Paul J Treffner - Academia.edu (original) (raw)
Papers by Paul J Treffner
Transportation Research Part F: Traffic Psychology and Behaviour, 2004
Using a closed-circuit driving track environment, we investigated the influence of using a hands-... more Using a closed-circuit driving track environment, we investigated the influence of using a hands-free mobile (or cell) phone on various biomechanical and perceptual factors that underlie the control of driving. Results showed that in three tasks representative of everyday driving conditions, the perceptual control of action was compromised when compared to a control condition where no mobile phone conversation was present. While conversing, critical control actions related to braking were postponed on approach to a corner. During controlled braking, as when approaching a stationary car at a traffic light, the degree of braking was reduced and braking style was altered in a non-optimal manner. During an obstacle avoidance task, car dynamics were affected as a result of the conversation. Interpretation of the results is motivated by the ecological approach to perception-action and the theory of affordances. It is concluded that a driverÕs sensitivity to prospective information about upcoming events and the associated perception and awareness of what the road environment affords may both significantly be degraded when simultaneously using a handsfree mobile phone.
Journal of Experimental Psychology: Human Perception and Performance, 1995
Human handedness was investigated in a 1:1 interlimb rhythmic coordination in which consistent an... more Human handedness was investigated in a 1:1 interlimb rhythmic coordination in which consistent and inconsistent left-handed and right-handed individuals oscillated hand-held pendulums. Mean phase difference (φstable) and its standard deviation (SD φ) were evaluated as functions of mode of coordination (in-phase vs. anti-phase) and the symmetry conditions imposed by controlling the natural frequencies of the left and right pendulums. The
Journal of Experimental Psychology: Human Perception and Performance, 2000
Journal of Experimental Psychology: Human Perception and Performance, 1991
Journal of Experimental Psychology: Human Perception and Performance, 1997
Predictions concerning the effects of handedness and attention on bimanual coordination were made... more Predictions concerning the effects of handedness and attention on bimanual coordination were made from a dynamical model that incorporates the body's lateral asymmetry. Both handedness and the direction of attention (to the left or right) were manipulated in an inphase 1:1 frequency locking task. Left-handed and right-handed participants had to coordinate the planar oscillations of 2 handheld pendulums while 1 pendulum oscillated between spatial targets positioned over either the left or right hand. Predictions from the model were that participants would show a phase lead with the preferred hand, and that, although the phase lead would be greater when attention was directed to the preferred hand, the variability of relative phase would be lower. Confirmation of these predictions suggests that the dynamical perspective offers the possibility of studying handedness and attention without compromising theoretical precision or experimental control.
![Research paper thumbnail of Erratum to “Intentional and attentional dynamics of speech–hand coordination” [Human Movement Science 21, nos. 5–6, pp. 641–697]](https://attachments.academia-assets.com/95943626/thumbnails/1.jpg)
](Human Movement Science, 2003
Human Movement Science, 2002
Interest is rapidly growing in the hypothesis that natural language emerged from a more primitive... more Interest is rapidly growing in the hypothesis that natural language emerged from a more primitive set of linguistic acts based primarily on manual activity and hand gestures. Increasingly, researchers are investigating how hemispheric asymmetries are related to attentional and manual asymmetries (i.e., handedness). Both speech perception and production have origins in the dynamical generative movements of the vocal tract known as articulatory gestures. Thus, the notion of a ''gesture'' can be extended to both hand movements and speech articulation. The generative actions of the hands and vocal tract can therefore provide a basis for the (direct) perception of linguistic acts. Such gestures are best described using the methods of dynamical systems analysis since both perception and production can be described using the same commensurate language. Experiments were conducted using a phase transition paradigm to examine the coordination of speech-hand gestures in both left-and right-handed individuals. Results address coordination (in-phase vs. anti-phase), hand (left vs. right), lateralization (left vs. right hemisphere), focus of attention (speech vs. tapping), and how dynamical constraints provide a foundation for human communicative acts. Predictions from the asymmetric HKB equation confirm the attentional basis of functional asymmetry. Of significance is a new understanding of the role of perceived synchrony (p-centres) during intentional cases of gestural coordination.
