Fig 2 - uploaded by Oliver Lindemann
Content may be subject to copyright.
Timing accuracy of visual stimulus presentation: a A single presentation of a white blank screen. b Consecutive presentations of white and blank screens. Yellow lines indicate markers sent via the serial port before and after presenting a stimulus, and cyan lines the display response, measured with an optical sensor
Source publication
Expyriment is an open-source and platform-independent lightweight Python library for designing and conducting timing-critical behavioral and neuroimaging experiments. The major goal is to provide a well-structured Python library for script-based experiment development, with a high priority being the readability of the resulting program code. Expyri...
Contexts in source publication
Context 1
... marker was sent to the oscilloscope via the serial port. The results revealed that the onset and offset of the white blank screen were aligned to the markers sent via the serial port, showing that the time that Expyriment reported the stimulus as being presented corresponded correctly to the time that the video card began drawing onto the display (Fig. 2a). Furthermore, the spacing between the onsets of successive stimulus presentations corresponded to about 17 ms, showing that Expyriment is capable of presenting one preloaded stim- ulus each screen refresh (Fig. ...
Context 2
... reported the stimulus as being presented corresponded correctly to the time that the video card began drawing onto the display (Fig. 2a). Furthermore, the spacing between the onsets of successive stimulus presentations corresponded to about 17 ms, showing that Expyriment is capable of presenting one preloaded stim- ulus each screen refresh (Fig. ...
Similar publications
Identifying strategies for researchers has been a problem investigated from different perspectives, such as choosing research topics or the effect of partner selection. Its importance lies in the effect these choices have in the long term and the importance of taking them into account at the beginning of the scientific career. This study aims to id...
Citations
... To achieve precisely 3.4 s of stimulation, the NEMOS® device was 102 controlled using two linear actuators which pressed the ON/OFF buttons. These 'push' commands 103 were sent at pre-programmed times via an Arduino mini, and were embedded within the task script, 104 which was programmed using the Expyriment Python package [33]. Two checks were implemented 105 to ensure that only trials with good connection between the electrodes and the skin were included. ...
Background: Transcutaneous auricular vagus nerve stimulation (taVNS) is a promising brain stimulation method for the treatment of pharmaco-resistant epilepsy and depression. Its clinical efficacy is thought to depend on taVNS-induced activation of the locus coeruleus. However, unlike for invasive VNS, there is little evidence for an effect of taVNS on noradrenergic activity.
Objective: We attempted to replicate recently published findings by Sharon et al. (2021), showing that short bursts of taVNS transiently increased pupil size and decreased EEG alpha power, two correlates of central noradrenergic activity.
Methods: Following the original study, we used a single-blind, sham-controlled, randomized cross-over design. We applied short-term (3.4 s) taVNS in healthy human volunteers (n=29), while collecting resting-state pupil-size and EEG data. To analyze the data, we used scripts provided by Sharon and colleagues.
Results: Consistent with Sharon et al. (2021), pupil dilation was significantly larger during taVNS than during sham stimulation (p = .009; Bayes factor supporting the difference = 7.45). However, we failed to replicate the effect of taVNS on EEG alpha power (p = .37); the data were four times more likely under the null hypothesis (BF10 = 0.28).
Conclusion: Our findings support the effectiveness of short-term taVNS in inducing transient pupil dilation, a correlate of phasic noradrenergic activity. However, we failed to replicate the recent finding by Sharon et al. (2021) that taVNS attenuates EEG alpha activity. Overall, this study highlights the need for continued research on the neural mechanisms underlying taVNS efficacy and its potential as a treatment option for pharmaco-resistant conditions. It also highlights the need for direct replications of influential taVNS studies.
... Experimental setup. Experiment 1 was implemented in Python with the expyriment package (Krause & Lindemann, 2014) and run on an ASUS UX31 laptop. The program presented the audio stimuli binaurally at a comfortable hearing level via headphones (Sennheiser HD 250 linear) and recorded the participants' written responses. ...
