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Sunday, October 13, 2024

Psychoactive drug

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Psychoactive_drug

The 2010 ISCD study "Drug Harms in the UK: a multi-criteria decision analysis" found that alcohol scored highest overall and in "Economic cost", "Injury", "Family adversities", "Environmental damage", and "Community harm".

A psychoactive drug, mind-altering drug, or consciousness-altering drug is a chemical substance that changes brain function and results in alterations in perception, mood, consciousness, cognition, or behavior. The term psychotropic drug is often used interchangeably, while some sources present narrower definitions. These substances may be used medically; recreationally; to purposefully improve performance or alter one's consciousness; as entheogens for ritual, spiritual, or shamanic purposes; or for research, including psychedelic therapy. Some categories of psychoactive drugs, which have therapeutic value, are prescribed by physicians and other healthcare practitioners. Examples include anesthetics, analgesics, anticonvulsant and antiparkinsonian drugs as well as medications used to treat neuropsychiatric disorders, such as antidepressants, anxiolytics, antipsychotics, and stimulant medications. Some psychoactive substances may be used in the detoxification and rehabilitation programs for persons dependent on or addicted to other psychoactive drugs.

Psychoactive substances often bring about subjective changes in consciousness and mood (although these may be objectively observed) that the user may find rewarding and pleasant (e.g., euphoria or a sense of relaxation) or advantageous in an objectively observable or measurable way (e.g. increased alertness), thus the effects are reinforcing to varying degrees. Substances which are rewarding and thus positively reinforcing have the potential to induce a state of addiction – compulsive drug use despite negative consequences. In addition, sustained use of some substances may produce physical or psychological dependence or both, associated with somatic or psychological-emotional withdrawal states respectively. Drug rehabilitation attempts to reduce addiction, through a combination of psychotherapy, support groups, and other psychoactive substances. Conversely, certain psychoactive drugs may be so unpleasant that the person will never use the substance again. This is especially true of certain deliriants (e.g. Jimson weed), powerful dissociatives (e.g. Salvia divinorum), and classic psychedelics (e.g. LSD, psilocybin), in the form of a "bad trip".

Psychoactive drug misuse, dependence, and addiction have resulted in legal measures and moral debate. Governmental controls on manufacture, supply, and prescription attempt to reduce problematic medical drug use; worldwide efforts to combat trafficking in psychoactive drugs are commonly termed the "war on drugs". Ethical concerns have also been raised about the overuse of these drugs clinically and about their marketing by manufacturers. Popular campaigns to decriminalize or legalize the recreational use of certain drugs (e.g., cannabis) are also ongoing.

History

Psychoactive drug use can be traced to prehistory. Archaeological evidence of the use of psychoactive substances, mostly plants, dates back at least 10,000 years; historical evidence indicates cultural use 5,000 years ago. There is evidence of the chewing of coca leaves, for example, in Peruvian society 8,000 years ago.

Psychoactive substances have been used medicinally and to alter consciousness. Consciousness altering may be a primary drive, akin to the need to satiate thirst, hunger, or sexual desire. This may be manifest in the long history of drug use, and even even children's desire for spinning, swinging, or sliding, suggesting that the drive to alter one's state of mind is universal.

In The Hasheesh Eater (1857), American author Fitz Hugh Ludlow was one of the first to describe in modern terms the desire to change one's consciousness through drug use:

[D]rugs are able to bring humans into the neighborhood of divine experience and can thus carry us up from our personal fate and the everyday circumstances of our life into a higher form of reality. It is, however, necessary to understand precisely what is meant by the use of drugs. We do not mean the purely physical craving ... That of which we speak is something much higher, namely the knowledge of the possibility of the soul to enter into a lighter being, and to catch a glimpse of deeper insights and more magnificent visions of the beauty, truth, and the divine than we are normally able to spy through the cracks in our prison cell. But there are not many drugs which have the power of stilling such craving. The entire catalog, at least to the extent that research has thus far written it, may include only opium, hashish, and in rarer cases alcohol, which has enlightening effects only upon very particular characters.

During the 20th century, the majority of countries initially responded to the use of recreational drugs by prohibiting production, distribution, or use through criminalization. A notable example occurred with Prohibition in the United States, where alcohol was made illegal for 13 years. In recent decades, an emerging view among governments and law enforcement holds that illicit drug use cannot be stopped through prohibition. One organization with that opinion, Law Enforcement Against Prohibition (LEAP), concluded that "[in] fighting a war on drugs the government has increased the problems of society and made them far worse. A system of regulation rather than prohibition is a less harmful, more ethical and a more effective public policy."

In some countries, there has been a move toward harm reduction by health services, where the use of illicit drugs is neither condoned nor promoted, but services and support are provided to ensure users have adequate factual information readily available, and that the negative effects of their use be minimized. Such is the case of the Portuguese drug policy of decriminalization, which achieved its primary goal of reducing the adverse health effects of drug abuse.

Terminology

Psychoactive and psychotropic are often used interchangeably in general and academic sources, to describe substances that act on the brain to alter cognition and perception; some sources make a distinction between the terms. One narrower definition of psychotropic refers to drugs used to treat mental disorders, such as anxiolytic sedatives, antidepressants, antimanic agents, and neuroleptics. Another use of psychotropic refers to substances with a high likelihood of abuse, including stimulants, hallucinogens, opioids, and sedatives/hypnotics including alcohol. In international drug control, "psychotropic substances" refers to the substances specified in the Convention on Psychotropic Substances, which does not include narcotics.

The term "drug" has become a skunked term; Drugs can have a negative connotation, often associated with illegal substances like cocaine or heroin. This is despite the fact that the terms "drug" and "medicine" are sometimes used interchangeably.

Novel psychoactive substances (NPS), also known as "designer drugs" are a category of psychoactive drugs (substances) that are designed to mimic the effects of often illegal drugs, usually in efforts to circumvent existing drug laws.

Types

Psychoactive drugs are divided according to their pharmacological effects. Common subtypes include:

Anxiolytics are medicinally used to reduce the symptoms of anxiety, and sometimes insomnia.

Example: benzodiazepines such as Xanax and Valium; barbiturates

Empathogen–entactogens alter one's emotional state, often resulting in an increased sense of empathy, closeness, and emotional communication.

Example: MDMA (ecstasy), MDA, 6-APB, AMT

Stimulants increase activity, or arousal, of the central nervous system, used to enhance alertness, attention, cognition, mood and physical performance. Some stimulants are used medicinally to treat individuals with ADHD and narcolepsy.

