Changes In Time Perception Research Articles

Neuropsychological approach in the investigation of time perception in late life depression

Late life depression is characterized by changes in time perception which are connected with the state of higher mental functions and their neuropsychological correlates. To the investigation of these connections our study was dedicated. A complex of methods included the Lurian neuropsychological diagnostics, prospective estimation of 5-, 10- and 15-second intervals and production of 1 min interval, retrospective estimation of the length of diagnostics and current time. Participants from control (n=26) and clinical (n=48) groups aged 50-81 were equal in sociodemographic characteristics. The interconnections between the characteristics of time perception and the different types of neuropsychological deficit as well as the characteristics of other higher mental functions were analyzed. With the purpose of the possibility of this multidimensional analysis the model of time perception was designed. The specifics of the inclusion and hierarchization of different components of the system with the purpose of achievement of adaptive result – time structuring of activity – was investigated. According to the hypotheses, in late life depression retrospective estimation deficit would be connected withmemory deterioration, therefore, with dysfunction of deeper subcortical structures; the elaborated model of time perception was assumed to be useful in the analysis of time perception in its connection with other higher mental functions in old age. According to the results, in normal aging changes in time perception areconnected with spatial deficit of memory, perception and praxis; in prospective judgments attention and control functions play a role. Time perception deficit is connected with dysfunction of deeper subcortical structures accenting in right hemisphere; prospective estimation – with prefrontal structures. In late life depression time perception deficit is connected with attention and control functions deficit;prospective judgments – with praxis; retrospective judgments – with memory deterioration. Prospective estimation deficit is connected with deficit in lefthemispheric structures and interhemispheric interaction; retrospective estimation deficit – with dysfunction of deeper subcortical structures. In different variantsof aging tendencies to overestimation/underproduction of short intervals are connected with left-hemispheric dysfunction; to underestimation/overproduction – right-hemispheric dysfunction. Consequently, the hypotheses were approved and a full picture of interconnections between time perception and other functions and their neuropsychological correlates in late life depression was obtained. The proposed model of time perception was appropriate for analysis of time perception as it allows to reveal impaired the same as intact units of a functional system and to assume the primary or the secondary nature of impairments. The features of time perception interpreted based on the model may become the detectors of cognitive as well asaffective dysfunction in old age.
 Keywords: time perception, neuropsychology, gerontology, gerontopsychology, late life, depression, late life depression, higher mental functions, functional system, model of time perception.

Patterns and neural mechanisms of time perception in individuals with clinical depression and subthreshold depression

Time perception is the basis of cognitive processing, and it may be affected by depression levels. People with depression often report slower subjective time experience; however, whether depression levels affect time perception has not been determined. More than 300 million people of all ages suffer from depression globally, and this number might be much larger if people with subthreshold depression, which indicates that an individual has clinically relevant depressive symptoms without meeting the criteria for full-blown major depressive disorder, are included. In this study, we examined the behavioral characteristics of time perception in patients with clinical depression and individuals with subthreshold depression based on a temporal bisection within the range of 400–1600 ms. The data were then fitted to a sigmoidal curve in order to calculate the subjective bisection point and Weber ratios. In addition, the event-related potential (ERP) responses of time perception in individuals with subthreshold depression were recorded to explore the possible mechanisms. The results were as follows: (1) The Weber ratios of individuals in the clinical and subthreshold depression groups were higher than those in the control group. There was no significant difference in the subjective bisection point between either the subthreshold depression group or the clinical depression group and the control group. Both the clinical and subthreshold depression groups had longer reaction times in each duration, and they tended to overestimate short durations and underestimate long durations. (2) The levels of depression (both trait depression and state depression) were positively related to the Weber ratio, and there was no correlation between the bisection point and either trait depression or state depression. (3) The P2 amplitude of the subthreshold depression group showed a decreasing trend, and the latency of the contingent negative variation (CNV) was delayed. The amplitude of the late positive component of timing (LPCt) decreased at the duration of 400 ms, but there was no difference in N1 between the subthreshold depression group and the control group. The above results suggest that there were similar changes in time perception between the subthreshold depression group and the clinical depression group; moreover, as the degree of depression increased, subjects showed greater variation in time perception. The higher Weber ratios of the clinical and subthreshold depression groups imply changes in the subjects’ internal clock, and such changes might be caused by the lack of sufficient cognitive resources for participating in time processing, which is revealed by the lower P2 amplitude. In the subthreshold depression group, the longer reaction time, longer CNV peak latency, and smaller LPCt amplitude, which is the positive deflection followed by CNV, suggest that the subthreshold depression group also exhibited some changes in temporal decision processes. In addition, there was no evidence of changes in working memory for the subthreshold depression group in time perception, as there was no difference in the bisection point. The current study did not record ERP signals of individuals with clinical depression; thus, it is necessary to explore the neural mechanism of time perception in individuals with clinical depression in the future.

