Damian G Kelty-Stephen

Damian G Kelty-Stephen
State University of New York at New Paltz | SUNY New Paltz · Department of Psychology

Ph.D. Experimental Psychology

About

140
Publications
69,391
Reads
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2,365
Citations
Additional affiliations
August 2017 - May 2021
Grinnell College
Position
  • Professor (Assistant)
July 2013 - July 2017
Grinnell College
Position
  • Professor (Assistant)
December 2011 - June 2013
Harvard University
Position
  • Staff Research Scientist
Education
August 2005 - May 2010
University of Connecticut
Field of study
  • Psychology
August 2001 - May 2005
College of William and Mary
Field of study
  • Psychology

Publications

Publications (140)
Article
Full-text available
Ergodicity breaking is a challenge for biological and psychological sciences. Ergodicity is a necessary condition for linear causal modeling. Long-range correlations and non-Gaussianity characterizing various biological and psychological measurements break ergodicity routinely, threatening our capacity for causal modeling. Long-range correlations (...
Article
Full-text available
Turing inspired a computer metaphor of the mind and brain that has been handy and has spawned decades of empirical investigation, but he did much more and offered behavioral and cognitive sciences another metaphor—that of the cascade. The time has come to confront Turing’s cascading instability, which suggests a geometrical framework driven by powe...
Preprint
Full-text available
Ergodicity breaking is a challenge for biological and psychological sciences. Ergodicity is a necessary condition for linear causal modeling. Long-range correlations and non-Gaussianity characterizing various biological and psychological measurements break ergodicity routinely, threatening our capacity for causal modeling. Long-range correlations (...
Preprint
Full-text available
The brain-as-computer metaphor has anchored the professed computational nature of mind, wresting it down from the intangible logic of Platonic philosophy to a material basis for empirical science. However, as with many long-lasting metaphors in science, the computer metaphor has been explored and stretched long enough to reveal its boundaries. Thes...
Article
Full-text available
The creativity and emergence of biological and psychological behavior tend to be nonlinear—biological and psychological measures contain degrees of irregularity. The linear model might fail to reduce these measurements to a sum of independent random factors (yielding a stable mean for the measurement), implying nonlinear changes over time. The pres...
Preprint
Full-text available
Turing inspired a computer metaphor of the mind and brain that has been handy and has spawned decades of empirical investigation, but he did much more and offered behavioral and cognitive sciences another metaphor—that of the cascade. The time has come to confront Turing’s cascading instability, which suggests a geometrical framework driven by powe...
Article
Full-text available
The stochastic processes underlying the growth and stability of biological and psychological systems reveal themselves when far from equilibrium. Far from equilibrium, nonergodicity reigns. Nonergodicity implies that the average outcome for a group/ensemble (i.e., of representative organisms/minds) is not necessarily a reliable estimate of the aver...
Preprint
Full-text available
The stochastic processes underlying the growth and stability of biological and psychological systems reveal themselves when far from equilibrium. Far from equilibrium, nonergodicity reigns. Nonergodicity implies that the average outcome for a group/ensemble (i.e., of representative organisms/minds) is not necessarily a reliable estimate of the aver...
Article
Full-text available
The ubiquity of tool use in human life has generated multiple lines of scientific and philosophical investigation to understand the development and expression of humans’ engagement with tools and its relation to other dimensions of human experience. However, existing literature on tool use faces several epistemological challenges in which the same...
Preprint
Full-text available
We see the computer metaphor of the brain as a holdover from premodern scientific traditions hoping to anchor the mind’s computational ability in a material anatomical part. Despite having prompted decades of valuable empirical insights, the computer metaphor has likely outgrown its usefulness. Brains are context-sensitive and capable of adapting t...
Preprint
Full-text available
The ubiquity of tool use in human life has generated multiple lines of scientific and philosophical investigation to understand the development and expression of humans’ engagement with tools and its relation to other dimensions of human experience. However, existing literature on tool use faces several epistemological challenges in which the same...
Article
Full-text available
Speech perception and memory for speech require active engagement. Gestural theories have emphasized mainly the effect of speaker's movements on speech perception. They fail to address the effects of listener movement, focusing on communication as a boundary condition constraining movement among interlocutors. The present work attempts to break new...
