Neuropsychology is the study and characterization of the behavioral modifications that follow a neurological trauma or condition. It is both an experimental and clinical field of psychology that aims to understand how behavior and cognition are influenced by brain functioning and is concerned with the diagnosis and treatment of behavioral and cognitive effects of neurological disorders. Whereas classical neurology focuses on the pathology of the nervous system and classical psychology is divorced from it, neuropsychology seeks to discover how the brain correlates with the mind through the study of neurological patients, it thus shares concerns with neuropsychiatry and with behavioral neurology in general. The term neuropsychology has been applied to lesion studies in animals, it has been applied in efforts to record electrical activity from individual cells in higher primates. In practice, neuropsychologists tend to work in research settings, clinical settings, or forensic settings or industry.
Neuropsychology is a new discipline within the field of psychology. The first textbook defining the field, Fundamentals of Human Neuropsychology, was published by Kolb and Whishaw in 1980. However, the history of its development can be traced back to the Third Dynasty in ancient Egypt even earlier. There is much debate as to. For many centuries, the brain was thought useless and was discarded during burial processes and autopsies; as the field of medicine developed its understanding of human anatomy and physiology, different theories were developed as to why the body functioned the way it did. Many times, bodily functions were approached from a religious point of view and abnormalities were blamed on bad spirits and the gods; the brain has not always been considered the center of the functioning body. It has taken hundreds of years to develop our understanding of the brain and how it affects our behaviors. In ancient Egypt, writings on medicine date from the time of the priest Imhotep, they took a more scientific approach to medicine and disease, describing the brain, trauma and remedies for reference for future physicians.
Despite this, Egyptians saw the heart not the brain as the seat of the soul. Aristotle reinforced this focus on the heart, he believed the heart to be in control of mental processes, looked on the brain, due to its inert nature, as a mechanism for cooling the heat generated by the heart. He drew his conclusions based on the empirical study of animals, he found that while their brains were cold to the touch and that such contact did not trigger any movements, the heart was warm and active and slowing dependent on mood. Such beliefs were upheld by many for years to come, persisting through the Middle Ages and the Renaissance period until they began to falter in the 17th Century due to further research; the influence of Aristotle in the development of neuropsychology is evident within language used in modern day, since we "follow our hearts" and "learn by the heart". Hippocrates looked upon the brain as the seat of the soul, he drew a connection between the brain and behaviors of the body saying "The brain exercises the greatest power in the man".
Apart from moving the focus from the heart as the "seat of the soul" to the brain, Hippocrates did not go into much detail about its actual functioning. However, by switching the attention of the medical community to the brain, the doors were opened to a more scientific discovery of the organ responsible for our behaviors. For years to come, scientists were inspired to explore the functions of the body and to find concrete explanations for both normal and abnormal behaviors. Scientific discovery led them to believe that there were natural and organically occurring reasons to explain various functions of the body, it could all be traced back to the brain. Over the years, science would continue to expand and the mysteries of the world would begin to make sense, or at least be looked at in a different way. Hippocrates introduced man to the concept of the mind –, seen as a separate function apart from the actual brain organ. Philosopher René Descartes expanded upon this idea and is most known by his work on the mind-body problem.
Descartes' ideas were looked upon as overly philosophical and lacking in sufficient scientific background. Descartes focused much of his anatomical experimentation on the brain, paying specific attention to the pineal gland – which he argued was the actual "seat of the soul". Still rooted in a spiritual outlook towards the scientific world, the body was said to be mortal, the soul immortal; the pineal gland was thought to be the place at which the mind would interact with the mortal and machine-like body. At the time, Descartes was convinced the mind had control over the behaviors of the body – but that the body could have influence over the mind, referred to as dualism; this idea that the mind had control over the body, but man's body could resist or influence other behaviors was a major turning point in the way many physiologists would look at the brain. The capabilities of the mind were observed to do much more than react, but to be rational and function in organized, thoughtful ways – much more complex than he thought the animal world to be.
