Opponent-process theory is a psychological and neurological model that accounts for a wide range of behaviors, including color vision. This model was first proposed in 1878 by Ewald Hering, a German physiologist, and later expanded by Richard Solomon, a 20th-century psychologist.
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The opponent-process theory was first developed by Ewald Hering. He noted that there are color combinations that we never see, such as reddish-green or bluish-yellow. Opponent-process theory suggests that color perception is controlled by the activity of three opponent systems. In the theory, he postulated about three independent receptor types which all have opposing pairs: white and black, blue and yellow, and red and green.
These three pairs produce combinations of colors for us through the opponent process. Furthermore, according to this theory, for each of these three pairs, three types of chemicals in the retina exist, in which two types of chemical reactions can occur. These reactions would yield one member of the pair in their building up phase, or anabolic process, whereas they would yield the other member while in a destructive phase, or a catabolic process.
The colors in each pair oppose each other. Red-green receptors cannot send messages about both colors at the same time. This theory also explains negative afterimages; once a stimulus of a certain color is presented, the opponent color is perceived after the stimulus is removed because the anabolic and catabolic processes are reversed. For example, red creates a positive (or excitatory) response while green creates a negative (or inhibitory) response. These responses are controlled by opponent neurons, which are neurons that have an excitatory response to some wavelengths and an inhibitory response to wavelengths in the opponent part of the spectrum.
According to this theory, color blindness is due to the lack of a particular chemical in the eye. The positive after-image occurs after we stare at a brightly illuminated image on a regularly lighted surface and the image varies with increases and decreases in the light intensity of the background.
The veracity of this theory, however, has recently been challenged. The main evidence for this theory derived from recordings of retinal and thalamic (LGN) cells, which were excited by one color and suppressed by another. Based on these oppositions, the cells were called "Blue-yellow", "Green-red" and "black-white" opponent cells. In a recent review of the literature, Pridmore [1] notes that the definition of the color 'green' has been very subjective and inconsistent and that most recordings of retinal and thalamic (LGN) neurons were of Red-cyan color, and some of Green-magenta color. As these colors are complementary and not opponent, he proposed naming these neurons as complementary cells.
A-process refers to the one of the emotional internal processes or responses of the opponent-process theory. The A-process is largely responsible for the initial, usually fast and immediate, emotional reaction to a stimulus. The theory considers it a primary process which may be affectively positive or negative, but never neutral. [2] The theory also proposes that this process automatically causes a B-process, which is subjectively and physiologically opposite in direction to the A-process. [2]
There is a peak response to any emotional stimulus which usually occurs rapidly, usually out of shock, but lasts only as long as the stimulus is present. In a physiological sense, the a-process is where the pupils dilate, the heart rate increases, and the adrenaline rushes. [3]
The A- and B-processes are consequently and temporarily linked but were believed to depend on different neurobiological mechanisms. [4] B-Process, the other part of opponent-process theory, occurs after the initial shock, or emotion and is evoked after a short delay. [4] A-process and B-process overlap in somewhat of an intermediate area. While A-process is still in effect, B-process starts to rise, ultimately leveling out a-process' initial spike in emotion. A-process ends once the stimulus is terminated, leaves, or ends. Physiologically, this is where breathing returns to normal, pulse slows back to its normal rate, and heart rate starts to drop. The B-process can be thought of as the "after-reaction". [3] Once B-process has ended, the body returns to homeostasis and emotions return to baseline.
Research on the brain mechanisms of drug addiction showed how the A-process is equated with the pleasure derived from drugs and once it weakens, it is followed by the strengthening of the B-process, which are the withdrawal symptoms. [5]
Richard Solomon developed a motivational theory based on opponent processes. Basically he states that every process that has an affective balance (i.e. is pleasant or unpleasant) is followed by a secondary, "opponent process". This opponent process sets in after the primary process is quieted. With repeated exposure, the primary process becomes weaker while the opponent process is strengthened. [8]
The most important contribution is Solomon's findings on work motivation and addictive behavior. According to opponent-process theory, drug addiction is the result of an emotional pairing of pleasure and the emotional symptoms associated with withdrawal. At the beginning of drug or any substance use, there are high levels of pleasure and low levels of withdrawal. Over time, however, as the levels of pleasure from using the drug decrease, the levels of withdrawal symptoms increase.
