Name: brain scanning techniques
Uploaded: 2024-10-24T14:03:06.000Z
Duration: 1 min 14 s
Channel: JoVE

L’imagerie cérébrale fait référence à diverses techniques utilisées pour visualiser la structure et l’activité du cerveau.
La tomodensitométrie crée des images tridimensionnelles, qui sont cruciales pour localiser et évaluer la gravité des anomalies cérébrales.
La TEP introduit un traceur légèrement radioactif dans le corps, mettant en évidence des régions cérébrales métaboliquement actives. Comme ces zones nécessitent plus de sang pendant l’activité, le traceur s’accumule, ce qui permet au scanner de visualiser les parties actives du cerveau pendant des tâches ou des comportements spécifiques.
L’IRM entoure le sujet d’un puissant champ magnétique et utilise des ondes radio pour susciter des réponses des tissus cérébraux. Il produit des images à haute résolution de la structure du cerveau qui sont essentielles pour les études comparatives des conditions cérébrales normales et anormales.
En revanche, l’IRMf surveille les changements dans le flux sanguin et les niveaux d’oxygène dans le cerveau, en corrélant ces changements à l’activité neuronale.
L’IRMf permet d’observer en temps réel la fonction cérébrale pendant que les individus effectuent des activités ou répondent à des stimuli.

imagerie cérébrale

Les technologies d’imagerie cérébrale fournissent des informations essentielles sur la structure et la fonction du cerveau humain, permettant aux professionnels de la santé et aux chercheurs de diagnostiquer, d’étudier et de traiter les troubles neurologiques ou psychiatriques plus efficacement.

Ces technologies comprennent la tomographie axiale informatisée (CT scan ou CT scan), la tomographie par émission de positons (TEP scan), l’imagerie par résonance magnétique (IRM), l’imagerie par résonance magnétique fonctionnelle (IRMf) et la stimulation magnétique transcrânienne (TMS).

Les tomodensitogrammes, qui utilisent la technologie des rayons X, créent des images tridimensionnelles détaillées du cerveau. Cette méthode est particulièrement utile dans les situations d'urgence en raison de sa rapidité et de son efficacité dans la détection des hémorragies, des tumeurs ou d'autres anomalies cérébrales. En fournissant une vue d'ensemble structurelle, les tomodensitogrammes constituent un outil fondamental en science médicale pour évaluer la gravité et la localisation des lésions cérébrales.

La tomographie par émission de positons (TEP) offre une perspective dynamique en utilisant un traceur légèrement radioactif pour identifier les zones métaboliquement actives du cerveau. Ces régions présentent une demande accrue de sang lors de diverses activités ou en réponse à certains stimuli, ce qui fait de la TEP une méthode essentielle pour étudier les fonctions cérébrales comme la mémoire et la cognition. Cette capacité à visualiser les parties actives du cerveau lors de tâches spécifiques aide à comprendre les changements métaboliques associés à divers troubles cérébraux.

L'IRM utilise un champ magnétique puissant combiné à des ondes radio pour obtenir des images détaillées des tissus cérébraux. Cette modalité est essentielle pour fournir des images haute résolution indispensables au diagnostic et à la compréhension d'un large éventail de conditions cérébrales, tant normales que pathologiques. Contrairement aux tomodensitogrammes, l'IRM n'utilise pas de rayonnement ionisant, ce qui en fait une option plus sûre pour une utilisation répétée, en particulier chez les populations vulnérables telles que les enfants et les femmes enceintes.

L'IRMf s'appuie sur la technologie de l’IRM pour mesurer et cartographier l'activité cérébrale. En surveillant les changements dans le flux sanguin et les niveaux d'oxygène, l'IRMf peut corréler ces variations physiques à l'activité neuronale. Cette technique permet aux chercheurs d'observer l'anatomie fonctionnelle du cerveau et offre une vue en temps réel des processus cérébraux lorsque les individus s'engagent dans des tâches ou répondent à divers stimuli. Cette application est essentielle pour comprendre les bases neuronales des comportements et pour améliorer la recherche en neurosciences cognitives.

La TMS utilise des champs magnétiques pour moduler l’activité électrique de zones cérébrales spécifiques, offrant ainsi une méthode non invasive pour modifier la fonction neuronale. Cette technologie est particulièrement efficace pour cartographier les régions fonctionnelles du cerveau, évaluer la connectivité et la fonctionnalité des circuits neuronaux et proposer des interventions thérapeutiques dans les troubles psychiatriques et neurologiques. La capacité d’influencer directement la fonction cérébrale grâce à la TMS ouvre de nouvelles perspectives pour le traitement de maladies telles que la dépression et la schizophrénie, pour lesquelles les thérapies traditionnelles se sont révélées insuffisantes.

