Making Sense of the Environment

Sleep is a reversible phase of diminished responsiveness, motor activity, and metabolism. This process is a complex and dynamic phenomenon, occurring in 4–5 cycles a night, and generally divided into non–rapid eye movement (NREM) sleep and REM sleep stages. NREM sleep, consisting of 3 stages, represents the period of transition from wakefulness, somnolence, and then deep sleep. REM sleep is characterized by rapid irregular eye movement, but with voluntary muscle atonia. The sleep stages and associated disorders are studied through the use of polysomnography, a multimodal test evaluating the brain waves, along with ocular and motor activities. Sleep disorders can be primary (which do not stem from any health problem) or can be attributable to underlying conditions or medications.

Circadian rhythm sleep–wake disorders are a group of conditions marked by recurrent patterns of sleep disruption. These disorders can be due to an alteration of the circadian system (intrinsic) or a misalignment between an individual’s inner circadian rhythm and the environment (extrinsic). The disruption impairs the individual’s daily activities. There are 6 different subtypes, including delayed and advanced sleep–wake phase disorder, irregular and non-24-hour sleep–wake rhythm disorder, shift-work disorder, and jet lag. Diagnosis is generally clinical, but using tools such a sleep diary and actigraphy help in determining the disorder. Management for circadian rhythm sleep–wake disorders involves light therapy, behavioral modification, and pharmacotherapy, such as with melatonin.

Hallucinogen use disorder is defined by the pathologic consumption of hallucinogenic substances that cause perceptual distortions (visual or auditory). Examples include psilocybin (mushrooms), lysergic acid diethylamide (LSD), and phencyclidine (PCP). These drugs are used for their psychedelic effects, i.e., a temporarily altered state of consciousness. Most hallucinogens produce nausea, vomiting, and mild sympathomimetic effects such as tachycardia, hypertension, mydriasis, hyperthermia, and diaphoresis. Although hallucinogens may cause hyperthermia in severe cases, they don’t result in dependence or withdrawal symptoms.

Medical forms of intervention do not only include drugs prescriptions and surgical procedures. Medical counseling, patient education, and various forms of psychotherapy are essential therapeutic pillars. This article offers a concise overview of medical intervention forms to help you make better therapeutic decisions in the future.

Before we dive into the effects of selective attention on perception, information integration and our ability to process information precisely, we need to define what we mean by selective attention and why to study attention in the first place.

The human brain is a very complex organ, structurally and functionally. Cognition is a term that psychologists use to describe a wide array of different brain processes and activities that include perception, thinking, reasoning, memory, attention and creating new information or ideas. This is however a limited view of cognition as now it became clear that cognition is the product of interplay between all of these components and more.

Learning and the development of memory are processes that cannot be strictly separated from psychology and sociology. Thus, this article deals with the physiology of learning and memory. Topics include understanding the relationship between experience and storage of acquired knowledge, how the brain deals with “useless” knowledge, and how a baby starts to understand its surroundings.

Etymologically, the term "sleep" comes from a word meaning "to slack"; the term's similarity to the word "slack" is no accident. Sleep is susceptible to various interferences, and many diseases, some harmless and some serious, first exhibit symptoms during sleep. It is therefore important to deal not only with the scientific findings, but also with possible sleep theories because many facts about sleep remain unknown. In the following guide, you will see what sleep is actually about, what stages it occurs in, and what sleep disturbances individuals may experience.

Why do you decide in favor of certain actions and behavior but not of others? To get to the bottom of this question, psychology has developed a number of learning models. Classical and operant conditioning, learning by self-control, and observational learning are important basics that psychotherapy is based on. The following article contains, in addition to all facts about learning, knowledge about memory and language that is relevant for your exams.

Every physician gets in touch with addicted patients, as 5–7 % of the population is addicted to legal or illegal drugs. But studies have revealed that primary care physicians only identify every 10th patient suffering from dependency syndrome. This article is supposed to help you recognize the typical symptoms of the respective drug consume and treat intoxications as well as withdrawal symptoms.