The theory was supported in a study Solomon conducted along with J.D. Corbit in 1974, in which the researchers analyzed the emotions of skydivers. It was found that beginners have greater levels of fear than more experienced skydivers, but less pleasure upon landing. However, as the skydivers kept on jumping, there was an increase in pleasure and a decrease in fear. A similar experiment was done with dogs. Dogs were put into a so-called Pavlov harness and were shocked with electricity for 10 seconds. This shock was the stimulus of the experiment. In the initial stage (consisting of the first few stimuli) the dogs experienced terror and panic. Then, when they stopped the stimuli, the dogs became stealthy and cautious. The experiment continued, and after many stimuli, the dogs went from unhappy to joyful and happy after the shocks stopped altogether. [9] In the opponent-process model, this is the result of a shift over time from fear to pleasure in the fear-pleasure emotion pair.
Another example of opponent processes is the use of nicotine. In the terms of Hedonism, one process (the initial process) is a hedonic reaction that is prompted by the use of nicotine. The user gains positive feelings through the inhalation of nicotine. This is then counteracted, or opposed, by the second, drug-opposite effect (the opponent process). The drug-opposite effect holds hedonic properties that are negative, which would be the decrease in positive feelings gained by the inhalation of nicotine. The counteraction takes place after the initial hedonic response as a means to restore homeostasis. In short, the use of nicotine jumpstarts an initial, pleasurable response. It is then counteracted by the opponent process that brings one back to their original level of homeostasis. The negative feelings begin to take hold again, which in this case would be the craving of nicotine. Repeated use of the substance will continue to strengthen the opponent process, but the feelings gained through the initial process will remain constant. This dynamic explains tolerance, which is the increase in the amount of drug/substance that is needed to overcome the opponent process that is increasing in strength. This also explains withdrawal syndrome, which occurs by the negative, drug-opposite effects remaining after the initial, pleasurable process dies out. [10]
Leo Hurvich and Dorothea Jameson proposed a neurological model of a general theory of neurological opponent processing in 1974. This led to Ronald C. Blue & Wanda E. Blue's general model of Correlational Holographic Opponent Processing. This model proposes that habituation is a neurological holographic wavelet interference of opponent processes that explains learning, vision, hearing, taste, balance, smell, motivation, and emotions.
Beyond addictive behavior, opponent-process theory can in principle explain why processes (i.e. situations or subjective states) that are aversive and unpleasant can still be rewarding. For instance, after being exposed to a stressful situation (cold pressor test), human participants showed greater physiological signs of well-being than those in the control condition. [11] Self-report measures and subjective ratings show that relief from physical pain can induce pleasant feelings, [12] and a reduction of negative affect. [13] Accordingly, opponent-process theory can also help to explain psychopathological behavior such as non-suicidal self-injury. [14]
Operant conditioning, also called instrumental conditioning, is a learning process where behaviors are modified through the association of stimuli with reinforcement or punishment. In it, operants—behaviors that affect one's environment—are conditioned to occur or not occur depending on the environmental consequences of the behavior.
Pleasure refers to experience that feels good, that involves the enjoyment of something. It contrasts with pain or suffering, which are forms of feeling bad. It is closely related to value, desire and action: humans and other conscious animals find pleasure enjoyable, positive or worthy of seeking. A great variety of activities may be experienced as pleasurable, like eating, having sex, listening to music or playing games. Pleasure is part of various other mental states such as ecstasy, euphoria and flow. Happiness and well-being are closely related to pleasure but not identical with it. There is no general agreement as to whether pleasure should be understood as a sensation, a quality of experiences, an attitude to experiences or otherwise. Pleasure plays a central role in the family of philosophical theories known as hedonism.
Classical conditioning is a behavioral procedure in which a biologically potent physiological stimulus is paired with a neutral stimulus. The term classical conditioning refers to the process of an automatic, conditioned response that is paired with a specific stimulus.
