Biological Psychology Commons^™

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 …

Difficult Turned Easy: Suggestion Renders A Challenging Visual Task Simple, Mathieu Landry, Jason Da Silva Castanheira, Jérôme Sackur, Amir Raz

Psychology Faculty Articles and Research

Suggestions can cause some individuals to miss or disregard existing visual stimuli, but can they infuse sensory input with nonexistent information? Although several prominent theories of hypnotic suggestion propose that mental imagery can change our perceptual experience, data to support this stance remain sparse. The present study addressed this lacuna, showing how suggesting the presence of physically absent, yet critical, visual information transforms an otherwise difficult task into an easy one. Here, we show how adult participants who are highly susceptible to hypnotic suggestion successfully hallucinated visual occluders on top of moving objects. Our findings support the idea that, at …

The Project Talent Twin And Sibling Study: Zygosity And New Data Collection, Carol A. Prescott, Ellen E. Walters, Thalida Em Arpawong, Catalina Zavala, Tara L. Gruenewald, Margaret Gatz

Psychology Faculty Articles and Research

The Project Talent Twin and Sibling (PTTS) study includes 4481 multiples and their 522 nontwin siblings from 2233 families. The sample was drawn from Project Talent, a U.S. national longitudinal study of 377,000 individuals born 1942–1946, first assessed in 1960 and representative of U.S. students in secondary school (Grades 9–12). In addition to the twins and triplets, the 1960 dataset includes 84,000 siblings from 40,000 other families. This design is both genetically informative and unique in facilitating separation of the ‘common’ environment into three sources of variation: shared by all siblings within a family, specific to twin-pairs, and associated with …

Positive Affect And Health: What Do We Know And Where Next Should We Go?, Sarah D. Pressman, Brooke N. Jenkins, Judith T. Moskowitz

Psychology Faculty Articles and Research

Positive affect (PA) is associated with better health across a wide range of physical health outcomes. This review reflects on why the study of PA is an essential component of our understanding of physical health and expands on pathways that connect these two variables. To encourage forward movement in this burgeoning research area, measurement and design issues in the study of PA and health are discussed, as are the connections between PA and a range of different health outcomes. Plausible biological, social, and behavioral pathways that allow for positive feelings to get under the skin and influence physical wellness are …

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 …

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, …

Entrainment Of Voluntary Movement To Undetected Auditory Regularities, Aaron Schurger, Nathan Faivre, Leila Cammoun, Bianca Trovó, Olaf Blanke

Psychology Faculty Articles and Research

In physics “entrainment” refers to the synchronization of two coupled oscillators with similar fundamental frequencies. In behavioral science, entrainment refers to the tendency of humans to synchronize their movements with rhythmic stimuli. Here, we asked whether human subjects performing a tapping task would entrain their tapping to an undetected auditory rhythm surreptitiously introduced in the guise of ambient background noise in the room. Subjects performed two different tasks, one in which they tapped their finger at a steady rate of their own choosing and one in which they performed a single abrupt finger tap on each trial after a delay …

Paradoxical Interaction Between Ocular Activity, Perception, And Decision Confidence At The Threshold Of Vision, Aaron Schurger

Psychology Faculty Articles and Research

In humans and some other species perceptual decision-making is complemented by the ability to make confidence judgements about the certainty of sensory evidence. While both forms of decision process have been studied empirically, the precise relationship between them remains poorly understood. We performed an experiment that combined a perceptual decision-making task (identifying the category of a faint visual stimulus) with a confidence-judgement task (wagering on the accuracy of each perceptual decision). The visual stimulation paradigm required steady fixation, so we used eye-tracking to control for stray eye movements. Our data analyses revealed an unexpected and counterintuitive interaction between the steadiness …

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 …

Placental Corticotropin-Releasing Hormone Mediates The Association Between Prenatal Social Support And Postpartum Depression, Jennifer Hahn-Holbrook, Christine Dunkel Schetter, Chander Arora, Calvin J. Hobel

