Reaction Time Cost Research Articles

The Effects of Single-Bout Exercise Interventions with Different Exercise Modalities on Executive Function in Youths.

This study aimed to investigate how single-bout open-skill exercise (OSE), closed-skill exercise (CSE), and mixed-skill exercise intervention (MSE) influence executive function. A total of 120 students aged between 18 and 25 were separated into three groups: closed-skill exercise, open-skill exercise, and mixed-skill exercise. A task-switching test was performed before and after a single bout of exercise intervention. The simple reaction time, choice reaction time, switch cost, and correction rate were tested in a task-switching test. The results were analyzed via a two-way analysis of variance, with a significance level of α = 0.05, to compare the effects of the intervention. Only open-skill exercise exhibited a significant effect on the simple reaction time (p < 0.05). In terms of choice reaction time and switch cost, all three intervention groups exhibited significant improvements, with no significant differences observed between the three groups (p < 0.05). The correction rate did not show a significant effect post-intervention, and no significant differences were observed between the groups. The correction rate showed no significant effect after the intervention or between groups. All three types of exercise can shorten choice reaction time and switch cost, but only OSE can reduce simple reaction time.

The time course of the spatial representation of ‘past’ and ‘future’ concepts: New evidence from the STEARC effect

Humans use space to think of and communicate the flow of time. This spatial representation of time is influenced by cultural habits so that in left-to-right reading cultures, short durations and past events are mentally positioned to the left of long durations and future events. The STEARC effect (Space Temporal Association of Response Codes) shows a faster classification of short durations/past events with responses on the left side of space and of long durations/future events with responses on the right side. We have recently showed that during the classification of time durations, space is a late heuristic of time because in this case, the STEARC appears only when manual responses are slow, not when they are fast. Here, we wished to extend this observation to the semantic classification of words as referring to the ‘past’ or the ‘future’. We hypothesised that the semantic processing of ‘past’ and ‘future’ concepts would have engaged slower decision processes than the classification of short versus long time durations. According to dual-route models of conflict tasks, if the task-dependent classification/decision process were to proceed relatively slowly, then the effects of direct activation of culturally preferred links between stimulus and response (S-R), i.e., past/left and future/right in the case of the present task, should attain higher amplitudes before the instruction-dependent correct response is selected. This would imply that, at variance with the faster classification of time durations, during the slower semantic classification of time concepts, in incongruent trials, the direct activation of culturally preferred S-R links should introduce significant reaction time (RT) costs and a corresponding STEARC at the fastest manual responses in the experiment too. The study's results confirmed this hypothesis and showed that in the classification of temporal words, the STEARC also increased as a function of the length of RTs. Taken together, the results from sensory duration and semantic classification STEARC tasks show that the occurrence, strength and time course of the STEARC varies significantly as a function of the speed and level of cognitive processing required in the task.

Decomposing working memory subprocesses with the reference-back paradigm: Event-related potentials and age-related differences.

We used a data-driven approach to study the electrophysiological correlates of the working memory subprocesses revealed by the reference-back paradigm. In the absence of prior research, we focused on how aging affects the four subprocesses: updating, substitution, gate opening, and gate closing. We conducted our experiment with 24 younger adults (M = 20.17±1.47) and 23 older adults (M = 67.35±4.01). Significant reaction time costs were observed for all four subprocesses, but age-related differences were found only in substitution, which was larger in older than younger adults, indicating it as being the most vulnerable subprocess in aging. Using difference waves, we identified event-related potential components that characterize the subprocesses we studied. Regarding updating: three occipital negativities between 80-180 ms, 300-400 ms, and 400-1,000 ms were observed, with only the latter range showing age group differences. Source analysis showed larger activity differences in the right frontal and temporal areas for younger adults. Regarding substitution: a frontal positivity between 250-600 ms emerged in younger adults, while a posterior positivity between 550-750 ms was found in older adults indicating different underlying processes supported by sLORETA results. Regarding gate opening: three parieto-occipital components were identified: a negativity between 150-250 ms, a positivity between 300-500 ms, and a positivity between 500-700 ms, all showing age-related differences. Regarding gate closing: we found an occipital negativity between 150-300 ms and a frontal positivity between 300-600 ms, neither of which changed between the age groups. From our findings, we conclude that the process of protecting information (gate closing) remains stable with age, despite older adults' sensitivity to interference. Conversely, we observed age-related differences in gate opening, which may have led to different strategies being used by the two age groups during substitution (the process by which new information is incorporated into working memory), as reflected in the distinct brain activity patterns observed.

