Clock Hand Research Articles

The AVERT MoCA Data: Scoring Reliability in a Large Multicenter Trial.

The Montreal Cognitive Assessment (MoCA) is a widely used cognitive screening tool in stroke. As scoring the visuospatial/executive MoCA items involves subjective judgement, reliability is important. Analyzing data on these items from A Very Early Rehabilitation Trial (AVERT), we compared the original scoring of assessors (n = 102) to blind scoring by a single, independent rater. In a sample of scoresheets from 1,119 participants, we found variable interrater reliability. The match between original assessors and the independent rater was the following: trail-making 97% (κ = 0.94), cube copy 90% (κ = 0.80), clock contour 92% (κ = 0.49), clock numbers 89% (κ = 0.67), and clock hands 72% (κ = 0.46). For all items except clock contour, the independent rater was "stricter" than the original assessors. Discrepancies were typically errors in original scoring, rather than borderline differences in subjective judgement. In trials that include the MoCA, researchers should emphasize scoring rules to assessors and implement independent data checking, especially for clock hands, to maximize accuracy.

Time as a measure: Elementary students positioning the hands of an analog clock

Elementary students have difficulty with the topic of time. The present study investigated students’ actions to position hour and minute hands on an analog clock to indicate particular times of the day. Using one-on-one interviews with students in Grades 2 and 4 (n = 48), we analyzed whether students were more accurate for one hand indicator (hour or minute) versus the other as well as their solution approaches as they positioned each hand. We first present a quantitative analysis of student performance to document whether hour and minute hands posed differential challenges for students as they positioned hands to indicate particular times. Results indicate the hour hand is significantly more challenging to position accurately than the minute hand. Students’ solutions reflected varied approaches, including consideration of the quantitative hour-minute multiplicative relationship, attention to part-whole relations, and matching numbers from the provided time to numerals on the clock. We discuss implications for theory and instruction, including the relationship of time to length measure learning trajectories and the current treatment of time in K-12 mathematics standards for the United States.

Time as a measure: Elementary students positioning the hands of an analog clock

Elementary students have difficulty with the topic of time. The present study investigated students’ actions to position hour and minute hands on an analog clock to indicate particular times of the day. Using one-on-one interviews with students in Grades 2 and 4 (n = 48), we analyzed whether students were more accurate for one hand indicator (hour or minute) versus the other as well as their solution approaches as they positioned each hand. We first present a quantitative analysis of student performance to document whether hour and minute hands posed differential challenges for students as they positioned hands to indicate particular times. Results indicate the hour hand is significantly more challenging to position accurately than the minute hand. Students’ solutions reflected varied approaches, including consideration of the quantitative hour-minute multiplicative relationship, attention to part-whole relations, and matching numbers from the provided time to numerals on the clock. We discuss implications for theory and instruction, including the relationship of time to length measure learning trajectories and the current treatment of time in K-12 mathematics standards for the United States.

Normative data for the Clock Drawing Test for French-Quebec mid- and older aged healthy adults

Objective: The Clock Drawing Test (CDT) is frequently used to screen for cognitive impairment, however, normative data for Rouleau et al.’s scoring system are scarce. The present study aims to provide norms for Rouleau et al.’s scoring system that are tailored to Quebec French-speaking mid- and older aged healthy adults.Methods: Six researchers from various research centers across the Province of Quebec (Canada) sent anonymous data for 593 (391 women) healthy community-dwelling volunteers (age range: 43–93 years; education range: 5–23 years) who completed the CDT ‘drawing on command’ version. This command version (setting the clock hands to 11:10, without a pre-drawn circle) was administrated as part of a more extensive neuropsychological assessment, or along with cognitive screening instruments. Each drawn clock was scored according to the quantitative criteria set by Rouleau et al.’s scoring system.Results: CDT scores were significantly correlated with age (r(592) = −.132, p = .001) and years of education (r(592) = .116, p = .005), but not with sex (r(592) = .065, p = .112). Since data were skewed towards higher test scores, the percentiles method was used for analysis. Percentile ranks stratified by age and education are presented.Conclusion: These normative data for Rouleau et al.’s scoring system will contribute towards adequately screening for cognitive decline in Quebec French-speaking healthy adults, by also taking into account individual characteristics such as age and education.

