Biopsychology put into action by a driver

Here is a quick run through of biopsychology by a driver who is falling asleep:

Our bodies are constantly working on a cellular level, making and developing new connections. The body’s neurons, neurotransmitters, brain circuitry, and basic biological processes underlying normal and abnormal reactions to environmental stimuli. For instance, if a driver were to fall asleep while driving and lose consciousness for a brief moment, the brain, nervous system, and endocrine system would all be alerted.

Sub-cortex

The Sub-cortex can be divided into three general areas: the Hindbrain, Midbrain, and Forebrain. There are parts within these three areas that contribute to the “jolt” and sudden alertness after falling asleep for a brief moment, especially when in a dangerous situation.

The Hind-brain consists of the cerebellum, medulla, pons, reticular formation, and brain-stem. Hopefully, many of the safe habits in driving have become second nature in the cerebellum, where complex movements are performed without unnecessary processing in the brainstem and higher brain centers. The medulla controls the vital life functions that should already be performing normally—heart rate, breathing and swallowing—or else a car accident may occur from the heart stopping, not from falling asleep. The pons regulates sleep/dreaming cycles and sends signals to the visual nuclei of the thalamus and to the cerebral cortex, which the sleepy driver no doubt disrupted, hence the sleepiness while driving. Because humans run on a circadian clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus in the brain, signals to the body will be focused on helping “shutting” down the body. So if the driving is occurring at night, then the risks are higher for the driver. The body’s temperature will lower, and inhibitors will increase. Melatonin is a hormone produced by the pineal gland and distributed in higher levels during the night, and less during the day. However, since the environment/situation does not suit the body for appropriate rest, the brain will determine that and send different signals to alert the body. The reticular formation (RF) is where the “jolt” happens— the mini spasm that surprises you awake. Not only does the RF prioritize and clean incoming messages, it is responsible for alertness and wakefulness. When the driver’s head dips down and nods sleepily, the RF recognizes this inimical event and send an alert message. Wake up!

The Midbrain is located above the medulla as a “switching center” between the Brainstem and the Forebrain. It’s a very small part of the brain and rarely mentioned, but important nonetheless.

The Forebrain consists of the thalamus and hypothalamus. The thalamus directs sensory traffic—vision, hearing, taste, and touch—and performs initial analysis on sensory messages. The feeling of the steering wheel slipping out of the driver’s hand and sound of horns aimed at the driver are sent to the Thalamus, which contributes to the “jolt” that wakes up the driver. The hypothalamus manages homeostasis and controls the pituitary gland, the “master gland” of hormone levels. Most likely, the steering wheel slipped out of the driver’s hand, and the driver loses control of the car. The car swerves, another cars honks. The sudden change alerts and frightens the driver into a state of emotional arousal, and adrenaline is released. (More about hormones and the endocrine system in a subsequent section.) The limbic system, part of the Forebrain, is formed by the hypothalamus, parts of the thalamus, and several structures buried within the cortex. The limbic system produces emotion and behavior—rage, fear, sexual response, and other instances of intense arousal. In the driver’s case, fear and surprise is intense. The hippocampus is part of the limbic system and is important for forming long-term memories. Depending on the intensity of the sleep-driving-scare, the driver may remember this years from this moment.

Cerebral Cortex

The Cerebral Cortex is divided into four regions, called lobes: the frontal lobe, parietal lobe, occipital lobe, and temporal lobe. The cerebral cortex is usually two to three millimeters thick of gray matter made of nerve cells. The white matter underneath carry signals between the nerve cells and other parts of the brain and body.

The frontal lobe is associated with reasoning, planning, parts of speech, movement emotions, and problem solving. Much of the higher thinking processes pass through here. The sleepy driver jolts awake, and the car has stepped into another lane. Now what? The natural reaction is to turn the steering wheel as far from an oncoming car as possible or even just freeze from the inability to react (both might cause an accident). Along with logical reasoning and planning, the driver can calculate the amount divergence necessary to travel back into the correct lane without crashing. The speed at which the frontal lobe is able to process this information is astonishing; the time frame from jolting awake, becoming alert, processing the surroundings, and reacting happens within two to three seconds, which is enough time to make it or break it.

The occipital lobe is associated with visual processing. When the reticular formation jolts the body awake, the eyes open wide to search for dangers. Sight is one of the major defense mechanisms installed to the human body for better interaction and perception of the environment. With sight, the driver is able to assess the situation better and articulate a process for safety.

The parietal lobe is associated with movement, orientation, recognition, and perception of stimuli. Without the parietal lobe, we would not be able to feel anything.

The temporal lobe is associated with perception and recognition of auditory stimuli, memory, and speech. An intense instance, say one with the sleepy driver almost crashing the car, the temporal lobe will later derive meaning from this visual memory and emotional association and apply it to another situation similar to it.

