Slow Breathing and Emotions Associated with Odor-Induced Autobiographical Memories

Abstract

An important feature of olfactory perception is its dependence on respiratory activity. By inspiration, olfactory information ascends directly to olfactory-related limbic structures. Therefore, every breath with odor molecules activates these limbic areas associated with emotional experience and memory retrieval. We tested whether odors associated with autobiographical memories can trigger pleasant emotional experiences and whether respiration changes during stimulation with these odors. During presentation of odors related to autobiographical memories and control odors, we measured minute ventilation, tidal volume, respiratory frequency, O2 consumption, and end tidal CO2 concentration. Findings showed that autobiographical memory retrieval was associated with increasing tidal volume and decreasing respiratory frequency more than during presentation of control odors. Subjective feelings such as emotional arousal during retrieval of the memory, arousal level of the memory itself, or pleasantness and familiarity toward the odor evoked by autobiographical memory were more specific emotional responses compared with those related to control odors. In addition, high trait anxiety subjects responded with a stronger feeling of being taken back in time and had high arousal levels with tidal volume increases. We discussed assumptions regarding how deep and slow breathing is related to pleasantness and comfortableness of an autobiographical memory.

Effects of pleasant olfactory mental imagery on the arterial oxygenation in patients with open heart surgery: A randomized controlled trial

“…In other words, deep breathing and pleasantness mutually affect each other. Pleasant olfactory mental imagery contributes to increased feelings of pleasantness and comfortableness, leading to deep breathing and reduced respiratory rate (39). The second hypothesis suggests that there is a deep synchronization between the brain's slow-wave (alpha waves) across the entire cortical mantle and slow and deep breathing pattern during sleep.…”

“…In a study, it was shown that olfactory mental imagery of pleasant odors can increase respiratory amplitude and respiratory minute volume only by increasing tidal volume and improving the breathing pattern without any changes in the respiratory rate, resulting in an improvement in the respiratory function (37). In addition, a study by Masaoka et al indicated that odors associated with autobiographical pleasant memory can prolong inspiratory and expiratory times, particularly expiratory, resulting in a deep and slow breathing pattern (39). Prolonged expiration triggered by olfactory imagery (39) increases intra-thoracic pressure (54) which pushes more blood into the heart with a subsequent increase in stroke volume.…”

“…Four pleasant odors (roses, banana, apple and lemon) were used for mental imagery stimuli according to previous studies (30,37,39). Pleasant olfactory stimuli were used as imagerydependent sniffing functionally contribute to emotional tone (30) and interact with hedonics such that sniffs tend to be larger during imagery of pleasant odors than imagery of unpleasant odors as in real perception of odor (30,31,33,49).…”

“…system (39). Therefore, an increase in pulmonary vagal tone leads to a deep and slow breathing pattern.…”

“…This increase in respiratory parameters is brought about by the elevated tidal volume and the improved breathing pattern and is not associated with the respiratory rate (37). A study revealed that odors associated with autobiographical pleasant memory can trigger a deep and slow breathing pattern (39).…”