The Time Course of Intentional Binding for Late Effects

Stimuli elicited by one’s own actions (i.e., effects) are perceived as temporally earlier compared to stimuli not elicited by one’s own actions. This phenomenon is referred to as intentional binding (IB), and is commonly used as an implicit measure of sense of agency. Typically, IB is investigated by employing the so-called clock paradigm, in which participants are instructed to press a key (i.e., perform an action), which is followed by a tone (i.e., an effect), while presented with a rotating clock hand. Participants are then asked to estimate the position of the clock hand at tone onset. This time point estimate is compared to a baseline estimate where the tone is presented without any preceding action. In the present study, we investigated IB for effects occurring after relatively long delay durations (500 ms, 650 ms, 800 ms), while manipulating the temporal predictability of the delay duration. We observed an increase of IB for longer delay durations, whereas the temporal predictability did not significantly influence the magnitude of IB. This extends previous findings obtained with the clock paradigm, which have shown an increase of IB for very short delay ranges (<250 ms), but a decrease for intermediate delay ranges up to delay durations of 650 ms. Our findings, thus, indicate rather complex temporal dynamics of IB that might look similar to a wave-shaped function.

Intentional binding of visual effects.

When an action produces an effect, the effect is perceived earlier in time compared to a stimulus without preceding action. This temporal bias is called intentional binding (IB) and serves as an implicit measure of sense of agency. Typically, IB is investigated by presenting a rotating clock hand while participants execute an action and perceive a resulting tone. Participants are asked to estimate the time point of tone onset by referring to the clock hand position. This timepoint estimate is compared to a timepoint estimate of a tone in a condition in which the tone occurs without preceding action. Studies employing this classic clock paradigm employed auditory action effects. We modified this paradigm to investigate potential IB of visual action effects, and, additionally, to investigate how IB differs for visual action effects (Experiment 1) in comparison to auditory action effects (Experiment 2). Our results show that, like the IB of anauditory effect, the time point of a visual action effect is shifted toward the causing action, and that the size of the IB depends on the delay durationof the effect. Comparable to auditory action effects, earlier action effects showed stronger IB compared to later action effects. Yet overall IB of the visual effects was weaker than IB of the auditory effects. As IB is seen as an indicator of sense of agency, this may have important implications for the design of human-machine interfaces.

Where Does the Transplanted Fat is Located in the Gluteal Region? Research Letter

ABSTRACTIntroduction: Liposuction is one of the most popular plastic surgery procedures. As in any surgery, there are risks and complications, especially when combined with fat injection. Case reports of fat embolism have been reported. A possible explanation is the puncture and tearing of gluteal vessels during the procedure, especially when a deep injection is planned. Objective: To identify the places where fat can be located after injection during a fat graft in the gluteus. Methods: An experimental study was done in which colorant was injected in four directions using four different quadrants of the gluteus. We Injected 10 cc six times following clock hands until 60 cc were injected, and the cutaneous flap and the muscles were then elevated. Our main purpose was to describe where the colorant went and if it was in contact with the vessels (superior and inferior gluteal vessels). In total, four gluteus muscles were injected and dissected. Results: Injection in the lower lateral quadrant was mainly into the muscle, and colorant was observed in the hypogastric vessels. The injection in the upper quadrants stayed mainly in the subcutaneous tissue. Conclusions. During surgery, it is important to identify the location of the perforators and to avoid a deep injection, especially from the lower lateral quadrant to the superior medial quadrant (Q4 to Q1), as the probability of puncturing and injecting fat into the main vessels from this direction is higher.