These ideas, although disregarded by many
Elkhonon Goldberg is a neuropsychologist and cognitive neuroscientist known for his work in hemispheric specialization and the "novelty-routinization" theory. Goldberg studied at Moscow State University with the great neuropsychologist Alexander Luria and moved to the United States in 1974, he is a Clinical Professor of Neurology at New York University School of Medicine, Diplomate of The American Board of Professional Psychology in Clinical Neuropsychology, Co-Founder and Chief Scientific Advisor of SharpBrains, an online brain fitness center. He offers post-doctoral training in Neuropsychology at Fielding Graduate University. Elkhonon Goldberg is the Founding Director of Luria Neuroscience Institute, an organization founded with the purpose of advancing research and disseminating knowledge about the brain and the mind, he describes himself as an atheist "with agnostic tendencies". At Moscow State University, Goldberg studied psychology and mathematics and was among the early proponents of the discipline known today as computational neuroscience.
In the United States Goldberg's work has been more clinical in nature. His research has focused on the function of the frontal lobes, hemispheric specialization, cognitive aging, general theory of functional cortical organization. Among the early critics of the fashionable notion of neocortical modularity, he introduced the notion of "cognitive gradient" to capture the distributed and emergent properties of functional cortical organization. Goldberg's work on frontal lobe functions includes the discovery of the "reticulo-frontal disconnection" syndrome, functional lateralization and gender differences in the prefrontal cortex, his work on memory includes the description of pure retrograde amnesia without anterograde amnesia, which in turn has led to the elucidation of the role of brain stem arousal mechanisms in memory. In clinical practice, Goldberg was among the early proponents of "cognitive fitness," purporting to harness the effects of lifelong neuroplasticity to delay and reverse the effects of cognitive aging.
First introduced by Michael Merzenich, the concept has gained the support of a number of leading neuroscientists. Nonetheless, it remains controversial and further research is required to validate it. Goldberg is an author of a number of scientific journal articles and book chapters, as well as of three books: Contemporary Neuropsychology and the Legacy of Luria, his work on hemispheric specialization culminated in the "novelty-routinization" theory positing that the two cerebral hemispheres are differentially involved in processing novel, unknown information and processing in terms of stable pattern-recognition devices for known situations of mental routine. As for left-handers and ambidextrals, Goldberg indicates that the two hemispheres are less differentiated in function and structure. For these individuals there may be instances in which the left hemisphere takes the role of novelty processing and the right the routine processing; the right hemisphere favors the "heteromodal association cortex" while the left favors the "modality-specific association cortex", both are engaged in complex information processing.
The latter deals with processing information arriving from individual sensory systems, such as visual and sensory ones. This kind of cortex, favoring more local connections between adjacent cortical regions, "dismantles the world around us to separate representations.... think of an object in a three-dimensional space projected onto the x, y, z coordinates...". On the other hand, the heteromodal association cortex, favoring distant inter-cortical connections, integrates information arriving from sensory channels, or puts "the synthetic picture of the multimedia world around us back together." Goldberg likens these differences in connectivity thus: the left hemisphere is like a fleet of taxicabs that traverses short town-like distances while the right is like a fleet of airplanes that traverses large continental distances. The novelty-routinization theory incorporates the more traditional distinction between verbal and nonverbal functions as a special case, but is more dynamic in nature, allows for evolutionary continuities, provides a neurodevelopmental framework.
