Illustrate the connection between neurological function and human behavior in perception and its disorders.
Neuropsychology is a multifaceted discipline which is responsible in the investigation of the relations between brain processes and mechanisms, and cognition and behavioral control. The science of neuropsychology is not quite old although humanity has always been interested in this field. Neuropsychologia was the international scientific journal and on the occasion of its foundation an autonomous field of scientific inquiry with that name was formally established.
Its traditional approach was the study of the associations between focal brain lesions and psychological defects, but today neuropsychology is in possession of refined methodologies and theoretical frameworks for understanding both how the mind works and how the brain works
(BerlucchiG., 2009). Perception and neuropsychology are connected as perception has quite a history of theory construction and research, as well as a major role in the psychological history. Therefore perceptual constructs are a recurrent topic in neuropsychology. Perception is the way one identifies, organizes and interprets the sensory information that is present in our environment.
It is divided into two: bottom-up and top-down processing. Bottom-up processing, as the name suggests, happen when we take in the sensory stimuli and then from that data, build it up to our cognitive understanding and form perceptions. Whereas, top-down processing happens when we decode or interpret the stimulus or sensation through our existing knowledge.
Perceptual processes are highly crucial because they give us the foundation for perceptual/mental depiction of the visual, auditory, somatosensory, olfactory, gustatory, and social worlds.
With that they also help us in governing and managing motor, cognitive, as well as social activities. All perceptual systems, (i.e. vision, audition, somatosensory perception, taste and smell, and social perception) are separated functional links and show a parallel-hierarchical kind of association of data processing and encoding. If an individual goes through a pathological ailment like the traumatic brain injury or other causes, perceptual functions and skills can be variably affected and have an adverse effect that could go ranging from the loss of stimulus detection to compromised recognition. The individual may be unable to perceive and process the nature of concepts or objects by using the sense organs. When the individual is not able to or there is some sort of impairment in attending to the auditory, visual or sensory stimuli that is given from one side of the body then spatial neglect syndromes are included.
Even though the functional specialization of perceptual structures, link of perceptual deficits within sensory modalities is the rule, and disorders of a single perceptual function or ability are rare and that is why it is difficult to pinpoint any one impairment when we talk about any perceptual disorders.
Some of the examples for perceptual disorders are Visual Object Agnosia, Apperceptive Agnosia, Associative Agnosia, Simultanagnosia, Prosopagnosia, Central Achromatopsia, Balint Syndrome, Capgras Syndrome, Fregoli Syndrome, Reduplicative Paramnesia and many more.
Although these disorders are very different from each other, some of them have one symptom is common, and that is; delusions. In this paper we will try to find out how delusion is a cause and a disorder as well. With delusions, we will look at hallucinations as well because they are one of the major symptoms found in perceptual as well as medical disorders.
When we talk about delusions, we see how common it is in almost all of the psychotic disorders and many more. But before going on to the disorders, knowing and understanding the meaning and the history behind delusion is important.
To simply put, any firm belief that conflicts with the reality is delusion. An individual will not abandon his or her beliefs even when encountered with contrary proof. This happens because in often cases delusions are strengthened by the misapprehension or interpretation of instances and events and most of them include a certain level of paranoia.
According to philosophers, Beliefs should: (1) be coherent, (a) within themselves and (b) as part of a wider web of beliefs; (2) be supported by subjectively sufficient evidence (i.e., the holder has confidence about the beliefs truth, while objective agreement is not necessary); (3) have an impact on (a) action and (b) emotion under relevant circumstances.
Every individual has many beliefs; some are simple beliefs that provide us with reasons for the events that happen in our everyday lives. Some beliefs are quite complex and they are crucial when it comes to form an identity. Our beliefs reinforce us and contribute in the formation of our behavior as well. Beliefs make us unique while at the same time joining us with community. Relationships are formed on the basis of shared beliefs. We feel safe when we are with people who share our ideas and beliefs. People rarely compromise with their beliefs and are ready to kill and die for them. Beliefs are one of the main sources of safety and comfort. Belief should be coherent, straight-forward and not self-contradictory. Kant believed that beliefs hover between certain knowledge and opinions. It happens when individual deems an idea to be true after using evidence and logic that may be insufficient objectively but highly sufficient subjectively. However, when these beliefs become delusions they have the capacity to harm the individual and bring distress to all the people surrounding his.
We put delusion in spotlight when we talk about mental illness because the kind of delusional belief one has, gives a lot of knowledge about the diagnosis and the proper treatment of the disorder as well as the active functional ability of the patient and the quality of life.
It was in c.1420 when in the first time in history the term delusion was used with intent to define an act of misleading someone. However, it wasnt until 1552 when the word delusion was used for indicating a mental illness. Although it was not properly used but nevertheless, it was a big step for medicine/psychiatry to include this term.