Subjective Perception of Time: Research Applied on Dynamic Psychology

The time marked by the clock hands, the so-called “objective time,” is deeply different from the one perceived by the individual. Starting from this hypothesis, directly connected to the subjective modality of “living” the time and defined as time perspective, we will try to understand how much it affects the various domains of people's lives, attitudes, and experiences. Therefore, the research investigates whether all our decisions can be influenced by one or more time perspectives beyond our awareness (i.e., by the process that allows us to organize our lived experiences in time categories). Last, but not least, we will try to understand if some time perspectives in specific contexts are more functional and adaptive than others.

Social Transmission of Experience of Agency: An Experimental Study.

The sense of controlling one’s own actions is fundamental to normal human mental function, and also underlies concepts of social responsibility for action. However, it remains unclear how the wider social context of human action influences sense of agency. Using a simple experimental design, we investigated, for the first time, how observing the action of another person or a robot could potentially influence one’s own sense of agency. We assessed how observing another’s action might change the perceived temporal relationship between one’s own voluntary actions and their outcomes, which has been proposed as an implicit measure of sense of agency. Working in pairs, participants chose between two action alternatives, one rewarded more frequently than the other, while watching a rotating clock hand. They judged, in separate blocks, either the time of their own action, or the time of a tone that followed the action. These were compared to baseline judgements of actions alone, or tones alone, to calculate the perceptual shift of action toward outcome and vice versa. Our design focused on how these two dependent variables, which jointly provide an implicit measure of sense of agency, might be influenced by observing another’s action. In the observational group, each participant could see the other’s actions. Multivariate analysis showed that the perceived time of action and tone shifted progressively toward the actual time of outcome with repeated experience of this social situation. No such progressive change occurred in other groups for whom a barrier hid participants’ actions from each other. However, a similar effect was observed in the group that viewed movements of a human-like robotic hand, rather than actions of another person. This finding suggests that observing the actions of others increases the salience of the external outcomes of action and this effect is not unique to observing human agents. Social contexts in which we see others controlling external events may play an important role in mentally representing the impact of our own actions on the external world.

Individuating in the dark: Diagrammatic reasoning and attentional shifts

AbstractThis inquiry first identifies signs whose representamen are inherently visuo-spatial (namely, Index) supplying rationale for dicisign status, then demonstrates how such results in difficulties without visual access. Virtually all of Peirce’s illustrations of Index surface in the visual modality: weathercock, clock hands (1903: EP 2: 274), pointing finger, smoke. Experimental findings from blind and sighted children suggest the less effective nature of semiotic alternatives to visual indexes (tactual landmarks), to disambiguate objects in other modalities. In short, delays in use of index leave blind children vulnerable to protracted means to individuate, and ultimately to reduced participation in joint attentional ventures.

Visuospatial working memory facilitates indoor wayfinding and direction giving

The goal was to test the role of verbal and visuospatial working memory in wayfinding and direction giving in an indoor environment using a dual task paradigm. One hundred ninety-two participants were asked to find their way through one floor of a complex building and to provide directions for a fictitious recipient to find the way in one of three conditions: control (no secondary task), verbal dual task (word-nonword judgments as secondary task), or visuospatial dual task (clock hand judgments as secondary task). Wayfinding was slower in the visuospatial dual task condition than in the control condition, with the verbal condition intermediate. Directions were less accurate in the visuospatial dual task condition than in control and verbal conditions. Women provided more information in wayfinding directions than did men. Together, these findings indicate that visuospatial working memory plays an important role in wayfinding and direction giving in an indoor environment.

