Interkeystroke Intervals Research Articles

Reversed asymmetrical switch costs in voluntary language switching: Evidence from typed responses

Aims and objectives/purpose/research questions: Prior research has put forward that asymmetrical switch costs in language switching do not occur when bilinguals are in a voluntary language-switching context. While several studies have provided evidence along these lines, two very recent studies have put this into question. This study further investigates the possibility that voluntary language switching abolishes asymmetrical switch costs. Design/methodology/approach: We presented German-English bilinguals ( n = 79) with pictures that had to be named in either German or English, whichever they chose, by typing. Data and analysis: Reaction times (both the latency of the first keystroke and interkeystroke intervals) were analyzed using linear mixed-effects regression modeling with the factors Trial type (switch vs. repetition trial) and Language (German vs. English), whereas the error rates were analyzed using logistic mixed-effects regression modeling. Findings/conclusions: The onset latencies and inter-keystroke intervals both showed larger second-language (English) than first-language (German) switch costs (i.e., reversed asymmetrical switch costs). As switch costs were modulated by language dominance in a voluntary language-switching context, this study provides evidence that voluntary language switching is not a boundary condition for asymmetrical switch costs. Originality: In contrast to most previous language-switching studies, we used typed rather than vocal responses in a voluntary language-switching paradigm. In addition, our findings further support and generalize very recent findings of (reversed) asymmetrical switch costs in voluntary language switching. Significance/implications: Since asymmetrical switch costs, an important measure of bilingual inhibitory control, are not consistently observed throughout the language-switching literature, it is essential to understand its boundary conditions.

A task segment framework to study keylogged translation processes

The Task Segment Framework (TSF) is a tool to analyze full typing flows of translation tasks as keylogged with timestamps recorded for keydown, keyup, mouse clicks and moves, and actions performed in other applications. The TSF assumes that intentional pauses flag stretches where subjects concentrate on unrecorded cognitive processes such as planning and assessment. The interspersed typing stretches are task segments, with or without text, where basic subtasks may be observed, mainly adding new text, changing existing text, and searching for information. Accumulated experience and planning allow translators to lump strategically similar activities together, in order to spare efforts and task switching costs while maximizing efficiency. Hence, task segments may contain activities of just one such subtask or many. Translation fluency is a key notion of the TSF, operationalized through many indicators such as typing speed, prior pause length, TS (task segment) length in events, text length as full words, number of typos and respites (=mid inter-keystroke intervals), subtask(s), and the like. The approach seems particularly sensitive to translation expertise levels and may be applied with variations to other multilectal mediated communication tasks. This article lays down the conceptual basis of the TSF and summarizes its basic notions and constructs.

A little doubt saves many mistakes: Early and late error detection in copy-typing

Abstract Based on internal predictions, action-errors can be detected relatively early. Different kinds of sensory feedback further provide information about the occurrence of errors later on. To investigate the mechanisms underlying error detection in copy-typing, ten-finger-typists and hunt-and-peck-typists copy typed with and without visibility of the screen and keyboard. We expected that error detection evolves in slower typing before, during, and after an error. Results showed that more errors were reported with visible screen than with covered screen in both groups underpinning the importance of distal action-effects for error detection. Importantly, ten-finger-typists showed pre-error-slowing in the inter-keystroke-intervals (IKIs) before reported errors, but hunt-and-peck-typists did not. In both groups, error-slowing was observed in the last IKI before both reported and unreported errors. Hence, internal predictions play a role in error detection in both groups, but in ten-finger-typists, internal models may be more precise, leading to earlier error detection. Alternatively, slowing down may increase the probability of detecting errors. Finally, in both groups post-error-slowing indicates that sensory feedback from performing keystrokes contributes to error detection. In conclusion, feedback from distal action-effects (i.e., the screen), movement related feedback, and predictive mechanisms contribute to error detection in typing.

Understanding the keystroke log: the effect of writing task on keystroke features

Keystroke logging is used to automatically record writers’ unfolding typing process and to get insight into moments when they struggle composing text. However, it is not clear which and how features from the keystroke log map to higher-level cognitive processes, such as planning and revision. This study aims to investigate the sensitivity of frequently used keystroke features across tasks with different cognitive demands. Two keystroke datasets were analyzed: one consisting of a copy task and an email writing task, and one with a larger difference in cognitive demand: a copy task and an academic summary task. The differences across tasks were modeled using Bayesian linear mixed effects models. Posterior distributions were used to compare the strength and direction of the task effects across features and datasets. The results showed that the average of all interkeystroke intervals were found to be stable across tasks. Features related to the time between words and (sub)sentences only differed between the copy and the academic task. Lastly, keystroke features related to the number of words, revisions, and total time, differed across tasks in both datasets. To conclude, our results indicate that the latter features are related to cognitive load or task complexity. In addition, our research shows that keystroke features are sensitive to small differences in the writing tasks at hand.