Examples: amphetamines, caffeine, cocaine, nicotine

Depressants reduce (or depress) activity and stimulation in the central nervous system. Drugs within this classification encompass a spectrum of substances with sedative, soporific, and anesthetic properties, and include sedatives, hypnotics, and opioids.

Examples: ethanol (alcohol), opioids such as morphine, fentanyl, and codeine, cannabis, barbiturates, and benzodiazepines

Hallucinogens, including psychedelics, dissociatives and deliriants, encompass substances that produce distinct alterations in perception, sensation of space and time, and emotional state.^[22]

Examples: Dextromethorphan, psilocybin, LSD, DMT (N,N-Dimethyltryptamine), mescaline, Salvia divinorum, datura, scopolamine

Uses

Use of psychoactive substances vary widely between cultures. Some substances may have controlled or illegal uses, others may have shamanic purposes, and others are used medicinally. Examples would be social drinking, nootropic supplements, and sleep aids. Caffeine is the world's most widely consumed psychoactive substance: it is legal and unregulated in nearly all jurisdictions; in North America, 90% of adults consume caffeine daily.

Mental disorders

Psychiatric medications are psychoactive drugs prescribed for the management of mental and emotional disorders, or to aid in overcoming challenging behavior. There are six major classes of psychiatric medications:

Antidepressants treat disorders such as clinical depression, dysthymia, anxiety, eating disorders, and borderline personality disorder.
Stimulants, used to treat disorders such as attention deficit hyperactivity disorder and narcolepsy, and for weight reduction.
Antipsychotics, used to treat psychotic symptoms, such as those associated with schizophrenia or severe mania, or as adjuncts to relieve clinical depression.
Mood stabilizers, used to treat bipolar disorder and schizoaffective disorder.
Anxiolytics, used to treat anxiety disorders.
Depressants, used as hypnotics, sedatives, and anesthetics, depending upon dosage.

In addition, several psychoactive substances are currently employed to treat various addictions. These include acamprosate or naltrexone in the treatment of alcoholism, or methadone or buprenorphine maintenance therapy in the case of opioid addiction.

Exposure to psychoactive drugs can cause changes to the brain that counteract or augment some of their effects; these changes may be beneficial or harmful. However, there is a significant amount of evidence that the relapse rate of mental disorders negatively corresponds with the length of properly followed treatment regimens (that is, relapse rate substantially declines over time), and to a much greater degree than placebo.

Military

Drugs used by militaries

Militaries worldwide have used or are using various psychoactive drugs to treat pain and to improve performance of soldiers by suppressing hunger, increasing the ability to sustain effort without food, increasing and lengthening wakefulness and concentration, suppressing fear, reducing empathy, and improving reflexes and memory-recall among other things.

Both military and civilian American intelligence officials are known to have used psychoactive drugs while interrogating captives apprehended in its "war on terror". In July 2012 Jason Leopold and Jeffrey Kaye, psychologists and human rights workers, had a Freedom of Information Act request fulfilled that confirmed that the use of psychoactive drugs during interrogation was a long-standing practice. Captives and former captives had been reporting medical staff collaborating with interrogators to drug captives with powerful psychoactive drugs prior to interrogation since the very first captives release. In May 2003 recently released Pakistani captive Sha Mohammed Alikhel described the routine use of psychoactive drugs. He said that Jihan Wali, a captive kept in a nearby cell, was rendered catatonic through the use of these drugs.

The first documented case of a soldier overdosing on methamphetamine during combat, was the Finnish corporal Aimo Koivunen, a soldier who fought in the Winter War and the Continuation War.

Psychochemical warfare

Psychoactive drugs have been used in military applications as non-lethal weapons.

Pain management

Psychoactive drugs are often prescribed to manage pain. The subjective experience of pain is primarily regulated by endogenous opioid peptides. Thus, pain can often be managed using psychoactives that operate on this neurotransmitter system, also known as opioid receptor agonists. This class of drugs can be highly addictive, and includes opiate narcotics, like morphine and codeine. NSAIDs, such as aspirin and ibuprofen, are also analgesics. These agents also reduce eicosanoid-mediated inflammation by inhibiting the enzyme cyclooxygenase.

Anesthesia

General anesthetics are a class of psychoactive drug used on people to block physical pain and other sensations. Most anesthetics induce unconsciousness, allowing the person to undergo medical procedures like surgery, without the feelings of physical pain or emotional trauma. To induce unconsciousness, anesthetics affect the GABA and NMDA systems. For example, Propofol is a GABA agonist, and ketamine is an NMDA receptor antagonist.

Performance-enhancement

Performance-enhancing substances, also known as performance-enhancing drugs (PEDs), are substances that are used to improve any form of activity performance in humans. A well-known example of cheating in sports involves doping in sport, where banned physical performance-enhancing drugs are used by athletes and bodybuilders. Athletic performance-enhancing substances are sometimes referred as ergogenic aids. Cognitive performance-enhancing drugs, commonly called nootropics, are sometimes used by students to improve academic performance. Performance-enhancing substances are also used by military personnel to enhance combat performance.

Recreation

Many psychoactive substances are used for their mood and perception altering effects, including those with accepted uses in medicine and psychiatry. Examples of psychoactive substances include caffeine, alcohol, cocaine, LSD, nicotine, cannabis, and dextromethorphan. Classes of drugs frequently used recreationally include:

Stimulants, which activate the central nervous system. These are used recreationally for their euphoric effects.
Hallucinogens (psychedelics, dissociatives and deliriants), which induce perceptual and cognitive alterations.
Hypnotics, which depress the central nervous system.
Opioid analgesics, which also depress the central nervous system. These are used recreationally because of their euphoric effects.
Inhalants, in the forms of gas aerosols, or solvents, which are inhaled as a vapor because of their stupefying effects. Many inhalants also fall into the above categories (such as nitrous oxide which is also an analgesic).

In some modern and ancient cultures, drug usage is seen as a status symbol. Recreational drugs are seen as status symbols in settings such as at nightclubs and parties. For example, in ancient Egypt, gods were commonly pictured holding hallucinogenic plants.

Because there is controversy about regulation of recreational drugs, there is an ongoing debate about drug prohibition. Critics of prohibition believe that regulation of recreational drug use is a violation of personal autonomy and freedom. In the United States, critics have noted that prohibition or regulation of recreational and spiritual drug use might be unconstitutional, and causing more harm than is prevented.