Water-clock-based autonomous flow sequencing in steadily rotating centrifugal microfluidic device

In this paper, we report the demonstration of a flow sequencing method in a centrifugal microfluidic device rotated at a constant speed. The simple poly-dimethylsioxiane chip, which consists of microchannels, chambers, and vent holes, was integrated in a compact disk substrate, and multistep flow sequencing was executed by simply spinning the device at a constant rotational speed. All the triggers were controlled by a water clock using the liquid meniscus as the clock hand. The flow modes to the sample chambers were switched by switching the air supply to the sample chambers, depending of on whether the meniscus water clock was inside the channel connection (disabling air supply) or outside it (enabling air supply). A four-step flow sequence was successfully executed using two different connections of the chambers, namely, parallel connection and serial connection. Highly reproducible autonomous trigger timing with a typical error of less than 3% was achieved. Delicate adjustment of the flow sequencing by varying the channel geometry was also demonstrated. The time-scaling of the flow sequencing was accomplished by changing the viscosity of the fluid in the water clock. Additionally, a four-step flow sequencing involving a flow injection chain was successfully demonstrated by serial connection. Through combinations and further variations of these concepts, it is expected that the proposed method would be used to realize higher-order flow programs in steadily spinning centrifugal microfluidic devices.

Mathematical understanding of nature: essays on amazing physical phenomena and their understanding by mathematicians

The eccentricity of the Keplerian orbit of Mars Rescuing the empennage Return along a sinusoid The Dirichlet integral and the Laplace operator Snell's law of refraction Water depth and Cartesian science A drop of water refracting light Maximal deviation angle of a beam The rainbow Mirages Tide, Gibbs phenomenon, and tomography Rotation of a liquid What force drives a bicycle forward? Hooke and Keplerian ellipses and their conformal transformations The stability of the inverted pendulum and Kapitsa's sewing machine Space flight of a photo camera cap The angular velocity of a clock hand and Feynman's oself-propagating pseudoeducationo Planetary rings Symmetry (and Curie's principle) Courant's erroneous theorems Ill-posed problems of mechanics Rational fractions of flows Journey to the center of the earth Mean frequency of explosions (according to Ya. B. Zel'dovich) and de Sitter's world The Bernoulli fountains of the Nikologorsky bridge Shape formation in a three-liter glass jar Lidov's moon landing problem The advance and retreat of glaciers The ergodic theory of geometric progressions The Malthusian partitioning of the world Percolation and the hydrodynamics of the universe Buffon's problem and integral geometry Average projected area The mathematical notion of potential Inversion in cylindrical mirrors in the subway Adiabatic invariants Universality of Hack's exponent for river lengths Resonances in the Shukhov tower, in the Sobolev equation, and in the tanks of spin-stabilized rockets The theory of rigid body rotation and hydrodynamics

Erratum to: Culture of sedimentation in the human–technology interaction

In the original publication, reference to Rosenberger (2009a) was incorrectly cited in Sects. 6 and 7. The text with corrected citations is provided below. Hermeneutics of technologies culturally interpreted can be called material hermeneutics. In other words, material hermeneutics is dealing with the art of embodied interpretation of material culture and technologies. In other words, material hermeneutics comprises of sensorimotor experience (Tripathi and Nath 2011). A hermeneutic relation is the one in which the user interfaces with the technology by reading off it and interpreting that readout (Ihde 1990, p. 80). Entering into a hermeneutic relation requires that a user possess the skills necessary to decipher the encoded meaning displayed by the technology. In many instances, if one possesses these interpretive skills, the meaning appears all at once in a perceptual gestalt. For example, when one knows how to ‘‘tell time,’’ one need not consciously deduce the meaning of the placement of the hands of an analogue clock; the time of day is conveyed immediately (Rosenberger 2009a). The first kind of relation that Ihde identifies is called an embodiment relation. When one shares an embodiment relation to a technology, one experiences the world through that technology (Ihde 1990, p. 72). Though using a technology may significantly alter a person’s perceptions or abilities, the user may become accustomed to the technology’s presence. The device itself withdraws into the background of the user’s awareness, and attention is focused on what is being done with the device. For example, one can become accustomed to looking through a magnifying glass. In Ihde’s language, this person embodies the technology (Rosenberger 2009a). In many cases, as Rosenberger elaborates ‘‘embodying a technology with any proficiency requires a degree of familiarity; only after becoming accustomed to its use can one think more about what one is doing with a device than about how the device is used. For example, after one has practiced riding a bike, one becomes less aware of the feeling of steering and pedalling’’ (Rosenberger 2009a). The third kind of relation to technology is called an alterity relation. The term ‘‘alterity,’’ borrowed from the philosophy of Emmanuel Levinas, refers to the special experience of the presence of another person (Rosenberger 2009a). According to Ihde, some of our relations to technology partially resemble the experience of interacting with a person. He says we relate to these devices as ‘‘quasiother’’ (Ihde 1990, p. 97). The standard example is the experience of using an automatic teller machine (ATM) to perform banking transactions. (In this form of relations, we have to trust the machine and follow the machine instructions.) A user is posed questions by the ATM’s screen and is asked for responses, and the range of interactions with the machine is typically limited to these questions and answers, says Rosenberger. It is important here to also review two variables that apply to each of these three kinds of relations to technology. Not everyone’s relationships with a technology are the same. These variables help articulate certain differences. The first is what Ihde calls transparency. This refers The online version of the original article can be found under doi:10.1007/s00146-015-0581-z.