People often think delusions usually mean grandeur or paranoia but there are a lot more types and they are classified and categorized as common themes. Some of those themes generally seen in psychiatry are:
Delusion of control: This false belief usually happens when the affected individual thinks that someone else (person, group of people, or external force) are controlling their thoughts, behavior, feelings, or impulses. The said individual may describe the incident as the experience that aliens have full control over him or her and are responsible for their behavior. In these cases the person affected has no control over the bodily movements. Thought broadcasting (the false belief that the affected person’s thoughts are heard aloud), thought insertion, and thought withdrawal (the belief that an outside force, person, or group of people is removing or extracting a person’s thoughts) are also examples of delusions of control.
Delusional jealousy (delusion of infidelity): In this the said individual has these false believes that his or her partner or lover is engaging in infidelity. This delusion comes from pathological jealousy. Here, the individual often collects “evidence” and confronts the partner about the nonexistent affair.
Persecutory delusions: These are one of the most common forms of delusions. The themes of being followed, drugged, cheated, poisoned, harassed, conspired against, spied on, attacked, or blocked in the quest of goals. Sometimes this delusion is fragmented and secluded (like the false belief that the fellow workers are harassing), but sometimes are well-organized belief systems that have a complex set of delusions (“systematized delusions”). A person with a set of persecutory delusions can believe that he or she has been accused of being a spy and is being hunted by a government organization. These systems of beliefs can be so broad and complex that they can explain everything that happens to the person.
Delusion of mind being read: The person has this false belief that others are able to know his or her thoughts. One difference between this and thought broadcasting is that here the individual does not believe that the thoughts are heard aloud.
Nihilistic delusion: here the central theme includes the nonexistence of the world, self or even parts of self. A person suffering from this form of delusion usually has the false belief that the world is ending.
Erotomania: this delusion pertains a belief that someone, (in most cases someone of higher status and position) is in love with the individual. It is usual for those with this nature of delusion to try to initiate interact the other person (through phone calls, letters, gifts, and sometimes stalking).
Somatic delusion: A delusion where the major theme is focused on physical functioning, bodily sensations, or physical appearance. Commonly the false belief is that the body is somehow changed, diseased, or abnormal. A classic example of this delusion would be an individual who believes that his or her body is infected with parasites.
Grandiose delusion: Here, the persons sense of self-importance is usually inflated or exaggerated. They usually have this conviction that they have super powers, talents, abilities or skills. Sometimes, they may actually believe that they are a famous celebrity (for example, an actor or a singer or even Christ). More commonly, a person with this delusion believes he or she has accomplished some great accomplishment for which they have not received satisfactory acknowledgment.
Delusion of reference: The individual has this false belief that trivial remarks, events, or matters in one’s surroundings have personal meaning or importance. For example, the individual may believe that he or she is getting distinct messages from the news newsreader on television. Usually they assign a negative meaning to these events but the “messages” can also have a grandiose quality.
Delusion of guilt or sin (or delusion of self-accusation): As the name suggests, this is a false emotion of guilt or remorse of delusional intensity. An example would be the person believing that he or she has committed some atrocious crime and must be punished sternly. Another common example in this case would be an individual who is convinced that he or she is responsible for some disaster (such as fire, flood, or earthquake) with which there can be no connection whatsoever.
Religious delusion: Any delusion with a religious or spiritual content. These may be combined with other delusions, such as grandiose delusions (the belief that the affected person was selected by God, for example), delusions of control, or delusions of guilt. Beliefs that would be considered normal for an individual’s religious or cultural background are not delusions.
Delusions of control, nihilistic delusions, and thought broadcasting, thought insertion, and thought withdrawal are usually considered bizarre delusions. Most persecutory, somatic, grandiose, and religious delusions, as well as most delusions of jealousy, delusions of mind being read, and delusions of guilt would be considered non-bizarre.
A hallucination happens when there is a false perception without any distinguishable external stimulus and shows an abnormality in the individuals perception. This perceptual problem can be seen in any of the sensory modalities. So this would mean the person could hear, see, feel, taste or smell something that is not real or does not exist at that point of time.
However, these false perceptions are not accounted for by the person’s religious or cultural background, and the person experiencing hallucinations may or may not have insight into them.
That is why, some people who hallucinate may know about their hallucinations and have the knowledge that the hallucinations are false, whereas some may have firm belief that whatever they are hearing, seeing, smelling or tasting is real. This usually leads to the individual having delusional interpretation or meaning attached to the hallucination.
Hallucinations and illusions may be used together but they are different from each other. When a person misinterprets the real external stimuli, it is known as illusion.