Bayesian multi-level modelling for predicting single and double feature visual search

Performance in visual search tasks is frequently summarised by “search slopes” - the additional cost in reaction time for each additional distractor. While search tasks with a shallow search slopes are termed efficient (pop-out, parallel, feature), there is no clear dichotomy between efficient and inefficient (serial, conjunction) search. Indeed, a range of search slopes are observed in empirical data. The Target Contrast Signal (TCS) Theory is a rare example of quantitative model that attempts to predict search slopes for efficient visual search. One study using the TCS framework has shown that the search slope in a double-feature search (where the target differs in both colour and shape from the distractors) can be estimated from the slopes of the associated single-feature searches. This estimation is done using a contrast combination model, and a collinear contrast integration model was shown to outperform other options. In our work, we extend TCS to a Bayesian multi-level framework. We investigate modelling using normal and shifted-lognormal distributions, and show that the latter allows for a better fit to previously published data. We run a new fully within-subjects experiment to attempt to replicate the key original findings, and show that overall, TCS does a good job of predicting the data. However, we do not replicate the finding that the collinear combination model outperforms the other contrast combination models, instead finding that it may be difficult to conclusively distinguish between them.

Planning ahead: Predictable switching recruits task-active and resting-state networks.

Switching is a difficult cognitive process characterised by costs in task performance; specifically, slowed responses and reduced accuracy. It is associated with the recruitment of a large coalition of task-positive regions including those referred to as the multiple demand cortex (MDC). The neural correlates of switching not only include the MDC, but occasionally the default mode network (DMN), a characteristically task-negative network. To unpick the role of the DMN during switching we collected fMRI data from 24 participants playing a switching paradigm that perturbed predictability (i.e., cognitive load) across three switch dimensions-sequential, perceptual, and spatial predictability. We computed the activity maps unique to switch vs. stay trials and all switch dimensions, then evaluated functional connectivity under these switch conditions by computing the pairwise mutual information functional connectivity (miFC) between regional timeseries. Switch trials exhibited an expected cost in reaction time while sequential predictability produced a significant benefit to task accuracy. Our results showed that switch trials recruited a broader activity map than stay trials, including regions of the DMN, the MDC, and task-positive networks such as visual, somatomotor, dorsal, salience/ventral attention networks. More sequentially predictable trials recruited increased activity in the somatomotor and salience/ventral attention networks. Notably, changes in sequential and perceptual predictability, but not spatial predictability, had significant effects on miFC. Increases in perceptual predictability related to decreased miFC between control, visual, somatomotor, and DMN regions, whereas increases in sequential predictability increased miFC between regions in the same networks, as well as regions within ventral attention/ salience, dorsal attention, limbic, and temporal parietal networks. These results provide novel clues as to how DMN may contribute to executive task performance. Specifically, the improved task performance, unique activity, and increased miFC associated with increased sequential predictability suggest that the DMN may coordinate more strongly with the MDC to generate a temporal schema of upcoming task events, which may attenuate switching costs.

Advanced treatment of pharmaceutical wastewater with foam fractionation coupled with heterogeneous Fenton

Biochemical effluents of pharmaceutical wastewater contain many humic substances and small amounts of suspended matter. In this study, foam fractionation coupled with heterogeneous Fenton (FF-HF) was designed as an advanced wastewater treatment process. Using the same settings based on separate optimizations, the dissolved organic matter (DOC) removal efficiency of FF-HF was 71.6 %, 23.7 % higher than that of HF alone. In addition, a shorter reaction time (37.3 % HF) and lower cost (31.6 % HF) were required for FF-HF. Thus, FF-HF is promising for the advanced treatment of pharmaceutical wastewater. According to the organic matter removal characterization, FF can effectively remove humic substances, organic colloids, and other macroscopic or hydrophobic organic matter. The design of the pre-FF process can decrease the pollutant load of HF, which explains the enhanced performance of the coupling process.

Omit needless words: Sentence length perception.

