 |
|
MIT neuroscientists find neural stopwatch in the brain
October 20, 2009Populations of neurons code time with extreme precision in the primate brain
What's New: MIT researchers have identified populations of neurons that code time with extreme precision in the primate brain. These neurons are found in two interconnected brain regions, the prefrontal cortex and the striatum, both of which are known to play critical roles in learning, movement, and thought control.
Why it matters: The timing of individual actions, whether we are speaking, driving a car, or playing the piano, require very precise control. Although our daily life is extremely dependent on this remarkable capability, surprisingly little has been known about how time is represented in the activity of brain cells. The discovery made by MIT neuroscientists is an important step toward answering this fundamental question.
How they did it: The team of researchers, led by Institute Professor Ann Graybiel, a member of the McGovern Institute for Brain Research and the Department of Brain and Cognitive Sciences, trained two macaque monkeys to perform a simple eye-movement task. After receiving a "go" signal, the monkeys were free to perform the task at their own speed. The researchers found that neurons in the prefrontal cortex and the striatum that consistently fired at specific times - 100 milliseconds, 110 msec, 150 msec, and so on - after the "go" signal. Like a stopwatch, these neurons provided a fine-scale coverage over a period of several seconds. The combined activity of these neurons provided "time stamps" that could specify any given time point with a remarkable precision of less than 50 milliseconds, more than sufficient to account for most behaviors.
Next steps: The discovery opens the door to many questions. How does the brain produce this time code, and how is it used to control behavior and learning? In the longer term, the ability to read the brain's natural time-code may facilitate the development of neural prosthetic devices for conditions such as Parkinson's disease, in which neurons in the prefrontal cortex and basal ganglia are disrupted and the ability to control the timing of movements is impaired.
Massachusetts Institute of Technology
How they did it: The team of researchers, led by Institute Professor Ann Graybiel, a member of the McGovern Institute for Brain Research and the Department of Brain and Cognitive Sciences, trained two macaque monkeys to perform a simple eye-movement task. After receiving a "go" signal, the monkeys were free to perform the task at their own speed. The researchers found that neurons in the prefrontal cortex and the striatum that consistently fired at specific times - 100 milliseconds, 110 msec, 150 msec, and so on - after the "go" signal. Like a stopwatch, these neurons provided a fine-scale coverage over a period of several seconds. The combined activity of these neurons provided "time stamps" that could specify any given time point with a remarkable precision of less than 50 milliseconds, more than sufficient to account for most behaviors.
Next steps: The discovery opens the door to many questions. How does the brain produce this time code, and how is it used to control behavior and learning? In the longer term, the ability to read the brain's natural time-code may facilitate the development of neural prosthetic devices for conditions such as Parkinson's disease, in which neurons in the prefrontal cortex and basal ganglia are disrupted and the ability to control the timing of movements is impaired.
Massachusetts Institute of Technology
Prefrontal Cortex Current Events and Prefrontal Cortex News RSSNew TMS clinic offers noninvasive treatment for major depression
Rush University Medical Center has opened the Transcranial Magnetic Stimulation (TMS) Clinic to offer patients suffering from major depression a safe, effective, non-drug treatment.
Time-Keeping Brain Neurons Discovered
Groups of neurons that precisely keep time have been discovered in the primate brain by a team of researchers that includes Dezhe Jin, assistant professor of physics at Penn State University and two neuroscientists from the RIKEN Brain Science Institute in Japan and the Massachusetts Institute of Technology (MIT).
Regulating emotion after experiencing a sexual assault
After exposure to extreme life stresses, what distinguishes the individuals who do and do not develop posttraumatic stress disorder (PTSD)?
Young Adults May Outgrow Bipolar Disorder
Bipolar disorder, or manic-depression, causes severe and unusual shifts in mood and energy, affecting a person's ability to perform everyday tasks. With symptoms often starting in early adulthood, bipolar disorder has been thought of traditionally as a lifelong disorder.
Beep, beep, oops, what was I doing?
"That blasted siren. I can't focus." That reaction to undesired distraction may signal a person's low working-memory capacity, according to a new study.
Short Stressful Events May Improve Working Memory
Experiencing chronic stress day after day can produce wear and tear on the body physically and mentally, and can have a detrimental effect on learning and emotion. However, acute stress -- a short stressful incident -- may enhance learning and memory.
Study sheds light on social brain development
The capacity to figure out what others are thinking and what they mean is an ability unique to people that's central to our lives.