Humans are expert at processing speech but how this feat is accomplished remains a major question in cognitive neuroscience. Capitalizing on the concept of channel capacity, we developed a unified measurement framework to investigate the respective influence of seven acoustic and linguistic features on speech comprehension, encompassing acoustic, sub-lexical, lexical and supra-lexical levels of description. We show that comprehension is independently impacted by all these features, but at varying degrees and with a clear dominance of the syllabic rate. Comparing comprehension of French words and sentences further reveals that when supra-lexical contextual information is present, the impact of all other features is dramatically reduced. Finally, we estimated the channel capacity associated with each linguistic feature and compared them with their generic distribution in natural speech. Our data reveal that while acoustic modulation, syllabic and phonemic rates unfold respectively at 5, 5, and 12 Hz in natural speech, they are associated with independent processing bottlenecks whose channel capacity are of 15, 15 and 35 Hz, respectively, as suggested by neurophysiological theories. They moreover point towards supra-lexical contextual information as the feature limiting the flow of natural speech. Overall, this study reveals how multilevel linguistic features constrain speech comprehension.
... To reduce ocular artefacts, participants were instructed to fixate on a cross on the monitor while listening to the stimuli. The stimulus presentation and response time recording was controlled using the opensource Expyriment software v0.9.0 (Krause & Lindemann, 2014). ...
The norepinephrine locus coeruleus system (LC NE) represents a promising treatment target in patients with insomnia disorder (ID) due to its well understood links to arousal and sleep regulation. However, consistent markers of LC NE activity are lacking. This study measured three potential indirect markers of LC NE activity – REM sleep, P3 amplitude during an auditory oddball paradigm (as a marker of phasic LC activation), and baseline pupil diameter (as a marker of tonic LC activation). The parameters were then combined in a statistical model and tested to compare LC NE activity between 20 subjects with insomnia disorder (13 female; age 44.2 ± 15.1 year) and 20 healthy, good sleeping controls (GSC; 11 female; age 45.4 ± 11.6 year). No group differences regarding the primary outcome parameters were detected. Specifically, insomnia disorder did not display the hypothesised changes in markers of LC NE function. While increased LC NE function remains an interesting speculative pathway for hyperarousal in insomnia disorder, the investigated markers do not appear closely related to each other and fail to discriminate between insomnia disorder and good sleeping controls in these samples.
... The experimenter was seated at another desk and registered participants' verbal responses by mouse click. We used OpenSesame (Mathôt et al., 2012) for stimuli presentation and collected force data at a separate PC using custommade software based on the Python-library Expyriment software (Krause & Lindemann, 2014). All instructions were given in English. ...
In numerical processing, the functional role of Spatial-Numerical Associations (SNAs, such as the association of smaller numbers with left space and larger numbers with right space, the Mental Number Line hypothesis) is debated. Most studies demonstrate SNAs with lateralized responses, and there is little evidence that SNAs appear when no response is required. We recorded passive holding grip forces in no-go trials during number processing. In Experiment 1, participants performed a surface numerical decision task (“Is it a number or a letter?”). In Experiment 2, we used a deeper semantic task (“Is this number larger or smaller than five?”). Despite instruction to keep their grip force constant, participants' spontaneous grip force changed in both experiments: Smaller numbers led to larger force increase in the left than in the right hand in the numerical decision task (500–700 ms after stimulus onset). In the semantic task, smaller numbers again led to larger force increase in the left hand, and larger numbers increased the right-hand holding force. This effect appeared earlier (180 ms) and lasted longer (until 580 ms after stimulus onset). This is the first demonstration of SNAs with passive holding force. Our result suggests that (1) explicit motor response is not a prerequisite for SNAs to appear, and (2) the timing and strength of SNAs are task-dependent. (216 words).