Elkhonon Goldberg. Contemporary Neuropsychology and the Legacy of Luria, Hillsdale, NJ: Lawrence Erlbaum, 1990. ISBN 978-0-8058-0334-1 Elkhonon Goldberg; the Executive Brain: Frontal Lobes and the Civilized Mind, NY: Oxford University Press, 2001. ISBN 978-0-19-515630-0 Elkhonon Goldberg; the Wisdom Paradox: How Your Mind Can Grow Stronger As Your Brain Grows Older, NY: Penguin, 2005. UK edition: Free Press, Simon & Schuster, 2005. ISBN 1-59240-187-2 Elkhonon Goldberg; the New Executive Brain: Frontal Lobes in a Complex World, NY: Oxford University Press, 2009. ISBN 978-0-19-532940-7 Elkhonon Goldberg. Creativity: The Human Brain in the Age of Innovation', NY: Oxford University Press, 2018. ISBN 978-0-19-046649-7 Brain fitness Alexander Luria Official website
Oliver Wolf Sacks, was a British neurologist, historian of science, author. Born in Britain, educated there, he spent his career in the United States, he believed that the brain is the "most incredible thing in the universe." He became known for writing best-selling case histories about both his patients' and his own disorders and unusual experiences, with some of his books adapted for plays by major playwrights, feature films, animated short films, dance, fine art, musical works in the classical genre. After Sacks received his medical degree from The Queen's College, Oxford in 1960, he interned at Middlesex Hospital before moving to the US, he interned at Mount Zion Hospital in San Francisco and completed his residency in neurology and neuropathology at the University of California, Los Angeles. He relocated to New York in 1965, where he first worked under a paid fellowship in neurochemistry and neuropathology at the Albert Einstein College of Medicine. Upon realising that the neuro-research career he envisioned for himself would be a poor fit, in 1966 he began serving as neurologist at Beth Abraham Hospital's chronic-care facility in the Bronx.
While there, he worked with a group of survivors of the 1920s sleeping sickness encephalitis lethargica, unable to move on their own for decades. His treatment of those patients became the basis of his book Awakenings. In the period from 1966 to 1991 he was a neurological consultant to various New York City-area nursing homes, at the Bronx Psychiatric Center. Sacks was the author of numerous best-selling books collections of case studies of people, including himself, with neurological disorders, he published hundreds of articles, not only articles about neurological disorders, but insightful book reviews and articles about the history of science, natural history, nature. His writings have been featured in a wide range of media, his books include a wealth of narrative detail about his experiences with his patients and his own experiences, how each coped with their condition illuminating how the normal brain deals with perception and individuality. In addition to the information content, the beauty of his writing style is treasured by many of his readers.
Awakenings was adapted into an Academy Award-nominated film in 1990, starring Robin Williams and Robert De Niro. He and his book Musicophilia: Tales of Music and the Brain were the subject of "Musical Minds", an episode of the PBS series Nova. Sacks was awarded a CBE for services to medicine in the 2008 Birthday Honours. Sacks was born in Cricklewood, England, the youngest of four children born to Jewish parents: Samuel Sacks, a Lithuanian Jewish doctor, Muriel Elsie Landau, one of the first female surgeons in England, one of 18 siblings. Sacks had an large extended family of eminent scientists and other notable individuals, including the director and writer Jonathan Lynn and first cousins, the Israeli statesman Abba Eban and the Nobel Laureate Robert Aumann. In December 1939 when Sacks was six years old, he and his older brother Michael were evacuated from London to escape the Blitz, sent to a boarding school in the Midlands where he remained until 1943. Unknown to his family, at the school, he and his brother Michael "... subsisted on meager rations of turnips and beetroot and suffered cruel punishments at the hands of a sadistic headmaster".
This is detailed in Uncle Tungsten: Memories of a Chemical Boyhood. Beginning at his return home at the age of 10 from the cruel and devastating boarding school experience, under his Uncle Dave's tutelage he became an intensely focused amateur chemist, as recalled in Uncle Tungsten, he attended St Paul's School in London, where he developed critically important lifelong friendships with Jonathan Miller and Eric Korn. During adolescence he shared an intense interest in biology with these friends, came to share his parents' enthusiasm for medicine, he entered The Queen's College, Oxford in 1951, obtaining a BA degree in physiology and biology in 1956. Although not required, Sacks chose to stay on for an additional year to undertake research, after he had taken a course by Hugh Macdonald Sinclair. Sacks recalls, "I had been seduced by a series of vivid lectures on the history of medicine" and nutrition, given by Sinclair. Sacks adds, "And now, in Sinclair's lectures, it was the history of physiology, the ideas and personalities of physiologists, which came to life."
