutsugu Hirono Department of Psychology, Kobe Gakuin University, Japan There are a number of techniques have been developed to induce positive mood status in a laboratory. Hypnosis, as well as imagination or adopting facial expression, is one of widely used mood induction procedures, and the elicited emotion under hypnotic mood induction procedure (HMIP) is considered to be ‘genuine’ (Friswell and McConkey, 1989) because hypnotized subjects are subjectively convinced of the reality of the suggested mood. It has also reported that hypnotized participants demonstrated psychological, behavioral, or psychophysiological change (Hinterberger, et al., 2011). In this study, we applied HMIP to investigate the neural substrate of positive emotion using functional magnetic resonance imaging (fMRI). This experiment was conducted in accordance with guidelines of review board of Kobe Gakuin University and The Brain Activity Imaging Center (ATR). Thirtyseven right-handed healthy participants who have not reported history of neurological and psychiatric problems took part in the experiment. They are voluntarily participated and provided the written informed consent. Among the 37participants, 10 (4 males, 6 females, mean age =22.1 years; age range =21- 27 years) are evaluated as highly hypnotizable participants by Stanford hypnotic scale, Form C (SHSS:C) and proceeded in the following fMRI experiment. Prior to an fMRI experiments, the participants were confirmed that they could intrinsically evoke strong positive emotion of happiness and change quickly into neutral (non-happy) states under the hypnotic suggestions. The blocked-designed fMRI experimental paradigm were proceeded the hypnotized participants to alter their emotions under auditory hypnotic suggestions in each block which continued 30s. Total of three sessions, consisted of 4 conditions (happy induction, happy state, neutral induction, and neutral state) were repeatedly executed. In each session, the valence of happiness is also rated 10-point scale of 0 (not happy at all) to 10 (the happiest as long as you imagine). fMRI was performed on a 3-Tesla magnetic resonance scanner with echo planar imaging, and the data were processed using Statistical Parametric Mapping (SPM8). Compared with in the neutral state, the participants who have evoked spontaneous positive emotion showed an overactivation in left supplementary motor area (SMA) which has been reported the relations to the emotional process in previous investigations (Etkin et al, 2011). This result indicated that HMIP is an effective technique to elicit intensive and intrinsic positive emotion, which is related to the SMA which could be the pathway of the prefrontal top-down emotion regulation circuitry. doi:10.1016/j.ijpsycho.2014.08.930
Semantic and physical features: Effects of emotional category and signal-to-noise ratio on eye movements Joanna Pilarczyk, Michał Kuniecki Jagiellonian University, Poland Emotional images are processed in a prioritized manner, attracting attention almost immediately. In the present study we used eye tracking to reveal what type of features within neutral, positive and negative images attract early visual attention: semantics, visual saliency or their interaction. Semantic regions of interest were selected by observers, while visual saliency was determined using the Graph Based Visual Saliency model. Images were transformed by adding pink noise in several proportions to be presented in a sequence of increasing and decreasing clarity. Locations of the first two fixations were analyzed. The results showed dominance of semantic features over visual saliency
in attracting attention. This dominance was linearly related to the signal-to-noise ratio. Semantic regions were fixated more often in emotional images than in neutral ones, if signal-to-noise ratio was high enough to allow participants to comprehend the gist of a scene. Visual saliency on its own did not attract attention above chance, even in the case of pure noise images. Regions both visually salient and semantically relevant attracted a similar amount of fixation compared to semantic regions alone, or even more in the case of neutral pictures. Results provide evidence for ultra-fast and robust detection of semantically relevant features. doi:10.1016/j.ijpsycho.2014.08.931