Imagerie cérébrale

L’imagerie cérébrale fait référence à diverses techniques utilisées pour visualiser la structure et l’activité du cerveau.
Les tomodensitogrammes créent des images tridimensionnelles, qui sont ...

Education

Enseignement

JoVE Core

Introduction to Psychology

Introduction à la psychologie

Unit 1

Unité 1

Biopsychology

Biopsychologie

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

Brain Imaging

brain scanning techniques

Brain scanning techniques help scientists and doctors see the structure and activity of the human brain. These methods support the diagnosis, study, and treatment of neurological and psychiatric disorders. The main techniques include computerized axial tomography, or CT, positron-emission tomography, or PET, magnetic resonance imaging, or MRI, functional magnetic resonance imaging, or fMRI, and transcranial magnetic stimulation, or TMS.

CT scans use X-ray technology to build detailed three-dimensional images of the brain. They are especially useful in emergency settings because they are fast and efficient. CT scans can help detect hemorrhages, tumors, and other brain abnormalities. They also provide a structural view that helps medical professionals judge the severity and location of brain lesions.

PET scans show brain activity by using a mildly radioactive tracer. The tracer highlights metabolically active areas, which are the parts of the brain with increased blood demand during tasks or in response to stimuli. This makes PET useful for studying functions such as memory and cognition. It also helps researchers understand metabolic changes linked to different brain disorders.

MRI uses a strong magnetic field and radio waves to produce high-resolution images of brain tissue. This method is important for diagnosing and understanding both normal and abnormal brain conditions. Unlike CT scans, MRI does not use ionizing radiation. That makes it a safer choice for repeated use, especially in children and pregnant women.

fMRI builds on MRI to measure and map brain activity. It tracks changes in blood flow and oxygen levels and connects those changes to neural activity. This gives researchers a real-time view of brain processes during tasks or when a person responds to stimuli. fMRI is a key tool for studying brain function and the neural basis of behavior.

TMS uses magnetic fields to change the electrical activity of specific brain areas. It is a non-invasive method, which means it does not require surgery. TMS can help map functional regions of the brain and test how different neural circuits are connected and working. It also has therapeutic uses in psychiatric and neurological disorders, including depression and schizophrenia, where traditional therapies may not be enough.

Brain Scanning Techniques

introduction to biological bases of psychology

introduction-to-biological-bases-of-psychology

Biological Factors Shaping Behavior and Mind

Biopsychology connects biology and psychology by showing how the body influences behavior and mental processes. It focuses on the nervous system, neurotransmitters, hormones, genetics, and evolutionary ideas. Together, these areas help explain why people think, feel, and act the way they do. The nervous system is the main foundation of biopsychology. It has two parts: the central nervous system, or CNS, and the peripheral nervous system, or PNS. The CNS includes the brain and spinal cord and...

nervous system

Nervous System: CNS, PNS, and Reflexes

The nervous system helps the body sense, move, and respond. It works through a network of nerve cells that carry signals around the body. This system has two main parts: the central nervous system and the peripheral nervous system. The central nervous system, or CNS, includes the brain and spinal cord. The brain acts as the body’s control center. It processes sensory information and helps coordinate responses. The spinal cord serves as a major pathway for signals between the brain and the rest...

neurons as communicators of the brain

Neuron Parts and Signal Transmission

Neurons are the cells that carry information through the brain and nervous system. They use electrical and chemical signals to help control body functions, from heartbeat regulation to complex thinking. Their structure is built for fast, efficient communication. The cell body, or soma, is the neuron’s control center. It contains the nucleus, which holds the cell’s genetic material and helps maintain the neuron’s health and function. The cytoplasm around it contains organelles that make...

neuronal communication

How Neurons Send Signals

Neurons send signals through electrochemical communication that supports brain and nervous system function. A key part of this process is the action potential, a rapid electrical change that starts when the neuron’s internal charge rises above a threshold. That signal then travels along the axon to the axon terminal, where it is ready to pass to another neuron. The connection point between two neurons is called a synapse. Synapses can be electrical or chemical, and each type moves information...

neurotransmitters

Brain Chemicals That Shape Mood and Movement

Neurotransmitters are chemical messengers that help neurons communicate. They play a major role in nervous system function, as well as in mood, movement, sleep, and social behavior. Serotonin is made in the brain and intestines. It is linked to well-being and happiness, and it helps regulate mood, appetite, and sleep. When serotonin levels are out of balance in the brain or in peripheral sites, depression and sleep problems can occur. Dopamine is produced in several brain areas, including the...

cerebral hemispheres

How the Brain’s Two Halves Work

The brain’s two cerebral hemispheres work together to process information and control the body. The left and right hemispheres are linked by the corpus callosum, a large bundle of nerve fibers. This connection lets the two sides share sensory and motor information, with each hemisphere controlling the opposite side of the body. The hemispheres are also specialized for different tasks. This is called lateralization, which means certain functions are handled more strongly by one side than the...