Short sentences improve readability. Short sentences also promote social justice through accessibility and inclusiveness. Despite this, much remains unknown about sentence length perception-an important factor in producing readable writing. Accordingly, we conducted a psychophysical study using procedures from Signal Detection Theory to examine sentence length perception in naive adults. Participants viewed real-world full-page text samples and judged whether a bolded target sentence contained more or fewer than 17 words. The experiment yielded four findings. First, naïve adults perceived sentence length in real-world text samples quickly (median = 300-400 ms) and precisely (median = ~90% correct). Second, flipping real-world text samples upside-down generated no reaction-time cost and nearly no loss in the precision of sentence length perception. This differs from the large inversion effects that characterize other highly practiced, real-world perceptual tasks involving canonically oriented stimuli, most notably face perception and reading. Third, participants significantly underestimated the length of mirror-reversed sentences-but not upside-down, nor standard sentences. This finding parallels participants' familiarity with commonly occurring left-justified right-ragged text, and suggests a novel demonstration of left-lateralized anchoring in scene syntax. Fourth, error patterns demonstrated that participants achieved their high speed, high precision sentence-length judgments by heuristically counting text lines, not by explicitly counting words. This suggests practical advice for writing instructors to offer students. When copy editing, students can quickly and precisely identify their long sentences via a line-counting heuristic, e.g., "a 17-word sentence spans about 1.5 text lines". Students can subsequently improve a long sentence's readability and inclusiveness by omitting needless words.

Restart errors reaction time of a two-step inhibition process account for the violation of the race model's independence in multi-effector selective stop signal task.

Goal-oriented actions often require the coordinated movement of two or more effectors. Sometimes multi-effector movements need to be adjusted according to a continuously changing environment, requiring stopping an effector without interrupting the movement of the others. This form of control has been investigated by the selective Stop Signal Task (SST), requiring the inhibition of an effector of a multicomponent action. This form of selective inhibition has been hypothesized to act through a two-step process, where a temporary global inhibition deactivating all the ongoing motor responses is followed by a restarting process that reactivates only the moving effector. When this form of inhibition takes place, the reaction time (RT) of the moving effector pays the cost of the previous global inhibition. However, it is poorly investigated if and how this cost delays the RT of the effector that was required to be stopped but was erroneously moved (Stop Error trials). Here we measure the Stop Error RT in a group of participants instructed to simultaneously rotate the wrist and lift the foot when a Go Signal occurred, and interrupt both movements (non-selective Stop version) or only one of them (selective Stop version) when a Stop Signal was presented. We presented this task in two experimental conditions to evaluate how different contexts can influence a possible proactive inhibition on the RT of the moving effector in the selective Stop versions. In one context, we provided the foreknowledge of the effector to be inhibited by presenting the same selective or non-selective Stop versions in the same block of trials. In a different context, while providing no foreknowledge of the effector(s) to be stopped, the selective and non-selective Stop versions were intermingled, and the information on the effector to be stopped was delivered at the time of the Stop Signal presentation. We detected a cost in both Correct and Error selective Stop RTs that was influenced by the different task conditions. Results are discussed within the framework of the race model related to the SST, and its relationship with a restart model developed for selective versions of this paradigm.

Neural processes underlying faking and concealing a personal identity: An electroencephalogram study

The detection of lies told about one's identity challenges traditional methods considering characteristics of the lie. This study explored the neural activities underlying identity deception by using electroencephalogram recordings to promote the development of a detection tool. The participants (N = 18) were required to tell a lie or the truth about true and false identity information with the differentiation of deception paradigm. The results showed deceptive (vs. honest) responses to true identity information were associated with a prolonged reaction time and enhanced upper alpha oscillations as well as the attenuated P300 and theta activities, which indicates identity concealment engaged portent honest response control and reduced processing of self-relevant information. By contrast, deceptive (vs. honest) responses to false identity information were associated with absent reaction time cost and decreased alpha activities, which suggests identity faking involved low cognitive conflict but required some degree of behavioral regulation.

Experimental study of a rapid rate biofuel production in a cyclone type reactor

A cyclone-type transesterification system at a pilot scale setup is developed to minimize production costs. This device works on the concept of a cyclone separator in which the straight vegetable oil was injected tangentially to create a vortex. Then a solution of methoxide was poured slowly. An electric heater was provided externally for the perfect reaction of SVOs with methoxide solution. Biodiesel is gaining prominence as substitute of fossil-fuel to minimize the diminution of fossil fuels. It is a safe storable, non-toxic renewable energy source with characteristics comparable to petro-diesel. In the present biodiesel production system, the denser particles were forced towards the chamber wall and light particles in the central position of the reactor. Hence, due to the gravity effect, denser particles fell below in the collection chamber and recirculated, and the biodiesel is obtained after the reactor's completion in a specific time. The developed system is an effective and efficient technique to reduce reaction time and production cost with enhanced production capacity in a small reactor.