Influences of positive emotion inducement on hemodynamic response to a mental work Xinxin Liua, Kazuma Ishimatsub, Midori Sotoyamaa, Kazuyuki Iwakiria a National Institute of Occupational Safety and Health, Japan b Graduate School of Health Care Sciences, Jikei Institute, Japan Underlying hemodynamics indicates that blood pressure is elevated by cardiac output and/or total peripheral resistance, and exaggerated increase of total peripheral resistance is considered to be a risk factor for cardiovascular disorders (Chida et al., 2010; Marrero et al., 1997). The present study investigated whether positive emotion inducement before a mental work influences underlying hemodynamics in increasing blood pressure. Seventeen healthy males performed an 8.6-minute, PC-based sustained attention to response task (SART, Robertson et al., 1997) following a 6minute pre-task period (pleasant pictures or grey screen presentation) and then relaxed for 30 min in order to recover their cardiovascular responses. In the SART, single digits (1 to 9) were presented visually for 250 ms, followed by a 900 ms encircled X mask. Participants responded with a key press to each digit, except the digit 3, which required the participants to withhold a response. During the pre-task period, 60 pleasant pictures (joyful families, cute animals, beautiful natural sceneries, etc.) were presented randomly under the positive emotion inducement condition, while a gray screen was presented under the control condition. The pleasant pictures were chosen from the International Affective Picture System and the mean scores of pleasure and arousal were 7.14 ± 0.43 and 4.19 ± 0.65, respectively. Throughout all of these periods, systolic blood pressure, diastolic blood pressure, mean blood pressure, heart rate, cardiac output, and total peripheral resistance were measured continuously. Compared to the pre-task period, blood pressures increased significantly during the SART. In the recovery period, blood pressures did not recover to the pre-task level. The change tendency of blood pressure was similar in both conditions, and no significant differences were detected between conditions. In contrast, the underlying hemodynamics in increasing blood pressure was different between conditions. The increase of total peripheral resistance under the positive emotion inducement condition was significantly lower than under the control condition (p b 0.05), while the response of cardiac output did not significantly differ between conditions. These results demonstrated that positive emotion inducement before a mental work influenced the underlying hemodynamics in increasing blood pressure. The increase of total peripheral resistance was inhibited under the positive emotion inducement condition, suggesting that positive emotion inducement before a mental work may be beneficial for preventing exaggerated increases in total peripheral resistance. doi:10.1016/j.ijpsycho.2014.08.932
International Journal of Psychophysiology 94 (2014) 120–261
Neural substrates of positive emotion induced in hypnosis Chihiro Hasegawa, Nobutsugu Hirono Department of Psychology, Kobe Gakuin University, Japan There are a number of techniques have been developed to induce positive mood status in a laboratory. Hypnosis, as well as imagination or adopting facial expression, is one of widely used mood induction procedures, and the elicited emotion under hypnotic mood induction procedure (HMIP) is considered to be ‘genuine’ (Friswell and McConkey, 1989) because hypnotized subjects are subjectively convinced of the reality of the suggested mood. It has also reported that hypnotized participants demonstrated psychological, behavioral, or psychophysiological change (Hinterberger, et al., 2011). In this study, we applied HMIP to investigate the neural substrate of positive emotion using functional magnetic resonance imaging (fMRI). This experiment was conducted in accordance with guidelines of review board of Kobe Gakuin University and The Brain Activity Imaging Center (ATR). Thirtyseven right-handed healthy participants who have not reported history of neurological and psychiatric problems took part in the experiment. They are voluntarily participated and provided the written informed consent. Among the 37participants, 10 (4 males, 6 females, mean age =22.1 years; age range =21- 27 years) are evaluated as highly hypnotizable participants by Stanford hypnotic scale, Form C (SHSS:C) and proceeded in the following fMRI experiment. Prior to an fMRI experiments, the participants were confirmed that they could intrinsically evoke strong positive emotion of happiness and change quickly into neutral (non-happy) states under the hypnotic suggestions. The blocked-designed fMRI experimental paradigm were proceeded the hypnotized participants to alter their emotions under auditory hypnotic suggestions in each block which continued 30s. Total of three sessions, consisted of 4 conditions (happy induction, happy state, neutral induction, and neutral state) were repeatedly executed. In each session, the valence of happiness is also rated 10-point scale of 0 (not happy at all) to 10 (the happiest as long as you imagine). fMRI was performed on a 3-Tesla magnetic resonance scanner with echo planar imaging, and the data were processed using Statistical Parametric Mapping (SPM8). Compared with in the neutral state, the participants who have evoked spontaneous positive emotion showed an overactivation in left supplementary motor area (SMA) which has been reported the relations to the emotional process in previous investigations (Etkin et al, 2011). This result indicated that HMIP is an effective technique to elicit intensive and intrinsic positive emotion, which is related to the SMA which could be the pathway of the prefrontal top-down emotion regulation circuitry. doi:10.1016/j.ijpsycho.2014.08.930