... The experimenter was seated at another desk and registered participants' verbal responses by mouse click. We used OpenSesame (Mathôt et al., 2012) for stimuli presentation and collected force data at a separate PC using custommade software based on the Python-library Expyriment software (Krause & Lindemann, 2014). All instructions were given in English. ...
In numerical processing, the functional role of Spatial-Numerical Associations (SNAs, such as the association of smaller numbers with left space and larger numbers with right space, the Mental Number Line hypothesis) is debated. Most studies demonstrate SNAs with lateralized responses, and there is little evidence that SNAs appear when no response is required. We recorded passive holding grip forces in no-go trials during number processing. In Experiment 1, participants performed a surface numerical decision task (“Is it a number or a letter?”). In Experiment 2, we used a deeper semantic task (“Is this number larger or smaller than five?”). Despite instruction to keep their grip force constant, participants' spontaneous grip force changed in both experiments: Smaller numbers led to larger force increase in the left than in the right hand in the numerical decision task (500–700 ms after stimulus onset). In the semantic task, smaller numbers again led to larger force increase in the left hand, and larger numbers increased the right-hand holding force. This effect appeared earlier (180 ms) and lasted longer (until 580 ms after stimulus onset). This is the first demonstration of SNAs with passive holding force. Our result suggests that (1) explicit motor response is not a prerequisite for SNAs to appear, and (2) the timing and strength of SNAs are task-dependent. (216 words).
... These sensors record force dynamics with millisecond resolution along three orthogonal axes, but only Fz force along the vertical axis through the sensors was analyzed and reported here. Two PCs were used: one for running the experiment under OpenSesame software [42] and another for force data acquisition under Expyriment software [43]. The first PC sent a trigger at the beginning of each trial to later identify a corresponding time point in the force data file. ...
Previous research demonstrated a close bidirectional relationship between spatial attention and the manual motor system. However, it is unclear whether an explicit hand movement is necessary for this relationship to appear. A novel method with high temporal resolution–bimanual grip force registration–sheds light on this issue. Participants held two grip force sensors while being presented with lateralized stimuli (exogenous attentional shifts, Experiment 1), left- or right-pointing central arrows (endogenous attentional shifts, Experiment 2), or the words "left" or "right" (endogenous attentional shifts, Experiment 3). There was an early interaction between the presentation side or arrow direction and grip force: lateralized objects and central arrows led to a larger increase of the ipsilateral force and a smaller increase of the contralateral force. Surprisingly, words led to the opposite pattern: larger force increase in the contralateral hand and smaller force increase in the ipsilateral hand. The effect was stronger and appeared earlier for lateralized objects (60 ms after stimulus presentation) than for arrows (100 ms) or words (250 ms). Thus, processing visuospatial information automatically activates the manual motor system, but the timing and direction of this effect vary depending on the type of stimulus.
... Auditors heard each phrase once only and could not change their response. Audio was presented, and ratings and response time were recorded using Expyriment (Krause and Lindemann, 2014). ...
Lateral vocalisation is assumed to arise from changes in coronal articulation but is typically characterised perceptually without linking the vocalised percept to a coronal articulation. Therefore, we examined how listeners' perception of coda /l/ as vocalised relates to coronal closure. Perceptual stimuli were acquired by recording laterals produced by six speakers of Australian English using electromagnetic articulography (EMA). Tongue tip closure was monitored for each lateral in the EMA data. Increased incidence of incomplete coronal closure was found in coda /l/ relative to onset /l/. Having verified that the dataset included /l/ tokens produced with incomplete coronal closure—a primary articulatory cue of vocalised /l/—we conducted a perception study in which four highly experienced auditors rated each coda /l/ token from vocalised (3) to non-vocalised (0). An ordinal mixed model showed that increased tongue tip (TT) aperture and delay correlated with vocalised percept, but auditors ratings were characterised by a lack of inter-rater reliability. While the correlation between increased TT aperture, delay, and vocalised percept shows that there is some reliability in auditory classification, variation between auditors suggests that listeners may be sensitive to different sets of cues associated with lateral vocalisation that are not yet entirely understood.
