Show Advanced Search


Containing Text
- - -
Filter by author or institution
Filter by publication date
October, 2006
Filter by journal section

Filter by science education

Consent Forms: Documents describing a medical treatment or research project, including proposed procedures, risks, and alternatives, that are to be signed by an individual, or the individual's proxy, to indicate his/her understanding of the document and a willingness to undergo the treatment or to participate in the research.

Misattribution of Arousal and Cognitive Dissonance

JoVE 10333

Source: Peter Mende-Siedlecki & Jay Van Bavel—New York University

A host of research in psychology suggests that feelings of psychological arousal may be relatively ambiguous, and under certain circumstances, can lead us to make inaccurate conclusions about our own mental states. Much of this work flows from seminal research conducted by Stanley Schacter and and Jerome Singer. If someone experiences arousal and does not have an obvious, appropriate explanation, they may attempt to explain their arousal in terms of other aspects of the situation or social context. For example, in one classic study, participants were told they were receiving a drug called “Suproxin,” in an attempt to test their vision.1 In reality, they received shots of epinephrine, which typically increases feelings of psychological arousal. While some participants were told that the drug would have side effects similar to epinephrine, others were not informed of the side effects, others were misinformed, and others received a placebo with no arousing side effects. Participants then interacted with a confederate, who was either behaving in a euphoric or an angry manner. The authors observed that participants who had no explanation for t

 Social Psychology

Thinking Too Much Impairs Decision-Making

JoVE 10334

Source: Peter Mende-Siedlecki & Jay Van Bavel—New York University

When we are considering a tough choice between two or more attractive options, we often end up actively weighing the pros and cons of each alternative. By reflecting on their advantages and disadvantages, we attempt to fit a complex, subjective decision into an orderly set of criteria. However, research in psychology suggests that this sort of introspective approach might not always yield the most optimal outcomes.1 In other words, sometimes thinking hard about a problem or a choice may not produce desired results. Similar results have been demonstrated in the domains of emotion (participants who ruminated about a bad mood showed less mood improvement than participants who were merely distracted from their mood;2 and memory (verbalizing the details of a criminal’s face led to poorer recognition in a photo array of possible suspects.3 Furthermore, Wilson and colleagues observed that reflecting on the reasons behind one’s attitudes (i.e., considering “why” one feels a certain way) can disrupt the consistency between attitudes and behavior, and can even change attitudes.4 Why might this be the case? Wilson and colleagues speculate

 Social Psychology

An All-on-chip Method for Rapid Neutrophil Chemotaxis Analysis Directly from a Drop of Blood

1Institute of Applied Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 2University of Science and Technology of China, 3Department of Physics and Astronomy, University of Manitoba, 4Department of Biosystems Engineering, University of Manitoba, 5Seven Oaks General Hospital, 6Department of Immunology, University of Manitoba, 7Department of Biological Sciences, University of Manitoba

JoVE 55615

 Immunology and Infection

A Community-based Stress Management Program: Using Wearable Devices to Assess Whole Body Physiological Responses in Non-laboratory Settings

1Department of Emergency Medicine, The University of Texas Health Science Center, 2Department of Integrative Physiology, The University of North Texas Health Science Center, 3Works of Wonder International, 4DeVos Graduate Sports Business Management Program, University of Central Florida

Video Coming Soon

JoVE 55816

 JoVE In-Press

Using Diffusion Tensor Imaging in Traumatic Brain Injury

JoVE 10276

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California

Traditional brain imaging techniques using MRI are very good at visualizing the gross structures of the brain. A structural brain image made with MRI provides high contrast of the borders between gray and white matter, and information about the size and shape of brain structures. However, these images do not detail the underlying structure and integrity of white matter networks in the brain, which consist of axon bundles that interconnect local and distant brain regions. Diffusion MRI uses pulse sequences that are sensitive to the diffusion of water molecules. By measuring the direction of diffusion, it is possible to make inferences about the structure of white matter networks in the brain. Water molecules within an axon are constrained in their movements by the cell membrane; instead of randomly moving in every direction with equal probability (isotropic movement), they are more likely to move in certain directions, in parallel with the axon (anisotropic movement; Figure 1). Therefore, measures of diffusion anisotropy are thought to reflect properties of the white matter such as fiber density, axon thickness, and degree of myelination. One common measure is fractional anisotropy


