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Psychological Terms – Alzheimer’s Disease
Alzheimer’s disease is a progressive, degenerative disorder of the brain that results in the deterioration of memory, cognition, and personality. Classified in DSM-5 as a neurocognitive disorder, it usually appears before the age of 65 and advances slowly, though cases may occur later in life. The disease is marked by amyloid plaques—abnormal protein deposits—and neurofibrillary tangles within neurons, leading to the death of brain cells and cortical atrophy. Neurochemically, Alzheimer’s involves a reduction in acetylcholine, a neurotransmitter essential for memory and learning. The condition has been linked to genetic mutations on chromosomes 14, 19, and 21, and mitochondrial DNA abnormalities. Beyond biological causes, Alzheimer’s has immense psychological and social impacts, affecting identity, emotional regulation, and interpersonal relationships. Cognitive therapies, memory aids, and environmental support are often employed to maintain patient autonomy.
Alzheimer’s disease is a progressive, degenerative disorder of the brain that results in the deterioration of memory, cognition, and personality. Classified in DSM-5 as a neurocognitive disorder, it usually appears before the age of 65 and advances slowly, though cases may occur later in life. The disease is marked by amyloid plaques—abnormal protein deposits—and neurofibrillary tangles within neurons, leading to the death of brain cells and cortical atrophy. Neurochemically, Alzheimer’s involves a reduction in acetylcholine, a neurotransmitter essential for memory and learning. The condition has been linked to genetic mutations on chromosomes 14, 19, and 21, and mitochondrial DNA abnormalities. Beyond biological causes, Alzheimer’s has immense psychological and social impacts, affecting identity, emotional regulation, and interpersonal relationships. Cognitive therapies, memory aids, and environmental support are often employed to maintain patient autonomy.
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Psychological Terms – Amacrine
Amacrine cells are specialized neurons located in the retina that lack distinct axons and instead connect bipolar cells to ganglion cells. They perform lateral communication within the inner retinal layers, modulating and integrating visual signals before these reach the optic nerve. Although the complete range of their functions is not fully understood, amacrine cells are thought to influence contrast sensitivity, motion detection, and temporal resolution. They contribute to the ability to detect changes in light intensity and movement, especially under low illumination. In the study of visual neuroscience, amacrine cells illustrate the complexity of neural networks within sensory processing and highlight how perception is shaped by pre-conscious neural organization.
Amacrine cells are specialized neurons located in the retina that lack distinct axons and instead connect bipolar cells to ganglion cells. They perform lateral communication within the inner retinal layers, modulating and integrating visual signals before these reach the optic nerve. Although the complete range of their functions is not fully understood, amacrine cells are thought to influence contrast sensitivity, motion detection, and temporal resolution. They contribute to the ability to detect changes in light intensity and movement, especially under low illumination. In the study of visual neuroscience, amacrine cells illustrate the complexity of neural networks within sensory processing and highlight how perception is shaped by pre-conscious neural organization.
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Psychological Terms – Amafufunyane
Amafufunyane is a culture-bound syndrome predominantly reported among Xhosa-speaking communities in southern Africa. It manifests in symptoms resembling possession or dissociative states, often involving shouting, hysteria, or hearing voices. Culturally, it is interpreted as spirit possession, often linked to social stress, witchcraft accusations, or interpersonal conflict. From a psychological standpoint, amafufunyane has been compared to dissociative identity disorder and psychogenic seizures. Anthropologists and transcultural psychiatrists study it to understand how mental distress is expressed through culturally specific idioms. It serves as a key example in cross-cultural psychology of how cultural belief systems shape the perception and treatment of psychological disorders.
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Psychological Terms – Amanita Muscaria
The Amanita muscaria, commonly known as the fly agaric mushroom, is notable for its bright red cap with white spots and its hallucinogenic properties. Historically, it has been used in shamanic rituals across Siberian and Northern European cultures. Psychologically, the mushroom’s active compounds—muscimol and ibotenic acid—affect the central nervous system, producing altered states of consciousness, distortions of perception, and euphoria. Though sometimes romanticized in folklore, its toxic properties can cause nausea, delirium, or coma in high doses. In modern psychology, its effects are studied within psychopharmacology and transpersonal psychology for their relation to mystical or visionary experiences.
The Amanita muscaria, commonly known as the fly agaric mushroom, is notable for its bright red cap with white spots and its hallucinogenic properties. Historically, it has been used in shamanic rituals across Siberian and Northern European cultures. Psychologically, the mushroom’s active compounds—muscimol and ibotenic acid—affect the central nervous system, producing altered states of consciousness, distortions of perception, and euphoria. Though sometimes romanticized in folklore, its toxic properties can cause nausea, delirium, or coma in high doses. In modern psychology, its effects are studied within psychopharmacology and transpersonal psychology for their relation to mystical or visionary experiences.