Lingering Neural Representations of Past Task Features Adversely Affect Future Behavior.

During goal-directed behavior, humans purportedly form and retrieve so-called event files, conjunctive representations that link context-specific information about stimuli, their associated actions, and the expected action outcomes. The automatic formation, and later retrieval, of such conjunctive representations can substantially facilitate efficient action selection. However, recent behavioral work suggests that these event files may also adversely affect future behavior, especially when action requirements have changed between successive instances of the same task context (e.g., during task switching). Here, we directly tested this hypothesis with a recently developed method for measuring the strength of the neural representations of context-specific stimulus-action conjunctions (i.e., event files). Thirty-five male and female adult humans performed a task switching paradigm while undergoing EEG recordings. Replicating previous behavioral work, we found that changes in action requirements between two spaced repetitions of the same task incurred a significant reaction time cost. By combining multivariate pattern analysis and representational similarity analysis of the EEG recordings with linear mixed-effects modeling of trial-to-trial behavior, we then found that the magnitude of this behavioral cost was directly proportional to the strength of the conjunctive representation formed during the most recent previous exposure to the same task, that is, the most recent event file. This confirms that the formation of conjunctive representations of specific task contexts, stimuli, and actions in the brain can indeed adversely affect future behavior. Moreover, these findings demonstrate the potential of neural decoding of complex task set representations toward the prediction of behavior beyond the current trial.SIGNIFICANCE STATEMENT Understanding how the human brain organizes individual components of complex tasks is paramount for understanding higher-order cognition. During complex tasks, the brain forms conjunctive representations that link individual task features (contexts, stimuli, actions), which aids future performance of the same task. However, this can have adverse effects when the required sequence of actions within a task changes. We decoded conjunctive representations from electroencephalographic recordings during a task that included frequent changes to the rules determining the response. Indeed, stronger initial conjunctive representations predicted significant future response-time costs when task contexts repeated with changed response requirements. Showing that the formation of conjunctive task representations can have negative future effects generates novel insights into complex behavior and cognition, including task switching, planning, and problem solving.

Pramipexole modulates fronto-subthalamic pathway in sequential working memory

Brain dopamine may regulate the ability to maintain and manipulate sequential information online. However, the precise role of dopamine remains unclear. This pharmacological fMRI study examined whether and how the dopamine D2/3 receptor agonist pramipexole modulates fronto-subthalamic or fronto-striatal pathways during sequential working memory. This study used a double-blind, randomized crossover design. Twenty-two healthy male volunteers completed a digit ordering task during fMRI scanning after receiving a single oral dose of 0.5-mg pramipexole or placebo. The pramipexole effects on task performance, regional activity, activity pattern similarity, and functional connectivity were analyzed. Pramipexole impaired task performance, leading to less accurate and slower responses in the digit ordering task. Also, it downregulated the maintenance-related subthalamic and dorsolateral prefrontal activity, increasing reaction times for maintaining sequences. In contrast, pramipexole upregulated the manipulation-related subthalamic and dorsolateral prefrontal activity, increasing reaction time costs for manipulating sequences. In addition, it altered the dorsolateral prefrontal activity pattern similarity and fronto-subthalamic functional connectivity. Finally, pramipexole reduced maintenance-related striatal activity, which did not affect the behavior. This study confirms the role of the fronto-subthalamic pathway in sequential working memory. Furthermore, it shows that D2 transmission can regulate sequential working memory by modulating the fronto-subthalamic pathway.

Development of a low-cost multi-channel nucleic acid detection PCR instrument and clinical detection application of COVID-19

Since the COVID-19 outbreak at the end of December 2019, a variety of novel Coronavirus nucleic acid detection methods have been proposed at home and abroad. Because of the disadvantages of most existing PCR instruments on the market such as long reaction time and high cost, this study developed a more timesaving and cheaper two-channel real-time quantitative PCR instrument. In this instrument, a PCR system combining a thermal cycle system and real-time fluorescence quantitative technology was designed. The software system and data processing, optical system, thermal cycle module, and hardware module of the PCR instrument were studied. The low-cost, portable real-time quantitative PCR system has been validated with consistent results compared to Bio-rad CFX Connect. At the same time, the same samples were used for the contract experiment with the hospital instrument, and the amplification result was better than the existing instrument in the hospital.

