Neurosciences Commons^™

Consciousness Explained Or Described?, Aaron Schurger, Michael S. A. Graziano

Psychology Faculty Articles and Research

Consciousness is an unusual phenomenon to study scientifically. It is defined as a subjective, first-person phenomenon, and science is an objective, third-person endeavor. This misalignment between the means—science—and the end—explaining consciousness—gave rise to what has become a productive workaround: the search for ‘neural correlates of consciousness’ (NCCs). Science can sidestep trying to explain consciousness and instead focus on characterizing the kind(s) of neural activity that are reliably correlated with consciousness. However, while we have learned a lot about consciousness in the bargain, the NCC approach was not originally intended as the foundation for a true explanation of consciousness. Indeed, it …

What Is The Readiness Potential?, Aaron Schurger, Pengbo 'Ben' Hu, Joanna Pak, Adina L. Roskies

Psychology Faculty Articles and Research

The readiness potential (RP) has been widely interpreted to indicate preparation for movement and is used to argue that our brains decide before we do. It thus has been a fulcrum for discussion about the neuroscience of free will.

Recent computational models provide an alternative framework for thinking about the significance of the RP, suggesting instead that the RP is a natural result of the operation of a stochastic accumulator process of decision-making, analyzed by time-locking to threshold-crossing events.

These models call for a reevaluation of: (i) the ontological standing of the RP as reflecting a real, causally efficacious signal …

Aberrant Maturation Of The Uncinate Fasciculus Follows Exposure To Unpredictable Patterns Of Maternal Signals, Steven J. Granger, Laura M. Glynn, Curt A. Sandman, Steven L. Small, Andre Obenaus, David B. Keator, Tallie Z. Baram, Hal S. Stern, Michael A. Yassa, Elyssia Poggi Davis

Psychology Faculty Articles and Research

Across species, unpredictable patterns of maternal behavior are emerging as novel predictors of aberrant cognitive and emotional outcomes later in life. In animal models, exposure to unpredictable patterns of maternal behavior alters brain circuit maturation and cognitive and emotional outcomes. However, whether exposure to such signals in humans alters the development of brain pathways is unknown. In mother–child dyads, we tested the hypothesis that exposure to more unpredictable maternal signals in infancy is associated with aberrant maturation of corticolimbic pathways. We focused on the uncinate fasciculus, the primary fiber bundle connecting the amygdala to the orbitofrontal cortex and a key …

An Integration-To-Bound Model Of Decision-Making That Accounts For The Spectral Properties Of Neural Data, Ramón Guevara Erra, Marco Arbotto, Aaron Schurger

Psychology Faculty Articles and Research

Integration-to-bound models are among the most widely used models of perceptual decision-making due to their simplicity and power in accounting for behavioral and neurophysiological data. They involve temporal integration over an input signal (“evidence”) plus Gaussian white noise. However, brain data shows that noise in the brain is long-term correlated, with a spectral density of the form 1/fα (with typically 1 < α < 2), also known as pink noise or ‘1/f’ noise. Surprisingly, the adequacy of the spectral properties of drift-diffusion models to electrophysiological data has received little attention in the literature. Here we propose a model of accumulation of evidence for decision-making that takes into consideration the spectral properties of brain signals. We develop a generalization of the leaky stochastic accumulator model using a Langevin equation whose non-linear noise term allows for varying levels of autocorrelation in the time course of the decision variable. We derive this equation directly from magnetoencephalographic data recorded while subjects performed a spontaneous movement initiation task. We then propose a nonlinear model of accumulation of evidence that accounts for the ‘1/f’ spectral properties of brain signals, and the observed variability in the power spectral properties of brain signals. Furthermore, our model outperforms the standard drift-diffusion model at approximating the empirical waiting time distribution.

Measuring Neural Time Series Data In A Sensory Deprivation Tank, Jackson Gregory, Tian Lan, Uri Maoz, Amir Raz

Student Scholar Symposium Abstracts and Posters

We are interested in studying the neurological and physiological effects of the float pod, also known as REST therapy, or sensory deprivation tank. Float pods rely on the concept of depriving most senses (from sound and light to temperature and proprioception) in a pool filled with buoyant salt water at body temperature. While float pods are most commonly used in spa environments, we intend to look at the potential benefits of floating under the empirical lens. In this study, we aim to measure neural activity using electroencephalography (EEG). We intend to look at the different levels of relaxation and the …

Does It Matter Whether You Or Your Brain Did It? An Empirical Investigation Of The Influence Of The Double Subject Fallacy On Moral Responsibility Judgments, Uri Maoz, Kellienne R. Sita, Jeroen J. A. Van Boxtel, Liad Mudrik

Psychology Faculty Articles and Research

Despite progress in cognitive neuroscience, we are still far from understanding the relations between the brain and the conscious self. We previously suggested that some neuroscientific texts that attempt to clarify these relations may in fact make them more difficult to understand. Such texts—ranging from popular science to high-impact scientific publications—position the brain and the conscious self as two independent, interacting subjects, capable of possessing opposite psychological states. We termed such writing ‘Double Subject Fallacy’ (DSF). We further suggested that such DSF language, besides being conceptually confusing and reflecting dualistic intuitions, might affect people’s conceptions of moral responsibility, lessening the …