Erratum to: Measuring sequences of keystrokes with jsPsych: Reliability of response times and interkeystroke intervals.

Erratum to: Measuring sequences of keystrokes with jsPsych: Reliability of response times and interkeystroke intervals.

Typing pictures: Linguistic processing cascades into finger movements

The present study investigated the effect of psycholinguistic variables on measures of response latency and mean interkeystroke interval in a typewritten picture naming task, with the aim to outline the functional organization of the stages of cognitive processing and response execution associated with typewritten word production. Onset latencies were modulated by lexical and semantic variables traditionally linked to lexical retrieval, such as word frequency, age of acquisition, and naming agreement. Orthographic variables, both at the lexical and sublexical level, appear to influence just within-word interkeystroke intervals, suggesting that orthographic information may play a relevant role in controlling actual response execution. Lexical-semantic variables also influenced speed of execution. This points towards cascaded flow of activation between stages of lexical access and response execution.

Measuring sequences of keystrokes with jsPsych: Reliability of response times and interkeystroke intervals.

Although the precision and reliability of response time (RT) measurements performed via Web-based interfaces have been evaluated, sequences of keystrokes have never been investigated in detail. Keystrokes often occur in much more rapid succession than RTs, and operating systems may interpret successive or concomitant keyboard events according to both automatic and user-based settings. Sequence keystroke timing could thus be more sensitive than single RTs to noise in online measurements. Here, we quantified the precision and reliability of timing measures performed during sequences of keystrokes. We used the JavaScript jsPsych library to create an experiment involving finger-movement sequences, and ran it online with 633 participants. We manipulated the structure of three keystroke motor sequences, targeting a replication of previous findings regarding both RTs and interkeystroke intervals (IKIs). Our online data accurately reproduced the original results and allowed for a novel assessment of demographic variables such as age and gender. In parallel, we also measured the objective timing accuracy of the jsPsych interface by using specialized hardware and software, showing a constant 60-ms delay for RTs and a 0-ms delay for IKIs across the sequences. The distribution of IKIs revealed quantizing for a majority of participants, most likely due to the sampling frequency of their USB keyboards. Overall, these findings indicate that JsPsych provides good reliability and accuracy in sequence keystroke timings for mental chronometry purposes, through online recordings.

Typing is writing: Linguistic properties modulate typing execution

Typing is becoming our preferred way of writing. Perhaps because of the relative recency of this change, very few studies have investigated typing from a psycholinguistic perspective. In addition, and despite obvious similarities between typing and handwriting, typing research has remained rather disconnected from handwriting research. The current study aimed at bridging this gap by evaluating how typing is affected by a number of psycholinguistic variables defined at the word, syllable, and letter levels. In a writing-to-dictation task, we assessed typing performance by measuring response accuracy, onset latencies - an index of response preparation and initiation - and interkeystroke intervals (IKIs) - an index of response execution processes. The lexical and sublexical factors revealed a composite pattern of effects. Lexical frequency improved response latencies and accuracy, while bigram frequency speeded up IKIs. Sound-spelling consistency improved latencies, but had an inhibitory effect on IKI. IKIs were also longer at syllable boundaries. Together, our findings can be fit within a framework for typed production that combines the previously developed theories of spelling and typing execution. At their interface, we highlight the need for an intermediate hierarchical stage, perhaps in the form of a graphemic buffer for typing.

Two thumbs and one index: A comparison of manual coordination in touch-typing and mobile-typing

It has been extensively demonstrated that in touch-typing, manual alternation is performed faster than manual repetition (see i.e. Rumelhart & Norman, 1982), due to parallel activation of successive keystrokes. In this experiment, we tested whether the manual coordination patterns typical of touch-typing can be observed in mobile-typing.We recruited skilled touch-typists and divided them into two groups depending on their typing habits on the mobile device. The “one-hand” group typed with one index finger on the mobile, and therefore produced words exclusively through manual repetition. The “two-hands” group used two thumbs, and therefore produced words through a combination of mobile-typing repetitions and alternations. The two groups were tested in a typing to dictation task with both a standard keyboard and a mobile keyboard. Results showed that manual alternation and manual repetition patterns are similar in touch-typing and in mobile-typing. For the “two-hands” group, the mean interkeystroke intervals (IKIs) for touch-typing decreased as manual alterations in words increased in both touch- and mobile-typing. The “one-hand” group showed an opposite pattern in mobile-typing. Bigram frequency was correlated with IKIs per bigrams in both tasks and groups, but the correlation for the “one-hand” group in mobile-typing was different. Our results suggest that manual coordination processes are the same in touch-typing and in mobile-typing despite different effectors, provided that both hands are used to type.