Ecological Psychology, 2008
We investigated how a listener's perceived meaning of a spoken sentence is influenced by the rela... more We investigated how a listener's perceived meaning of a spoken sentence is influenced by the relative timing between a speaker's speech and accompanying hand gestures. Participants viewed a computer-animated character who uttered the phrase, "Put the book there now." while executing a simple right-handed beat gesture whose location relative to the utterance was precisely controlled in a frame-by-frame fashion. The participant's task consisted of making a judgment about two related aspects of the actor's perceived speech: (a) Which word was emphasized? and (b) How clear was the emphasis? That is, did it make sense? The results revealed that the perceived emphasis was determined by the timing (phasing) of the speaker's hand gesture. Furthermore, the clarity of the perceived emphasis (i.e., meaningfulness) was influenced by the affordances in the immediate environment of the speaker. Discussion addresses the primacy of ostensive specification and gesture in communicative events, the dynamics of speech-hand coordination during both actual and virtual dialogue, and the role of environmental affordances in grounding informative communicative acts in the ecology of organism-environment dynamics. The question of the extent to which hand gestures (and other movements sometimes referred to as "body language") might provide a basis for human communication continues to challenge theories of language and language development. The fact that most of us move our hands in spontaneous gesture even if we cannot be seen, for example when talking to a blind person or to someone by telephone (Iverson & Goldin-Meadow, 1997), suggests that a speaker's accompanying hand
Ecological Psychology, 1999
ABSTRACT
Behavioral and Brain Sciences, 1996
We show that left-handers can be considered as a “special” population. We indicate that the asymm... more We show that left-handers can be considered as a “special” population. We indicate that the asymmetries in performance exhibited by left-handers are due to a basic asymmetry in the underlying coordination dynamics that constrains bimanual coordination. In contrast to the claims of Latash & Anson, we argue that considerable knowledge has been gained regarding the essential equations of motion that govern biological coordination.
Handedness and attentional asymmetries in bimanual rhythmic coordination were examined as a funct... more Handedness and attentional asymmetries in bimanual rhythmic coordination were examined as a function of movement speed. In an in-phase 1: 1 frequency locking task, left-handed and right-handed subjects controlled the oscillations of either the right or the left hand so as to contact spatial targets. The task was performed at three frequencies of coupled movement. Coordination dynamics incorporating the body's functional asymmetry predicted that left-handers and right-handers would deviate from zero relative phase in opposite ...
Motor Control, 1997
Handedness and attentional asymmetries in bimanual rhythmic coordination were examined as a funct... more Handedness and attentional asymmetries in bimanual rhythmic coordination were examined as a function of movement speed. In an in-phase 1:1 frequency locking task, left-handed and right-handed subjects controlled the oscillations of either the right or the left hand so as to contact spatial targets. The task was performed at three frequencies of coupled movement. Coordination dynamics incorporating the body's functional asymmetry predicted that left-handers and right-handers would deviate from zero relative phase in opposite directions, that the deviation would be greater for preferred-hand targeting, and that this deviation would be greater at higher movement frequencies. The results confirmed the major predictions and suggested that asymmetry due to handedness is magnified by attention.
Journal of Motor Behavior, 1992
Learning a bimanual rhythmic task is explored from the perspective that motor skill acquisition i... more Learning a bimanual rhythmic task is explored from the perspective that motor skill acquisition involves the successive reparameterization of a dynamical control structure in the direction of increasing stability, where the intentional process of reparameterization is itself dynamical. Subjects learned to oscillate pendulums held in the right and left hands such that the right hand frequency was twice that of the left (2:1 frequency lock). Over 12 learning sessions of 20 trials each, we interpreted the decreasing fluctuations in the frequency locking to be an index of the increasing concavity of the underlying potential, a measure of stability; the time required to achieve the 2: 1 pattern was interpreted as indexing the relaxation time of an intentional dynamic. Power spectral analyses of the phase velocity ratio exhibited two strategies for acquiring the interlimb movement pattern: (a) adding spectral peaks at integer multiples of the left hand frequency or (b) distributing power across many frequencies in a l/f-like manner. Results are discussed in terms of the promise of a dynamical approach to learning coordinated movements.