In reinforcement theory, it is argued that human behavior is a result of "contingent consequences" to human actions. The publication pushes forward the idea that "you get what you reinforce". This means that behavior, when given the right types of reinforcers, can be changed for the better and negative behavior can be reinforced away.
The nucleus accumbens is a region in the basal forebrain rostral to the preoptic area of the hypothalamus. The nucleus accumbens and the olfactory tubercle collectively form the ventral striatum. The ventral striatum and dorsal striatum collectively form the striatum, which is the main component of the basal ganglia. The dopaminergic neurons of the mesolimbic pathway project onto the GABAergic medium spiny neurons of the nucleus accumbens and olfactory tubercle. Each cerebral hemisphere has its own nucleus accumbens, which can be divided into two structures: the nucleus accumbens core and the nucleus accumbens shell. These substructures have different morphology and functions.
Habituation is a form of non-associative learning in which an innate (non-reinforced) response to a stimulus decreases after repeated or prolonged presentations of that stimulus. Responses that habituate include those that involve the intact organism or those that involve only components of the organism. The broad ubiquity of habituation across all biologic phyla has resulted in it being called "the simplest, most universal form of learning...as fundamental a characteristic of life as DNA." Functionally-speaking, by diminishing the response to an inconsequential stimulus, habituation is thought to free-up cognitive resources to other stimuli that are associated with biologically important events. For example, organisms may habituate to repeated sudden loud noises when they learn these have no consequences. A progressive decline of a behavior in a habituation procedure may also reflect nonspecific effects such as fatigue, which must be ruled out when the interest is in habituation. Habituation is clinically relevant, as a number of neuropsychiatric conditions, including autism, schizophrenia, migraine, and Tourette's, show reductions in habituation to a variety of stimulus-types both simple (tone) and complex (faces).
Motivational salience is a cognitive process and a form of attention that motivates or propels an individual's behavior towards or away from a particular object, perceived event or outcome. Motivational salience regulates the intensity of behaviors that facilitate the attainment of a particular goal, the amount of time and energy that an individual is willing to expend to attain a particular goal, and the amount of risk that an individual is willing to accept while working to attain a particular goal.
Some philosophers, such as Jeremy Bentham, Baruch Spinoza, and Descartes, have hypothesized that the feelings of pain and pleasure are part of a continuum.
The hedonic treadmill, also known as hedonic adaptation, is the observed tendency of humans to quickly return to a relatively stable level of happiness despite major positive or negative events or life changes.
Sensitization is a non-associative learning process in which repeated administration of a stimulus results in the progressive amplification of a response. Sensitization often is characterized by an enhancement of response to a whole class of stimuli in addition to the one that is repeated. For example, repetition of a painful stimulus may make one more responsive to a loud noise.
Affect, in psychology, refers to the underlying experience of feeling, emotion, attachment, or mood. In psychology, "affect" refers to the experience of feeling or emotion. It encompasses a wide range of emotional states and can be positive or negative. Affect is a fundamental aspect of human experience and plays a central role in many psychological theories and studies. It can be understood as a combination of three components: emotion, mood, and affectivity. In psychology, the term "affect" is often used interchangeably with several related terms and concepts, though each term may have slightly different nuances. These terms encompass: emotion, feeling, mood, emotional state, sentiment, affective state, emotional response, affective reactivity, disposition. Researchers and psychologists may employ specific terms based on their focus and the context of their work.
Kent C. Berridge is an American academic, currently working as a professor of psychology (biopsychology) and neuroscience at the University of Michigan. Berridge was a joint winner of the 2018 Grawemeyer Award for Psychology.
The reward system is a group of neural structures responsible for incentive salience, associative learning, and positively-valenced emotions, particularly ones involving pleasure as a core component. Reward is the attractive and motivational property of a stimulus that induces appetitive behavior, also known as approach behavior, and consummatory behavior. A rewarding stimulus has been described as "any stimulus, object, event, activity, or situation that has the potential to make us approach and consume it is by definition a reward". In operant conditioning, rewarding stimuli function as positive reinforcers; however, the converse statement also holds true: positive reinforcers are rewarding.