... These sensors record force dynamics with millisecond resolution along three orthogonal axes, but only Fz force along the vertical axis through the sensors was analyzed and reported here. Two PCs were used: one for running the experiment under OpenSesame software [42] and another for force data acquisition under Expyriment software [43]. The first PC sent a trigger at the beginning of each trial to later identify a corresponding time point in the force data file. ...
Previous research demonstrated a close bidirectional relationship between spatial attention and the manual motor system. However, it is unclear whether an explicit hand movement is necessary for this relationship to appear. A novel method with high temporal resolution-bimanual grip force registration-sheds light on this issue. Participants held two grip force sensors while being presented with lateralized stimuli (exogenous attentional shifts, Experiment 1), left- or right-pointing central arrows (endogenous attentional shifts, Experiment 2), or the words "left" or "right" (endogenous attentional shifts, Experiment 3). There was an early interaction between the presentation side or arrow direction and grip force: lateralized objects and central arrows led to a larger increase of the ipsilateral force and a smaller increase of the contralateral force. Surprisingly, words led to the opposite pattern: larger force increase in the contralateral hand and smaller force increase in the ipsilateral hand. The effect was stronger and appeared earlier for lateralized objects (60 ms after stimulus presentation) than for arrows (100 ms) or words (250 ms). Thus, processing visuospatial information automatically activates the manual motor system, but the timing and direction of this effect vary depending on the type of stimulus.
... The study was approved by the Ethics Committee Social Sciences (ECSS) of the Radboud University Nijmegen (approval code ECSW 2014-2411-276). The experiment was programmed in Expyriment (Krause & Lindemann, 2014), and carried out on a computer in a sound-proof booth at the Donders Center for Cognition. The full experiment consisted of two sessions. ...
When learners acquire new words in a second language (L2), their lexical representations and links are initially imprecise. As new, similar words are learned, these representations must become more specific to avoid errors. This study investigated whether contrasting similar words triggers this sharpening process and facilitates learning. In a multiple-choice learning task, 114 adults acquired orthographically and semantically similar L2 (pseudo)words by either contrasting them or not. In Experiment 1, participants contrasted the L2 words, and in Experiment 2 they contrasted words in their first language. Only contrasting orthographically similar L2 words facilitated their acquisition. We conclude that contrasting underspecified representations serves as a learning mechanism that guides attention to relevant lexical information. As such, it enables learners to build more specific representations and is conducive to learning. Possibilities for further research and potential implications for L2 vocabulary instruction are discussed.
... Among the software tools that allow management of the experimental protocol, accurate presentation of stimuli, and collection of participant responses are Psychopy (Peirce, 2007) and Expyrement (Krause and Lindemann, 2014). Both provide an open-source software library that allows a very range of visual and auditory stimuli and a great variety of experimental designs to be generated within a framework based on Python. ...
Computational tools can transform the manner by which neuroscientists perform their experiments. More than helping researchers to manage the complexity of experimental data, these tools can increase the value of experiments by enabling reproducibility and supporting the sharing and reuse of data. Despite the remarkable advances made in the Neuroinformatics field in recent years, there is still a lack of open-source computational tools to cope with the heterogeneity and volume of neuroscientific data and the related metadata that needs to be collected during an experiment and stored for posterior analysis. In this work, we present the Neuroscience Experiments System (NES), a free software to assist researchers in data collecting routines of clinical, electrophysiological, and behavioral experiments. NES enables researchers to efficiently perform the management of their experimental data in a secure and user-friendly environment, providing a unified repository for the experimental data of an entire research group. Furthermore, its modular software architecture is aligned with several initiatives of the neuroscience community and promotes standardized data formats for experiments and analysis reporting.
