Lesion studies have historically been a staple of neuroscience research to investigate the necessity of a brain region for a specific behavior or phenotype. Using physical or pharmacological methods to ablate neurons raises concerns about the specificity and totality of the lesions.
What is a brain lesion study?
This technique of study involves study lesions of the brain, whether the result of injury, illness, or induced by the researcher. The two brain structures that are most often used in this type of study is the amygdala and the hippocampus.
What is lesion study design?
Lesion Study Designs Lesion studies in humans are in part “experiments of nature”: obviously, the lesions themselves are not produced experimentally. Rather, patients with lesions are invited to participate in an experiment, thus allowing designs driven by behavior or by lesion location.
What can we learn from the lesion method?
The lesion method provides unique insight into how the human brain generates emotion and feeling. Recent work has explored a number of interesting topics including the dissociation of emotional experience from memory in patients with amnesia, the reliability of specific emotional deficits following …
What is the role of the etiology of a lesion?
The etiology of a lesion is also usually associated with the pattern of damage (e.g., strokes follow vascular branches). Including patients with diverse etiologies can mitigate these problems by reducing lesion covariance and decoupling deficits from a specific neurological disease. Experimental tasks are never truly process-pure.
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Why are lesion studies useful?
Large-sample lesion studies could offer complementary data: when administered the same battery of tasks, such data could let us see what dissociations between psychological processes are possible and hence serve to separate or combine processes into revised architectures of cognition.
What is the purpose of lesion?
In neuroscience, a lesion generally refers to damage to the brain. Lesions played an important role in coming to understand brain functions, as neuroscientists were able to match deficits in behavior with the area of the brain that was lesioned in order to deduce what the function of that brain region was.
What is the lesion method?
The lesion method refers to an approach whereby a focal area of brain damage is correlated with the development of a defect in some aspect of cognition or behavior, and then an inference is made that the damaged brain region is part of the neural substrate for the impaired function.
What does lesion mean in psychology?
A lesion is damage to a part of the brain that results in destruction to the neurons. Lesions can come from natural sources (like brain injury or disease) but can also be deliberately caused. Lesion methods are when lesions to a specific part of the brain are deliberately created.
What are the 3 types of lesions?
Primary skin lesions tend to be divided into three groups:Lesions formed by fluid within the skin layers: Examples include vesicles and pustules.Lesions that are solid masses: Examples include nodules and tumors.Flat lesions: Examples include patches and macules.
Is a lesion a tumor?
A lesion describes any area of damaged tissue. All tumors are lesions, but not all lesions are tumors. Other brain lesions can be caused by stroke, injury, encephalitis and arteriovenous malformation.
How are lesion studies done?
An ablation experiment (or lesioning study) is a research method in which areas of the brain are removed or disabled in order to determine their specific functions. Ablation is when tissue is removed using surgery, lasers, or vaporization.
What is an example of a lesion?
Examples include chickenpox and shingles. MRSA and cellulitis are two potentially life threatening infections that involve skin lesions. Some skin lesions, such as moles and freckles, are hereditary. Birthmarks are lesions that exist at the time of birth.
What's the difference between a lesion and a mass?
A bone lesion is considered a bone tumor if the abnormal area has cells that divide and multiply at higher-than-normal rates to create a mass in the bone. The term "tumor" does not indicate whether an abnormal growth is malignant (cancerous) or benign, as both benign and malignant lesions can form tumors in the bone.
Why results from lesion studies Case studies should be interpreted cautiously?
The results from these studies should be interpreted with caution for several reasons. First, the patients observed in many of these studies had diffuse damage to frontal cortex and underlying white matter, making it difficult to discern which frontal areas are particularly involved in planning and problem solving.
What diseases can cause lesions on the brain?
AdvertisementBrain aneurysm.Brain AVM (arteriovenous malformation)Brain tumor (both cancerous and noncancerous)Encephalitis (brain inflammation)Epilepsy.Hydrocephalus.Multiple sclerosis.Stroke.More items...
What does it mean if you have a lesion?
A lesion is an area of tissue that has been damaged through injury or disease.
What does it mean if you have a lesion?
A lesion is an area of tissue that has been damaged through injury or disease.
What is an example of lesion?
Freckles and flat moles are examples of macule skin lesions. Nodules refer to “knot” like growths of abnormal tissue that develop under the skin. For instance, lymph nodes can develop nodules that are visible from the surface of the skin upon inspection.
What are lesions in the body?
A skin lesion is a part of the skin that has an abnormal growth or appearance compared to the skin around it. Two categories of skin lesions exist: primary and secondary. Primary skin lesions are abnormal skin conditions present at birth or acquired over a person's lifetime.
What are medical lesions?
A Lesion is a CELL PATHOLOGICAL ABNORMALITY. A Lesion is an area of abnormal TISSUE. A Lesion may be: benign (not cancer) or. malignant (cancer).
What is lesion study?
Lesion studies have been fundamental to many core theories in cognitive and behavioral neuroscience. Lesion work in human and nonhuman primate lesion studies has unique inferential strengths that are distinct from temporary manipulations or correlative measures of neural activity. New methodological developments are underway ...
How are chronic lesions studied?
Conventionally, chronic lesions are studied to test the role a region plays in a particular function, usually by comparing the effects of damage to one region against a control group of healthy subjects or subjects with damage to a different region ( Figure 2 A ). In investigations of humans, variability in lesion size and extent is unavoidable, and subjects are typically classified into groups based on some a priori anatomical criteria, thus limiting the spatial resolution of these studies. Voxel-based lesion–behavior mapping (VLBM), or lesion–symptom mapping, takes advantage of the variability of lesions in human patients to make associations between lesions and behavioral performance without the constraint of an ROI 99., 100., 101., 102. ( Figure 2 B). In its most common application, VLBM uses massive univariate statistics to compare the behavior of patients with damage in each voxel against all other patients in a dataset. This method can thus reveal where damage was most strongly associated with a change in behavior at a more granular level than is possible with group comparisons.