In simpler words, an illusion is basically seeing, hearing, smelling, tasting, or feeling something that is actually there, but it is perceived or interpreted it incorrectly.
Hearing ones name being called out when television is playing could be a common example of illusion. Here the person is misinterpreting actual external stimuli.
True hallucinations do not include false perceptions that occur while dreaming, while falling asleep, or while waking up. Unusual perceptual experiences one may have while falling asleep are referred to as hypnagogic experiences. Unusual perceptual experiences one may have while waking up are referred to as hypnopompic experiences. Hallucinations also do not include very vivid experiences one may have while fully awake (such as particularly vivid daydreaming or imaginative play).
There are not a lot of definite causes for delusions. It is still not fully proven that what could cause delusion. However, there are some broad areas that can give us a clue when searching the source origin of delusion.
Genetic: genes can play a major role in developing delusions. It is more likely for an individual to develop delusion or delusional disorder when it is passed down from genes especially when they are from parents or even close family members. There can be a predisposition or a diathesis that can be developed with the help of a contributing factor like a stressful trigger (stressor).
Biological: according to many researches, any sort of abnormalities in certain areas of brain may be responsible for it. When there is an imbalance of chemicals that are present in the brain, known as the neurotransmitter, it can lead to delusions or mental disorder in general. The transmission can be interrupted which could hinder the nerve cells in delivering the message to each other and lead to the symptoms. Brain traumas can also be a cause as they can disrupt the message network.
Psychological or environmental: when people have maladaptive psychological or environmental space, they can be triggered by stress of any kind and that can lead to the symptoms. People who are alone have a higher risk for developing delusions.
Apart from these there are other causes too, that technically are mental health conditions that can cause delusions and hallucinations but needed to be pointed out. In the given mental health problems, delusion and hallucination work as a symptom too.
Alcoholism: Delusional thoughts and behavior can be a cause of alcohol abuse because the extreme intake of alcohol can result in brain damage and that can be a contributing factor in developing mental illness. Also, withdrawal symptoms that can result from alcoholism can also lead to delusions of depression, extreme anxiety and feelings of persecution.
Alzheimers disease, Dementia & Lewy body dementia: There have been several reports of patients with frontotemporal dementia due to a genetic cause (an abnormal change in a gene called C9ORF72) who frequently report very bizarre delusions. One can see the onset of delusion in these disorders usually when it is in the middle to late stage. Patient can encounter memory loss and confusion like having problems in remembering objects and people. This can lead to false beliefs. The affected person may feel or have a firm belief that he or she is stalked by the police or others are trying to steal personal possessions. This could result in paranoia because of the suspicious delusions.
Bipolar disorder: There are mainly two moods; mania or depression. The individual will usually feel euphoria and a surge of energy which can be included with delusion of grandeur. When the person is at a depressive state, the feeling of hopelessness may be accompanied by delusions of paranoia.
Brain tumor: It can lead to symptoms may be similar to schizophrenia. It can cause the total change in feelings and mood and may let people behave in contrasted manner. There can also be difficulty in recalling things and memory in general.
Depression: It is seen that there is an increased energy loss and drive gets into inhibition, emotional numbness and fear and how fear turns the life-historically understandable worries about poverty, illness, guilt and hopelessness into delusional convictions.
Drug abuse: It is similar to alcoholism and can cause delusions even after the person is not doing drugs at the time. This can typically be delusions of paranoia.
Flakka: Alpha-PVP is a synthetic drug. It is extremely potent and addictive (even more than methamphetamine) and quite inexpensive. It is linked with paranoia, delusions and hallucinations.
Human Immunodeficiency Virus: Patients have been seen suffering from persecutory and grandiose delusions and not hallucinations. Neuropsychiatric symptoms see in patients having HIV/AIDS may be because of the presence of HIV. It can also happen because of various other infections in the Central Nervous System, tumors, or other inflammatory illnesses.
Huntingtons disease: It has been seen that approximately 3-11% of the patients suffer delusions while simultaneously having this disease. Patients tend to develop major depressive disorder as well.
Parkinsons disease: According to researchers, delusion can be a side effect of the medication for this disease. Some people may experience delusions after their medications effects wear off.
Postpartum depression: In some cases when anxiety, stress and overwhelming and intrusive thoughts persist for a longer period of time, it can lead to delusions. Mother may start getting delusional thoughts about the infants health and wellbeing.
Psychotic disorder, schizoaffective disorders & Schizophrenia: delusion is one of the major symptoms in these disorders.
Steroid abuse: Although it is rare, but few cases have seen people suffering from delusion of persecution and grandeur.
Partners of individual with Delusional disorder: In some cases, people tend to share the delusions. This mostly happens to people who live together and have little or no interaction with the world outside.
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