lobes of the cerebrum

How Brain Lobes Shape Perception

The cerebral cortex is divided into two hemispheres, and each hemisphere has four lobes: frontal, parietal, temporal, and occipital. Together, these lobes support the brain’s main cognitive and sensory jobs. They work as a team to help you think, feel, move, and respond to the world. The frontal lobe sits behind the forehead and acts as a control center for personality, intelligence, and voluntary muscle movement. It also contains the prefrontal cortex, a region that helps with planning,...

spinal cord

Spinal Cord Nerves and Reflexes

The spinal cord is a major part of the central nervous system. It runs from the base of the brainstem to the lumbar region of the vertebral column. It helps keep the body stable and carries signals between the brain and the rest of the body. The spinal cord sits inside the bony spine for protection. It is divided into 30 segments that match the vertebrae. Each segment connects to a specific body region through paired spinal nerves. These spinal nerves are grouped by where they leave the...

lateralization

Brain Hemisphere Specialization

Brain hemisphere specialization divides mental tasks between the left and right sides of the brain. This split can improve neural efficiency and support more complex human abilities. Each hemisphere tends to handle the work it does best, which helps cognitive processing run more smoothly. The left hemisphere is especially strong in logic and language-related tasks. It supports analytical thinking, which means breaking a problem into parts and solving it step by step. This is important for...

human genetics

Genes, Behavior, and Mental Health

Human genetics explains how genes can influence behavior, emotions, and mental health. It also shows how a person’s genetic code can shape physical traits and the risk of disease. Each individual carries a unique set of genes, so the effects can be subtle or more noticeable. Genes help direct how the brain, hormones, and cells work. These body systems are all shaped by genetic instructions, and they help produce differences in thoughts and behavior. Human genetics therefore links biology with...

genetic material

Chromosomes, DNA, and Inherited Traits

Chromosomes, DNA, and inherited traits explain how genetic information is organized in the human body. Each cell contains a nucleus, and the nucleus holds 46 chromosomes arranged in 23 pairs. These chromosomes are tightly coiled structures made of DNA, which carries the instructions passed from parents to offspring. An individual inherits one set of chromosomes from the mother through the egg and one set from the father through the sperm. This combination creates a unique genetic makeup. Of...

genetic variation

How Alleles Shape Inherited Traits

Genetic variation helps explain why individuals in the same species can look and act differently. It comes from differences in DNA sequences. This diversity matters because it helps a species survive and adapt when the environment changes. Variation starts at fertilization, when an egg and sperm cell join. Each of these cells carries 23 chromosomes, so the fertilized egg can have up to 46 chromosomes. Chromosomes are long DNA strands that contain genes, which are the basic units of heredity. <br...

behavioral genetics and its designs

How Behavior Genetics Studies Inheritance

Behavior genetics studies how inherited genes influence human behavior. It looks at how genes passed from parents to offspring help shape behavioral traits and tendencies. The field also examines how inherited factors and environmental influences work together. Researchers use family studies, twin studies, and adoption studies to separate genetic and environmental effects. Family studies track traits within biological families to find possible genetic patterns. They have helped identify...

organization of the brain

Brain Regions and Their Key Functions

The brain is the main control center of the nervous system. It processes sensory input, makes decisions, and directs body actions. Its structure is divided into the hindbrain, midbrain, and forebrain, and each part supports important functions. The hindbrain sits at the base of the brain. It helps regulate automatic life processes. The medulla oblongata controls involuntary functions such as heartbeat, breathing, and blood pressure. Nearby, the pons acts as a bridge between brain regions,...

evolutionary psychology

Evolutionary Psychology and Human Behavior

Evolutionary psychology explains human behavior and mental processes through natural selection. It uses Darwin’s idea that traits can spread when they help survival and reproduction. In this view, some common behaviors may be adaptations that were useful to our ancestors. One clear example is fear of snakes. This fear is nearly universal, which suggests that early humans who avoided snakes were more likely to survive deadly encounters. Over many generations, that caution could be passed on and...

neuroplasticity

How the Brain Rewires Itself

Neuroplasticity is the brain’s ability to change its structure and function in response to learning, experience, or injury. It allows neural circuits to reorganize over time. This flexibility supports lifelong development and adaptation. One part of this change begins when dendrites and axons grow. Dendrites receive signals, and axons send them. As they grow, the brain’s circuitry becomes more complex and can support more connections. Next, synaptogenesis occurs. Synaptogenesis is the...