PROFESSIONAL BURNOUT AND TIME PERCEPTION IN POSTTRAUMATIC STRESS DISORDER

The professional burnout and its prevention is one of the central issues in clinical psychology and organizational psychology. Despite a big array of this subject publications, the study of professional burnout predictors and search for the tools providing its effective prevention continues. Objective: studying of individual psychological characteristics of persons with PTSD within the framework of professional burnout and proactive coping. Type of the study: analytic, prospective. Sampling: 148 people who sought psychotherapy, of which Group 1 is comprised of people with PTSD - 65 people, and Group 2 is comprised of people without PTSD - 83 people. Methods of research - psychological tests: "Zimbardo Time Perspective Inventory» (ZTPI), "Maslach Burnout Inventory" (MBI), "Proactive Coping Inventory" (PCI), "BAK-conflict". Results: According to the MBI questionnaire, 75 % of the people examined in Group 1 and 28 % those in Group 2 had high and extremely high rates of professional burnout; differences on the scales of the ZTPI questionnaire are "negative past" and "fatalistic present". According to the "BAK-conflict" questionnaire, the following indicators were detected in Group 1: low self-esteem, poor quality of relationships in a dyad (the "You sphere") and relationships in a team (the "Us sphere"); disorders of perception of time parameters (the "Grand-Us sphere"); as well as the risk factors of psychosomatic diseases - an excess in the corporeality sphere, a deficit in the spheres of sociability and spirituality. According to the PCI questionnaire in Group 1, the subjects used "proactive overcoming", "reflexive overcoming", "preventive overcoming", and the "search for emotional support". Conclusions: Due to the changes in perception of time (the predominance of negative past and fatalistic present) patients with PTSD undergo a deformation of the personality relations system of attitudes and a reduction of proactive coping, which may be a cause of relations development. For the prevention of relationships in individuals with PTSD during the psychotherapeutic intervention it is necessary to take into account the "traumatic experience", to form a strong "Me-concept" of the personality based on the adequate development of the perception of time, harmonious You-relations, relying on the experience of ancestors (Grand-Us) that allows to reduce the importance of the "negative past" and the "fatalistic present," and to build a long-term perspective of the future.

Differential effects of cannabinoid CB1 inverse agonists and antagonists on impulsivity in male Sprague Dawley rats: identification of a possibly clinically relevant vulnerability involving the serotonin 5HT1A receptor.

Cannabinoid CB1 inverse agonists hold therapeutic promise as appetite suppressants but have produced suicidal behaviors among a small subpopulation in clinical trials. Anatomical and pharmacological evidence implicate the 5HT1A serotonin receptor in suicide in humans and impulsivity in humans and animals. The objective of the study is to assess whether 5HT1A blockade is necessary for CB1 ligands to produce impulsivity. Sprague Dawley rats were administered the CB1 inverse agonist AM 251, the CB1 antagonist AM 6527, or the peripherally restricted antagonist AM 6545, with or without pretreatment with the 5HT1A antagonist WAY 100,635 (WAY) on the paced fixed consecutive number (FCN) task, which measures choice to terminate a chain of responses prematurely. As FCN is sensitive to changes in time perception, which have been demonstrated with CB1 blockade, a novel variable consecutive number task with discriminative stimulus (VCN-S D ) was also performed and proposed to be less sensitive to changes in timing. Pretreatment with WAY enabled mild but significant reductions in FCN accuracy for AM 251 and AM 6527. No effects were found for AM 6545. On the VCN-S D task, substantial impairments were found for the combination of WAY and AM 251. AM 251, but not the antagonists AM 6527 or AM 6545, produced impulsivity only following systemic 5HT1A blockade. Although preliminary, the results may indicate that disrupted serotonin signaling produces a vulnerability to undesirable effects of CB1 inverse agonists, which is not evident in the general population. Furthermore, neutral CB1 antagonists do not produce this effect and therefore may have greater safety.

