Affective sensation is an occurrence of

sensation Sensation (psychology) refers to the processing of the senses by the sensory system. Sensation or sensations may also refer to: In arts and entertainment In literature *Sensation (fiction), a fiction writing mode *Sensation novel, a British ...

accompanied with a strong

compulsion Compulsion may refer to: * Compulsive behavior, a psychological condition in which a person does a behavior compulsively, having an overwhelming feeling that they must do so. * Obsessive–compulsive disorder, a mental disorder characterized by i ...

to act on it. It refers, mostly in neuroscience, to the

emotion Emotions are mental states brought on by neurophysiological changes, variously associated with thoughts, feelings, behavioral responses, and a degree of pleasure or displeasure. There is currently no scientific consensus on a definition. ...

sensibility Sensibility refers to an acute perception of or responsiveness toward something, such as the emotions of another. This concept emerged in eighteenth-century Britain, and was closely associated with studies of sense perception as the means thro ...

in response to affective

stimuli A stimulus is something that causes a physiological response. It may refer to: *Stimulation **Stimulus (physiology), something external that influences an activity **Stimulus (psychology), a concept in behaviorism and perception *Stimulus (economi ...

of a particular valence. It is transmitted via the spinothalamic tract through the

spinal cord The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spi ...

, and can be associated with

reflex action In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a stimulus. Reflexes are found with varying levels of complexity in organisms with a nervous system. A reflex occurs ...

s such as the scratch,

gag A gag is usually an item or device designed to prevent speech, often as a restraint device to stop the subject from calling for help and keep its wearer silent. This is usually done by blocking the mouth, partially or completely, or attempting ...

, and

withdrawal Withdrawal means "an act of taking out" and may refer to: * Anchoresis (withdrawal from the world for religious or ethical reasons) * ''Coitus interruptus'' (the withdrawal method) * Drug withdrawal * Social withdrawal * Taking of money from a ban ...

reflex In biology, a reflex, or reflex action, is an involuntary, unplanned sequence or action and nearly instantaneous response to a stimulus. Reflexes are found with varying levels of complexity in organisms with a nervous system. A reflex occurs ...

es.

Sensory processing Sensory processing is the process that organizes sensation from one's own body and the environment, thus making it possible to use the body effectively within the environment. Specifically, it deals with how the brain processes multiple sensory mod ...

in the brain interacts with behavioral choices, such as decisions to eat or to stop eating, in both healthy individuals and those with

eating disorder An eating disorder is a mental disorder defined by abnormal eating behaviors that negatively affect a person's physical or mental health. Only one eating disorder can be diagnosed at a given time. Types of eating disorders include binge eating d ...

Background and mechanism

Affective sensory information is transmitted via the

spinothalamic tract The spinothalamic tract is a part of the anterolateral system or the ventrolateral system, a sensory pathway to the thalamus. From the ventral posterolateral nucleus in the thalamus, sensory information is relayed upward to the somatosensory cor ...

. The sensation information is then accompanied by a compulsion to act. For instance, the bottom-up approach would have an itch accompanied by the need to scratch, and a painful stimulus inducing the desire to withdraw from the pain. The location of the spinothalamic tract is important clinically due of the characteristic sensory deficits that follow certain

injuries. For instance, a unilateral spinal lesion will produce sensory loss of touch, pressure, vibration, and

proprioception Proprioception ( ), also referred to as kinaesthesia (or kinesthesia), is the sense of self-movement, force, and body position. It is sometimes described as the "sixth sense". Proprioception is mediated by proprioceptors, mechanosensory neurons ...

below the lesion on the same side. The pathways for pain and temperature, however, cross the spinal cord midline to ascend on the opposite side of the cord. Therefore, diminished sensation of pain below the lesion will be observed on the side opposite the mechanosensory loss and the lesion.

Affect

Affective sensation deals with response-

emotionality Emotionality is the observable behavioral and physiological component of emotion. It is a measure of a person's emotional reactivity to a stimulus. Most of these responses can be observed by other people, while some emotional responses can only b ...

and is distinct from presentative, or neutral, sensation. This is due to affective stimuli which can have positive, negative, or neutral valence. These stimuli can be sensed individually as well as in an integrated manner such that positive and negative affective stimuli can be combined to influence experiential affective sensation and response. In the case of combination,

recency Serial-position effect is the tendency of a person to recall the first and last items in a series best, and the middle items worst. The term was coined by Hermann Ebbinghaus through studies he performed on himself, and refers to the finding that r ...

and

contrast effect A contrast effect is the enhancement or diminishment, relative to normal, of perception, cognition or related performance as a result of successive (immediately previous) or simultaneous exposure to a stimulus of lesser or greater value in the sa ...

s on overall affect are influential such that, for example, a negative stimuli followed by a positive stimuli yields an overall positive affect.

Emotional sensing

Subjective well-being draws from both cognitive and affective components, combining general evaluations of ones' life with overall affective sensitive-impressions. Neural measures of affective quality of life have been positively correlated with greater left alpha activity in the superior PFC, gray matter volume in multiple prefrontal cortices, spontaneous activity in the right amygdala, and even emotional intelligence. Those with affective disorders may also demonstrate differences in affective sensation as a result of mood-dependent alterations in brain arousal regulation, especially seen between those with mania, depression, and those without the disorder. Negative affectivity tends to be related to greater levels of social anxiety, anxious arousal, and anxiety sensitivity.

Physical and mental modulation

Physical pathological sensation, as occurs in IBS,

COPD Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. The main symptoms include shortness of breath and a cough, which may or may not produce mu ...

, and other illnesses, is also influential in affective sensation and response. The emotional response to especially a chronic illness can be correlated with its severity. This has been shown in COPD, where emotionally-driven descriptions of sensation due to breathing impairments may reflect the severity of the illness and probability of long-term, responsal behavior changes. Additionally, in IBS patients, affective sensation and its correlative brain areas including the ACC, insula, and VMPFC demonstrated heightened fMRI activity in response to painful visceral stimuli, and an inability to down-regulate their activation and modulate the emotional response to pain. This link between perceptual intensity and affective sensation persists in the case of chili pepper consumption. Those individuals who eat chili peppers more often, and presumably enjoy them, also report less burning sensation in response to eating chilis. While this could be due to either individual taste-perception differences or intensity judgement differences, it is more likely due to the latter because previous spicy food-consumption experiences do not correlate with the differences in affective sensation responses.

Taste sensation

Affective sensation can also be modulated using the top-down approach with cognitive factors influencing hedonic experience, such as with soup labeled "rich and delicious" inducing greater positive affect than when labeled "boiled vegetable water." This modulation can be seen in the orbitofrontal cortex and pregenual cingulate cortex. Taste serves to identify potential nutrients and toxins. For example, when one tastes a potentially nutritious stimulus, the connectivity between the insula and a feeding network including the

hypothalamus The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...

ventral pallidum The ventral pallidum (VP) is a structure within the basal ganglia of the brain. It is an output nucleus whose fibres project to thalamic nuclei, such as the ventral anterior nucleus, the ventral lateral nucleus, and the medial dorsal nucleus. The ...

, and

striatum The striatum, or corpus striatum (also called the striate nucleus), is a nucleus (a cluster of neurons) in the subcortical basal ganglia of the forebrain. The striatum is a critical component of the motor and reward systems; receives glutamate ...

is greater than when tasting a potentially harmful stimulus. These results support the existence of an integrated supramodal flavor system in the anterior ventral insula that preferentially communicates with the circuits guiding feeding when the flavor is potentially nutritive.

References