Some people who take psychoactive drugs experience drug or substance induced psychosis. A 2019 systematic review and meta-analysis by Murrie et al. found that the pooled proportion of transition from substance-induced psychosis to schizophrenia was 25% (95% CI 18%–35%), compared with 36% (95% CI 30%–43%) for brief, atypical and not otherwise specified psychoses. Type of substance was the primary predictor of transition from drug-induced psychosis to schizophrenia, with highest rates associated with cannabis (6 studies, 34%, CI 25%–46%), hallucinogens (3 studies, 26%, CI 14%–43%) and amphetamines (5 studies, 22%, CI 14%–34%). Lower rates were reported for opioid (12%), alcohol (10%) and sedative (9%) induced psychoses. Transition rates were slightly lower in older cohorts but were not affected by sex, country of the study, hospital or community location, urban or rural setting, diagnostic methods, or duration of follow-up.

Ritual and spiritual

Offerings

Alcohol and tobacco (nicotine) have been and are used as offerings in various religions and spiritual practices. Coca leaves have been used as offerings in rituals.

Alcohol

According to the Catholic Church, the sacramental wine used in the Eucharist must contain alcohol. Canon 924 of the present Code of Canon Law (1983) states:

§3 The wine must be natural, made from grapes of the vine, and not corrupt.

Psychoactive use

Entheogen

Timothy Leary was a leading proponent of spiritual hallucinogen use.

Certain psychoactives, particularly hallucinogens, have been used for religious purposes since prehistoric times. Native Americans have used peyote cacti containing mescaline for religious ceremonies for as long as 5700 years. The muscimol-containing Amanita muscaria mushroom was used for ritual purposes throughout prehistoric Europe.

The use of entheogens for religious purposes resurfaced in the West during the counterculture movements of the 1960s and 70s. Under the leadership of Timothy Leary, new spiritual and intention-based movements began to use LSD and other hallucinogens as tools to access deeper inner exploration. In the United States, the use of peyote for ritual purposes is protected only for members of the Native American Church, which is allowed to cultivate and distribute peyote. However, the genuine religious use of peyote, regardless of one's personal ancestry, is protected in Colorado, Arizona, New Mexico, Nevada, and Oregon.

Psychedelic therapy

Psychedelic therapy (or psychedelic-assisted therapy) refers to the proposed use of psychedelic drugs, such as psilocybin, MDMA, LSD, and ayahuasca, to treat mental disorders. As of 2021, psychedelic drugs are controlled substances in most countries and psychedelic therapy is not legally available outside clinical trials, with some exceptions.

Psychonautics

The aims and methods of psychonautics, when state-altering substances are involved, is commonly distinguished from recreational drug use by research sources. Psychonautics as a means of exploration need not involve drugs, and may take place in a religious context with an established history. Cohen considers psychonautics closer in association to wisdom traditions and other transpersonal and integral movements.

Self-medication

Self-medication, sometime called do-it-yourself (DIY) medicine, is a human behavior in which an individual uses a substance or any exogenous influence to self-administer treatment for physical or psychological conditions, for example headaches or fatigue.

The substances most widely used in self-medication are over-the-counter drugs and dietary supplements, which are used to treat common health issues at home. These do not require a doctor's prescription to obtain and, in some countries, are available in supermarkets and convenience stores.

Sex

Sex and drugs date back to ancient humans and have been interlocked throughout human history. Both legal and illegal, the consumption of drugs and their effects on the human body encompasses all aspects of sex, including desire, performance, pleasure, conception, gestation, and disease.

There are many different types of drugs that are commonly associated with their effects on sex, including alcohol, cannabis, cocaine, MDMA, GHB, amphetamines, opioids, antidepressants, and many others.

Social movements

Cannabis

In the US, NORML (National Organization for the Reform of Marijuana Laws) has led since the 1970s a movement to legalize cannabis nationally. The so-called "420 movement" is the global association of the number 420 with cannabis consumption: April 20th – fourth month, twentieth day – has become an international counterculture holiday based on the celebration and consumption of cannabis;4:20 pm on any day is a time to consume cannabis.

Operation Overgrow

Operation Overgrow is the name, given by cannabis activists, of an "operation" to spread marijuana seeds wildly "so it grows like weed". The thought behind the operation is to draw attention to the debate about legalization/decriminalization of marijuana.

Suicide

A drug overdose involves taking a dose of a drug that exceeds safe levels. In the UK (England and Wales) until 2013, a drug overdose was the most common suicide method in females. In 2019 in males the percentage is 16%. Self-poisoning accounts for the highest number of non-fatal suicide attempts. In the United States about 60% of suicide attempts and 14% of suicide deaths involve drug overdoses. The risk of death in suicide attempts involving overdose is about 2%.

Most people are under the influence of sedative-hypnotic drugs (such as alcohol or benzodiazepines) when they die by suicide, with alcoholism present in between 15% and 61% of cases. Countries that have higher rates of alcohol use and a greater density of bars generally also have higher rates of suicide. About 2.2–3.4% of those who have been treated for alcoholism at some point in their life die by suicide. Alcoholics who attempt suicide are usually male, older, and have tried to take their own lives in the past. In adolescents who misuse alcohol, neurological and psychological dysfunctions may contribute to the increased risk of suicide.

Overdose attempts using painkillers are among the most common, due to their easy availability over-the-counter.

Route of administration

Psychoactive drugs are administered via oral ingestion as a tablet, capsule, powder, liquid, and beverage; via injection by subcutaneous, intramuscular, and intravenous route; via rectum by suppository and enema; and via inhalation by smoking, vaporizing, and snorting. The efficiency of each method of administration varies from drug to drug.

The psychiatric drugs fluoxetine, quetiapine, and lorazepam are ingested orally in tablet or capsule form. Alcohol and caffeine are ingested in beverage form; nicotine and cannabis are smoked or vaporized; peyote and psilocybin mushrooms are ingested in botanical form or dried; and crystalline drugs such as cocaine and methamphetamine are usually inhaled or snorted.

Determinants of effects

The theory of dosage, set, and setting is a useful model in dealing with the effects of psychoactive substances, especially in a controlled therapeutic setting as well as in recreational use. Dr. Timothy Leary, based on his own experiences and systematic observations on psychedelics, developed this theory along with his colleagues Ralph Metzner, and Richard Alpert (Ram Dass) in the 1960s.

Dosage

The first factor, dosage, has been a truism since ancient times, or at least since Paracelsus who said, "Dose makes the poison." Some compounds are beneficial or pleasurable when consumed in small amounts, but harmful, deadly, or evoke discomfort in higher doses.

Set

The set is the internal attitudes and constitution of the person, including their expectations, wishes, fears, and sensitivity to the drug. This factor is especially important for the hallucinogens, which have the ability to make conscious experiences out of the unconscious. In traditional cultures, set is shaped primarily by the worldview, health and genetic characteristics that all the members of the culture share.

Setting

The third aspect is setting, which pertains to the surroundings, the place, and the time in which the experiences transpire.