Sacks became involved with the school's Laboratory of Human Nutrition under Sinclair. Sacks focused his research on Jamaica ginger, a toxic and abused drug known to cause irreversible nerve damage. After devoting months to research, he was disappointed by the lack of help and guidance he received from Sinclair. Sacks stopped working on the subject; as a result he became depressed: "I felt myself sinking into a state of quiet but in some ways agitated despair." His tutor at Queen's and his parents, seeing his lowered emotional state, suggested he extricate himself from academic studies for a period. His parents suggested he spend the summer of 1955 living on Israeli kibbutz Ein HaShofet, where the physical labour would help him. Sacks would describe his experience on the kibbutz as an "anodyne to the lonely, torturing months in Sin
Memory is the faculty of the brain by which information is encoded and retrieved when needed. Memory is vital to experiences, it is the retention of information over time for the purpose of influencing future action. If we could not remember past events, we could not learn or develop language, relationships, or personal identity. Memory is understood as an informational processing system with explicit and implicit functioning, made up of a sensory processor, short-term memory, long-term memory; this can be related to the neuron. The sensory processor allows information from the outside world to be sensed in the form of chemical and physical stimuli and attended to various levels of focus and intent. Working memory serves as an encoding and retrieval processor. Information in the form of stimuli is encoded in accordance with explicit or implicit functions by the working memory processor; the working memory retrieves information from stored material. The function of long-term memory is to store data through various categorical models or systems.
Explicit and implicit functions of memory are known as declarative and non-declarative systems. These systems lack thereof. Declarative, or explicit, memory is the conscious recollection of data. Under declarative memory resides episodic memory. Semantic memory refers to memory, encoded with specific meaning, while episodic memory refers to information, encoded along a spatial and temporal plane. Declarative memory is the primary process thought of when referencing memory. Non-declarative, or implicit, memory is the unconscious recollection of information. An example of a non-declarative process would be the unconscious learning or retrieval of information by way of procedural memory, or a priming phenomenon. Priming is the process of subliminally arousing specific responses from memory and shows that not all memory is consciously activated, whereas procedural memory is the slow and gradual learning of skills that occurs without conscious attention to learning. Memory is not a perfect processor, is affected by many factors.
The ways by which information is encoded and retrieved can all be corrupted. The amount of attention given new stimuli can diminish the amount of information that becomes encoded for storage; the storage process can become corrupted by physical damage to areas of the brain that are associated with memory storage, such as the hippocampus. The retrieval of information from long-term memory can be disrupted because of decay within long-term memory. Normal functioning, decay over time, brain damage all affect the accuracy and capacity of the memory. Memory loss is described as forgetfulness or amnesia. Sensory memory holds sensory information less than one second; the ability to look at an item and remember what it looked like with just a split second of observation, or memorization, is the example of sensory memory. It is an automatic response. With short presentations, participants report that they seem to "see" more than they can report; the first experiments exploring this form of sensory memory were conducted by George Sperling using the "partial report paradigm".
Subjects were presented with a grid of 12 letters, arranged into three rows of four. After a brief presentation, subjects were played either a high, medium or low tone, cuing them which of the rows to report. Based on these partial report experiments, Sperling was able to show that the capacity of sensory memory was 12 items, but that it degraded quickly; because this form of memory degrades so participants would see the display but be unable to report all of the items before they decayed. This type of memory cannot be prolonged via rehearsal. Three types of sensory memories exist. Iconic memory is a fast decaying store of visual information. Echoic memory is a fast decaying store of auditory information, another type of sensory memory that stores sounds that have been perceived for short durations. Haptic memory is a type of sensory memory. Short-term memory is known as working memory. Short-term memory allows recall for a period of several seconds to a minute without rehearsal, its capacity is very limited: George A. Miller, when working at Bell Laboratories, conducted experiments showing that the store of short-term memory was 7±2 items.
