Visceral functions are largely regulated by autonomic reflexes. In most autonomic reflexes, sensory input is transmitted to brain centers that integrate this information and respond by modifying the activity of preganglionic autonomic neurons.Cognitive learning psychology definition the neural centers that directly control the activity of autonomic nerves are influenced by higher brain areas, as well as by sensory input.Cognitive learning psychology definition

The medulla oblongata of the brain stem is the area that most directly controls the activity of the autonomic system. Almost all autonomic responses can be elicited by experimental stimulation of the medulla, where centers for the control of the cardiovascular, pulmonary, urinary, reproductive, and digestive systems are located.Cognitive learning psychology definition much of the sensory input to these centers travels in the afferent fibers of the vagus nerve—a mixed nerve containing both sensory and motor fibers.Cognitive learning psychology definition the reflexes that result are listed in table 9.8.

Although it directly regulates the activity of autonomic motor fibers, the medulla itself is responsive to regulation by higher brain areas.Cognitive learning psychology definition one of these areas is the hypothalamus, the brain region that contains centers for the control of body temperature, hunger, and thirst; for regulation of the pituitary gland; and (together with the limbic system and cerebral cortex) for various emotional states.Cognitive learning psychology definition

As described in chapter 8, the limbic system is a group of fiber tracts and nuclei that form a ring around the brain stem. It includes the cingulate gyrus of the cerebral cortex, the hypothalamus, the fornix (a fiber tract), the hippocampus, and the amygdaloid nucleus (see fig. 8.14).Cognitive learning psychology definition the limbic system is involved in basic emotional drives, such as anger, fear, sex, and hunger. The involvement of the limbic system with the control of autonomic function is responsible for the visceral responses that are characteristic of these emotional states.Cognitive learning psychology definition blushing, pallor, fainting, breaking out in a cold sweat, a racing heartbeat, and "butterflies in the stomach" are only some of the many visceral reactions that accompany emotions as a result of autonomic activation.Cognitive learning psychology definition

The autonomic correlates of motion sickness—nausea, sweating, and cardiovascular changes—are eliminated by cutting the motor tracts of the cerebellum.Cognitive learning psychology definition this demonstrates that impulses from the cerebellum to the medulla oblongata influence activity of the autonomic nervous system. Experimental and clinical observations have also demonstrated that the frontal and temporal lobes of the cerebral cortex influence lower brain areas as part of their involvement in emotion and personality.Cognitive learning psychology definition

Ft traditionally, the distinction between the somatic system and the autonomic nervous system was drawn on ^ ji i~i the t>as's tl13* the former is under conscious control whereas the latter is not.Cognitive learning psychology definition recently, however, we have learned that conscious processes in the cerebrum can influence autonomic activity. In biofeedback techniques, data obtained from devices that detect and amplify changes in blood pressure and heart rate, for example, are "fed back" to patients in the form of light signals or audible tones.Cognitive learning psychology definition the patients can often be trained to consciously reduce the frequency of the signals and, eventually, to control visceral activities without the aid of a machine.Cognitive learning psychology definition biofeedback has been used successfully to treat hypertension, stress, and migraine headaches.