Patterns of muscle activity for digital coarticulation

Although piano playing is a highly skilled task, basic features of motor pattern generation may be shared across tasks involving fine movements, such as handling coins, fingering food, or using a touch screen. The scripted and sequential nature of piano playing offered the opportunity to quantify the neuromuscular basis of coarticulation, i.e., the manner in which the muscle activation for one sequential element is altered to facilitate production of the preceding and subsequent elements. Ten pianists were asked to play selected pieces with the right hand at a uniform tempo. Key-press times were recorded along with the electromyographic (EMG) activity from seven channels: thumb flexor and abductor muscles, a flexor for each finger, and the four-finger extensor muscle. For the thumb and index finger, principal components of EMG waveforms revealed highly consistent variations in the shape of the flexor bursts, depending on the type of sequence in which a particular central key press was embedded. For all digits, the duration of the central EMG burst scaled, along with slight variations across subjects in the duration of the interkeystroke intervals. Even within a narrow time frame (about 100 ms) centered on the central EMG burst, the exact balance of EMG amplitudes across multiple muscles depended on the nature of the preceding and subsequent key presses. This fails to support the idea of fixed burst patterns executed in sequential phases and instead provides evidence for neuromuscular coarticulation throughout the time course of a hand movement sequence.

Measuring motor speed through typing: a surrogate for the finger tapping test

Motor speed is an important indicator and predictor of both cognitive and physical function. One common assessment of motor speed is the finger-tapping test (FTT), which is typically administered as part of a neurological or neuropsychological assessment. However, the FTT suffers from several limitations, including infrequent in-person administration, the need for a trained assessor and dedicated equipment, and potential short-term sensory-motor fatigue. In this article, we propose an alternative method of measuring motor speed, with face validity to the FTT, that addresses these limitations by measuring the interkeystroke intervals (IKI) of familiar and repeated login data collected in the home during a subject's regular computer use. We show significant correlations between the mean tapping speeds from the FTT and the median IKIs of the nondominant (r = .77) and dominant (r = .70) hands, respectively, in an elderly cohort of subjects living independently. Finally, we discuss how the proposed method for measuring motor speed fits well into the framework of unobtrusive and continuous in-home assessment.

Linguistic units in word typing

This study reports on two experiments in which German participants had to type words presented to them in various modes. Experiment 1 compares typing following visual and oral word presentation with typing following picture presentation. In the second experiment typing responses following oral and visual word presentation were delayed by an extended preparatory period. Both experiments demonstrate significantly increased inter-keystroke intervals (IKIs) at exclusive syllable (S) boundaries and combined syllable and morpheme (SM) boundaries in comparison to within-syllable (L) boundaries. SM-IKIs are significantly larger than S-IKIs and influenced by word frequencies, indicating lexical dependencies. SM-IKIs were found to be significantly longer for oral than for visual word presentation. This is taken as an indication that additional processes are involved in the accessing of graphemic word forms when words are presented orally. Two effects of the typing delay were identified: a decrease of word initial latencies and the disappearance of size differences between SM-IKIs following visual and oral word presentation. On the other hand, the persistence of augmented SM- and S-IKIs in the delayed typing task indicates that input into the motor system is constituted by sub-word units instead by fully specified words. As SM- and S-IKIs reflect influences of different hierarchical levels of language processing, these findings suggest a processing architecture in which the peripheral motor system essentially connects at several hierarchical levels with central processing units.

Medical terminology: A phonological analysis for teaching english pronunciation

The present study investigated the effect of psycholinguistic variables on measures of response latency and mean interkeystroke interval in a typewritten picture naming task, with the aim to outline the functional organization of the stages of cognitive processing and response execution associated with typewritten word production. Onset latencies were modulated by lexical and semantic variables traditionally linked to lexical retrieval, such as word frequency, age of acquisition, and naming agreement. Orthographic variables, both at the lexical and sublexical level, appear to influence just within-word interkeystroke intervals, suggesting that orthographic information may play a relevant role in controlling actual response execution. Lexical-semantic variables also influenced speed of execution. This points towards cascaded flow of activation between stages of lexical access and response execution.