Modern estimates of the capacity of short-term memory are lower of the order of 4–5 items. For example, in recalling a ten-digit telephone number, a person could chunk the digits into three groups: first, the area code a three-digit chunk and lastly a four-digit chunk; this method of remembering telephone numbers is far more effective than attempting to remember a string of 10 digits. This may be reflected in some countries in the tendency to display telephone numbers as several chunks of two to four numbers. Short-term memory is believed to rely on an acoustic code for storing information, to a lesser extent a visual code. Conrad found that test subjects had more difficulty recalling collections of letters that were acoustically similar (e.g. E
Wisconsin Card Sorting Test
The Wisconsin Card Sorting Test is a neuropsychological test of "set-shifting", i.e. the ability to display flexibility in the face of changing schedules of reinforcement. The WCST was written by Esta A. Berg; the Professional Manual for the WCST was written by Robert K. Heaton, Gordon J. Chelune, Jack L. Talley, Gary G. Kay, Glenn Curtiss. A number of stimulus cards are presented to the participant; the participant is not how to match. The original WCST used paper cards and was carried out with the experimenter on one side of the desk facing the participant on the other; the test takes 12–20 minutes to carry out and generates a number of psychometric scores, including numbers and percentiles of: categories achieved, trials and perseverative errors. Since 1948, the test has been used by neuropsychologists and clinical psychologists in patients with acquired brain injury, neurodegenerative disease, or mental illness such as schizophrenia, it is one of several psychological tests which can be administered to patients to measure frontal lobe dysfunction.
When administered, the WCST allows the clinician speculate to the following "frontal" lobe functions: strategic planning, organized searching, utilizing environmental feedback to shift cognitive sets, directing behavior toward achieving a goal, modulating impulsive responding. The test can be administered to those from 6.5 years to 89 years of age. The WCST, relies upon a number of cognitive functions including attention, working memory, visual processing; the WCST test may be used to help measure an individual's competence in abstract reasoning, the ability to change problem-solving strategies when needed. In this test, a number of cards are presented to the participants; the figures on the cards differ with respect to color and shape. Psychological tests such as the WCST, administered alone, cannot be used to measure the effects of a frontal lobe injury, or the aspects of cognitive function it may affect, such as working memory. A subject show dysfunction in executive function overall. Test results can be made misleading after testing the same individual over a long period of time.
The subject may get better at a task, but not because of an improvement in executive cognitive function. He/she may have learned some strategies for doing this particular task that made it no longer a good measurement tool; the trademark "Wisconsin Card Sorting Test" was registered in 2000 with the United States Patent and Trademark Office by Wells Print and Digital Services of Madison, Wisconsin. Although filed in 1998, the trademark application states the mark has been in use in commerce since at least 1970; the trademark covers "psychological testing materials, namely printed tests, printed cards, printed instruction manuals in the field of psychological evaluation." This trademark does not cover the computer implementation of the test, distributed by Psychological Assessment Resources, Inc. sometimes referred to as WCST. Online demonstration of the Wisconsin Card Sorting Test via PsyToolkit Strauss, Esther. A Compendium of Neuropsychological Tests: Administration and Commentary. Oxford: Oxford University Press.
ISBN 978-0-19-515957-8. Retrieved 14 July 2013
Pasko Rakic is a Yugoslav-born American neuroscientist, who presently works in the Yale School of Medicine Department of Neuroscience in New Haven, Connecticut. His main research interest is in the evolution of the human brain, he was the founder and served as Chairman of the Department of Neurobiology at Yale, was founder and Director of the Kavli Institute for Neuroscience. He is best known for elucidating the mechanisms involved in development and evolution of the cerebral cortex. In 2008, Rakic shared the inaugural Kavli Prize in Neuroscience, he is the Dorys McConell Duberg Professor of Neuroscience, leads an active research laboratory, serves on Advisory Boards and Scientific Councils of a number of Institutions and Research Foundations. Rakic was born on May 1933, in Ruma, his father, Toma Rakić, was Croatian from Pula, but emigrated to Yugoslavia, where in the town of Novi Sad he studied to become an accountant and tax official. His mother, Juliana Todorić, of Serbian and Slovakian descent was born in Dubrovnik and moved to Ruma, where they met and got married in 1929.