The Split Brain

JoVE 10162

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California

The study of how damage to the brain affects cognitive functioning has historically been one of the most important tools for cognitive neuroscience. While the brain is one of the most well protected parts of the body, there are many events that can affect the functioning of the brain. Vascular issues, tumors, degenerative diseases, infections, blunt force traumas, and neurosurgery are just some of the underlying causes of brain damage, all of which may produce different patterns of tissue damage that affect brain functioning in different ways. The history of neuropsychology is marked by several well-known cases that led to advances in the understanding of the brain. For instance, in 1861 Paul Broca observed how damage to the left frontal lobe resulted in aphasia, an acquired language disorder. As another example, a great deal about memory has been learned from patients with amnesia, such as the famous case of Henry Molaison, known for many years in the neuropsychology literature as "H.M.," whose temporal lobe surgery led to a profound deficit in forming certain kinds of new memories. While the observation and testing of patients with focal brain damage has provi


Executive Function in Autism Spectrum Disorder

JoVE 10268

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California

Attention, working-memory, planning, impulse control, inhibition, and mental flexibility are important components of human cognition that are often referred to as executive functions. Autism spectrum disorder is a developmental disorder that is characterized by impairments in social interaction, communication, and repetitive behaviors. It is a disorder that lasts a lifetime, and is thought to affect 0.6% of the population. The symptoms of autism suggest a deficit in executive function, which may be assessed by specialized neuropsychological tests. By employing several tests that each emphasize different aspects of executive function, we can gain a more complete picture of the cognitive profile of the disorder. One such task, known as the Wisconsin Card Sorting Test (WCST), is a cognitively complex task used widely in research and clinical studies as a highly sensitive measure of deficits in executive function. It tests a person's ability to shift attention and tests their flexibility with changing rules and reinforcement.1 In the WCST, a participant is presented with four stimulus cards, incorporating three stimulus parameters: color, shape, and number. The participant is asked to sort


Measuring Grey Matter Differences with Voxel-based Morphometry: The Musical Brain

JoVE 10299

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California

Experience shapes the brain. It is well understood that our brains are different as a result of learning. While many experience-related changes manifest themselves at the microscopic level, for example by neurochemical adjustments in the behavior of individual neurons, we may also examine anatomical changes to the structure of the brain at a macroscopic level. One famous example of this kind of change comes from the case of the London taxi drivers, who along with learning the complex routes of the city show larger volume in the hippocampus, a brain structure known to play a role in navigational memory.1 Many traditional methods of examining brain anatomy require painstaking tracing of anatomical regions of interest in order to measure their size. However, using modern neuroimaging techniques, we can now compare the anatomy of the brains across groups of people using automated algorithms. While these techniques do not avail themselves of the sophisticated knowledge that human neuroanatomists may bring to the task, they are quick, and sensitive to very small differences in anatomy. In a structural magnetic resonance image of the brain, the intensity of each volumetric pixel, or voxel, relat


Visual Attention: fMRI Investigation of Object-based Attentional Control

JoVE 10272

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel— University of Southern California

The human visual system is incredibly sophisticated and capable of processing large amounts of information very quickly. However, the brain's capacity to process information is not an unlimited resource. Attention, the ability to selectively process information that is relevant to current goals and to ignore information that is not, is therefore an essential part of visual perception. Some aspects of attention are automatic, while others are subject to voluntary, conscious control. In this experiment we explore the mechanisms of voluntary, or "top-down" attentional control on visual processing. This experiment leverages the orderly organization of visual cortex to examine how top-down attention can selectively modulate the processing of visual stimuli. Certain regions of the visual cortex appear to be specialized for processing specific visual items. Specifically, work by Kanwisher et al.1 has identified an area in the fusiform gyrus of the inferior temporal lobe that is significantly more active when subjects view faces compared to when they observe other common objects. This area has come to be known as the Fusiform Face Area (FFA). Another brain region, known as the Para