Reaction Time “Mismatch Costs” Change with the Likelihood of Stimulus–Response Compatibility

Dyadic interactions require dynamic correspondence between one’s own movements and those of the other agent. This mapping is largely viewed as imitative, with the behavioural hallmark being a reaction-time cost for mismatched actions. Yet the complex motor patterns humans enact together extend beyond direct-matching, varying adaptively between imitation, complementary movements, and counter-imitation. Optimal behaviour requires an agent to predict not only what is likely to be observed but also how that observed action will relate to their own motor planning. In 28 healthy adults, we examined imitation and counter-imitation in a task that varied the likelihood of stimulus–response congruence from highly predictable, to moderately predictable, to unpredictable. To gain mechanistic insights into the statistical learning of stimulus–response compatibility, we compared two computational models of behaviour: (1) a classic fixed learning-rate model (Rescorla–Wagner reinforcement [RW]) and (2) a hierarchical model of perceptual-behavioural processes in which the learning rate adapts to the inferred environmental volatility (hierarchical Gaussian filter [HGF]). Though more complex and hence penalized by model selection, the HGF provided a more likely model of the participants’ behaviour. Matching motor responses were only primed (faster) in the most experimentally volatile context. This bias was reversed so that mismatched actions were primed when beliefs about volatility were lower. Inferential statistics indicated that matching responses were only primed in unpredictable contexts when stimuli–response congruence was at 50:50 chance. Outside of these unpredictable blocks the classic stimulus–response compatibility effect was reversed: Incongruent responses were faster than congruent ones. We show that hierarchical Bayesian learning of environmental statistics may underlie response priming during dyadic interactions.

Proactive and reactive control differ between task switching and response rule switching: Event-related potential evidence

The distinction between task-switching (T-switch) and response-rule switching (RR-switch) has been reported in previous studies. However, it is unclear whether the neural correlates of proactive and reactive control differ between T-switch and RR-switch. In this study, a modified cue-target task was adopted. When the cue in the current trial differed from that in the preceding trial in shape (or color), the participants had to perform a T-switch (or RR-switch). Otherwise, they performed the same task following the same response rule. The behavioral results showed that the switch cost was greater for the RR-switch than for the T-switch. The event-related potential results indicated that (1) for cues, the switch-positivity in the late positive component (LPC) (500–800 ms) was more enhanced for the RR-switch than for the T-switch over the central to parietal regions, reflecting increased proactive control for the RR-switch compared with the T-switch; (2) for targets, the P3 amplitude was more attenuated in the RR-switch than the T-switch over the central and parietal regions, reflecting increased reactive control for the RR-switch; and (3) under the T-switch, the switch-positivity in the cue-LPC was negatively correlated with accuracy cost, while under the RR-switch, the switch negativity in the target-P3 was positively correlated with the reaction time cost. These findings suggest that similar proactive and reactive control are recruited in the T-switch and RR-switch, whereas cognitive control efforts clearly differ between them, perhaps due to different sub-processes.

Altered Neural Reactivity in Adolescents With Nonsuicidal Self-Injury During Exposure to Self-Injury Related Cues: Electrophysiological Evidence From a Two-Choice Oddball Paradigm.

BackgroundNonsuicidal self-injury (NSSI) may be a type of addiction, that is characterized by cue reactivity. We aimed to explore the behavioral performance and neural reactivity during exposure to self-injury cues in adolescents with NSSI and major depressive disorder (MDD).MethodsEighteen MDD patients, 18 MDD patients with NSSI, and 19 healthy controls (HC) were recruited to perform a two-choice oddball paradigm. All subjects were 12–18 years old. Neutral cues and self-injury related cues separately served as deviant stimuli. Difference waves in N2 and P3 (N2d and P3d) were derived from deviant waves minus standard waves. Accuracy cost and reaction time (RT) cost were used as behavioral indexes, while the N2d and P3d were used as electrophysiological indexes; the N2d reflects early conflict detection, and the P3d reflects the process of response inhibition.ResultsNo significant main effects of group or cue or an effect of their interaction were observed on accuracy cost and P3d latency. For RT cost, N2d amplitude, and N2d latency, there was a significant main effect of cue. For P3d amplitude, there was a significant main effect of cue and a significant group × cue interaction. In the NSSI group, the P3d amplitude with self-injury cues was significantly larger than that with neutral cues. However, there was no such effect in the MDD and HC groups.ConclusionsAdolescents with NSSI showed altered neural reactivity during exposure to self-injury cue. Further studies with larger sample sizes are needed to confirm our results.