The cerebral cortex is highly wrinkled; this makes the brain more efficient because it can increase the amount of neural connects within a confined space. The corticalization of the cerebral cortex can be separated into two hemispheres: the left and right hemisphere, both perform different functions. The corpus callosum—a bundle of axons that join the two hemispheres—relays and integrates motor, sensory and cognitive performances between the two bisections. The left hemisphere is associated with logical ability, while the right hemisphere is associated with creativity and emotion. For the sleepy driver, the event was emotionally intense, but the processing was mainly dealt by the left hemisphere for problem solving and troubleshooting. Interestingly, the cerebellum, mentioned in a previous section, resembles a small brain and even has two hemispheres made of highly folded surfaces.

The Nervous System

The nervous system: a network that relays messages back and forth from the brain to different parts of the body through the spinal cord to other nerve extensions. When the brain receives a message from the body, it configures the message and responds immediately. Such as in the sleepy driver’s instance, s/he may have lost grip of the steering wheel. The message travels from the palm to the brain stem. The message is either relayed with an instinct reaction from the cerebellum or directed to the forebrain by the thalamus. The brain forms a message and sends it down the nervous system accordingly to one of the two compositions: peripheral nervous system and central nervous system.

The peripheral nervous system (PNS) can be broken down into the autonomic nervous system and somatic nervous system. The autonomic nervous system consists of the sympathetic division that regulated the body’s unconscious actions, and the parasympathetic division, which is responsible for the stimulation of “rest-and-digest”—salivation, lacrimation, urination, digestion, defecation and sexual arousal. The two divisions are complementary in that one deals with “fight-or-flight” and the other with “feed-and-breed.” The sleepy driver has stimulated the sympathetic division with the brief moment of danger. After the arousal, the parasympathetic division applies neural brakes, returning the internal responses to a calm and collected state. The somatic nervous system consists of the sensory nervous system and motor nervous system. The sensory nervous system processes sensory information from the sensory systems—vision, hearing, somatic sensation, gustation, olfaction, and vestibular system (balance/movement)—by using sensory receptors, neural pathways, and parts of the brain. The motor nervous system is involved with movement; it sends messages to and from the body’s muscles.

Comprised of the brain and spinal cord, the central nervous system (CNS) serves as the body’s command central. The spinal cord takes charge of simple, swift reflexes that do not require brain power, such as the knee-jerker reflex.

Unlike the peripheral nervous system, the CNS axons are fairly short, around a few millimeters; axons in the peripheral nervous system can run over a meter long. The PNS connects the CNS with the rest of the body through bundles of sensory and motor axons called nerves. The somatic nervous system is the brain’s communication link with the outside world. Its sensory component connects the sense organs to the brain; the motor components link the CNS with the body’s skeletal muscles, the muscles that control voluntary movements. The autonomic nervous system carries the messages or signals that control our internal organs to perform life sustaining jobs. The sensory nervous system carries the visual image (such as the car steering into the wrong lane), and the motor nervous system sends instructions to muscles (steering the back into the right lane). The neurons are responsible for sending the messages in a rapid speed, and they make up billions of cells in the brain and spinal cord. Messages sent from all over the body are thanks to neurons.

The Endocrine System

The endocrine system sends follow up messages that support and sustain the emergency response initiated by the nervous system. Although the endocrine system is slower acting, it includes the important glands—pineal gland, pituitary gland, thyroid gland, parathyroid gland, and adrenal glands—that help us function. The pineal glands a small gland that produces melatonin, which affects the modulation of sleep patterns in both seasonal and circadian rhythms. The sleepy driver must have disrupted this rhythm, or else s/he would be well rested. The pituitary gland helps control growth, blood pressure, certain functions of sex organs, thyroid glands, metabolism, and much more. Although the pituitary sits below the hypothalamus in the brain and is the size of a pea, it is an important part of the endocrine system. The thyroid gland is one of largest endocrine glands and consists of two lobes controlling energy efficiency, protein production, and body sensitivity to hormones. The parathyroid glands are small endocrine glands that produce parathyroid hormone. Humans usually have four parathyroid glands, which play a key role in regulating the amount of calcium in the blood and within the bones. The adrenal glands are responsible for releasing hormones in response to stress; they affect the kidneys through the secretion of aldosterone. The glands sync to produce a stable living environment inside the body or even to combat unfavorable external environments.

The biological processes of the body are not only sectioned into specific roles; they combine to produce an elaborate system we use even in the slightest moments. In this instance, the driver has dozed off, jolted awake and swerved the car back into place within several seconds and used much of their body’s systems. Even now, reading this paper, there are many nerves activating, then inactivating.

Edited by: Kim Rooney