Event-related Potentials and the Oddball Task

JoVE 10273

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California

Given the overwhelming amount of information captured by the sensory organs, it is crucial that the brain is able to prioritize the processing of certain stimuli, to spend less effort on what might not be currently important and to attend to what is. One heuristic the brain uses is to ignore stimuli that are frequent or constant in favor of stimuli that are unexpected or unique. Therefore, rare events tend to be more salient and capture our attention. Furthermore, stimuli that are relevant to our current behavioral goals are prioritized over those that are irrelevant. The neurophysiological correlates of attention have been experimentally examined through the use of the oddball paradigm. Originally introduced in 1975, the oddball task presents the participant with a sequence of repetitive audio or visual stimuli, infrequently interrupted by an unexpected stimulus.1 This interruption by a target stimulus has been shown to elicit specific electrical events that are recordable at the scalp known as event-related potentials (ERPs). An ERP is the measured brain response resulting from a specific sensory, cognitive, or motor event. ERPs are measured using electroencephalography (EEG), a noninv


Language: The N400 in Semantic Incongruity

JoVE 10275

Source: Laboratories of Sarah I. Gimbel and Jonas T. Kaplan— University of Southern California

Understanding language is one of the most complex cognitive tasks that humans are capable of. Given the incredible amount of possible choices when combining individual words to form meaning in sentences, it is crucial that the brain is able to identify when words form coherent combinations and when an anomaly appears that undermines meaning. Extensive research has shown that certain scalp-recorded electrical events are sensitive to deviations in this kind of expectation. Importantly, these electrical signatures of incongruity are specific to unexpected meanings, and are therefore different from the brain's general responses to other kinds of anomalies. The neurophysiological correlates of semantic incongruity have been experimentally examined through the use of paradigms that present semantically congruent and incongruent ends to sentences. Originally introduced in 1980, the semantic incongruity task presents the participant with a series of sentences that end with either a congruent or incongruent word. To test that the response is from semantic incongruity and not more generally due to surprise, some sentences included words presented in a different size.1 The semantically incongrue


Decoding Auditory Imagery with Multivoxel Pattern Analysis

JoVE 10267

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California

Imagine the sound of a bell ringing. What is happening in the brain when we conjure up a sound like this in the "mind's ear?" There is growing evidence that the brain uses the same mechanisms for imagination that it uses for perception.1 For example, when imagining visual images, the visual cortex becomes activated, and when imagining sounds, the auditory cortex is engaged. However, to what extent are these activations of sensory cortices specific to the content of our imaginations? One technique that can help to answer this question is multivoxel pattern analysis (MPVA), in which functional brain images are analyzed using machine-learning techniques.2-3 In an MPVA experiment, we train a machine-learning algorithm to distinguish among the various patterns of activity evoked by different stimuli. For example, we might ask if imagining the sound of a bell produces different patterns of activity in auditory cortex compared with imagining the sound of a chainsaw, or the sound of a violin. If our classifier learns to tell apart the brain activity patterns produced by these three stimuli, then we can conclude that the auditory cortex is activated in a distinct


Tubal Cytology of the Fallopian Tube as a Promising Tool for Ovarian Cancer Early Detection

1Department of Pathology, University of Arizona College of Medicine, 2Department of Obstetrics and Gynecology, Henan Provincial People's Hospital, 3Department of Obstetrics and Gynecology, University of Arizona College of Medicine, 4University of Arizona Cancer Center, 5Department of Pathology, University of Texas Southwestern Medical Center, 6Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center

JoVE 55887


Movement-Related Changes in Cortico-Pallidal Coupling Revealed by Simultaneous Intracranial and Magnetoencephalography Recordings in Dystonia Patients