This theory clearly states that the effects are equally the result of chemical, pharmacological, psychological, and physical influences. The model that Timothy Leary proposed applied to the psychedelics, although it also applies to other psychoactives.

Effects

Psychoactive drugs operate by temporarily affecting a person's neurochemistry, which in turn causes changes in a person's mood, cognition, perception and behavior. There are many ways in which psychoactive drugs can affect the brain. Each drug has a specific action on one or more neurotransmitter or neuroreceptor in the brain.

Drugs that increase activity in particular neurotransmitter systems are called agonists. They act by increasing the synthesis of one or more neurotransmitters, by reducing its reuptake from the synapses, or by mimicking the action by binding directly to the postsynaptic receptor. Drugs that reduce neurotransmitter activity are called antagonists, and operate by interfering with synthesis or blocking postsynaptic receptors so that neurotransmitters cannot bind to them.

Exposure to a psychoactive substance can cause changes in the structure and functioning of neurons, as the nervous system tries to re-establish the homeostasis disrupted by the presence of the drug (see also, neuroplasticity). Exposure to antagonists for a particular neurotransmitter can increase the number of receptors for that neurotransmitter or the receptors themselves may become more responsive to neurotransmitters; this is called sensitization. Conversely, overstimulation of receptors for a particular neurotransmitter may cause a decrease in both number and sensitivity of these receptors, a process called desensitization or tolerance. Sensitization and desensitization are more likely to occur with long-term exposure, although they may occur after only a single exposure. These processes are thought to play a role in drug dependence and addiction. Physical dependence on antidepressants or anxiolytics may result in worse depression or anxiety, respectively, as withdrawal symptoms. Unfortunately, because clinical depression (also called major depressive disorder) is often referred to simply as depression, antidepressants are often requested by and prescribed for patients who are depressed, but not clinically depressed.

Affected neurotransmitter systems

The following is a brief table of notable drugs and their primary neurotransmitter, receptor or method of action. Many drugs act on more than one transmitter or receptor in the brain.

Addiction and dependence

Addiction and dependence glossary

Psychoactive drugs are often associated with addiction or drug dependence. Dependence can be divided into two types: psychological dependence, by which a user experiences negative psychological or emotional withdrawal symptoms (e.g., depression) and physical dependence, by which a user must use a drug to avoid physically uncomfortable or even medically harmful physical withdrawal symptoms. Drugs that are both rewarding and reinforcing are addictive; these properties of a drug are mediated through activation of the mesolimbic dopamine pathway, particularly the nucleus accumbens. Not all addictive drugs are associated with physical dependence, e.g., amphetamine, and not all drugs that produce physical dependence are addictive drugs, e.g., oxymetazoline.

Many professionals, self-help groups, and businesses specialize in drug rehabilitation, with varying degrees of success, and many parents attempt to influence the actions and choices of their children regarding psychoactives.

Common forms of rehabilitation include psychotherapy, support groups and pharmacotherapy, which uses psychoactive substances to reduce cravings and physiological withdrawal symptoms while a user is going through detox. Methadone, itself an opioid and a psychoactive substance, is a common treatment for heroin addiction, as is another opioid, buprenorphine. Recent research on addiction has shown some promise in using psychedelics such as ibogaine to treat and even cure drug addictions, although this has yet to become a widely accepted practice.

Legality

The legality of psychoactive drugs has been controversial through most of recent history; the Second Opium War and Prohibition are two historical examples of legal controversy surrounding psychoactive drugs. However, in recent years, the most influential document regarding the legality of psychoactive drugs is the Single Convention on Narcotic Drugs, an international treaty signed in 1961 as an Act of the United Nations. Signed by 73 nations including the United States, the USSR, Pakistan, India, and the United Kingdom, the Single Convention on Narcotic Drugs established Schedules for the legality of each drug and laid out an international agreement to fight addiction to recreational drugs by combatting the sale, trafficking, and use of scheduled drugs. All countries that signed the treaty passed laws to implement these rules within their borders. However, some countries that signed the Single Convention on Narcotic Drugs, such as the Netherlands, are more lenient with their enforcement of these laws.

In the United States, the Food and Drug Administration (FDA) has authority over all drugs, including psychoactive drugs. The FDA regulates which psychoactive drugs are over the counter and which are only available with a prescription. However, certain psychoactive drugs, like alcohol, tobacco, and drugs listed in the Single Convention on Narcotic Drugs are subject to criminal laws. The Controlled Substances Act of 1970 regulates the recreational drugs outlined in the Single Convention on Narcotic Drugs. Alcohol is regulated by state governments, but the federal National Minimum Drinking Age Act penalizes states for not following a national drinking age. Tobacco is also regulated by all fifty state governments. Most people accept such restrictions and prohibitions of certain drugs, especially the "hard" drugs, which are illegal in most countries.

In the medical context, psychoactive drugs as a treatment for illness is widespread and generally accepted. Little controversy exists concerning over the counter psychoactive medications in antiemetics and antitussives. Psychoactive drugs are commonly prescribed to patients with psychiatric disorders. However, certain critics believe that certain prescription psychoactives, such as antidepressants and stimulants, are overprescribed and threaten patients' judgement and autonomy.

Effect on animals

A number of animals consume different psychoactive plants, animals, berries and even fermented fruit, becoming intoxicated. An example of this is cats after consuming catnip. Traditional legends of sacred plants often contain references to animals that introduced humankind to their use. Animals and psychoactive plants appear to have co-evolved, possibly explaining why these chemicals and their receptors exist within the nervous system.

Widely used psychoactive drugs

This is a list of commonly used drugs that contain psychoactive ingredients. Please note that the following lists contains legal and illegal drugs (based on the country's laws).

Common legal drugs

The most widely consumed psychotropic drugs worldwide are:

Common prescribed drugs

Common street drugs

Freedom of thought

From Wikipedia, the free encyclopedia

Freedom of thought is the freedom of an individual to hold or consider a fact, viewpoint, or thought, independent of others' viewpoints.

Overview

Every person attempts to have a cognitive proficiency by developing knowledge, concepts, theories and assessing them in the given environment. This cognitive proficiency gives a sense of contentment and replaces the feeling of helplessness. Apart from bringing ease to the ego of a person, new knowledge and ideas also bring a hope for the future.

Freedom of thought is the precursor and progenitor of—and thus is closely linked to—other liberties, including freedom of religion, freedom of speech, and freedom of expression. Though freedom of thought is axiomatic for many other freedoms, they are in no way required for it to operate and exist. The conception of a freedom or a right does not guarantee its inclusion, legality, or protection via a philosophical caveat. It is a very important concept in the Western world and nearly all democratic constitutions protect these freedoms.