Performance Investigation of Fiber Distributed Data Interface in Networking

Abstract: The extent of the ring, the number of stations on the ring, the number of stations waiting to communicate, and the frame size are all setup and workload characteristics that affect the performance of an FDDI LAN. In addition, the target token rotation time is a significant parameter that network management may regulate to optimise performance (TTRT). The influence of the TTRT on various performance indicators for different ring topologies was investigated using analytical modelling and simulation approaches. The performance of the FDDI network is the topic of this research. The functionality of the FDDI network was then assessed in terms of efficiency, reaction time, and network cost using various values of ring latency, fixed target token rotation time (TTRT), and number of stations. The entire project is done in MATLAB. Keywords: FDDI LAN, TTRT, Interface, Networking, MATLAB

A single rapid route synthesis of magnetite/chitosan nanocomposite: Competitive study

At last decides, the modification of synthesis protocol towards shorter reaction time, fewer steps, and lower resources cost was needed. The synthesis of magnetite (Fe3O4) polymer nanocomposite is heavily studied nowadays due to its promising applications. In this study, magnetite chitosan nanocomposite was synthesized through two competitive routes; a new single route synthesis based on co-precipitation at hydrothermal conditions, and the second route a conventional multi-synthetic route based on using the blending solution method after magnetite nanoparticles synthesis by the co-precipitation method of magnetite. The synthesized Fe3O4 and its nanocomposites are characterized by several techniques, including Fourier transition infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibration sample magnetometer (VSM). The results showed magnetite polymer nanocomposite synthesized via a single synthetic route had less particle size, more distribution in the chitosan matrix, and higher magnetization saturation than that synthesized via a multi-synthetic route. Adsorption of Rodamine 6G dye on magnetite chitosan nanocomposite was studied in different parameters. The adsorption results showed a rapid process following the Tempkin isotherm.

High verbal working memory load impairs gesture-speech integration

Abstract While previous studies have shown the importance of visuo-spatial working memory in the processing of co-speech iconic gestures, clear evidence for a potential involvement of the verbal working memory (vWM) is currently lacking. To address this issue, participants in the present study were presented with a dual task paradigm. The main outcome variable was the performance on a Stroop-like gesture task which provides a behavioural index of gesture-speech integration. Participants performed this task under conditions of either high or low concurrent vWM load. Unlike in previous studies, the number of words to remember in the high load condition was determined by their individual verbal span rather than being fixed. Results showed reaction time costs in the form of longer reaction times for semantically incongruent gesture-speech combinations as compared to congruent combinations. However, this semantic congruency effect disappeared when the vWM load increased. This result suggests a causal involvement of verbal working memory capacity in gesture-speech integration.

Supercritical hydrothermal synthesis of nano-ZrO2: Influence of technological parameters and mechanism

Supercritical hydrothermal synthesis is a promising technology to produce nano-ZrO2 due to its simple craft, short reaction time and low cost. In this paper, nano-ZrO2 particles with an average particle size of 5.66–35.43 nm were successfully prepared by supercritical hydrothermal method. Meanwhile, the influences of reaction temperature, pressure, time, precursor concentration and pH value on the particle size distributions and surface topographies of nano-ZrO2 were investigated under different conditions. Reaction time and precursor concentration were strong influencing factors of particle sizes and distributions. The reaction mechanisms of different crystal forms were controlled by pH value of the precursor. Under acidic conditions, soluble [Zr4(OH)8(H2O)16] 8+ was produced due to the hydrolysis of precursors, and the appearance of abundant monoclinic nucleus was triggered subsequent condensation of [Zr4(OH)8(H2O)16] 8+. In-situ crystallization dominated the crystallization process and the tetragonal phase was formed by the rearrangement of the precursor structures. The intermediate product Zr(OH)3NO3 was detected under high pH conditions.