1Movement Disorders and Neuromodulation Unit, Department of Neurology, Charité - Universitätsmedizin Berlin, 2Department of Neurosurgery, Charité - Universitätsmedizin Berlin, 3Physikalisch-Technische Bundesanstalt, Institut Berlin

Video Coming Soon

JoVE 56659

 JoVE In-Press

Conscious and Non-conscious Representations of Emotional Faces in Asperger's Syndrome

1Institute of Statistical Science, Academia Sinica, 2Max Planck Institute for Human Cognitive and Brain Sciences, 3Department of Psychology, Fo Guang University, 4Department of Electrical Engineering, Fu Jen Catholic University, 5State Research Institute of Physiology and Basic Medicine, 6Novosibirsk State University, 7Imaging Research Center, Taipei Medical University

JoVE 53962


Object Substitution Masking

JoVE 10279

Source: Laboratory of Jonathan Flombaum—Johns Hopkins University

Visual masking is a term used by perceptual scientists to refer to a wide range of phenomena in which in an image is presented but not perceived by an observer because of the presentation of a second image. There are several different kinds of masking, many of them relatively intuitive and unsurprising. But one surprising and important type of masking is called Object Substitution Masking. It has been a focus of research in vision science since it was discovered, relatively recently, around 1997 by Enns and Di Lollo.1 This video will demonstrate standard procedures for how to conduct an object substitution experiment, how to analyze the results, and it will also explain the hypothesized causes for this unusual form of masking.

 Sensation and Perception

Decision-making and the Iowa Gambling Task

JoVE 10208

Source: Laboratories of Jonas T. Kaplan and Sarah I. Gimbel—University of Southern California

Decision-making is an important component of human executive function, in which a choice about a course of action or cognition is made from many possibilities. Damage to the inferior parts of the frontal lobes can affect a person's ability to make good decisions. However, while decision-making deficits can have a large impact on one's life, these deficits can be difficult to quantify in the laboratory. In the mid-1990s, a task was designed to mimic real life decision-making in the laboratory. This task, known as the Iowa Gambling Task (IGT), is a cognitively complex task used widely in research and clinical studies as a highly sensitive measure of decision-making ability.1-3 In the IGT, a participant is shown four decks of cards and chooses to reveal a card from one deck on each turn. When a card is turned over, the participant will receive some money, but sometimes will also be required to pay a penalty. Two of the decks have higher payoffs, but also have high penalties such that choosing from these decks leads to a net loss in the long term. The other two decks have lower payoffs, but also present smaller penalties, so that choosing from these decks leads to a net gain. Thus, to make an a


Assessment of Viability of Human Fat Injection into Nude Mice with Micro-Computed Tomography

1Hagey Laboratory for Pediatric Regenerative Medicine, Department of Surgery, Plastic and Reconstructive Surgery Division, Stanford University School of Medicine, 2Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine

JoVE 52217


Using fMRI to Dissect Moral Judgment

JoVE 10306

Source: William Brady & Jay Van Bavel—New York University

In examining the roles of reason and emotion in moral judgments, psychologists and philosophers alike point to the trolley dilemma and the footbridge dilemma. With the trolley dilemma, most people say that it is appropriate to pull a switch to stop a train from hitting five people by diverting it to kill one person. However, with the footbridge dilemma, most people say it is inappropriate to push a large man off of a bridge in order to hit a train (killing him) and stop it from running into five people. Reason would dictate that in both of the foregoing dilemmas, one life should be sacrificed to save five lives. But to many people, pushing the large man just “feels wrong” because it triggers more negative emotions than pulling a switch. In this case, emotion seems to trump reason.   In recent years, psychology and neuroscience have entered the debate over the roles of reason and emotion in moral judgment. Researchers can scan brain activity as individuals make making moral judgments. Research shows that different brain areas associated are active during contemplation of the footbridge dilemma versus the trolley dilemma. Inspired by Greene, Sommerville, Nystrom, Darley and Cohen, thi

 Social Psychology

More Results...