Who am I? Adolescents' replies depend on others
Ask middle-school students if they are popular or make friends easily, they likely will depend on social comparisons with their peers for an answer. Such reliance on the perceived opinions of others, or reflected self-appraisals, has long been assumed, but new evidence supporting this claim has now been found in the teen brain.
Neuroimaging suggests that truthfulness requires no act of will for honest people
A new study of the cognitive processes involved with honesty suggests that truthfulness depends more on absence of temptation than active resistance to temptation.
Map of your brain may reveal early mental illness
John Csernansky wants to take your measurements. Not the circumference of your chest, waist and hips. No, this doctor wants to stretch a tape measure around your hippocampus, thalamus and prefrontal cortex.
More Prefrontal Cortex Current Events and Prefrontal Cortex News Articles
 |
The Prefrontal Cortex, Fourth Edition by Joaquin Fuster (Editor) This is the fourth edition of the undisputed classic on the prefrontal cortex, the principal "executive" structure of the brain. Because of its role in such cognitive functions as working memory, planning, and decision-making, the prefrontal cortex is critically involved in the organization of behavior, language, and reasoning. Prefrontal dysfunction lies at the foundation of several psychotic and neurodegenerative disorders, including schizophrenia and dementia. * Written by an award-winning author who discovered "memory cells"-the physiological substrate of working memory * Provides an in-depth examination of the contributions of every relevant methodology, from comparative anatomy to modern imaging * Well-referenced with more than... |
 |
The Prefrontal Cortex: Executive and Cognitive Functions by A. C. Roberts (Editor), T. W. Robbins (Editor), L. Weiskrantz (Editor) The prefrontal cortex, one of the most important areas of research in contemporary neuropsychology, appears to be linked with executive processes affecting many diverse areas of cognition, including working memory, information processing, behavioral organization, and attention. This state-of-the-art account of our knowledge of the prefrontal cortex brings together contributions from some of the world's leading researchers on the subject. The authors discuss the many recent theoretical and technical advances in the field--from advances in our understanding of the neural architecture of the prefrontal cortex to the use of functional neuroimaging and from new ideas about the relationships between neuronal activity and behavior to comparisons between human and non-human primate cognition. One... |
 |
Prefrontal Cortex Cognitive Deficits in Children Treated Early and Continuously for PKU (Monographs of the Society for Research in Child Development) by Adele Diamond (Editor), Meredith Prevor (Editor), Glenda Callender (Editor), Donald P. Druin (Editor) The metabolic disorder phenylketonuria (PKU) is the most common biochemical cause of mental retardation, and affects roughly one in 10,000 children. Bridging basic neuroscience research and clinical studies, this longitudinal study (a) provides evidence that cognitive deficits result from even moderate amino acid imbalances considered acceptable under the standard treatment for PKU, (b) characterizes the nature of those cognitive deficits, and (c) identifies their biological cause. The authors discuss possible steps to correct the problem, and possible implications of the findings for children with other developmental disabilities, such as attention deficit disorder. |
 |
Prefrontal Cortex: Roles, Interventions and Traumas by Lorenzo LoGrasso (Editor), Giovanni Morretti (Editor) Intellectual disabilities have been related to the dysfunction of the prefrontal cortex. The prefrontal cortex is located on the anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas. This brain region has been implicated in planning complex cognitive behaviors, personality expression, and moderating correct social behavior. This book presents a review of present day evidence of the reduction of the prefrontal cortex; links between abnormalities and functional or clinical features of intellectual disabilities such as schizophrenia. The book presents the latest research from around the world in this field. |
 |
Development of the Prefrontal Cortex: Evolution, Neurobiology, and Behavior by Norman A. Krasnegor (Editor), G. Reid Lyon (Editor), Patricia S. Goldman-Rakic (Editor) Prominent investigators in the fields of neuroscience and behavior come together in this volume to examine the brain's prefrontal cortex. Exploring evolutionary issues, neurobiology, neuropsychology, and neuropathology, these experts advance the knowledge of the growth, structure, and function of this brain region as it relates to human behavior and development. Based on multiple human and primate research studies, the book sheds light on typical brain growth and simultaneously describes the functional and developmental consequences of acquired and developmental damage to the prefontal cortex. The authors address specific types of brain injuries and lesions, explaining how these factors can affect cognitive, behavioral, and social functions such as memory, attention, decision making, and... |