For instance, the United States Bill of Rights contains the famous guarantee in the First Amendment that laws may not be made that interfere with religion "or prohibiting the free exercise thereof". U.S. Supreme Court Justice Benjamin Cardozo reasoned in Palko v. Connecticut (1937):

Freedom of thought... is the matrix, the indispensable condition, of nearly every other form of freedom. With rare aberrations a pervasive recognition of this truth can be traced in our history, political and legal.

Such ideas are also a vital part of international human rights law. In the Universal Declaration of Human Rights (UDHR), which is legally binding on member states of the International Covenant on Civil and Political Rights (ICCPR), "freedom of thought" is listed under Article 18:

Everyone has the right to freedom of thought, conscience and religion; this right includes freedom to change his religion or belief, and freedom, either alone or in community with others and in public or private, to manifest his religion or belief in teaching, practice, worship and observance.

The United Nations' Human Rights Committee states that this "distinguishes the freedom of thought, conscience, religion or belief from the freedom to manifest religion or belief. It does not permit any limitations whatsoever on the freedom of thought and conscience or on the freedom to have or adopt a religion or belief of one's choice. These freedoms are protected unconditionally". Similarly, Article 19 of the UDHR guarantees that "Everyone has the right to freedom of opinion and expression; this right includes freedom to hold opinions without interference".

Article 9 of the European Convention on Human Rights states, "Everyone has the right to freedom of thought, conscience and religion."

History of development and suppression

It is impossible to know with certainty what another person is thinking, making suppression difficult. The concept is developed throughout the Bible, most fully in the writings of Saul of Tarsus (e.g., "For why should my freedom [eleutheria] be judged by another's conscience [suneideseos]?" 1 Corinthians 10:29).

Although Greek philosophers Plato and Socrates had discussed freedom of thought minimally, the edicts of King Ashoka (3rd century BC) have been called the first decree respecting freedom of conscience. In European tradition, aside from the decree of religious toleration by Constantine I at Milan in 313, the philosophers Themistius, Michel de Montaigne, Baruch Spinoza, John Locke, Voltaire, Alexandre Vinet, and John Stuart Mill and the theologians Roger Williams and Samuel Rutherford have been considered major proponents of the idea of freedom of conscience (or "soul liberty" in the words of Williams).

Queen Elizabeth I revoked a thought censorship law in the late sixteenth century, because, according to Sir Francis Bacon, she did "not [like] to make windows into men's souls and secret thoughts". During her reign, however, a number of books published by theorist Giordano Bruno spurred controversy, mentioning topics banned by the Catholic Church such as the possibility of an infinite universe. Unwilling to recant these ideas, Bruno was eventually burned as a heretic in Rome by the Italian Inquisition, in turn becoming a martyr for free thought.

Oliver Cromwell is described by Ignaz von Döllinger as "the first among the mighty men of the world to set up one special religious principle, and to enforce it so far as in him lay: ... The principle of liberty of conscience and the repudiation of religious coercion".

However, freedom of expression can be limited through censorship, arrests, book burning, or propaganda, and this tends to discourage freedom of thought. Examples of effective campaigns against freedom of expression are the Soviet suppression of genetics research in favor of a theory known as Lysenkoism, the book-burning campaigns of Nazi Germany, the radical anti-intellectualism enforced in Cambodia under Pol Pot and in Nazi Germany under Adolf Hitler, the strict limits on freedom of expression imposed by the Communist governments of the People's Republic of China and Cuba or by Capitalist dictatorships such as those of Augusto Pinochet in Chile and Francisco Franco in Spain.

The Sapir–Whorf hypothesis, which states that thought can be embedded in language, would support the claim that an effort to limit the use of words of language is actually a form of restricting freedom of thought. This was explored in George Orwell's novel 1984, with the idea of Newspeak, a stripped-down form of the English language alleged to lack the capacity for metaphor and limiting expression of original ideas.

More recently, the development of neuroimaging technologies have raised concerns about entities being able to read and subsequently suppress thought. Although the issue is complicated by the mind-body problem, these concerns form the emerging field of neuroethics and neuroprivacy.

Self-ownership

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Self-ownership

Self-ownership, also known as sovereignty of the individual or individual sovereignty, is the concept of property in one's own person, expressed as the moral or natural right of a person to have bodily integrity and be the exclusive controller of one's own body and life. Self-ownership is a central idea in several political philosophies that emphasize individualism, such as libertarianism, liberalism, and anarchism.

Definitional issues

The self

American libertarian socialist Stephen Pearl Andrews frequently discussed the sovereignty of the individual in his writings. In The Science of Society, he says that Protestantism, democracy and socialism are "three partial announcements of one generic principle" which is "the sovereignty of the individual". Andrews considered the sovereignty of the individual to be "the basis of harmonious intercourse amongst equals, precisely as the equal Sovereignty of States is the basis of harmonious intercourse between nations mutually recognizing their independence of each other."

Discussion of the boundary of self with respect to ownership and responsibility has been explored by legal scholar Meir Dan-Cohen in his essays on The Value of Ownership and Responsibility and the Boundaries of the Self.The emphasis of this work illuminates the phenomenology of ownership and our common usage of personal pronouns to apply to both body and property – this serves as the folk basis for legal conceptions and debates about responsibility and ownership.Another view holds that labor is alienable because it can be contracted out, thus alienating it from the self. In this view, the choice of a person to voluntarily sell oneself into slavery is also preserved by the principle of self-ownership.

Labour markets and private property

For anarcho-communist political philosopher L. Susan Brown: "Liberalism and anarchism are two political philosophies that are fundamentally concerned with individual freedom yet differ from one another in very distinct ways. Anarchism shares with liberalism a commitment to individual freedom while rejecting liberalism's competitive property relations". Scholar Ellen Meiksins Wood says that "there are doctrines of individualism that are opposed to Lockean individualism... and non-Lockean individualism may encompass socialism".

Right-libertarian conceptions of self-ownership extend the concept to include control of private property as part of the self. According to Gerald Cohen, "the libertarian principle of self-ownership says that each person enjoys, over herself and her powers, full and exclusive rights of control and use, and therefore owes no service or product to anyone else that she has not contracted to supply".

Philosopher Ian Shapiro says that labor markets affirm self-ownership because if self-ownership were not recognized, then people would not be allowed to sell the use of their productive capacities to others. He says that the individual sells the use of his productive capacity for a limited time and conditions but continues to own what he earns from selling the use of that capacity and the capacity itself, thereby retaining sovereignty over himself while contributing to economic efficiency. A common view within classical liberalism is that sovereign-minded individuals usually assert a right of private property external to the body, reasoning that if a person owns themselves, they own their actions, including those that create or improve resources, therefore they own their own labour and the fruits thereof.