Semantic and physical features: Effects of emotional category and signal-to-noise ratio on eye movements Joanna Pilarczyk, Michał Kuniecki Jagiellonian University, Poland Emotional images are processed in a prioritized manner, attracting attention almost immediately. In the present study we used eye tracking to reveal what type of features within neutral, positive and negative images attract early visual attention: semantics, visual saliency or their interaction. Semantic regions of interest were selected by observers, while visual saliency was determined using the Graph Based Visual Saliency model. Images were transformed by adding pink noise in several proportions to be presented in a sequence of increasing and decreasing clarity. Locations of the first two fixations were analyzed. The results showed dominance of semantic features over visual saliency
in attracting attention. This dominance was linearly related to the signal-to-noise ratio. Semantic regions were fixated more often in emotional images than in neutral ones, if signal-to-noise ratio was high enough to allow participants to comprehend the gist of a scene. Visual saliency on its own did not attract attention above chance, even in the case of pure noise images. Regions both visually salient and semantically relevant attracted a similar amount of fixation compared to semantic regions alone, or even more in the case of neutral pictures. Results provide evidence for ultra-fast and robust detection of semantically relevant features. doi:10.1016/j.ijpsycho.2014.08.931
Influences of positive emotion inducement on hemodynamic response to a mental work Xinxin Liua, Kazuma Ishimatsub, Midori Sotoyamaa, Kazuyuki Iwakiria a National Institute of Occupational Safety and Health, Japan b Graduate School of Health Care Sciences, Jikei Institute, Japan Underlying hemodynamics indicates that blood pressure is elevated by cardiac output and/or total peripheral resistance, and exaggerated increase of total peripheral resistance is considered to be a risk factor for cardiovascular disorders (Chida et al., 2010; Marrero et al., 1997). The present study investigated whether positive emotion inducement before a mental work influences underlying hemodynamics in increasing blood pressure. Seventeen healthy males performed an 8.6-minute, PC-based sustained attention to response task (SART, Robertson et al., 1997) following a 6minute pre-task period (pleasant pictures or grey screen presentation) and then relaxed for 30 min in order to recover their cardiovascular responses. In the SART, single digits (1 to 9) were presented visually for 250 ms, followed by a 900 ms encircled X mask. Participants responded with a key press to each digit, except the digit 3, which required the participants to withhold a response. During the pre-task period, 60 pleasant pictures (joyful families, cute animals, beautiful natural sceneries, etc.) were presented randomly under the positive emotion inducement condition, while a gray screen was presented under the control condition. The pleasant pictures were chosen from the International Affective Picture System and the mean scores of pleasure and arousal were 7.14 ± 0.43 and 4.19 ± 0.65, respectively. Throughout all of these periods, systolic blood pressure, diastolic blood pressure, mean blood pressure, heart rate, cardiac output, and total peripheral resistance were measured continuously. Compared to the pre-task period, blood pressures increased significantly during the SART. In the recovery period, blood pressures did not recover to the pre-task level. The change tendency of blood pressure was similar in both conditions, and no significant differences were detected between conditions. In contrast, the underlying hemodynamics in increasing blood pressure was different between conditions. The increase of total peripheral resistance under the positive emotion inducement condition was significantly lower than under the control condition (p b 0.05), while the response of cardiac output did not significantly differ between conditions. These results demonstrated that positive emotion inducement before a mental work influenced the underlying hemodynamics in increasing blood pressure. The increase of total peripheral resistance was inhibited under the positive emotion inducement condition, suggesting that positive emotion inducement before a mental work may be beneficial for preventing exaggerated increases in total peripheral resistance. doi:10.1016/j.ijpsycho.2014.08.932