![The neuropsychology of ventral prefrontal cortex: Decision-making and reversal learning [An article from: Brain and Cognition]](http://ecx.images-amazon.com/images/I/51SY68ZAKPL._SL160_.jpg) |
The neuropsychology of ventral prefrontal cortex: Decision-making and reversal learning [An article from: Brain and Cognition] by L. Clark (Author), R. Cools (Author), T.W. Robbins (Author) This digital document is a journal article from Brain and Cognition, published by Elsevier in 2004. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: Converging evidence from human lesion, animal lesion, and human functional neuroimaging studies implicates overlapping neural circuitry in ventral prefrontal cortex in decision-making and reversal learning. The ascending 5-HT and dopamine neurotransmitter systems have a modulatory role in both processes. There is accumulating evidence that measures of decision-making and reversal learning may be useful as functional markers of ventral prefrontal cortex integrity in psychiatric and neurological disorders. Whilst... |
![When ''happy'' means ''sad'': Neuropsychological evidence for the right prefrontal cortex contribution to executive semantic processing [An article from: Neuropsychologia]](http://ecx.images-amazon.com/images/I/51PPQSTG2AL._SL160_.jpg) |
When ''happy'' means ''sad'': Neuropsychological evidence for the right prefrontal cortex contribution to executive semantic processing [An article from: Neuropsychologia] by D. Samson (Author), C. Connolly (Author), G.W. Humphreys (Author) This digital document is a journal article from Neuropsychologia, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: The contribution of the left inferior prefrontal cortex in semantic processing has been widely investigated in the last decade. Converging evidence from functional imaging studies shows that this region is involved in the ''executive'' or ''controlled'' aspects of semantic processing. In this study, we report a single case study of a patient, PW, with damage to the right prefrontal and temporal cortices following stroke. PW showed a problem in executive control of semantic processing, where he could not easily... |
|
The Prefrontal Cortex: Its Structure, Function and Pathology (Progress in Brain Research) by J.P.C. de Bruin (Editor), M.A. Corner (Editor), M.G.P. Feenstra (Editor), C.G. Van Eden (Editor), H.B.M. Uylings (Editor) Thanks to a resurgence of interest and a recent proliferation of research techniques, much new and illuminating data has emerged during the last decade relating to the prefrontal cortex, particularly in primates and rodents. In view of this progress, the 16th International Summer School of Brain Research was held in Amsterdam, The Netherlands from 28 August to 1 September 1989, devoted to the topic of `The Prefrontal Cortex: Its Structure, Function and Pathology'. The edited proceedings, embodied in this 85th volume of `Progress in Brain Research', fall into three sections - the first of which, following two introductory chapters, discusses the present knowledge of the organization of prefrontal cortical systems. In the second section, developmental and plasticity aspects in... | |
|
Structure and Functions of the Human Prefrontal Cortex (Annals of the New York Academy of Sciences ; Vol. 769) by Jordan Grafman (Editor), Keith J. Holyoak (Editor), Francois Boller (Editor) This volume contains papers that deal with the structure and functions of the human prefrontal cortex, including a review of recent work on its neuroanatomy, neurochemistry, neural development and degeneration, and neuropsychology. In addition, papers focus on novel and competing theories of human prefrontal cortical functions, utilising convergent evidence from the fields of comparative neuropsychology, cognitive sciences, artificial intelligence, neuropsychiatry, and cognitive neuropsychology. The book provides a broad overview on the subject of the human prefrontal cortex and integration of human prefrontal cortical functioning, and offer in-depth comparisons of alternative testable theories of human prefrontal cortical functions. | |
![Anticipatory anxiety-induced changes in human lateral prefrontal cortex activity [An article from: Biological Psychology]](http://ecx.images-amazon.com/images/I/51H6KB16YQL._SL160_.jpg) |
Anticipatory anxiety-induced changes in human lateral prefrontal cortex activity [An article from: Biological Psychology] by K. Morinaga (Author), J. Akiyoshi (Author), H. Matsushita (Author), Ichioka (Author) This digital document is a journal article from Biological Psychology, published by Elsevier in 2007. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser. Description: It has been suggested that frontal brain asymmetry is associated with differences in basic emotional dimensions, particularly in activation of systems underlying avoidance-withdrawal behavior. We examined regional cerebral oxygenated hemoglobin (O"2Hb) levels in human medial prefrontal cortex (MPFC) using near-infrared reflection spectroscopy (NIRS) prior to and during anticipatory anxiety to determine if NIRS could detect any anxiety-related changes. Transient anxiety was induced in 56 normal volunteers by... |
| © 2009 BrightSurf.com |