In Human Action, Austrian School economist Ludwig von Mises argues that labor markets are the rational conclusion of self-ownership and argues that collective ownership of labor ignores differing values for the labor of individuals:

Of course, people believe that there is an essential difference between the tasks incumbent upon the comrades of the socialist commonwealth and those incumbent upon slaves or serfs. The slaves and serfs, they say, toiled for the benefit of an exploiting lord. But in a socialist system, the produce of labor goes to society of which the toiler himself is a part; here the worker works for himself, as it were. What this reasoning overlooks is that the identification of the individual comrades and the totality of all comrades with the collective entity pocketing the produce of all work is merely fictitious. Whether the ends which the community's officeholders are aiming at agreeing or disagreeing with the wishes and desires of the various comrades are of minor importance. The main thing is that the individual's contribution to the collective entity's wealth is not requited in the shape of wages determined by the market.
— Ludwig von Mises

Other scholars are critical of the idea of private property, specifically within anarchism. The anarchist Oscar Wilde said:

For the recognition of private property has really harmed Individualism, and obscured it, by confusing a man with what he possesses. It has led Individualism entirely astray. It has made gain, not growth its aim. So that man thought that the important thing was to have, and did not know that the important thing is to be. The true perfection of man lies, not in what man has, but in what man is... With the abolition of private property, then, we shall have true, beautiful, healthy Individualism. Nobody will waste his life in accumulating things, and the symbols for things. One will live. To live is the rarest thing in the world. Most people exist, that is all".
— Oscar Wilde

Within anarchism, the concept of wage slavery refers to a situation perceived as quasi-voluntary slavery, where a person's livelihood depends on wages, especially when the dependence is total and immediate. It is a negatively connoted term used to draw an analogy between slavery and wage labor by focusing on similarities between owning and renting a person. The term "wage slavery" has been used to criticize economic exploitation and social stratification, with the former seen primarily as unequal bargaining power between labor and capital (particularly when workers are paid comparatively low wages, e.g. in sweatshops) and the latter as a lack of workers' self-management, fulfilling job choices and leisure in an economy.With the advent of the Industrial Revolution, thinkers such as Pierre-Joseph Proudhon and Karl Marx elaborated the comparison between wage labor and slavery in the context of a critique of societal property not intended for active personal use while Luddites emphasized the dehumanization brought about by machines. Emma Goldman famously denounced "wage slavery" by saying: "The only difference is that you are hired slaves instead of block slaves".

Within left-libertarianism, scholars such as Hillel Steiner, Peter Vallentyne, Philippe Van Parijs, Michael Otsuka and David Ellerman root an economic egalitarianism in the classical liberal concepts of self-ownership and land appropriation, combined with geoist or physiocratic views regarding the ownership of land and natural resources (e.g. those of John Locke and Henry George). Left-libertarians "maintain that the world's natural resources were initially unowned or belonged equally to all, and it is illegitimate for anyone to claim exclusive private ownership of these resources to the detriment of others. Such private appropriation is legitimate only if everyone can appropriate an equal amount, or if those who appropriate more are taxed to compensate those who are thereby excluded from what was once common property". This position is articulated in contrast to the position of other libertarians who argue for a right to appropriate parts of the external world based on sufficient use, even if this homesteading yields unequal results. Some left-libertarians of the Steiner–Vallentyne type support some form of income redistribution on the grounds of a claim by each individual to be entitled to an equal share of natural resources.

History

John Locke wrote in his Two Treatises on Government that "every man has a Property in his own Person". Libertarian philosopher Robert Nozick interprets Locke as saying that the individual "has a right to decide what would become of himself and what he would do, and as having a right to reap the benefits of what he did". Josiah Warren was the first who wrote about the "sovereignty of the individual".

Cognitive liberty

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Cognitive_liberty

Cognitive liberty, or the "right to mental self-determination", is the freedom of an individual to control their own mental processes, cognition, and consciousness. It has been argued to be both an extension of, and the principle underlying, the right to freedom of thought. Though a relatively recently defined concept, many theorists see cognitive liberty as being of increasing importance as technological advances in neuroscience allow for an ever-expanding ability to directly influence consciousness.Cognitive liberty is not a recognized right in any international human rights treaties, but has gained a limited level of recognition in the United States, and is argued to be the principle underlying a number of recognized rights.

Overview

The term "cognitive liberty" was coined by neuroethicist Wrye Sententia and legal theorist and lawyer Richard Glen Boire, the founders and directors of the non-profit Center for Cognitive Liberty and Ethics (CCLE). Sententia and Boire define cognitive liberty as "the right of each individual to think independently and autonomously, to use the full power of his or her mind, and to engage in multiple modes of thought."

The CCLE is a network of scholars dedicated to protecting freedom of thought in the modern world of accelerating neurotechnologies. They seek to develop public policies that will preserve and enhance freedom of thought, and offer guidance with regard to relevant developments in neurotechnology, psychopharmacology, cognitive sciences and law.

Sententia and Boire conceived of the concept of cognitive liberty as a response to the increasing ability of technology to monitor and manipulate cognitive function, and the corresponding increase in the need to ensure individual cognitive autonomy and privacy. Sententia divides the practical application of cognitive liberty into two principles:

As long as their behavior does not endanger others, individuals should not be compelled against their will to use technologies that directly interact with the brain or be forced to take certain psychoactive drugs.
As long as they do not subsequently engage in behavior that harms others, individuals should not be prohibited from, or criminalized for, using new mind-enhancing drugs and technologies.

These two facets of cognitive liberty are reminiscent of Timothy Leary's "Two Commandments for the Molecular Age", from his 1968 book The Politics of Ecstasy:

Thou shalt not alter the consciousness of thy fellow man
Thou shalt not prevent thy fellow man from altering his own consciousness.

Supporters of cognitive liberty therefore seek to impose both a negative and a positive obligation on states: to refrain from non-consensually interfering with an individual's cognitive processes, and to allow individuals to self-determine their own "inner realm" and control their own mental functions.

