Time-oriented attention improves accuracy in a paced finger tapping task

Finger tapping is a task widely used in a variety of experimental paradigms, in particular to understand sensorimotor synchronization and time processing in the range of hundreds of milliseconds (millisecond timing). Normally, subjects don’t receive any instruction about what to attend to and the results are seldom interpreted taking into account the possible effects of attention. In this work we show that attention can be oriented to the purely temporal aspects of a paced finger tapping task and that it affects performance. Specifically, time-oriented attention improves the accuracy in paced finger tapping and it also increases the resynchronization efficiency after a period perturbation. We use two markers of the attention level: auditory ERPs and subjective report of the mental workload. In addition, we propose a novel algorithm to separate the auditory, stimulus-related components from the somatosensory, response-related ones, which are naturally overlapped in the recorded EEG.

Research of the Technical Seismicity Due to Blasting Works in Quarries and Their Impact on the Environment and Population

Vibrations caused by blasting works have an impact not only on buildings but also the internal environment of the buildings. If these buildings are situated in the surroundings of quarries, the citizens can perceive these vibrations negatively. By applying an appropriate millisecond timing interval, it is possible to lower the intensity of vibrations to the levels that the citizens will not perceive as negative effects inside the buildings. The limit values for this vibration intensity have not been defined to date. For the protection of the building from the vibrations, normative values of the particle velocity and frequency were determined. Hygienic standards for the inhabitants of the housing were applied, which assessed the impact of the vibration on humans through the measurement of the vibration acceleration in the housing. In this article, the results of the research carried out in Trebejov Quarry are presented. The experimental blasts carried out in Trebejov Quarry proved that the reduction in the vibration intensity under the value 2 mm.s−1 led to the satisfaction of the inhabitants.

Navigating Through Time: A Spatial Navigation Perspective on How the Brain May Encode Time

Interval timing, which operates on timescales of seconds to minutes, is distributed across multiple brain regions and may use distinct circuit mechanisms as compared to millisecond timing and circadian rhythms. However, its study has proven difficult, as timing on this scale is deeply entangled with other behaviors. Several circuit and cellular mechanisms could generate sequential or ramping activity patterns that carry timing information. Here we propose that a productive approach is to draw parallels between interval timing and spatial navigation, where direct analogies can be made between the variables of interest and the mathematical operations necessitated. Along with designing experiments that isolate or disambiguate timing behavior from other variables, new techniques will facilitate studies that directly address the neural mechanisms that are responsible for interval timing.

Motor Timing as a Predictor of Attention, Working Memory and Impulsivity in Alcohol and/or Cocaine Use Disorders

In recent years, there has been a growing interest in neuropsychological deficits in patients with Cocaine Use Disorder (CUD) and Alcohol Use Disorder (AUD). Besides deficits in working memory (WM), impulsivity and attention, chronic alcohol and cocaine use have neurotoxic effects on frontostriatal areas in the brain. Individuals with deficits in these brain regions experience motor-timing deficits. It is unclear whether observed temporal processing deficits, in fact, reflect increased sustained attention or WM demands (which are required by timing tasks), or whether motor-timing deficits reflect some other process. The main questions of this were: (i) Can attention and WM be explained by motor-timing performance, and (ii), is impulsivity related to motor timing performance, in an inpatient SUD population? The study sample consisted of 74 abstinent patients who completed selected neuropsychological and motor-timing tasks. No significant correlation was found between performance on motor tasks and impulsivity. With regard to visual and auditory WM, motor timing was a significant predictor but only under conditions that required increased cognitive demands. Motor-timing performance contributed to a small portion of the variance in attention, but only for spatial abilities and only at increased cognitive demands. These preliminary findings suggest that, in line with the literature, millisecond timing engages other cognitive functions, but only minimally. As such motor timing should be regarded as a separate neurocognitive concomitant. Impulsivity was not associated with millisecond motor timing. More research is needed to further investigate these preliminary findings.

Motor Timing as a Predictor of Attention, Working Memory and Impulsivity in Alcohol and/or Cocaine Use Disorders

In recent years, there has been a growing interest in neuropsychological deficits in patients with Cocaine Use Disorder (CUD) and Alcohol Use Disorder (AUD). Besides deficits in working memory (WM), impulsivity and attention, chronic alcohol and cocaine use have neurotoxic effects on frontostriatal areas in the brain. Individuals with deficits in these brain regions experience motor-timing deficits. It is unclear whether observed temporal processing deficits, in fact, reflect increased sustained attention or WM demands (which are required by timing tasks), or whether motor-timing deficits reflect some other process. The main questions of this were: (i) Can attention and WM be explained by motor-timing performance, and (ii), is impulsivity related to motor timing performance, in an inpatient SUD population? The study sample consisted of 74 abstinent patients who completed selected neuropsychological and motor-timing tasks. No significant correlation was found between performance on motor tasks and impulsivity. With regard to visual and auditory WM, motor timing was a significant predictor but only under conditions that required increased cognitive demands. Motor-timing performance contributed to a small portion of the variance in attention, but only for spatial abilities and only at increased cognitive demands. These preliminary findings suggest that, in line with the literature, millisecond timing engages other cognitive functions, but only minimally. As such motor timing should be regarded as a separate neurocognitive concomitant. Impulsivity was not associated with millisecond motor timing. More research is needed to further investigate these preliminary findings.

