Neuroscience
-
Meta Analysis
Effect of Mirror Therapy on Recovery of Stroke Survivors: A Systematic Review and Network Meta-analysis.
Mirror therapy (MT) as a relatively new rehabilitation technique has been widely applied in stroke patients. A number of randomized controlled trials (RCTs) have investigated the effects of MT for stroke survivors. The main purpose of this network meta-analysis was to investigate the effects of MT on motor function, activities of daily living (ADL), and pain perception in stroke survivors. ⋯ Network meta-analysis showed that MT combined with electrical stimulation (ES) for less than 4 weeks along with conventional rehabilitation therapy (CT), and MT accompanied with CT for less than 4 weeks might be the most suitable interventions for improvement of motor function and ADL, respectively. Overall, MT could effectively improve motor function and ADL, as well as relieve pain for stroke survivors. The study was registered at PROSPERO (CRD42017081742).
-
Review
Automatic frequency-shift detection in the auditory system: A review of psychophysical findings.
The human brain has the task of binding successive sounds produced by the same acoustic source into a coherent perceptual stream, and binding must be selective when several sources are concurrently active. Binding appears to obey a principle of spectral proximity: pure tones close in frequency are more likely to be bound than pure tones with remote frequencies. It has been hypothesized that the binding process is realized by automatic "frequency-shift detectors" (FSDs), comparable to the detectors of spatial motion in the visual system. ⋯ A number of variants of this study have been performed since 2005, in order to confirm the existence of FSDs, to characterize their properties, and to clarify as far as possible their neural underpinnings. The results obtained up to now suggest that the working of the FSDs exploits an implicit sensory memory which is powerful with respect to both capacity and retention time. Tones within chords can be perceptually enhanced by small frequency shifts, in a manner suggesting that the FSDs can serve in auditory scene analysis not only as binding tools but also, to a limited extent, as segregation tools.
-
The world is richly structured on multiple spatiotemporal scales. In order to represent spatial structure, many machine-learning models repeat a set of basic operations at each layer of a hierarchical architecture. ⋯ Because our brains also process temporal information that is rich and occurs across multiple time scales, might the brain employ an analogous set of operations for temporal information processing? Here we define a candidate set of temporal operations, and we review evidence that they are implemented in the mammalian cerebral cortex in a hierarchical manner. We conclude that multiple consecutive stages of cortical processing can be understood to perform temporal pooling, temporal normalization and temporal pattern completion.
-
Music is a curious example of a temporally patterned acoustic stimulus, and a compelling pan-cultural phenomenon. This review strives to bring some insights from decades of music psychology and sensorimotor synchronization (SMS) literature into the mainstream auditory domain, arguing that musical rhythm perception is shaped in important ways by temporal processing mechanisms in the brain. The feature that unites these disparate disciplines is an appreciation of the central importance of timing, sequencing, and anticipation. ⋯ We then move away from music to explore the perceptual effects of rhythmic timing in pattern detection, auditory scene analysis, and speech perception. Finally, we review the neurophysiology of general timing processes that may underlie aspects of the perception of rhythmic patterns. We conclude with a brief summary and outlook for future research.
-
Predictive coding is possibly one of the most influential, comprehensive, and controversial theories of neural function. While proponents praise its explanatory potential, critics object that key tenets of the theory are untested or even untestable. The present article critically examines existing evidence for predictive coding in the auditory modality. ⋯ More work exists on the proposed oscillatory signatures of predictive coding, and on the relation between attention and precision. However, results on these latter two assumptions are mixed or contradictory. Looking to the future, more collaboration between human and animal studies, aided by model-based analyses will be needed to test specific assumptions and implementations of predictive coding - and, as such, help determine whether this popular grand theory can fulfill its expectations.