Emotional centers of the brain are primarily present in the right hemisphere’s tempoparietal and the limbic systems (Lezak, Howieson and Loring, 2004 p. 209). The Limbic components of the brain are found to be very much associated with the different emotions expressed by the body. High activities within the amygdala are likely to facilitate immediate and accurate recall of emotions expressed by an individual (Welsh, 2006 p.
214). According to Sadock and Kaplan (2007), amygdala, septum, basal forebrain, nucleus accumbens and orbitofrontal cortex all create the physiological processing center of emotions with each specific contribution to the individual characteristics of a person (p. 89). The atrophy of amygdala is another hypothesized cause of the emotional decline of Alzheimer’s disease patients.
The developing lesions degenerate the emotional memory enhancement effect, which consequently decline the capacity of the brain to retrieve and process emotional expressions (Porth, p. 1238). According to Sadock and Kaplan (2007), each parietal hemisphere comprises different hypothetical emotional triggers wherein left hemisphere produces depression, aphasia and logic intellect, while right hemisphere produces the general emotions, such as humor, affect, socialization, and body image (p. 88-89).
In the study of Cadieux and Greve (1997), patients were grouped into two to test their capacities on left hemisphere’s verbal function and right hemisphere’s spatial function. Prior to the study, the hypothesis predicted that Alzheimer patients with problems in emotion processing system –evidenced by difficulty or incapacity to respond with facial expression – must have greater problem in the right hemisphere. However, based from the results, both groups possessed problems in their emotion processing system.
As explained by Cadieux and Greve (1997), low spatial Alzheimer patients (right hemisphere) had emotion processing problems independent from the memory and language functions, while the low verbal Alzheimer patients were unable to comprehend the instructions well due to their language deficit. Despite of these results, patients with disrupted right hemisphere had shown marked problems in their capacity to respond using emotional facial expressions, which were independent from existing verbal or language problem.
According to Lezak, Howieson and Loring (2004), patients with problems in their right hemisphere are usually incapable of responding appropriately to emotional stimuli present in their environment (p. 208). The destruction of the tempoparietal section, specifically in the right hemisphere, can cause malfunction in the visual emotion centers of the brain disabling or impairing the capacity of the person to render emotion responses related to this area (e. g. humor, affect, socialization, etc.).
This explains the poor emotion responses of low spatial patients in the study of Cadieux and Greve. On the other hand, amygdala is considered the most critical component of emotion processing wherein internal and external stimuli are both integrated. Amygdala mediates the retrieval ad recall of learned emotional responses, such as anxiety, fear, panic, etc, in order to provide the most appropriate emotional response on any given event encountered by the body.
According to Balch (2006), patients with Alzheimer’s disease are unlikely to control the mood swings of their behavior since the brain function neither intends to nor can control this aspect of function (p. 193). Older patients with Alzheimer’s disease have been proven to process emotion stimuli related to a particular event. In the study of Abrisquenta-Gomez, Bueno and Oliveira et al. (2002), elder patients on their middle to late stage of dementia were able to classify the pictures as positive or negative similar to those provided by healthy elder subjects.
As supported by the study of Hamann, Monarch and Goldstein (2002), patients with Alzheimer’s disease are capable of perceiving emotional stimuli occurring in their environment, which suggests the intact emotional stimuli for patients with the said disease. Supported by the study of Koff, Zaitchik and Montepare et al. (1999), the ability to process emotional information between Alzheimer patients and health elderly individuals was evaluated via audiovisual assessment procedures (e. g. nonverbal sounds, emotional drawings, gestures, etc. ).
In the results of the study, they were able to confirm that Alzheimer patients do not entirely possess primary deficit in recognizing emotions; however, the study suggests that the primary difficulties experienced by Alzheimer patients are due to the cognitive impairments brought by Alzheimer’s disease. Indeed, Alzheimer patients possess the capacity to recognize the emotional stimuli from non-verbal resources; however, they are unable to determine correctly the proper response appropriate for the stimuli due to their compromised intellectual capacity to determine descriptively the emotions being introduced.