Cognitive entrainment to isochronous rhythms is independent of both sensory modality and top-down attention

The anisochrony of a stimulus sequence was manipulated parametrically to investigate whether rhythmic entrainment is stronger in the auditory modality than in the visual modality (Experiment 1), and whether it relies on top-down attention (Experiment 2). In Experiment 1, participants had to respond as quickly as possible to a target presented after a sequence of either visual or auditory stimuli. The anisochrony of this sequence was manipulated parametrically, rather than in an all or none fashion; that is, it could range from smaller to larger deviations of the isochrony (0, 10, 20, 50, 100, 150 and 200 ms). We compared rhythmic entrainment patterns for auditory and visual modalities. Results showed a peak of entrainment for both isochrony and deviations of isochrony up to 50 ms (i.e., participants were equally fast both after the isochronous sequences and after 10, 20 and 50 ms deviations), suggesting that anisochronous sequences can also produce entrainment. Beyond this entrainment window, the reaction times became progressively slower. Surprisingly, no differences were found between the entrainment patterns for auditory and visual rhythms. In Experiment 2, we used a dual-task methodology by adding a working memory n-back task to the procedure of Experiment 1. Results did not show interference of the secondary task in either auditory or visual modalities, with participants showing the same entrainment pattern as in Experiment 1. These results suggest that rhythmic entrainment constitutes a cognitive process that occurs by default (automatically), regardless of the modality in which the stimuli are presented, and independent of top-down attention, to generate behavioural benefits.Financial support for this research was provided by a “Formación del Profesorado Universitario” (FPU) grant from the Ministerio de Educación, Cultura y Deporte, Spanish Government, to Diana Cutanda, the Spanish Ministerio de Economía y Competitividad (PLAN NACIONAL de I+D+i, grant number: PSI2014-58041-P) to AC and by the Junta de Andalucía (SEJ-3054) to AC and DS

Neural and behavioural basis of preparation guided by rhythms

Temporal regularities present in our environment allow us not only to synchronize our movements to an external rhythm but also to generate temporal expectations about when a relevant event is going to occur (Nobre, Correa, & Coull, 2007). This synchronization, known as rhythmic entrainment, results in behavioural benefits in response to the events matching the temporal structure of the sequences, such as an enhancement of the reaction times (RT; Correa & Nobre, 2008; Sanabria, Capizzi, & Correa, 2011; Sanabria & Correa, 2013), time judgment (Barnes & Jones, 2000) or pitch judgment accuracy (Jones, Moynihan, McKenzie, & Puente, 2002). While several studies have suggested that this process is independent of top-down attention (Rohenkohl, Coull, & Nobre, 2011; Triviño et al., 2011; Correa et al., 2014), to our knowledge, only two of them have focused directly on the role of attention in the rhythmic entrainment, showing contradictory results (De la Rosa, Sanabria, Capizzi, & Correa, 2012; Schwartze, Rothermich, Schmidt-Kassow, & Kotz, 2011). The aim of the present thesis is to investigate whether top-down attentional processes are involved in the rhythmic entrainment and, moreover, to account for the role of the rhythmic entrainment as a basic process in a general predictive system. De la Rosa and colleagues (De la Rosa, Sanabria, Capizzi, & Correa, 2012) conducted an experiment under the dual-task paradigm in order to study the resistance of rhythmic entrainment to the concurrent performance of a secondary working memory task. According to the dual-task paradigm, the inclusion of a secondary would result in an impairment of performance in the primary task if both tasks compete for common limited resources (Logan, 1978, 1979).Tesis Univ. Granada. Programa Oficial de Doctorado en PsicologíaBeca del Programa Nacional de Formación de Profesorado Universitario (FPU) del Ministerio de Educación, Cultura y Deporte

"Lost in time" but still moving to the beat.

Motor synchronization to the beat of an auditory sequence (e.g., a metronome or music) is widespread in humans. However, some individuals show poor synchronization and impoverished beat perception. This condition, termed "beat deafness", has been linked to a perceptual deficit in beat tracking. Here we present single-case evidence (L.A. and L.C.) that poor beat tracking does not have to entail poor synchronization. In a first Experiment, L.A., L.C., and a third case (L.V.) were submitted to the Battery for The Assessment of Auditory Sensorimotor and Timing Abilities (BAASTA), which includes both perceptual and sensorimotor tasks. Compared to a control group, L.A. and L.C. performed poorly on rhythm perception tasks, such as detecting time shifts in a regular sequence, or estimating whether a metronome is aligned to the beat of the music or not. Yet, they could tap to the beat of the same stimuli. L.V. showed impairments in both beat perception and tapping. In a second Experiment, we tested whether L.A., L.C., and L.V.'s perceptual deficits extend to an implicit timing task, in which they had to respond as fast as possible to a different target pitch after a sequence of standard tones. The three beat-deaf participants benefited similarly to controls from a regular temporal pattern in detecting the pitch target. The fact that synchronization to a beat can occur in the presence of poor perception shows that perception and action can dissociate in explicit timing tasks. Beat tracking afforded by implicit timing mechanisms is likely to support spared synchronization to the beat in some beat-deaf participants. This finding suggests that separate pathways may subserve beat perception depending on the explicit/implicit nature of a task in a sample of beat-deaf participants

Metasurfaces for sound absorption over a broad range of wave incidence angles

Control of reflected waves that meet surfaces from oblique directions is crucial, for instance, in closed spaces. Metasurfaces composed of Helmholtz resonators can be efficient and compact absorbers but have limited ability to achieve high absorption over a wide incidence angle range, especially when designed for high performance in the region approaching grazing incidence. In turn, sonic crystals can be used to manipulate wave propagation direction at low frequencies. We propose a type of absorber that combines a surface of 2D Helmholtz resonators and a 2D sonic crystal with cylindrical scatterers arranged in a hexagonal lattice. The combined effect of both structures yields a metasurface that can achieve high absorption over a broad range of incidence angles. Here, an analytic model to estimate the behavior of the absorbers for wavelengths that are much longer than the unit cell dimensions is presented. The model is used in combination with an optimization strategy to realize designs for single frequency and octave-band performance. The test cases show that surfaces with absorption coefficient values above 0.9 for the range of incidence angle extending from 0◦ until 83◦ can be realized. The performance of the absorbers is verified with a finite element model and experimentally

Phononic Crystal and Resonator-Based Metasurface Combination for Wide-Angle Sound Absorption

A combination of a hexagonal lattice of close cylinders and a metasurface containing Helmholtz resonators (HRs) is presented in this contribution. The arrangement has been optimized to enhance sound absorption of plane waves arriving at a wide range of incidence angles. In room acoustics, this is useful for adapting the absorption performance to realistic sound field characteristics