Desires are states of mind that are expressed by terms like "wanting", "wishing", "longing" or "craving". A great variety of features is commonly associated with desires. They are seen as propositional attitudes towards conceivable states of affairs. They aim to change the world by representing how the world should be, unlike beliefs, which aim to represent how the world actually is. Desires are closely related to agency: they motivate the agent to realize them. For this to be possible, a desire has to be combined with a belief about which action would realize it. Desires present their objects in a favorable light, as something that appears to be good. Their fulfillment is normally experienced as pleasurable in contrast to the negative experience of failing to do so. Conscious desires are usually accompanied by some form of emotional response. While many researchers roughly agree on these general features, there is significant disagreement about how to define desires, i.e. which of these features are essential and which ones are merely accidental. Action-based theories define desires as structures that incline us toward actions. Pleasure-based theories focus on the tendency of desires to cause pleasure when fulfilled. Value-based theories identify desires with attitudes toward values, like judging or having an appearance that something is good.
Addiction is a neuropsychological disorder characterized by a persistent and intense urge to use a drug or engage in a behaviour that produces natural reward, despite substantial harm and other negative consequences. Repetitive drug use often alters brain function in ways that perpetuate craving, and weakens self-control. This phenomenon – drugs reshaping brain function – has led to an understanding of addiction as a brain disorder with a complex variety of psychosocial as well as neurobiological factors that are implicated in addiction's development. Classic signs of addiction include compulsive engagement in rewarding stimuli, preoccupation with substances or behavior, and continued use despite negative consequences. Habits and patterns associated with addiction are typically characterized by immediate gratification, coupled with delayed deleterious effects.
Hedonic motivation refers to the influence of a person's pleasure and pain receptors on their willingness to move towards a goal or away from a threat. This is linked to the classic motivational principle that people approach pleasure and avoid pain, and is gained from acting on certain behaviors that resulted from esthetic and emotional feelings such as: love, hate, fear, joy, etc. According to the hedonic principle, our emotional experience can be thought of as a gauge that ranges from bad to good and our primary motivation is to keep the needle on the gauge as close to good as possible.
Personality theories of addiction are psychological models that associate personality traits or modes of thinking with an individual's proclivity for developing an addiction. Models of addiction risk that have been proposed in psychology literature include an affect dysregulation model of positive and negative psychological affects, the reinforcement sensitivity theory model of impulsiveness and behavioral inhibition, and an impulsivity model of reward sensitization and impulsiveness.
Pavlovian-instrumental transfer (PIT) is a psychological phenomenon that occurs when a conditioned stimulus that has been associated with rewarding or aversive stimuli via classical conditioning alters motivational salience and operant behavior. Two distinct forms of Pavlovian-instrumental transfer have been identified in humans and other animals – specific PIT and general PIT – with unique neural substrates mediating each type. In relation to rewarding stimuli, specific PIT occurs when a CS is associated with a specific rewarding stimulus through classical conditioning and subsequent exposure to the CS enhances an operant response that is directed toward the same reward with which it was paired. General PIT occurs when a CS is paired with one reward and it enhances an operant response that is directed toward a different rewarding stimulus.
The alpha-5 nicotinic acetylcholine receptor(α5 nAChR) also known as the α5 receptor is a type of ligand gated nicotinic acetylcholine receptor involved in pain regulation. One of the 5 transmembrane subunits of this receptor is the α5 subunit and is transcribed by the CHRNA5 gene. This receptor is commonly associated with nicotine addiction, immunotherapy, cancer, pain and attention.
Mindfulness-Oriented Recovery Enhancement (MORE) is an evidence-based mind-body therapy program developed by Eric Garland. It is a therapeutic approach grounded in affective neuroscience that combines mindfulness training with reappraisal and savoring skills. Garland developed this approach by combining the key features of mindfulness training, "Third Wave" cognitive-behavioral therapy, and principles from positive psychology.
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