Feedback delays can enhance anticipatory synchronization in human-machine interaction.

Research investigating the dynamics of coupled physical systems has demonstrated that small feedback delays can allow a dynamic response system to anticipate chaotic behavior. This counterintuitive phenomenon, termed anticipatory synchronization, has been observed in coupled electrical circuits, laser semi-conductors, and artificial neurons. Recent research indicates that the same process might also support the ability of humans to anticipate the occurrence of chaotic behavior in other individuals.

Anticipation in manual tracking with multiple delays.

Two experiments are reported showing that behavior exhibited in manual tracking is consistent with behavior predicted by a dynamical systems phenomenon known as anticipating synchronization (Voss, 2000). They extend a prior investigation of the effect of delay on anticipatory manual tracking (Stepp, 2009) by also manipulating coupling strength. The coupling scheme in Experiment 1 and that in Experiment 2 go beyond the single delayed feedback coupling used in previous research and articulations of anticipating synchronization.

A negative group delay model for feedback-delayed manual tracking performance.

We propose that feedback-delayed manual tracking performance is limited by fundamental constraints imposed by the physics of negative group delay. To test this hypothesis, the results of an experiment in which subjects demonstrate both reactive and predictive dynamics are modeled by a linear system with delay-induced negative group delay. Although one of the simplest real-time predictors conceivable, this model explains key components of experimental observations.

Criticality as a Set-Point for Adaptive Behavior in Neuromorphic Hardware.

Neuromorphic hardware are designed by drawing inspiration from biology to overcome limitations of current computer architectures while forging the development of a new class of autonomous systems that can exhibit adaptive behaviors. Several designs in the recent past are capable of emulating large scale networks but avoid complexity in network dynamics by minimizing the number of dynamic variables that are supported and tunable in hardware. We believe that this is due to the lack of a clear understanding of how to design self-tuning complex systems.

Synaptic plasticity enables adaptive self-tuning critical networks.

During rest, the mammalian cortex displays spontaneous neural activity. Spiking of single neurons during rest has been described as irregular and asynchronous. In contrast, recent in vivo and in vitro population measures of spontaneous activity, using the LFP, EEG, MEG or fMRI suggest that the default state of the cortex is critical, manifested by spontaneous, scale-invariant, cascades of activity known as neuronal avalanches.

Philosophy for the rest of cognitive science.

Cognitive science has always included multiple methodologies and theoretical commitments. The philosophy of cognitive science should embrace, or at least acknowledge, this diversity. Bechtel's (2009a) proposed philosophy of cognitive science, however, applies only to representationalist and mechanist cognitive science, ignoring the substantial minority of dynamically oriented cognitive scientists.

Whole body lexical decision.

When a person standing upright raises an arm on cue, muscles of the left and right sides of the body exhibit changes prior to and specific to the responding arm. We had standing participants perform a visual lexical decision task ("is this letter string a word?"), responding yes by raising one arm and no by raising the other arm. We recorded onset of the arm movement and onset of electromyographic activity in thigh, trunk, and shoulder muscles.

Anticipation in feedback-delayed manual tracking of a chaotic oscillator.

Manual tracking of non-chaotic targets, with and without feedback delay, as well as discrete prediction of chaotic maps have each been demonstrated by humans. Feedback-delayed tracking of chaotic targets, on the other hand, has not been well investigated. To this end, 10 participants were asked to track a chaotically moving target presented on a computer display by means of controlling a similar on-screen object using a pressure sensitive tablet and hand-held stylus.