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Psychological Terms – Amantadine
Amantadine is a pharmaceutical compound that enhances dopamine availability in the brain by blocking its reuptake. It is primarily prescribed for Parkinson’s disease and certain drug-induced movement disorders (such as those caused by antipsychotic medications). By increasing dopaminergic activity, amantadine helps alleviate motor rigidity, bradykinesia, and tremors. It also exhibits antiviral properties against influenza A. In psychological contexts, amantadine’s influence on the dopamine system has informed research into reward mechanisms, motivation, and neuroplasticity. Its psychotropic effects occasionally make it relevant to studies of mood regulation and cognitive enhancement.
Amantadine is a pharmaceutical compound that enhances dopamine availability in the brain by blocking its reuptake. It is primarily prescribed for Parkinson’s disease and certain drug-induced movement disorders (such as those caused by antipsychotic medications). By increasing dopaminergic activity, amantadine helps alleviate motor rigidity, bradykinesia, and tremors. It also exhibits antiviral properties against influenza A. In psychological contexts, amantadine’s influence on the dopamine system has informed research into reward mechanisms, motivation, and neuroplasticity. Its psychotropic effects occasionally make it relevant to studies of mood regulation and cognitive enhancement.
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Psychological Terms – Amaurosis
Amaurosis denotes a loss of vision not attributable to visible damage of the eyes themselves but rather to lesions or dysfunction within the optic nerve or associated neural pathways. The term is often used in neurology and neuropsychology to distinguish cortical or neural blindness from ocular damage. For example, amaurosis fugax describes transient vision loss caused by reduced blood flow to the retina or optic nerve. Studying such conditions helps researchers understand the distinction between perception and sensation, emphasizing how brain damage can interrupt visual awareness despite intact sensory organs.
Amaurosis denotes a loss of vision not attributable to visible damage of the eyes themselves but rather to lesions or dysfunction within the optic nerve or associated neural pathways. The term is often used in neurology and neuropsychology to distinguish cortical or neural blindness from ocular damage. For example, amaurosis fugax describes transient vision loss caused by reduced blood flow to the retina or optic nerve. Studying such conditions helps researchers understand the distinction between perception and sensation, emphasizing how brain damage can interrupt visual awareness despite intact sensory organs.
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Psychological Terms – Amaurotic Familial Idiocy
This historical term, now replaced by Tay–Sachs disease, refers to a rare hereditary neurological disorder characterized by progressive deterioration of the nervous system. The disease, caused by a genetic mutation that leads to insufficient breakdown of fatty substances in nerve cells, results in developmental regression, paralysis, and early death. It is most prevalent among individuals of Ashkenazi Jewish descent. Psychologically, the condition is significant for its role in the study of genetic inheritance and the impact of neurodegeneration on developmental processes.
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Psychological Terms – Ambient System
The ambient visual system is the component of the visual system responsible for spatial orientation and the perception of movement and balance. It integrates central and peripheral visual input to create awareness of body position and motion in the environment. This system operates largely outside conscious awareness and is essential for activities such as walking, driving, or maintaining posture. The ambient system works in coordination with the focal system, which handles detailed visual tasks like object recognition. In cognitive psychology, understanding this distinction illuminates how humans process information at both conscious and subconscious levels simultaneously.
The ambient visual system is the component of the visual system responsible for spatial orientation and the perception of movement and balance. It integrates central and peripheral visual input to create awareness of body position and motion in the environment. This system operates largely outside conscious awareness and is essential for activities such as walking, driving, or maintaining posture. The ambient system works in coordination with the focal system, which handles detailed visual tasks like object recognition. In cognitive psychology, understanding this distinction illuminates how humans process information at both conscious and subconscious levels simultaneously.
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Psychology Terms - Alogia
Essentially devoid of words, but typically (in reference to one of the negative symptoms of schizophrenia, for instance) interpreted as a deficiency of cognition deduced from poverty of speech or content.
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Essentially devoid of words, but typically (in reference to one of the negative symptoms of schizophrenia, for instance) interpreted as a deficiency of cognition deduced from poverty of speech or content.
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Psychology Terms - Alpha blocking
The inhibition of the alpha wave in an EEG recording of an individual who is focused on or concentrating on a task.
The inhibition of the alpha wave in an EEG recording of an individual who is focused on or concentrating on a task.