Human Movement Science, 2002
Two experiments addressed the relation between postural stability, perceptual sensitivity, and st... more Two experiments addressed the relation between postural stability, perceptual sensitivity, and stability of driving performance. A vehicle was fitted with differential GPS for measuring position and speed, position sensors for measuring brake and accelerator depression, force transducers for measuring door, console and footrest bracing forces, and an accelerometer for measuring the 3D accelerations of the vehicle. In Experiment 1, we investigated whether the initiation of deceleration and the control of braking might be due to sensitivity to the perceptual variable tau, which specifies time-to-contact (TTC), and in particular, whether its first derivative, tau-dot, is used to maintain a constant deceleration profile. Using both untrained experienced drivers (EDs) and trained driving instructors from the Holden Performance Driving Centre (HPDC), results confirmed that, regardless of skill level, tau-dot was maintained at a value close to 0.5 and, as predicted by Lee [Perception 5 (1976) 437], braking was initiated when TTC % 5 s. In Experiment 2, we wished to quantify the purported differences in driving behaviour between EDs and HPDC instructors during a variety of everyday manoeuvres. Results indicated that instructors utilised a different cornering trajectory, a different emergency braking strategy, and were able to perform a high-speed swerve and recovery task more effectively than the EDs. In general, the instructors applied greater bracing forces using the door and console compared with EDs. The instructors also applied greater footrest forces during emergency braking than did the EDs. The greater use of bracing by instructor drivers to resist g-forces represents a strategy of active stabilisation that enhances both postural stability, as well as overall stability and consistency of driving performance. Results are discussed with regard to the dynamics of perceptual-motor coordination, and how increased stability might improve sensitivity to relevant perceptual information. We conclude that driver-training programmes that focus on increasing driver stability (as a prerequisite for increased control) show great promise as a means to improving oneÕs attention during driving, and hence have the potential to dramatically improve road safety in general.
Experimental Brain Research, 1996
The symmetrical dynamics of 1 : 1 rhythmic bimanual coordination may be specified by an order par... more The symmetrical dynamics of 1 : 1 rhythmic bimanual coordination may be specified by an order parameter equation involving the relative phase between rhythmic components, and an interlimb coupling which determines the relative attractiveness of in-phase and anti-phase patterns. Symmetry breaking of these dynamics can occur via the difference in the natural frequencies, Am, of the left and right rhythmic components, or by the intrinsic asymmetrical dynamics of the body. The latter is captured by additional terms that render the symmetrical coupling slightly anisotropic. A major prediction resulting from this step is that although Am = 0, as the frequency of coordination is increased, the asymmetrical coupling will increase and the symmetrical coupling will decrease. This results in a greater left-limb bias in lefthanders and right-limb bias in right-handers. This "increased handedness" prediction was confirmed in an experiment in which 20 left-handed and 20 righthanded individuals performed 1 : 1 coordination with hand-held rigid pendulums. Manipulations of left and right pendulum lengths controlled Aco, and the coupled frequency was determined by a metronome. Also confirmed was the prediction that the small shift in equilibria from in-phase and anti-phase due to the intrinsic asymmetry should be amplified in left-handers when Ac0> 0 and in right-handers when A0~ < 0. Further, the bias in left-handers was more consistent than the bias in right-handers, and a subgroup of righthanders was identified who performed similarly to left
Transportation Research Part F: Traffic Psychology and Behaviour, 2004
Using a closed-circuit driving track environment, we investigated the influence of using a hands-... more Using a closed-circuit driving track environment, we investigated the influence of using a hands-free mobile (or cell) phone on various biomechanical and perceptual factors that underlie the control of driving. Results showed that in three tasks representative of everyday driving conditions, the perceptual control of action was compromised when compared to a control condition where no mobile phone conversation was present. While conversing, critical control actions related to braking were postponed on approach to a corner. During controlled braking, as when approaching a stationary car at a traffic light, the degree of braking was reduced and braking style was altered in a non-optimal manner. During an obstacle avoidance task, car dynamics were affected as a result of the conversation. Interpretation of the results is motivated by the ecological approach to perception-action and the theory of affordances. It is concluded that a driverÕs sensitivity to prospective information about upcoming events and the associated perception and awareness of what the road environment affords may both significantly be degraded when simultaneously using a handsfree mobile phone.
Journal of Experimental Psychology: Human Perception and Performance, 1995
Human handedness was investigated in a 1:1 interlimb rhythmic coordination in which consistent an... more Human handedness was investigated in a 1:1 interlimb rhythmic coordination in which consistent and inconsistent left-handed and right-handed individuals oscillated hand-held pendulums. Mean phase difference (φstable) and its standard deviation (SD φ) were evaluated as functions of mode of coordination (in-phase vs. anti-phase) and the symmetry conditions imposed by controlling the natural frequencies of the left and right pendulums. The
Journal of Experimental Psychology: Human Perception and Performance, 2000
Journal of Experimental Psychology: Human Perception and Performance, 1991
Journal of Experimental Psychology: Human Perception and Performance, 1997
Predictions concerning the effects of handedness and attention on bimanual coordination were made... more Predictions concerning the effects of handedness and attention on bimanual coordination were made from a dynamical model that incorporates the body's lateral asymmetry. Both handedness and the direction of attention (to the left or right) were manipulated in an inphase 1:1 frequency locking task. Left-handed and right-handed participants had to coordinate the planar oscillations of 2 handheld pendulums while 1 pendulum oscillated between spatial targets positioned over either the left or right hand. Predictions from the model were that participants would show a phase lead with the preferred hand, and that, although the phase lead would be greater when attention was directed to the preferred hand, the variability of relative phase would be lower. Confirmation of these predictions suggests that the dynamical perspective offers the possibility of studying handedness and attention without compromising theoretical precision or experimental control.