What is lesion evidence?
Lesion evidence provides fertile ground for new hypotheses about neural function that may be tested with other methods. For example, lesion studies in NHPs that demonstrated a double dissociation for the functions of mid- and posterior dorsolateral PFC generated testable predictions about the function of homologous regions. Subsequent human functional imaging experiments confirmed the association of these regions with monitoring information in working memory and conditional selection between competing responses, respectively 89., 90., 91., 92.. Similarly, studies of the contributions of perirhinal cortex to memory in macaques 93., 94. led to a series of neuropsychological and fMRI studies in humans that continue to elucidate perirhinal cortex function today 95., 96..
What is the significance of studies of focal brain damage?
Studies of humans with focal brain damage and non-human animals with experimentally induced brain lesions have provided pivotal insights into the neural basis of behavior. As the repertoire of neural manipulation and recording techniques expands, the utility of studying permanent brain lesions bears re-examination.
What is the etiology of a lesion?
The etiology of a lesion is also usually associated with the pattern of damage ( e.g., strokes follow vascular branches). Including patients with diverse etiologies can mitigate these problems by reducing lesion covariance and decoupling deficits from a specific neurological disease. Neuropsychological Screening.
What was the first evidence that complex cognitive processes, such as those underlying language, have dissociable components that depend
In the 19th century, case studies of patients with focal brain damage provided the first evidence that complex cognitive processes, such as those underlying language, have dissociable components that depend on different regions of the brain 1., 2.. Brain lesion studies constituted the foundation of cognitive neuroscience ...
Is the control group demographically matched to the lesion group?
The control group should be demographically matched to the lesion group and be recruited from the same population. However, there are other factors that accompany brain damage (e.g., the use of psychoactive medication) that are not controlled for in these comparisons.
What is a lesion study?
Lesion studies (which generate lesion data), localize human brain function by studying the correlation between a behavioural disorder and the location of brain injury. These studies have greatly advanced our understanding of brain function. In 1861, Paul Broca boldly suggested that the third convolution of the inferior frontal gyrus is involved with speech production. This study founded a long tradition of neuropychological research which is still relevant today. The advantages of this type study can be appreciated by considering the vast amount of knowledge on cognitive function that it has brought about. Carl Wernicke discovered that damage to the left posterior temporal cortex leads to difficulty in language comprehension. Beginning in…show more content…
What causes dementia with Lewys Bodies?
Dementia with Lewys Bodies (DLB) is caused by small deposits of proteins found in the nerve cells of the brain. Their presence in the brain leads to the degeneration of brain tissue. This is the third most common form of dementia. Rarer forms of dementia are: Fronto temperal dementia which is brain damage usually focused in the front or temporal parts of the brain.
When was lesioning used?
In the 1950s and 1960s, lesioning was a common treatment for these disorders. However, it had mixed results and, with the discovery of other treatments, was rarely used by the 1980s. Now, lesioning is considered an option for people with movement disorders that don’t respond well to other treatments. Although lesioning is not a commonly used ...
What is lesioning in the brain?
Overview. Lesioning is when small areas of damage (lesions) are made in your brain. These lesions target cells that control movement and are used to treat movement disorders, such as essential tremor, Parkinson’s disease, and dystonia. In the 1950s and 1960s, lesioning was a common treatment for these disorders.
What type of radiation is used to create a lesion?
Radiofrequency is a type of high-frequency radio wave that can be used to create a lesion. The waves are passed through a probe in the brain that’s used to target the correct tissue. Radiosurgery. Radiosurgery uses targeted radiation to lesion brain tissue. It’s most commonly used for thalamotomies.
What is the procedure to make a lesion in the Globus pallidus?
This helps them narrow down the target even more. There are several different types of lesioning surgery. These include: Pallidotomy. In this procedure, surgeons make a lesion in the Globus pallidus, a part of the brain that’s overactive in Parkinson’s disease.
What is the rarest type of lesioning?
This procedure targets the subthalamus, a small area of the brain that plays a role in motor control. It’s the rarest type of lesioning. Each of these procedures can be done using one of the following techniques: Radiofrequency. Radiofrequency is a type of high-frequency radio wave that can be used to create a lesion.
How long does it take to recover from a lesion?
After a lesioning procedure, you’ll probably spend two or three days in the hospital. Full recovery usually takes about six weeks, but it’s different for everyone. You should avoid any strenuous activity during those six weeks or until your doctor advises you that it’s alright to do so.
Can lesioning help with movement?
Lesioning can’t cure movement disorders, but in some cases, it can help ease your symptoms. Studies of lesioning have found varying results, which is one reason these procedures are rarely performed. However, some research has shown success for people whose symptoms are not well-controlled by medicine.
Review Articles
Heffner, H. E. (2004). The neurobehavioral study of auditory cortex. In P. Heil, R. König, E. Budinger, and H. Scheich (Eds.) Auditory Cortex - Towards a Synthesis of Human and Animal Research " Lawrence Erlbaum Associates, Mahwah NJ, pp. 111-126.
Macaques
Heffner, H. E. and Harrington, I. A. (2003). Intensity discrimination following cortical lesions in macaques: Detection of increments, decrements, and amplitude modulation. Abstracts of the Twenty Sixth Meeting of the Association for Research in Otolaryngology, 26, 233.
Dogs
Heffner, R. S., & Heffner, H. E. (1984). Hearing loss in dogs after lesions of the brachium of the inferior colliculus and medial geniculate. Journal of Comparative Neurology, 230, 207-217.