Mooney Face Stimuli For Visual Perception Research, Caspar M. Schwiedrzik, Lucia Melloni, Aaron Schurger

Psychology Faculty Articles and Research

In 1957, Craig Mooney published a set of human face stimuli to study perceptual closure: the formation of a coherent percept on the basis of minimal visual information. Images of this type, now known as "Mooney faces", are widely used in cognitive psychology and neuroscience because they offer a means of inducing variable perception with constant visuospatial characteristics (they are often not perceived as faces if viewed upside down). Mooney's original set of 40 stimuli has been employed in several studies. However, it is often necessary to use a much larger stimulus set. We created a new set of over …

Treating Adhd With Suggestion: Neurofeedback And Placebo Therapeutics, Robert T. Thibault, Samuel Vassière, Jay A. Olson, Amir Raz

Psychology Faculty Articles and Research

Objective: We propose that clinicians can use suggestion to help treat conditions such as ADHD. Methods: We use EEG neurofeedback as a case study, alongside evidence from a recent pilot experiment utilizing a sham MRI scanner to highlight the therapeutic potential of suggestion-based treatments. Results: The medical literature demonstrates that many practitioners already prescribe treatments that hardly outperform placebo comparators. Moreover, the sham MRI experiment showed that, even with full disclosure of the procedure, suggestion alone can reduce the symptomatology of ADHD. Conclusion: Non-deceptive suggestion-based treatments, especially those drawing on accessories from neuroscience, may offer a safe complement and potential …

Network Specialization During Adolescence: Hippocampal Effective Connectivity In Boys And Girls, Jeffrey D. Riley, E. Elinor Chen, Jessica Winsell, Elyssia Poggi Davis, Laura M. Glynn, Tallie Z. Baram, Curt A. Sandman, Steven L. Small, Ana Solodkin

Psychology Faculty Articles and Research

Adolescence is a complex period of concurrent mental and physical development that facilitates adult functioning at multiple levels. Despite the growing number of neuroimaging studies of cognitive development in adolescence focusing on regional activation patterns, there remains a paucity of information about the functional interactions across these participating regions that are critical for cognitive functioning, including memory. The current study used structural equation modeling (SEM) to determine how interactions among brain regions critical for memory change over the course of adolescence. We obtained functional MRI in 77 individuals aged 8–16 years old, divided into younger (ages 8–10) and older (ages …

Volition And Action In The Human Brain: Processes, Pathologies, And Reasons, Itzhak Fried, Patrick Haggard, Biyu J. He, Aaron Schurger

Psychology Faculty Articles and Research

Humans seem to decide for themselves what to do, and when to do it. This distinctive capacity may emerge from an ability, shared with other animals, to make decisions for action that are related to future goals, or at least free from the constraints of immediate environmental inputs. Studying such volitional acts proves a major challenge for neuroscience. This review highlights key mechanisms in the generation of voluntary, as opposed to stimulus-driven actions, and highlights three issues. The first part focuses on the apparent spontaneity of voluntary action. The second part focuses on one of the most distinctive, but elusive, …

On Reporting The Onset Of The Intention To Move, Uri Maoz, Liad Mudrik, Ram Rivlin, Ian Ross, Adam Mamelak, Gideon Yaffe

Psychology Faculty Books and Book Chapters

"In 1965, Hans Kornhuber and Luder Deecke made a discovery that greatly influenced the study of voluntary action. Using electroencephalography (EEG), they showed that when aligning some tens of trials to movement onset and averaging, a slowly decreasing electrical potential emerges over central regions of the brain. It starts 1 second ( s) or so before the onset of the voluntary action1 and continues until shortly after the action begins. They termed this the Bereitschaftspotential, or readiness potential (RP; Kornhuber & Deecke, 1965).2 This became the first well-established neural marker of voluntary action. In that, the RP allowed for more …

“Me & My Brain”: Exposing NeuroscienceʼS Closet Dualism, Liad Mudrik, Uri Maoz

Psychology Faculty Articles and Research

Our intuitive concept of the relations between brain and mind is increasingly challenged by the scientific world view. Yet, although few neuroscientists openly endorse Cartesian dualism, careful reading reveals dualistic intuitions in prominent neuroscientific texts. Here, we present the “double-subject fallacy”: treating the brain and the entire person as two independent subjects who can simultaneously occupy divergent psychological states and even have complex interactions with each other—as in “my brain knew before I did.” Although at first, such writing may appear like harmless, or even cute, shorthand, a closer look suggests that it can be seriously misleading. Surprisingly, this confused …

Increasing Parity Is Associated With Cumulative Effects On Memory, Laura M. Glynn

Psychology Faculty Articles and Research

BACKGROUND: The purpose of this investigation was to determine if reproductive experience is associated with cumulative effects on human memory performance during pregnancy and if these effects persist into the postpartum period.

METHODS: Verbal recall memory performance was assessed in 254 women four times during pregnancy and at 3 months postpartum. The relation between parity and memory function was evaluated with hierarchical linear modeling and analysis of covariance (ANCOVA).

RESULTS: The data indicate that the previously documented adverse effects of pregnancy on memory performance are compounded with successive pregnancies. During gestation and postpartum, multiparity was associated with poorer memory function, …