Freedom from interference

This first obligation, to refrain from non-consensually interfering with an individual's cognitive processes, seeks to protect individuals from having their mental processes altered or monitored without their consent or knowledge, "setting up a defensive wall against unwanted intrusions". Ongoing improvements to neurotechnologies, such as transcranial magnetic stimulation and electroencephalography (or "brain fingerprinting"), and to pharmacology, in the form of selective serotonin reuptake inhibitors (SSRIs), nootropics, modafinil and other psychoactive drugs, are continuing to increase the ability to both monitor and directly influence human cognition. As a result, many theorists have emphasized the importance of recognizing cognitive liberty in order to protect individuals from the state using such technologies to alter those individuals' mental processes: "states must be barred from invading the inner sphere of persons, from accessing their thoughts, modulating their emotions or manipulating their personal preferences." These specific ethical concerns regarding the use of neuroscience technologies to interfere or invade the brain form the fields of neuroethics and neuroprivacy.

This element of cognitive liberty has been raised in relation to a number of state-sanctioned interventions in individual cognition, from the mandatory psychiatric 'treatment' of homosexuals in the US before the 1970s, to the non-consensual administration of psychoactive drugs to unwitting US citizens during CIA Project MKUltra, to the forcible administration of mind-altering drugs on individuals to make them competent to stand trial. Futurist and bioethicist George Dvorsky, chair of the Board of the Institute for Ethics and Emerging Technologies has identified this element of cognitive liberty as being of relevance to the debate around the curing of autism spectrum conditions. Duke University School of Law Professor Nita A. Farahany has also proposed legislative protection of cognitive liberty as a way of safeguarding the protection from self-incrimination found in the Fifth Amendment to the US Constitution, in the light of the increasing ability to access human memory. Her book 'The Battle for Your Brain: Defending the Right to Think Freely in the Age of Neurotechnology' discusses the matter in great detail.

Though this element of cognitive liberty is often defined as an individual's freedom from state interference with human cognition, Jan Christoph Bublitz and Reinhard Merkel among others suggest that cognitive liberty should also prevent other, non-state entities from interfering with an individual's mental "inner realm". Bublitz and Merkel propose the introduction of a new criminal offense punishing "interventions severely interfering with another's mental integrity by undermining mental control or exploiting pre-existing mental weakness." Direct interventions that reduce or impair cognitive capacities such as memory, concentration, and willpower; alter preferences, beliefs, or behavioral dispositions; elicit inappropriate emotions; or inflict clinically identifiable mental injuries would all be prima facie impermissible and subject to criminal prosecution. Sententia and Boire have also expressed concern that corporations and other non-state entities might utilize emerging neurotechnologies to alter individuals' mental processes without their consent.

Freedom to self-determine

Where the first obligation seeks to protect individuals from interference with cognitive processes by the state, corporations or other individuals, this second obligation seeks to ensure that individuals have the freedom to alter or enhance their own consciousness. An individual who enjoys this aspect of cognitive liberty has the freedom to alter their mental processes in any way they wish to, whether through indirect methods such as meditation, yoga or prayer, or through direct cognitive intervention through psychoactive drugs or neurotechnology.

As psychotropic drugs are a powerful method of altering cognitive function, many advocates of cognitive liberty are also advocates of drug law reform, claiming that the "war on drugs" is in fact a "war on mental states". The CCLE, as well as other cognitive liberty advocacy groups such as Cognitive Liberty UK, have lobbied for the re-examination and reform of prohibited drug law; one of the CCLE's key guiding principles is that "governments should not criminally prohibit cognitive enhancement or the experience of any mental state". Calls for reform of restrictions on the use of prescription cognitive-enhancement drugs (also called smart drugs or nootropics) such as Prozac, Ritalin and Adderall have also been made on the grounds of cognitive liberty.

This element of cognitive liberty is also of great importance to proponents of the transhumanist movement, a key tenet of which is the enhancement of human mental function. Wrye Sententia has emphasized the importance of cognitive liberty in ensuring the freedom to pursue human mental enhancement, as well as the freedom to choose against enhancement. Sententia argues that the recognition of a "right to (and not to) direct, modify, or enhance one's thought processes" is vital to the free application of emerging neurotechnology to enhance human cognition and that something beyond the current conception of freedom of thought is needed. Sententia claims that "cognitive liberty's strength is that it protects those who do want to alter their brains, but also those who do not".

Relationship with recognized human rights

Cognitive liberty is not currently recognized as a human right by any international human rights treaty. While freedom of thought is recognized by Article 18 of the Universal Declaration of Human Rights (UDHR), freedom of thought can be distinguished from cognitive liberty in that the former is concerned with protecting an individual's freedom to think whatever they want, whereas cognitive liberty is concerned with protecting an individual's freedom to think however they want. Cognitive liberty seeks to protect an individual's right to determine their own state of mind and be free from external control over their state of mind, rather than just protecting the content of an individual's thoughts. It has been suggested that the lack of protection of cognitive liberty in previous human rights instruments was due to the relative lack of technology capable of directly interfering with mental autonomy at the time the core human rights treaties were created. As the human mind was considered invulnerable to direct manipulation, control or alteration, it was deemed unnecessary to expressly protect individuals from unwanted mental interference. With modern advances in neuroscience and in anticipation of its future development however, it is argued that such express protection is becoming increasingly necessary.

Cognitive liberty then can be seen as an extension of or an "update" to the right to freedom of thought as it has been traditionally understood. Freedom of thought should now be understood to include the right to determine one's own mental state as well as the content of one's thoughts. However, some have instead argued that cognitive liberty is already an inherent part of the international human rights framework as the principle underlying the rights to freedom of thought, expression and religion. The freedom to think in whatever manner one chooses is a "necessary precondition to those guaranteed freedoms." Daniel Waterman and Casey William Hardison have argued that cognitive liberty is fundamental to Freedom of Thought because it encompasses the ability to have certain types of experiences, including the right to experience altered or non-ordinary states of consciousness. It has also been suggested that cognitive liberty can be seen to be a part of the inherent dignity of human beings as recognized by Article 1 of the UDHR.

Most proponents of cognitive liberty agree, however, that cognitive liberty should be expressly recognized as a human right in order to properly provide protection for individual cognitive autonomy.

At least one scholar and proponent of cognitive liberty, Christoph Bublitz, has used the term 'freedom of mind' to describe cognitive liberty: "mind altering interventions primary affect another sense of freedom, freedom of mind, a concept that has not received much attention although it should rank among the most important legal and political freedoms…This freedom is not often regarded in its own right but should be recognized and more fully developed in face of emerging mind-altering technologies…Freedom of mind is the freedom of a person to use her mental capacities as she pleases, free from external interferences and internal impediments".

Legal recognition

In the United States

Richard Glen Boire of the Center for Cognitive Liberty and Ethics filed an amicus brief with the US Supreme Court in the case of Sell v. United States, in which the Supreme Court examined whether the court had the power to make an order to forcibly administer antipsychotic medication to an individual who had refused such treatment, for the sole purpose of making them competent to stand trial.