Preprint
Full-text available
The creativity and emergence of biological and psychological behavior tend to be nonlinear—biological and psychological measures contain degrees of irregularity. The linear model might fail to reduce these measurements to a sum of independent random factors (yielding a stable mean for the measurement), implying nonlinear changes over time. The pres...
Article
Full-text available
When humans handle a tool, such as a tennis racket or hammer, for the first time, they often wield it to determine its inertial properties. The mechanisms that contribute to perception of inertial properties are not fully understood. The present study’s goal was to investigate how proprioceptive afferents contribute to effortful perception of heavi...
Preprint
Full-text available
Speech perception and memory for speech require active engagement. Gestural theories have emphasized mainly the effect of the movements of the speaker on speech perception. They fail to address the effects of listener movement, focusing on communication as a boundary condition constraining movement among interlocutors. The present work attempts to...
Article
Full-text available
Quiet standing exhibits strongly intermittent variability that has inspired at least two interpretations. First, variability can be intermittent through the alternating engagement and disengagement of complementary control processes at distinct scales. A second and perhaps deeper way to interpret this intermittency is through the possibility that p...
Article
Full-text available
Modern biomedical, behavioral and psychological inference about cause-effect relationships respects an ergodic assumption, that is, that mean response of representative samples allow predictions about individual members of those samples. Recent empirical evidence in all of the same fields indicates systematic violations of the ergodic assumption. I...
Article
Full-text available
Visually guided postural control emerges in response to task constraints. Task constraints generate physiological fluctuations that foster the exploration of available sensory information at many scales. Temporally correlated fluctuations quantified using fractal and multifractal metrics have been shown to carry perceptual information across the bo...
Article
Full-text available
The ‘quiet eye’ (QE) approach to visually-guided aiming behavior invests fully in perceptual information’s potential to organize coordinated action. Sports psychologists refer to QE as the stillness of the eyes during aiming tasks and increasingly into self- and externally-paced tasks. Amidst the ‘noisy’ fluctuations of the athlete’s body, quiet ey...
Article
Full-text available
We tested for transposition effects (TEs) in Hindi (a Modern Indo-Aryan language) using unprimed lexical decision. TEs are less accurate and slower responses to transposed-nonwords (e.g., ‹PSATE›, formed from base-word ‹PASTE›) than corresponding replaced-nonwords (e.g., ‹PLUTE›). In Hindi’s orthography, letters map transparently to phonemes (excep...
Article
Full-text available
Intermittency is a flexible control process entailing context-sensitive engagement with task constraints. The present work aims to situate the intermittency of dexterous behavior explicitly in multifractal modeling for non-Gaussian cascade processes. Multiscale probability density function (PDF) analysis of the center of pressure (CoP) fluctuations...
Article
Full-text available
Standing still and focusing on a visible target in front of us is a preamble to many coordinated behaviors (e.g., reaching an object). Hiding behind its apparent simplicity is a deep layering of texture at many scales. The task of standing still laces together activities at multiple scales: from ensuring that a few photoreceptors on the retina cove...
Article
Full-text available
Healthy human postural sway exhibits strong intermittency, reflecting a richly interactive foundation of postural control. From a linear perspective, intermittent fluctuations might be interpreted as engagement and disengagement of complementary control processes at distinct timescales or from a nonlinear perspective, as cascade-like interactions a...
Preprint
Full-text available
Intermittency is a flexible control process entailing context-sensitive engagement with task constraints. The present work aims to situate the intermittency of dexterous behavior explicitly in multifractal modeling for non-Gaussian cascade processes. Multiscale probability density function (PDF) analysis of the center of pressure (CoP) fluctuations...
Preprint
Full-text available
As a hallmark of dexterity, intermittency warrants explicit acknowledgment in models of dexterous behavior. However, intermittency poses a major challenge to modeling itself. The present work aims to situate investigation of intermittency on a firmer multifractal footing. In a previous study (Furmanek et al., 2020), multiscale probability density f...
Preprint
Full-text available
Modern biomedical, behavioral and psychological inference about cause-effect relationships respects an ergodic assumption, that is, that mean response of representative samples allow predictions about individual members of those samples. Recent empirical evidence in all of the same fields indicates systematic violations of the ergodic assumption. I...