brain imaging

Brain scanning techniques help scientists and doctors see the structure and activity of the human brain. These methods support the diagnosis, study, and treatment of neurological and psychiatric disorders. The main techniques include computerized axial tomography, or CT, positron-emission tomography, or PET, magnetic resonance imaging, or MRI, functional magnetic resonance imaging, or fMRI, and transcranial magnetic stimulation, or TMS. CT scans use X-ray technology to build detailed...

the endocrine system

Endocrine Glands and Hormone Signals

The endocrine system is a network of glands that send hormone signals through the body. Hormones are chemical messengers that help control many body functions. They enter the bloodstream and travel to cells with the right receptors, or target sites, so the signal can be received. Because of this, hormone effects are widespread, unlike the more localized effects of neurotransmitters. This signaling helps the body keep a stable internal environment, called homeostasis. Several major glands...

somatosensory, motor, and association cortex

somatosensory-motor-and-association-cortex

Brain Cortex Areas for Sensation and Movement

The brain cortex uses separate areas for sensation, movement, and higher thinking. The somatosensory cortex is in the parietal lobes. It helps the brain interpret touch, temperature, and proprioception, which is awareness of body position. The somatosensory cortex has an organized map of the body. Neurons at the top of this region mainly process signals from the lower body. Neurons at the bottom handle input from the upper body. This layout helps the brain locate sensory input with precision.

major hormones and their functions

Hormone Imbalances and Their Effects

Hormones are chemical messengers made by endocrine glands. They help control body functions and keep internal conditions stable. When hormone levels shift too far up or down, normal body processes can be disrupted. Several major hormones have clear roles in the body. Oxytocin is made in the hypothalamus and released by the pituitary gland. It supports social bonding, childbirth, and lactation. Low oxytocin can affect social interaction and stress response, and it may contribute to depression.

inheritance

Genes, Traits, and Mendel's Rules

Genes, traits, and Mendel's rules explain how characteristics pass from parents to offspring. Gregor Mendel's pea plant experiments changed how scientists understand heredity. His work showed that traits are controlled by discrete units inside organisms called genes. Genes usually come in pairs. One gene is inherited from each parent, and together they make a person's genotype. Genotype is the genetic blueprint for potential traits. Examples include blood type, eye color, and inherited...

gene-environment interactions

How Environment Shapes Gene Expression

Environmental factors can change how genes are expressed. Gene expression is a dynamic process, and traits can differ even in people with the same DNA. Radiation, temperature, behavior, nutrition, and stress all help shape the final outcome. The reaction range helps explain this process. It means genes set a possible range for a trait, while the environment helps decide where a person falls within that range. For example, genetics may allow a height range from 5'5" to 6'1", but nutrition,...

heritability

Heritability and the Environment

Heritability describes how genetic differences contribute to trait variation in a population. It is a statistical measure, so it shows how much of the spread in a trait can be linked to genes across a group. It does not tell you how “genetic” a trait is in an individual person. Heritability is usually expressed as a percentage. That percentage can change depending on which population is studied and what environmental conditions are present. This means heritability is context-dependent, not...

natural selection and adaptation

Adaptation in Changing Environments

Natural selection explains how organisms become better suited to their environments over time. It favors individuals with traits that improve survival and reproduction. Adaptation is the result. It includes genetic changes that help an organism function in specific conditions, such as extreme cold or thinner air at high altitudes. Adaptation is not only physical. Psychological adaptation also helps organisms, especially humans, succeed in their surroundings. These responses come from both...

natural selection and mating preferences

How Selection Shapes Mate Choice

Natural selection and mating preferences work together to shape how organisms survive and reproduce. Natural selection favors traits that help an organism fit its environment. Mating preferences are part of sexual selection, which influences who mates with whom and how genes are passed on. Evolutionary psychologists argue that these preferences are tied to instincts that support reproduction. For females, conception, pregnancy, and nursing create a strong need to choose mates who can offer...

criticisms of the evolutionary perspective

criticisms-of-the-evolutionary-perspective

Social Learning vs. Evolutionary Psychology

Social learning theory and evolutionary psychology offer two different ways to explain sexual behavior. A study in which strangers gave students compliments and then asked for casual sex showed a clear gender gap. None of the women said yes, while 70% of the men agreed. Evolutionary psychology explains this result by arguing that natural selection may have shaped women to be more selective about sexual partners. From this view, selectivity can help improve survival and reproductive success. It...

key terms and concepts

Explore brain scanning techniques used to study structure and activity, including CT, PET, MRI, fMRI, and TMS in neurological research and care.

Brain Scanning Techniques | JoVE K12

JoVE Core Introduction to Psychology offers an engaging learning experience on the fundamental principles of psychology through concise video lessons. Students will explore important topics such as cognitive processes, emotional regulation, and neural mechanisms, establishing a strong foundation in the study of the mind and human behavior. This series provides an accessible and captivating approach to grasp the essential concepts of the discipline.

introduction to psychology

Brain Scanning Techniques

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