Parkinson's disease patients showed delayed awareness of motor intention

Although dopamine plays an important role for motor control and modulates the frontal function via basal ganglia-thalamo-cortical loop, it is not known whether dopamine can affect the awareness of motor intention or not. To test this hypothesis, we applied Libet's clock paradigm to Parkinson's disease (PD) patients. Thirteen PD patients and 13 age-matched, healthy controls took part in the experiment which consisted of three judgment paradigms: W, M and S judgment. In W and M judgments, subjects were asked to press the key at self-willed timing. In W judgment, subjects reported the location of the clock's hand when they became aware of the intention (W-time). In M judgment, subjects reported the time when they became aware of the actual movement (M-time). In S judgment, subjects reported the time of the electrical stimulation given to their hand (S-time). W-time was significantly shorter in PD patients than in healthy control subjects while M-time and S-time were not different between the two groups. Delayed awareness of motor intention but not of action in PD patients might be related to dopamine depletion in those patients.

Segmentation of Clock Drawings Based on Spatial and Temporal Features

The Clock Drawing Test (CDT) is an inexpensive and effective measure for early detection of cognitive impairment in the elderly, which is important for timely diagnosis and initiation of appropriate treatment. Currently, medical experts assess the drawings based on their judgement and a number of available scoring systems. An automatic system for assessment of CDT drawings would simultaneously decrease the waiting time for a specialist appointment and improve accessibility of the test to the patients. Published research has only started to address the problem of automatic assessment of CDT drawings and existing systems require user intervention during the segmentation of the CDT drawing into its composing parts, such as numbers and clock hands. In this paper, a new set of temporal and spatial features automatically extracted from the CDT data acquired using a graphics tablet is proposed. Consequently, a Support Vector Machine (SVM) classifier is employed to segment the CDT drawings into their elements, such as numbers and clock hands, on the basis of the extracted features. The proposed algorithm is tested on two data sets, the first set consisting of 65 drawings made by healthy people, and the second consisting of 100 drawings reproduced from actual drawings of dementia patients. The test on both data sets shows that the proposed method outperforms the current state-of-the-art method for CDT drawing segmentation.