Human Movement Science, 2003
Human Movement Science, 2002
Interest is rapidly growing in the hypothesis that natural language emerged from a more primitive... more Interest is rapidly growing in the hypothesis that natural language emerged from a more primitive set of linguistic acts based primarily on manual activity and hand gestures. Increasingly, researchers are investigating how hemispheric asymmetries are related to attentional and manual asymmetries (i.e., handedness). Both speech perception and production have origins in the dynamical generative movements of the vocal tract known as articulatory gestures. Thus, the notion of a ''gesture'' can be extended to both hand movements and speech articulation. The generative actions of the hands and vocal tract can therefore provide a basis for the (direct) perception of linguistic acts. Such gestures are best described using the methods of dynamical systems analysis since both perception and production can be described using the same commensurate language. Experiments were conducted using a phase transition paradigm to examine the coordination of speech-hand gestures in both left-and right-handed individuals. Results address coordination (in-phase vs. anti-phase), hand (left vs. right), lateralization (left vs. right hemisphere), focus of attention (speech vs. tapping), and how dynamical constraints provide a foundation for human communicative acts. Predictions from the asymmetric HKB equation confirm the attentional basis of functional asymmetry. Of significance is a new understanding of the role of perceived synchrony (p-centres) during intentional cases of gestural coordination.
Ecological Psychology, 2008
We investigated how a listener's perceived meaning of a spoken sentence is influenced by the rela... more We investigated how a listener's perceived meaning of a spoken sentence is influenced by the relative timing between a speaker's speech and accompanying hand gestures. Participants viewed a computer-animated character who uttered the phrase, "Put the book there now." while executing a simple right-handed beat gesture whose location relative to the utterance was precisely controlled in a frame-by-frame fashion. The participant's task consisted of making a judgment about two related aspects of the actor's perceived speech: (a) Which word was emphasized? and (b) How clear was the emphasis? That is, did it make sense? The results revealed that the perceived emphasis was determined by the timing (phasing) of the speaker's hand gesture. Furthermore, the clarity of the perceived emphasis (i.e., meaningfulness) was influenced by the affordances in the immediate environment of the speaker. Discussion addresses the primacy of ostensive specification and gesture in communicative events, the dynamics of speech-hand coordination during both actual and virtual dialogue, and the role of environmental affordances in grounding informative communicative acts in the ecology of organism-environment dynamics. The question of the extent to which hand gestures (and other movements sometimes referred to as "body language") might provide a basis for human communication continues to challenge theories of language and language development. The fact that most of us move our hands in spontaneous gesture even if we cannot be seen, for example when talking to a blind person or to someone by telephone (Iverson & Goldin-Meadow, 1997), suggests that a speaker's accompanying hand
Ecological Psychology, 1999
ABSTRACT
Behavioral and Brain Sciences, 1996
We show that left-handers can be considered as a “special” population. We indicate that the asymm... more We show that left-handers can be considered as a “special” population. We indicate that the asymmetries in performance exhibited by left-handers are due to a basic asymmetry in the underlying coordination dynamics that constrains bimanual coordination. In contrast to the claims of Latash & Anson, we argue that considerable knowledge has been gained regarding the essential equations of motion that govern biological coordination.
Handedness and attentional asymmetries in bimanual rhythmic coordination were examined as a funct... more Handedness and attentional asymmetries in bimanual rhythmic coordination were examined as a function of movement speed. In an in-phase 1: 1 frequency locking task, left-handed and right-handed subjects controlled the oscillations of either the right or the left hand so as to contact spatial targets. The task was performed at three frequencies of coupled movement. Coordination dynamics incorporating the body's functional asymmetry predicted that left-handers and right-handers would deviate from zero relative phase in opposite ...
Motor Control, 1997
Handedness and attentional asymmetries in bimanual rhythmic coordination were examined as a funct... more Handedness and attentional asymmetries in bimanual rhythmic coordination were examined as a function of movement speed. In an in-phase 1:1 frequency locking task, left-handed and right-handed subjects controlled the oscillations of either the right or the left hand so as to contact spatial targets. The task was performed at three frequencies of coupled movement. Coordination dynamics incorporating the body's functional asymmetry predicted that left-handers and right-handers would deviate from zero relative phase in opposite directions, that the deviation would be greater for preferred-hand targeting, and that this deviation would be greater at higher movement frequencies. The results confirmed the major predictions and suggested that asymmetry due to handedness is magnified by attention.