Preprint
Full-text available
The ‘quiet eye’ (QE) approach to visually-guided aiming behavior invests fully in perceptual information's potential to organize coordinated action. Sports psychologists refer to QE as the stillness of the eyes during aiming tasks and increasingly into self- and externally-paced tasks. Amidst the ‘noisy’ fluctuations of the athlete’s body, quiet ey...
Article
Full-text available
Vector autoregression (VAR) modeling allows probing bidirectional relationships in gender/sex development and may support hypothesis testing following multi-modal data collection. We show VAR in three lights: supporting a hypothesis, rejecting a hypothesis, and opening up new questions. To illustrate these capacities of VAR, we reanalyzed longitudi...
Preprint
Full-text available
Standing still and focusing on a visible target in front of us is a preamble to many coordinated behaviors (e.g., reaching an object). Hiding behind its apparent simplicity is a deep layering of texture at many scales. The task of standing still laces together activities at multiple scales: from ensuring that a few photoreceptors on the retina cove...
Preprint
Full-text available
A growing consensus across otherwise disparate perspectives on perception and action is that visually guided postural control emerges from within task constraints. Task constraints generate physiological fluctuations across various parts of the body. These fluctuations foster exploration of the available sensory information. For instance, standard...
Article
Full-text available
Research into haptic perception typically concentrates on mechanoreceptors and their supporting neuronal processes. This focus risks ignoring crucial aspects of active perception. For instance, bodily movements influence the information available to mechanoreceptors, entailing that movement facilitates haptic perception. Effortful manual wielding o...
Preprint
Full-text available
Healthy human postural sway exhibits strong intermittency, reflecting a richly interactive foundation of postural control. From a linear perspective, intermittent fluctuations might be interpreted as engagement and disengagement of complementary control processes at distinct timescales or from a nonlinear perspective, as cascade-like interactions a...
Preprint
Full-text available
Quiet standing exhibits strongly intermittent variability reflecting a richly interactive foundation. This intermittency can be understood in various ways. First, variability can be intermittent through the engagement and disengagement of complementary control processes at distinct scales. A second and perhaps a deeper way to understand this interm...
Preprint
Full-text available
Research into haptic perception typically concentrates on mechanoreceptors and their supporting neuronal processes. This focus risks ignoring crucial aspects of active perception. For instance, bodily movements influence the information available to mechanoreceptors, entailing that movement facilitates haptic perception. Effortful manual wielding o...
Article
Full-text available
Effortful touch by the hand is essential to engaging with and perceiving properties of objects. The temporal structure of whole-body coordination must reflect the prospective control that provides for both the engagement with and perception of properties of the hefted objects. In the present study, we found signatures of multifractality in the time...
Article
Objective To define static, dynamic, and cognitive fit and their interactions as they pertain to exosystems and to document open research needs in using these fit characteristics to inform exosystem design. Background Initial exosystem sizing and fit evaluations are currently based on scalar anthropometric dimensions and subjective assessments. As...
Preprint
Full-text available
Vector autoregression (VAR) modeling allows probing bidirectional relationships in gender development and may support hypothesis testing following multi-modal data collection. We show VAR in three lights: supporting a hypothesis, rejecting a hypothesis, and opening up new questions. To illustrate these capacities of VAR, we reanalyzed longitudinal...
Preprint
Full-text available
A long history of research has pointed to the importance of fractal fluctuations in physiology, but so far, the physiological evidence of fractal fluctuations has been piecemeal and without clues to bodywide integration. What remains unknown is how fractal fluctuations might interact across the body and how those interactions might support the coor...
Article
Full-text available
Movement coordination depends on directing our limbs to the right place and in the right time. Movement science can study this central requirement in the Fitts task that asks participants to touch each of two targets in alternation, as accurately and as fast as they can. The Fitts task is an experimental attempt to focus on how the movement system...
Article
Full-text available
Children with Attention-Deficit Hyperactivity Disorder (ADHD) struggle to perform a host of daily activities. Many of these involve forceful interaction with objects and thus implicate dynamic touch. Therefore, deficits in dynamic touch could underlie functional difficulties presented by ADHD children. We investigated whether performance on a dynam...
Article
Full-text available
The applied muscular effort to wield, hold, or balance an object shapes the medium by which action-relevant perceptual judgments (e.g., heaviness, length, width, and shape) are derived. Strikingly, the integrity of these judgments is retained over a range of exploratory conditions, a phenomenon known as perceptual invariance. For instance, judgment...