Psychology Faculty Articles and Research

Three decades of research point to both biological and psychological risk factors for postpartum depression, but very little research integrates the two. This study bridged this gap by testing whether prenatal social support predicted depressive symptoms at 8 weeks postpartum in a multiethnic sample of 210 women and whether the stress hormone placental corticotropinreleasing hormone (pCRH), measured at 19, 29, and 37 weeks’ gestation, mediated this relationship. We found that prenatal family support predicted significantly fewer depressive symptoms postpartum and more gradual increases in pCRH from 29 to 37 weeks’ gestation. Furthermore, steeper increases in pCRH during this same period …

The Role Of Self‐Injury In The Organisation Of Behaviour, Curt A. Sandman, Aaron S. Kemp, Christopher Mabini, David Pincus, Magnus Magnusson

Psychology Faculty Articles and Research

Background—Self-injuring acts are among the most dramatic behaviours exhibited by human beings. There is no known single cause and there is no universally agreed upon treatment. Sophisticated sequential and temporal analysis of behaviour has provided alternative descriptions of self-injury that provide new insights into its initiation and maintenance.

Method—Forty hours of observations for each of 32 participants were collected in a contiguous two-week period. Twenty categories of behavioural and environmental events were recorded electronically that captured the precise time each observation occurred. Temporal behavioural/ environmental patterns associated with self-injurious events were revealed with a method (tpatterns; THEME) for …

Parental Precaution: Neurobiological Means And Adaptive Ends, Jennifer Hahn-Holbrook, Colin Holbrook, Martie G. Haselton

Psychology Faculty Articles and Research

Humans invest precious reproductive resources in just a few offspring, who remain vulnerable for an extended period of their lifetimes relative to other primates. Therefore, it is likely that humans evolved a rich precautionary psychology that assists in the formidable task of protecting offspring. In this review, we integrate precautionary behaviors during pregnancy and postpartum with the adaptive functions they may serve and what is known of their biological mediators, particularly brain systems motivating security and attachment. We highlight the role of reproductive hormones in (i) priming parental affiliation with young to incentivize offspring protection, (ii) focusing parental attention on …

Maternal Defense: Breastfeeding Heightens Aggression By Reducing Stress, Jennifer Hahn-Holbrook, Julianne Holt-Lunstad, Colin Holbrook, Sarah M. Coyne, E. Thomas Lawson

Psychology Faculty Articles and Research

Mothers in numerous species exhibit heightened aggression in defense of their young. This shift typically coincides with the duration of lactation in nonhuman mammals, which suggests that human mothers may display similarly accentuated aggressiveness while breast feeding. Here we report the first behavioral evidence for heightened aggression in lactating humans. Breast-feeding mothers inflicted louder and longer punitive sound bursts on unduly aggressive confederates than did formula-feeding mothers or women who had never been pregnant. Maternal aggression in other mammals is thought to be facilitated by the buffering effect of lactation on stress responses. Consistent with the animal literature, our results …

Functionality, Parsimony, Discovery, Avoiding Hamartia: How Evolutionary Perspectives Are Changing Psychology, Brooke N. Jenkins, Aaron T. Goetz

Psychology Faculty Articles and Research

Evolutionary psychology offers an important perspective to scientific psychology. Evolutionary psychology, in its short existence, has added an abundance of knowledge to the social sciences, let alone psychology. The study of human cognition and behavior remains incomplete without an evolutionary perspective. Here, we argue that evolutionary psychology uniquely provides a complete understanding of scientific psychology because it explains the functions of our psychological traits, provides us with the most parsimonious explanation of many psychological phenomena, predicts undocumented phenomena, and possibly allows us to avoid the downfalls of some of our contemptible evolved psychological mechanisms.

Evidence For Menstrual Cycle Shifts In Women’S Preferences For Masculinity: A Response To Harris (In Press) “Menstrual Cycle And Facial Preferences Reconsidered", Lisa Debruine, Benedict C. Jones, David Frederick, Martie Haselton, Ian S. Penton-Voak, David I. Perrett

Psychology Faculty Articles and Research

Over the last decade, a growing literature has shown that women in the fertile phase of the menstrual cycle demonstrate stronger preferences for men with masculine traits than they do when in the non-fertile phases of the cycle (see Gangestad and Thornhill, 2008 and Jones et al., 2008 for recent reviews). In a recent article, Harris (in press; Sex Roles) failed to replicate this increase in women's preferences for masculine faces when women are near ovulation. Harris represented her study as one of only three studies on the topic, and as the largest of the existing studies. There are, however, …