Due to the nature of his father's job as Director of Regional Tax Services, the family moved to different towns every few years. Their daughter and son, completed Gimnasium in the town of Sremska Mitrovica. Vera graduated in mathematics from Belgrade University, Pasko obtained his medical degree from the University of Belgrade School of Medicine, where he embarked on a career as a neurosurgeon, his research career began in 1962, with a Fulbright Fellowship at Harvard University in Boston, MA, where he met professor Paul Yakovlev, who introduced him to the joy of studying human brain development, which inspired him to abandon neurosurgery. In 1966, he returned to Belgrade and obtained his graduate degree in Developmental Biology and Genetics in 1969. During work on his doctoral thesis, Rakic made his first significant discovery, internationally recognized, he accepted a faculty position at Harvard Medical School, where he worked and taught for eight years. In 1978, he was recruited by George Palade to Yale University, where he founded and served as Chair of the Department of Neurobiology and the director of the Kavli Institute for Neuroscience until 2015, when he returned to work full-time on his research projects, funded by US Public Health Services and various private foundations.
He was president of the Society for Neuroscience from 1995 to 1996. Rakic is known for his studies of the evolution of the brain. More he has discovered and formulated basic cellular and molecular mechanisms of proliferation and migration of neurons in the cerebral cortex, the brain's outer layer, which plays a key role in cognition and human exceptional mental capacities. According to Nature Medicine, his first experiments at Harvard required an large research grant, that enabled exposure of non-human primate rhesus monkeys to so much radioactive thymidine that manufacturers had to retool their entire production system to provide it. Rakic injected the monkeys' fetuses with radioactive thymidine at a particular time after conception. Only replicating cells took up the radioactive label, which enabled Rakic to trace the lineages of brain cells as they were created, he and his team sliced the brain of each monkey into 7,000 sections, which were stored in Rakic's collection for the benefit of future researchers.
Because he used a radiolabel that decays the slides should be useful for years, have so far led to more than 24 papers. This material has provided evidence that contributed one of the significant tenets of Neuroscience, that neurons of the cerebral cortex last for the entire lifespan and are irreplaceable; this and other material, such as tissue from monkeys of different age, are available in MacBrainResource. Rakic discovered the early commitment of newborn neurons to their laminar and areal fates and proposed differential cell adhesion as the basic mechanism for their surface-mediating migration along transient radial glial scaffolding; these studies led him to postulate the "radial unit hypothesis" and "protomap" hypotheses of cortical development and evolution that provide the framework for understanding basic principles of normal and pathological development of the human brain. These concept were further elaborated in his paper published in the journal Neuron in 2013. Rakic provided direct cellular evidence for the competitive interactions among binocular visual connections before birth, showed that axons and neurotransmitter receptors are overproduced before declining to the adult levels by a process of competitive selective elimination.
Rakic is known for failing to identify adult neurogenesis in the primate cerebral cortex. Grass Foundation Award, 1985 Karl Spencer Lashley Award, American Philosophical Society, 1986 Francois I Medal, College de France, 1986 Kreig Cortical Discoverer Award, 1989 Marta Philipson Award, Stockholm 2000 Pasarow Foundation Award, 2001 Fyssen International Science Prize, 1992 F. O. Schmitt Medal, 1992 Weinstein-Goldenson Award 1994, he was married t
Arousal is the physiological and psychological state of being awoken or of sense organs stimulated to a point of perception. It involves activation of the ascending reticular activating system in the brain, which mediates wakefulness, the autonomic nervous system, the endocrine system, leading to increased heart rate and blood pressure and a condition of sensory alertness and readiness to respond. Arousal is mediated by several different neural systems. Wakefulness is regulated by the ARAS, composed of projections from five major neurotransmitter systems that originate in the brainstem and form connections extending throughout the cortex. Activation of these neurons produces an increase in cortical activity and subsequently alertness. Arousal is important in regulating consciousness, attention and information processing, it is crucial for motivating certain behaviours, such as mobility, the pursuit of nutrition, the fight-or-flight response and sexual activity. It is important in emotion and has been included in theories such as the James-Lange theory of emotion.
