Could Self-Consciousness Be Enhanced in Alzheimer’s Disease? An Approach from Emotional Sensorial Stimulation

Abstract

Alzheimer’s disease (AD) provides a valuable field of research into impairment of self-consciousness (SC), because AD patients have a reduced capacity to understand their mental world, to experience and relive previous personal events, as well as to interpret thoughts, feelings, and beliefs about themselves. Several studies observed that AD patients had an altered SC, but not a complete abolition of it. Emotions are an integral part of the construction of personal identity, therefore of Self. In general, most studies on emotion in AD patients have observed that emotion is not completely abolished and it lets them better remember autobiographical events with greater emotional charge. The positive effect of autobiographical memories rich in emotional content, evoked directly/automatically by sensorial stimuli such as familiar odors or music, could be used to reestablish/reinforce the permanence and coherence of the Self in AD. We studied the research of empirical evidence supporting the power of the sensorial cues associated with emotion, which could be capable of enhancing the SC in AD. We presented the studies about “Emotional stimulations” using odor, music, or taste cues in AD. All studies have shown to have a positive impact on SC in AD patients such as odor-evoked autobiographical memories, taste/odor-evoked autobiographical memories, emotional sensorial stimulation using musical cues, and multi-sensorial stimulations using healing gardens. We found research supporting the notion that emotional sensorial stimulations can even temporarily exalt memory, affective state, and personal identity, that is, the SC in AD. The emotional sensory stimulations could be used as a tool to activate the SC in AD and hence improve the quality of life of patients and caregivers.

Emotion Processing Dysfunction in Alzheimer’s Disease: An Overview of Behavioral Findings, Systems Neural Correlates, and Underlying Neural Biology

“…81 Studies have shown a positive effect of sensorial stimulation by familiar music/odor/taste on episodic autobiographical memory, which in turn may improve self-awareness in AD. 79 As described earlier, for episodic and autobiographical memory, the presence of emotional benefit may depend upon task complexity. 82 Cognitive demand may mask the benefits in AD.…”

“…78 Associated with amygdala atrophy and hippocampal deafferentation, dysfunctional episodic memory is noted in early stage AD 78 and may lead to over-generality or inability to reach past personal events. 79 A fundamental component of self-awareness, autobiographical memory is impaired 80 as a result of amygdala–hippocampus atrophy in AD. 81 Studies have shown a positive effect of sensorial stimulation by familiar music/odor/taste on episodic autobiographical memory, which in turn may improve self-awareness in AD.…”

Preserved Consciousness in Alzheimer’s Disease and Other Dementias: Caregiver Awareness and Communication Strategies

“…Additionally, while many patients display anosognosia (lack of awareness regarding their deficit), others display considerable awareness about their deficits ( Bird et al, 2010 ). Even in those with evident anosognosia, several studies suggest that while self-consciousness is altered, it is anything but absent ( Arroyo-Anlló et al, 2020 ). Despite the challenges and barriers to education and communication strategies, it has been established that dementia and AD patients do retain a sense of self, consciousness, memory ( Arroyo-Anlló et al, 2020 ), social sensitivity, and emotion ( Fredericks et al, 2018 ).…”

“…There is a growing interest in exploring the potential to utilize sensory perceptions to facilitate positive emotions and interactions in AD patients. Newer studies suggest that emotional sensorial stimulations and multisensorial stimulations in AD patients that include odor (e.g., El Haj et al, 2018 ), music (e.g., Gulliver et al, 2021 ), taste (mealtime interventions) (e.g., Smith and D’Amico, 2020 ), and healing gardens (e.g., Uwajeh et al, 2019 ) have a positive impact on self-consciousness (SC); elicit autobiographical memories; can temporarily exalt memory, affective state, and personal identity; and could therefore serve to improve QOL in patients and caregivers ( Arroyo-Anlló et al, 2020 ). It is worth noting that other studies suggest that rich sensory stimulation alone is insufficient, highlighting the importance of the emotional component of the sensorial stimuli as the key element that can enhance cognitive, affective, and behavioral components of the patient’s well-being ( Arroyo-Anlló et al, 2020 ).…”

“…Newer studies suggest that emotional sensorial stimulations and multisensorial stimulations in AD patients that include odor (e.g., El Haj et al, 2018 ), music (e.g., Gulliver et al, 2021 ), taste (mealtime interventions) (e.g., Smith and D’Amico, 2020 ), and healing gardens (e.g., Uwajeh et al, 2019 ) have a positive impact on self-consciousness (SC); elicit autobiographical memories; can temporarily exalt memory, affective state, and personal identity; and could therefore serve to improve QOL in patients and caregivers ( Arroyo-Anlló et al, 2020 ). It is worth noting that other studies suggest that rich sensory stimulation alone is insufficient, highlighting the importance of the emotional component of the sensorial stimuli as the key element that can enhance cognitive, affective, and behavioral components of the patient’s well-being ( Arroyo-Anlló et al, 2020 ). With emotion as a focus, Arroyo-Anlló and Gil (2020) poignantly stated:We focus on something essential in life that can be stimulated by daily activities such as smell, taste, and music, because although the patient is unable to identify/name the smell, dish, or musical piece, they can experience emotions, relive situations, find the emotions that contribute to and recognize it.…”