No lab, no problem

We present new opportunities for psycholinguistic research that are made available by presenting experiments online over the web. We focus on PsychoPy3, which is a new version of a system for the development and delivery of behavioural experiments. Crucially, it allows for both these functions to be performed online. We note that experiments delivered over the web have significant efficiency advantages. They also open up new opportunities to increase the ecological validity of experiments and to facilitate the participation of members of populations that have thus far been less studied in the psycholinguistic literature. We discuss the crucial matter of millisecond timing in online experiments. The technical details of implementation of a behavioural psycholinguistic experiment are presented, along with listings of additional technical resources and support. Our overall evaluation is that although online experimentation still has technical challenges and improvements are ongoing, it may well represent the future of behavioural psycholinguistic research.

Precise timing is ubiquitous, consistent and coordinated across a comprehensive, spike-resolved flight motor program

Sequences of action potentials, or spikes, carry information in the number of spikes and their timing. Spike timing codes are critical in many sensory systems, but there is now growing evidence that millisecond-scale changes in timing also carry information in motor brain regions, descending decision-making circuits, and individual motor units. Across all the many signals that control a behavior how ubiquitous, consistent, and coordinated are spike timing codes? Assessing these open questions ideally involves recording across the whole motor program with spike-level resolution. To do this, we took advantage of the relatively few motor units controlling the wings of a hawk moth, Manduca sexta. We simultaneously recorded nearly every action potential from all major wing muscles and the resulting forces in tethered flight. We found that timing encodes more information about turning behavior than spike count in every motor unit, even though there is sufficient variation in count alone. Flight muscles vary broadly in function as well as in the number and timing of spikes. Nonetheless, each muscle with multiple spikes consistently blends spike timing and count information in a 3:1 ratio. Coding strategies are consistent. Finally, we assess the coordination of muscles using pairwise redundancy measured through interaction information. Surprisingly, not only are all muscle pairs coordinated, but all coordination is accomplished almost exclusively through spike timing, not spike count. Spike timing codes are ubiquitous, consistent, and essential for coordination.Significance StatementBrains can encode precise sensory stimuli and specific motor systems also appear to be precise, but how important are millisecond changes in timing of neural spikes across the whole motor program for a behavior? We record every spike that the hawk moth’s nervous system sends to its wing muscles. We show that all muscles convey the majority of their information in spike timing. The number of spikes does play a role, but not in a coordinated way across muscles. Instead, all coordination is done using in the millisecond timing of in spikes. The importance and prevalence of timing across the motor program pose new questions for how nervous systems create precise, coordinated motor commands.

Robustness of STDP to spike timing jitter

ABSTRACTIn Hebbian plasticity, neural circuits adjust their synaptic weights depending on patterned firing of action potential on either side of the synapse. Spike-timing-dependent plasticity (STDP) is an experimental implementation of Hebb’s postulate that relies on the precise order and the millisecond timing of the paired activities in pre- and postsynaptic neurons. In recent years, STDP has attracted considerable attention in computational and experimental neurosciences. However, canonical STDP is assessed with deterministic (constant) spike timings and time intervals between successive pairings, thus exhibiting a regularity that strongly differs from the biological variability. Hence, the emergence of STDP from noisy neural activity patterns as expected in in vivo-like firing remains unresolved. Here, we used noisy STDP stimulations where the spike timing and/or the interval between successive pairings were jittered. We explored with a combination of experimental neurophysiology and mathematical modeling, the impact of jittering on three distinct forms of STDP at corticostriatal synapses: NMDAR-mediated tLTP, endocannabinoid-mediated tLTD and endocannabinoid-mediated tLTP. As the main result, we found a differential sensitivity to jittered spike timing: NMDAR-tLTP was highly fragile whereas endocannabinoid-plasticity (tLTD and tLTP) appeared more resistant. Moreover, when the frequency or the number of pairings was increased, NMDAR-tLTP became more robust and could be expressed despite strong jittering of the spike timing. Taken together, our results identify endocannabinoid-mediated plasticity as a robust form of STDP while the sensitivity to jitter of NMDAR-tLTP varies with activity frequency. This provides new insights into the mechanisms at play during the different phases of learning and memory and the emergence of Hebbian plasticity in in vivo-like firing.

Open source tools for temporally controlled rodent behavior suitable for electrophysiology and optogenetic manipulations

Understanding how the brain controls behavior requires observing and manipulating neural activity in awake behaving animals. Neuronal firing is timed at millisecond precision. Therefore, to decipher temporal coding, it is necessary to monitor and control animal behavior at the same level of temporal accuracy. However, it is technically challenging to deliver sensory stimuli and reinforcers as well as to read the behavioral responses they elicit with millisecond precision. Presently available commercial systems often excel in specific aspects of behavior control, but they do not provide a customizable environment allowing flexible experimental design while maintaining high standards for temporal control necessary for interpreting neuronal activity. Moreover, delay measurements of stimulus and reinforcement delivery are largely unavailable. We combined microcontroller-based behavior control with a sound delivery system for playing complex acoustic stimuli, fast solenoid valves for precisely timed reinforcement delivery and a custom-built sound attenuated chamber using high-end industrial insulation materials. Together this setup provides a physical environment to train head-fixed animals, enables calibrated sound stimuli and precisely timed fluid and air puff presentation as reinforcers. We provide latency measurements for stimulus and reinforcement delivery and an algorithm to perform such measurements on other behavior control systems. Combined with electrophysiology and optogenetic manipulations, the millisecond timing accuracy will help interpret temporally precise neural signals and behavioral changes. Additionally, since software and hardware provided here can be readily customized to achieve a large variety of paradigms, these solutions enable an unusually flexible design of rodent behavioral experiments.