Journal of Motor Behavior, 1992
Learning a bimanual rhythmic task is explored from the perspective that motor skill acquisition i... more Learning a bimanual rhythmic task is explored from the perspective that motor skill acquisition involves the successive reparameterization of a dynamical control structure in the direction of increasing stability, where the intentional process of reparameterization is itself dynamical. Subjects learned to oscillate pendulums held in the right and left hands such that the right hand frequency was twice that of the left (2:1 frequency lock). Over 12 learning sessions of 20 trials each, we interpreted the decreasing fluctuations in the frequency locking to be an index of the increasing concavity of the underlying potential, a measure of stability; the time required to achieve the 2: 1 pattern was interpreted as indexing the relaxation time of an intentional dynamic. Power spectral analyses of the phase velocity ratio exhibited two strategies for acquiring the interlimb movement pattern: (a) adding spectral peaks at integer multiples of the left hand frequency or (b) distributing power across many frequencies in a l/f-like manner. Results are discussed in terms of the promise of a dynamical approach to learning coordinated movements.
Human Movement Science, 2002
Two experiments addressed the relation between postural stability, perceptual sensitivity, and st... more Two experiments addressed the relation between postural stability, perceptual sensitivity, and stability of driving performance. A vehicle was fitted with differential GPS for measuring position and speed, position sensors for measuring brake and accelerator depression, force transducers for measuring door, console and footrest bracing forces, and an accelerometer for measuring the 3D accelerations of the vehicle. In Experiment 1, we investigated whether the initiation of deceleration and the control of braking might be due to sensitivity to the perceptual variable tau, which specifies time-to-contact (TTC), and in particular, whether its first derivative, tau-dot, is used to maintain a constant deceleration profile. Using both untrained experienced drivers (EDs) and trained driving instructors from the Holden Performance Driving Centre (HPDC), results confirmed that, regardless of skill level, tau-dot was maintained at a value close to 0.5 and, as predicted by Lee [Perception 5 (1976) 437], braking was initiated when TTC % 5 s. In Experiment 2, we wished to quantify the purported differences in driving behaviour between EDs and HPDC instructors during a variety of everyday manoeuvres. Results indicated that instructors utilised a different cornering trajectory, a different emergency braking strategy, and were able to perform a high-speed swerve and recovery task more effectively than the EDs. In general, the instructors applied greater bracing forces using the door and console compared with EDs. The instructors also applied greater footrest forces during emergency braking than did the EDs. The greater use of bracing by instructor drivers to resist g-forces represents a strategy of active stabilisation that enhances both postural stability, as well as overall stability and consistency of driving performance. Results are discussed with regard to the dynamics of perceptual-motor coordination, and how increased stability might improve sensitivity to relevant perceptual information. We conclude that driver-training programmes that focus on increasing driver stability (as a prerequisite for increased control) show great promise as a means to improving oneÕs attention during driving, and hence have the potential to dramatically improve road safety in general.
Experimental Brain Research, 1996
The symmetrical dynamics of 1 : 1 rhythmic bimanual coordination may be specified by an order par... more The symmetrical dynamics of 1 : 1 rhythmic bimanual coordination may be specified by an order parameter equation involving the relative phase between rhythmic components, and an interlimb coupling which determines the relative attractiveness of in-phase and anti-phase patterns. Symmetry breaking of these dynamics can occur via the difference in the natural frequencies, Am, of the left and right rhythmic components, or by the intrinsic asymmetrical dynamics of the body. The latter is captured by additional terms that render the symmetrical coupling slightly anisotropic. A major prediction resulting from this step is that although Am = 0, as the frequency of coordination is increased, the asymmetrical coupling will increase and the symmetrical coupling will decrease. This results in a greater left-limb bias in lefthanders and right-limb bias in right-handers. This "increased handedness" prediction was confirmed in an experiment in which 20 left-handed and 20 righthanded individuals performed 1 : 1 coordination with hand-held rigid pendulums. Manipulations of left and right pendulum lengths controlled Aco, and the coupled frequency was determined by a metronome. Also confirmed was the prediction that the small shift in equilibria from in-phase and anti-phase due to the intrinsic asymmetry should be amplified in left-handers when Ac0> 0 and in right-handers when A0~ < 0. Further, the bias in left-handers was more consistent than the bias in right-handers, and a subgroup of righthanders was identified who performed similarly to left