Data
Complete list of embedded models from Hypotheses 1 and 2. (DOCX)
Data
Description of data file. (DOCX)
Article
Full-text available
By definition, perception is a multisensory process that unfolds in time as a complex sequence of exploratory activities of the organism. In such a system perception and action are integrated, and multiple energy arrays are available simultaneously. Perception of affordances interweaves sensory and motor activities into meaningful behavior given ta...
Article
Full-text available
Collaboration with undergraduate students at a small liberal-arts college has accelerated our research programs. Liberal-arts students bring interdisciplinary flair—or sometimes just a fresh perspective not yet pigeonholed by post-graduate specialization. Liberal-arts students come from diverse backgrounds and reach beyond their comfort zones to tr...
Article
Full-text available
Reading research uses different tasks to investigate different levels of the reading process, such as word recognition, syntactic parsing, or semantic integration. It seems to be tacitly assumed that the underlying cognitive process that constitute reading are stable across those tasks. However, nothing is known about what happens when readers swit...
Presentation
Full-text available
Gender science epitomises the complexity of goal-directed experience: it exemplifies nonlinear interaction across many scales of space and time. Nonlinear dynamics provides a particularly good geometry-called "multifractal"-for quantifying, modelling, and predicting such interactions across scales of space and time. That sounds complex which I regr...
Article
Full-text available
INTRODUCTION: Human-spacesuit fit is not well understood, especially the relation to operational performance and injury risk. Current fit decisions use subjective feedback. This work developed and evaluated new metrics for quantifying fit and assessed metric sensitivity to changes in padding between the human and hip brief assembly (HBA). METHODS:...
Article
Full-text available
Movement science is a field that is quickly growing in its scope, leaning heavily on psychological expertise for research design with human participants but requiring computational and engineering ability. Undergraduate psychology curricula are in a unique position to train some of its future scholars. This report reviews an attempt to pilot a clas...
Data
Model predictions representing the effects of multifractality WMF × tMF as well as its interactions with Precursor, with entropy measures ψ and ξ on the mouse-tracking measure of area under the curve (AUC). These ψ × ξ × WMF × tMF × Precursor interaction effects on AUC manifested differently across all context conditions: in real-speech context (le...
Data
All coefficients from Poisson regression predicting cumulative “GA” responses without any block or trial effects.
Data
Coefficients from Poisson regression of trial-by-trial x-position flips.
Data
Model predictions representing the effects of multifractal-based nonlinear estimate tMF as well as its interactions with Precursor, with entropy measures ψ and ξ on the mouse-tracking measure of maximum displacement (MD). These ψ × ξ × tMF×Precursor interaction effects on MD manifested differently across all context conditions: in real-speech conte...
Data
Model predictions representing the effects of multifractality WMF and its interactions with slow entropy ψ × WMF, with fast entropy ξ × WMF, and with precursor Precursor × WMF on x-position flips. Panels show predictions specific to real-speech contexts (top left and in solid black), simulated-speech contexts (top right and in dashed black), and to...
Data
All coefficients from logistic regression predicting “GA” vs. “DA” without any block or trial effects.
Data
All coefficients from Poisson regression predicting cumulative “GA” responses with block or trial effects.
Data
Significant effects (p < 0.05) from linear regression of trial-by-trial area under the curve (AUC).
Data
Model predictions representing the effects of multifractality WMF as well as its interactions with Precursor, with entropy measures ψ and ξ on the mouse-tracking measure of maximum displacement (MD). These ψ × ξ × WMF×Precursor interaction effects on MD manifested differently across all context conditions: in real-speech context (left panel), in si...
Data
Significant effects (p < 0.05) from linear regression of trial-by-trial maximum displacement (MD).
Article
Movement science is a field that is quickly growing in its scope, leaning heavily on psychological expertise for research design with human participants but requiring computational and engineering ability. Undergraduate psychology curricula are in a unique position to train some of its future scholars. This report reviews an attempt to pilot a clas...
Preprint
Full-text available
The milkshake acting like a computer is an idea that appeared on my stupid professional website ten years ago when I was first struggling to begin a straight-faced professional, academic “web presence.” This text here has no new empirical evidence and is not an attempt to develop theory in any way. It is an attempt to thank the digital community of...