In the United Kingdom

In the case of R v Hardison, the defendant, charged with eight counts under the Misuse of Drugs Act 1971 (MDA), including the production of DMT and LSD, claimed that cognitive liberty was safeguarded by Article 9 of the European Convention on Human Rights. Hardison argued that "individual sovereignty over one's interior environment constitutes the very core of what it means to be free", and that as psychotropic drugs are a potent method of altering an individual's mental process, prohibition of them under the MDA was in opposition to Article 9. The court however disagreed, calling Hardison's arguments a "portmanteau defense" and relying upon the UN Drug Conventions and the earlier case of R v Taylor to deny Hardison's right to appeal to a superior court. Hardison was convicted and given a 20-year prison sentence, though he was released on 29 May 2013 after nine years in prison.

Criticism

The recent development of neurosciences is increasing the possibility of controlling and influence specific mental functions. The risks inherent in removing restrictions on controlled cognitive-enhancing drugs, including of widening the gap between those able to afford such treatments and those unable to do so, have caused many to remain skeptical about the wisdom of recognizing cognitive liberty as a right. Political philosopher and Harvard University professor Michael J. Sandel, when examining the prospect of memory enhancement, wrote that "some who worry about the ethics of cognitive enhancement point to the danger of creating two classes of human beings – those with access to enhancement technologies, and those who must make do with an unaltered memory that fades with age."

Stimulus control

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Stimulus_control

In behavioral psychology, stimulus control is a phenomenon in operant conditioning that occurs when an organism behaves in one way in the presence of a given stimulus and another way in its absence. A stimulus that modifies behavior in this manner is either a discriminative stimulus or stimulus delta. For example, the presence of a stop sign at a traffic intersection alerts the driver to stop driving and increases the probability that braking behavior occurs. Stimulus control does not force behavior to occur, as it is a direct result of historical reinforcement contingencies, as opposed to reflexive behavior elicited through classical conditioning.

Some theorists believe that all behavior is under some form of stimulus control. For example, in the analysis of B. F. Skinner, verbal behavior is a complicated assortment of behaviors with a variety of controlling stimuli.

Characteristics

The controlling effects of stimuli are seen in quite diverse situations and in many aspects of behavior. For example, a stimulus presented at one time may control responses emitted immediately or at a later time; two stimuli may control the same behavior; a single stimulus may trigger behavior A at one time and behavior B at another; a stimulus may control behavior only in the presence of another stimulus, and so on. These sorts of control are brought about by a variety of methods and they can explain many aspects of behavioral processes.

In simple, practical situations, for example if one were training a dog using operant conditioning, optimal stimulus control might be described as follows:

The behavior occurs immediately when the discriminative stimulus is given.
The behavior never occurs in the absence of the stimulus.
The behavior never occurs in response to some other stimulus.
No other behavior occurs in response to this stimulus.

Establishing stimulus control through operant conditioning

Discrimination training

Operant stimulus control is typically established by discrimination training. For example, to make a light control a pigeon's pecks on a button, reinforcement only occurs following a peck to the button. Over a series of trials the pecking response becomes more probable in the presence of the light and less probable in its absence, and the light is said to become a discriminative stimulus or S^D. Virtually any stimulus that the animal can perceive may become a discriminative stimulus, and many different schedules of reinforcement may be used to establish stimulus control. For example, a green light might be associated with a VR 10 schedule and a red light associated with a FI 20-sec schedule, in which case the green light will control a higher rate of response than the red light.

Generalization

After a discriminative stimulus is established, similar stimuli are found to evoke the controlled response. This is called stimulus generalization. As the stimulus becomes less and less similar to the original discriminative stimulus, response strength declines; measurements of the response thus describe a generalization gradient.

An experiment by Hanson (1959) provides an early, influential example of the many experiments that have explored the generalization phenomenon. First a group of pigeons was reinforced for pecking a disc illuminated by a light of 550 nm wavelength, and never reinforced otherwise. Reinforcement was then stopped, and a series of different wavelength lights was presented one at a time. The results showed a generalization gradient: the more the wavelength differed from the trained stimulus, the fewer responses were produced.

Many factors modulate the generalization process. One is illustrated by the remainder of Hanson's study, which examined the effects of discrimination training on the shape of the generalization gradient. Birds were reinforced for pecking at a 550 nm light, which looks yellowish-green to human observers. The birds were not reinforced when they saw a wavelength more toward the red end of the spectrum. Each of four groups saw a single unreinforced wavelength, either 555, 560, 570, or 590 nm, in addition to the reinforced 550 wavelength. The birds were then tested as before, with a range of unreinforced wavelengths. This procedure yielded sharper generalization gradients than did the simple generalization procedure used in the first procedure. In addition, however, Hansen's experiment showed a new phenomenon, called the "peak shift". That is, the peak of the test gradients shifted away from the S^D, such that the birds responded more often to a wavelength they had never seen before than to the reinforced S^D. An earlier theory involving inhibitory and excitatory gradients partially explained the results, A more detailed quantitative model of the effect was proposed by Blough (1975). Other theories have been proposed, including the idea that the peak shift is an example of relational control; that is, the discrimination was perceived as a choice between the "greener" of two stimuli, and when a still greener stimulus was offered the pigeons responded even more rapidly to that than to the originally reinforced stimulus.

Matching to sample

In a typical matching-to-sample task, a stimulus is presented in one location (the "sample"), and the subject chooses a stimulus in another location that matches the sample in some way (e.g., shape or color). In the related "oddity" matching procedure, the subject responds to a comparison stimulus that does not match the sample. These are called "conditional" discrimination tasks because which stimulus is responded to depends or is "conditional" on the sample stimulus.

The matching-to-sample procedure has been used to study a very wide range of problems. Of particular note is the "delayed matching to sample" variation, which has often been used to study short-term memory in animals. In this variation, the subject is exposed to the sample stimulus, and then the sample is removed and a time interval, the "delay", elapses before the choice stimuli appear. To make a correct choice the subject has to retain information about the sample across the delay. The length of the delay, the nature of the stimuli, events during the delay, and many other factors have been found to influence performance on this task.

Cannabinoids

Psychoactive cannabinoids produce discriminative stimulus effects by stimulation of CB1 receptors in the brain.

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Sunday, October 13, 2024

History

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Overview

History of development and suppression

Definitional issues

The self

Labour markets and private property

History

Overview

Freedom from interference

Freedom to self-determine

Relationship with recognized human rights

Legal recognition

In the United States

In the United Kingdom

Criticism

Characteristics

Establishing stimulus control through operant conditioning

Discrimination training

Generalization

Matching to sample

Cannabinoids