PubMed Health⌕ Search

Biomedical subjects

Stephen J Guastello

Publications and source records attributed to Stephen J Guastello.

10 recordsLinked to original sources
PubMed2007

The emergence of leadership in coordination-intensive groups.

Although group coordination was introduced to psychology in the early 1990s, it was not until the advent of nonlinear dynamical systems (NDS) that it was possible to gain an understanding of how the process of implicit learning and self-organization take place in conditions where no hierarchical (management) influences are involved. This experimental study examined how leaders might emerge from coordination-intensive task groups where verbal interaction is not possible. NDS and game-theoretical research indicate that the presence of leaders is not required to produce coordination. Thus the question remains as to whether leaders would emerge from coordination-intensive task groups in the similar manner to how they emerge from other types of groups. In the experiment, 13 4-person groups were allowed to discuss the coordination (card game) task while performing it; 13 other groups worked nonverbally. Split-plot ANOVA showed that verbalizing groups performed better than nonverbalizing groups overall and showed more acute coordination learning curves. Nonlinear regression for temporal dynamics within verbalizing and nonverbalizing groups showed asymptotic stability for initial coordination learning and transfer to a coordination rule of equal difficulty, but a chaotic function was observed when the teams switched to a more difficult coordination rule. A questionnaire measured leadership emergence at the end of the game along with other social contributions to the groups' efforts. The average level of leadership emergence for individuals did not differ between verbal and nonverbal conditions, although differences in other social contributions were observed. This experiment illustrates, furthermore, how the nonlinear science paradigm produces new hypotheses concerning verbalization that would not have been formulated otherwise. New avenues of study concerning coordination, leadership, and hierarchies are also discussed.

Adult↗
PubMed2007

Commentary on paradigms and key word index for NDPLS articles 1997-2006.

Although a paradigm shift in the sense of a postmodern worldview might be taking shape in society at large, the core concepts of nonlinear science date back a century, and are only tangentially influenced by other intellectual developments. Relative to contemporary science it offers new concepts concerning events that transpire over time, new hypotheses, new methods for answering new questions, some efficient answers, and a new perspective for understanding what we do not know in addition to knowing how we know what we know. Paradoxically, nonlinear science can be viewed as a narrow specialty within a specific discipline and as a general systems theory that identifies common themes that underlie phenomena found in a wide range of disciplines and specialties. The key word index illustrates the breadth of concepts and applications found in NDPLS, and some pathways for continued growth of the field.

Journal Article↗
PubMed2006

Electrodermal arousal between participants in a conversation: nonlinear dynamics and linkage effects.

Physiological linkages between two people in conversation were investigated from a nonlinear dynamical systems theory perspective. Thirty-seven pairs of college students engaged in a 20-minute discussion while connected to electrodes that measured their electrodermal response (ED). Greater incidents of linkage were detected through the nonlinear regression analysis compared to linear models. The nonlinear models were exponential structures that determined positive Lyapunov exponents (and thus the presence of chaos) for 73 out of 74 participants. Results support the use of nonlinear models for interpersonal linkage effects of this type. For each participant, Social Sensitivity from the Social Skills Inventory was correlated with the nonlinear model R(2) coefficient, but not with the size of the Lyapunov exponent. The latter results supported the conclusion that empathy acted as a moderator of the nonlinear process that underlies changes in ED levels over time.

Adult↗
PubMed2005

Origins of group coordination: nonlinear dynamics and the role of verbalization.

Coordination occurs when two or more people do the same or complimentary tasks simultaneously; its explanation game theory, nonlinear dynamics, and implicit learning theory. In the experiment, 12 four-person groups were allowed to discuss the coordination (card game) task while performing it; 12 other groups worked nonverbally. One to three group members were replaced during the game. Split-plot ANOVA showed that verbalizing groups performed better than nonverbalizing groups overall and showed more acute coordination learning curves, but verbalization did not compensate for the replacement of personnel. Groups that changed one or two players showed positive coordination transfer, but groups that changed three players did not. Nonlinear regression for temporal dynamics within verbalizing and nonverbalizing groups showed asymptotic stability for initial coordination learning and transfer to a difficult rule, a chaotic function when replacements were introduced, and asymptotic stability again when the team with replacements switched to the difficult rule.

Cooperative Behavior↗
PubMed2005

A rugged landscape model for self-organization and emergent leadership in creative problem solving and production groups.

The process by which an initially leaderless group differentiates into one containing leadership and secondary role structures was examined using the swallowtail catastrophe model and principles of selforganization. The objectives were to identify the control variables in the process of leadership emergence in creative problem solving groups and production groups. In the first of two experiments, groups of university students (total N = 114) played a creative problem solving game. Participants later rated each other on leadership behavior, styles, and variables related to the process of conversation. A performance quality measure was included also. Control parameters in the swallowtail catastrophe model were identified through a combination of factor analysis and nonlinear regression. Leaders displayed a broad spectrum of behaviors in the general categories of Controlling the Conversation and Creativity in their role-play. In the second experiment, groups of university students (total N = 197) engaged in a laboratory work experiment that had a substantial production goal component. The same system of ratings and modeling strategy was used along with a work production measure. Leaders in the production task emerged to the extent that they exhibited control over both the creative and production aspects of the task, they could keep tension low, and the externally imposed production goals were realistic.

Adult↗
PubMed2005

Statistical distributions and self-organizing phenomena: what conclusions should be drawn?

Some salient properties of the inverse power law distribution, the exponential distribution, catastrophe distributions, and the relationships among them were explored and compared. Self-organizing events may display any of these distributions. Catastrophe functions and their distributions do not display fractional (fractal) dimensions. Thus it is possible to have self-organization without the fractal. An empirical example from leadership emergence research illustrated a situation where a power law distribution provided a poor characterization of the data, but a swallowtail catastrophe model did so quite well. The results call into question some simplistic assumptions about the relationships among fractals, inverse power laws, self-organization and so-called pink noise.

Fractals↗
PubMed2004

Coordination learning in stag hunt games with application to emergency management.

Response teams for natural disaster emergencies require coordinated and self-organized efforts for rescue, medical services, damage containment, and evacuation. The unfolding of events depends on initial conditions of specific time, location, and preparedness of the response teams. This study considered a new range of emergency response situations where the perpetrator is a sentient attacker that learns with repeated exchanges. The strategy is conceptualized as a stag hunt coordination game on the part of the defense agents and a strictly competitive game with respect to the attacking adversary. Participants were 28 university students who played an iterative board game (The Creature that Ate Sheboygan) wherein a team of three Humans represented military and civil resources, against one Godzilla-type monster. The Monster gained points by destroying buildings and human combat power. The Humans gained points by wearing down the Monster's defenses and containing damage caused by the Monster. Experimental manipulations and empirical analysis showed the following: Communication outages among the Humans assisted the Monster, but the ability to communicate only equalized the Humans' chances rather than providing them with an advantage. Coordination among Humans was instant, but it fluctuated greatly as a result of the Monster's progress. Nonlinear analysis showed an asymptotic decline in coordination to a non-zero level in response to outcome uncertainty. Learning effects were noted for Humans and Monsters, but there were significant interactions with communication blackout conditions

Adult↗