手指の二点間到達運動における運動意志中断に関連した脳活動

We investigate brain potentials related to the abandonment of the motor intention prior to movement in human volitional finger movement. Subjects are instructed to conduct a point-to-point finger reaching movement with the right index finger. The time to begin this movement is indicated with a clock making one revolution in 4 s. The time at which the clock hand passes the 3 o'clock position is adopted as the go-signal in the go task. In the series of trials, the pre-stop task is conducted with a red light-emitting diode stop-signal presented randomly at 0.1, 0.2, 0.3, 0.4, or 0.5 s before the go-signal. Cerebral potentials at the scalp are recorded using a 20-channel electroencephalography (EEG) system. In the go task without the stop-signal, clear movement-related cortical potentials are observed. In the pre-stop task with the stop-signal, the subjects are able to inhibit finger movement. A positive EEG potential distributed at the midline fronto-central scalp at 300-500 ms after the go-signal is observed only in the pre-stop task. This result suggests that the observed positive component is associated with the interruption of motor intention, as well as the revision of motor planning, in the motor cortices prior to the movement.

Individual differences in attributional style but not in interoceptive sensitivity, predict subjective estimates of action intention.

The debate on the existence of free will is on-going. Seminal findings by Libet et al. (1983) demonstrate that subjective awareness of a voluntary urge to act (the W-judgment) occurs before action execution. Libet’s paradigm requires participants to perform voluntary actions while watching a clock hand rotate. On response trials, participants make a retrospective judgment related to awareness of their urge to act. This research investigates the relationship between individual differences in performance on the Libet task and self-awareness. We examined the relationship between W-judgment, attributional style (AS; a measure of perceived control) and interoceptive sensitivity (IS; awareness of stimuli originating from one’s body; e.g., heartbeats). Thirty participants completed the AS questionnaire (ASQ), a heartbeat estimation task (IS), and the Libet paradigm. The ASQ score significantly predicted performance on the Libet task, while IS did not – more negative ASQ scores indicated larger latency between W-judgment and action execution. A significant correlation was also observed between ASQ score and IS. This is the first research to report a relationship between W-judgment and AS and should inform the future use of electroencephalography (EEG) to investigate the relationship between AS, W-judgment and RP onset. Our findings raise questions surrounding the importance of one’s perceived control in determining the point of conscious intention to act. Furthermore, we demonstrate possible negative implications associated with a longer period between conscious awareness and action execution.

Distorted subjective reports of stimulus onsets under dual-task conditions: Delayed conscious perception or estimation bias?

We investigated whether selecting a response for one task delays the conscious perception of another stimulus (delayed conscious perception hypothesis). In two experiments, participants watched a revolving clock hand while performing two tasks in close succession (i.e. a dual-task). Two stimuli were presented with varying stimulus onset asynchrony (SOA). After each trial, participants separately estimated the onsets of the two stimuli on the clock face. Across two experiments and four conditions, we manipulated response requirements and assessed their impact on perceived stimulus onsets. Results showed that (a) providing speeded responses to the stimuli did lead to greater SOA-dependent misperceptions of both stimulus onsets as compared to a solely perceptual condition, and (b) that response grouping reduced these misperceptions. Overall, the results provide equivocal evidence for the delayed conscious perception hypothesis. They rather suggest that participants' estimates of the two stimulus onsets are biased by the interval between their responses.

Self-assembly of silver nanoparticles illuminated by a visible-near-infrared lamp.

Silver nanoparticles (NPs) with diameters of 5-10 nm were synthesized by using formaldehyde (HCHO) to reduce silver nitrate (AgNO3) and polyethylenemine (PEI) as a stabilizer. It was found that on the carbon-supported cupper grid (Cu/polyvinylformal (PVF)/C) and under a visible-near-infrared (VIS-NIR, 400-860 nm) lamp illuminating at about 75 degrees C for six minutes, the spherical Ag NPs self-assembled into bigger NPs, triangular nanoprisms, or structures like clock hands. On the glass slides, the NPs firstly self-assembled into spherical particles with 3-6 microm in sizes, then assembled into chain structures comprised of 3-20 spherical particles after being illuminated by the VIS-NIR lamp for about nine minutes. The violent thermal motion of the NPs after being illuminated by the VIS-NIR lamp leads to the self-assembly and the shapes of the self-assembled particles are related to the interactions between the substrates and the samples.