According to Hans Eysenck, differences in baseline arousal level lead people to be extraverts or introverts. The Yerkes-Dodson law states that an optimal level of arousal for performance exists, too little or too much arousal can adversely affect task performance. One interpretation of the Yerkes-Dodson Law is the Easterbrook cue-utilisation hypothesis. Easterbrook states. Wakefulness is regulated by the ascending reticular activating system, composed of five major neurotransmitter systems – the acetylcholine, dopamine and serotonin systems – that originate in the brainstem and form connections which extend throughout the cerebral cortex; when stimulated, these systems alertness. The noradrenergic system is a bundle of axons that originate in the locus coeruleus and ascends up into the neocortex, limbic system, basal forebrain. Most of the neurons are projected to the posterior cortex, important with sensory information, alertness; the activation of the locus coeruleus and release of norepinephrine causes wakefulness and increases vigilance.
The neurons that project into the basal forebrain impact cholinergic neurons that results in a flood of acetylcholine into the cerebral cortex. The acetylcholinergic system has its neurons located in the basal forebrain. Stimulation of these neurons result in cortical activity, shown from EEG records, alertness. All of the other four neurotransmitters play a role in activating the acetylcholine neurons. Another arousal system, the dopaminergic system, releases dopamine produced by the substantia nigra; the neurons arise in the ventral tegmental area in the midbrain, projects to the nucleus accumbens, the striatum forebrain, limbic system, prefrontal cortex. The limbic system is important for control of mood, the nucleus accumbens signal excitement and arousal; the path terminating in the prefrontal cortex is important in regulating motor movements reward oriented movements. The serotonergic system has all of its serotonergic neurons originating in the raphe nuclei; this system projects to the prefrontal cortex.
Stimulation of these axons and release of serotonin causes cortical arousal and impacts locomotion and mood. The neurons of the histaminergic system are in the tuberomammillary nucleus of the hypothalamus; these neurons send pathways to the cerebral cortex and the basal forebrain, where they stimulate the release of acetylcholine into the cerebral cortex. All of these systems show similar redundancy; the pathways described are ascending pathways, but there arousal pathways that descend. One example is the ventrolateral preoptic area, which release GABA reuptake inhibitors, which interrupt wakefulness and arousal. Neurotransmitters of the arousal system, such as acetylcholine and norepinephrine, work to inhibit the ventrolateral preoptic area. Arousal is important in regulating consciousness and information processing, it is crucial for motivating certain behaviors, such as mobility, the pursuit of nutrition, the fight-or-flight response and sexual activity. Arousal is an essential element in many influential theories of emotion, such as the James-Lange theory of emotion or the Circumplex Model.
According to Hans Eysenck, differences in baseline arousal level lead people to be either extraverts or introverts. Research suggests that extroverts and introverts have different arousability, their baseline arousal level is the same. The Yerkes–Dodson law states that there is a relationship between arousal and task performance arguing that there is an optimal level of arousal for performance, too little or too much arousal can adversely affect task performance. One interpretation of the Yerkes–Dodson law is the Easterbrook cue-utilisation theory, it predicted that high levels of arousal will lead to attention narrowing, during which the range of cues from the stimulus and the environment decreases. According to this hypothesis, attention will be focused on the arousing details of the stimulus, so that information central to the source of the emotional arousal will be encoded while peripheral details will not. In positive psychology, arousal is described as a respon