The influence of social stress on time perception and psychophysiological reactivity.

Time perception is a fundamental component of everyday life. Although time can be measured using standard units, the relationship between an individual's experience of perceived time and a standard unit is highly sensitive to context. Stressful and threatening stimuli have been previously shown to produce time distortion effects, such that individuals perceive the stimuli as lasting for different amounts of time as compared to a standard unit. As a highly social species, humans are acutely sensitive to social stressors; however, time distortion effects have not been studied in the context of social stress. We collected psychophysiological (electrocardiogram and impedance cardiography) and time perception data before, during, and after a modified version of the Trier Social Stress Test for 42 participants. Based on prior theories and evidence from the time perception literature, we hypothesized that experiencing a stressful event would result in time distortion. This hypothesis was supported by the data, with individuals on average reproducing short and long duration negative and positive stimuli as lasting longer after experiencing social stress, t(41) = -3.55, p = .001, and t(41) = -4.12, p < .001 for negative stimuli, and t(41) = -2.43, p = .02, and t(41) = -3.07, p = .004 for positive stimuli. However, changes in time perception were largely unrelated to psychophysiological reactivity to social stress. These findings are in line with some other studies of time distortion, and provide evidence for the interoceptive salience model of time perception. Implications for mechanisms of time distortion are discussed.

ТАЙМ-МЕНЕДЖМЕНТ ЯК ВИЯВ СВІТОГЛЯДУ СУЧАСНОЇ ЛЮДИНИ

Planning of time always was an inalienable part of social and economic life. However, nowadays time management became so current because of essential changes in society development. Massive production, strict competition, secularization, modern cult of success caused sufficient changes in time perception. Workers, producers, agents, especially in developed countries involved into dynamic economic relations, which demand planning of time and strict daily routine. In our opinion, two main reasons of time management popularity are world-view changes, which make modern secular society radically transforms surroundings of existing and high competition between producers and workers. Time management has its positive advantages, namely it discipline peoples, rise their productivity, reduce wasting of time. However, time management can turn into end in itself.

Effects of mindfulness training on different components of impulsivity in borderline personality disorder: results from a pilot randomized study.

BackgroundImpulsivity is considered a core characteristic of borderline personality disorder (BPD). Previous research on the effects of mindfulness training (MT) has shown that it might modify impulsivity-related aspects of BPD. Therefore, the aim of this study was to investigate the impact of MT on various facets of impulsivity in BPD patients.MethodsSubjects with BPD diagnosis (n = 64) were randomly assigned to 10 weeks of MT (n = 32) or interpersonal effectiveness skills training (IE; n = 32). All participants were assessed pre- and post-intervention with a self-reported measure of impulsivity and five behavioral neuropsychological tasks to evaluate response inhibition, tolerance for delay rewards, and time perception.ResultsAn interaction effect of time × group was only observed for some of the behavioral paradigms used. Participants in the MT group improved their ability to delay gratification and showed changes in time perception, consistent with a decrease in impulsivity. No differences were observed between treatments in terms of trait impulsivity and response inhibition.ConclusionsMindfulness training might improve some aspects of impulsivity but not others. Further study is warranted to better determine the effects of mindfulness training on the components of impulsivity.Trial registrationClinicalTrials.gov Identifier: NCT02397031.Electronic supplementary materialThe online version of this article (doi:10.1186/s40479-015-0035-8) contains supplementary material, which is available to authorized users.

Memory, Time and Autonoetic Consciousness

Memory and time have multifaceted links. Along the time axis, memory is divided into short- and long-term memory. Another popular time-dependent distinction is between new and old memories and anterograde and retrograde memory impairments, respectively. Time-embedment characterizes the processing of mnemonic information, which encompasses the stages of registration, encoding, consolidation, and storage. Along the content axis, memory is partitioned into five long-term memory systems (procedural, priming, perceptual, semantic, and episodic), which are regarded to build up on each other from both a phylogenetic and ontogenetic perspective. These memory systems are accompanied by different niveaus of self and levels of consciousness. Among these long-term memory systems, the episodic memory system holds a special connection with time, which we aim to detail. In 2005, Tulving defined the episodic memory system as the conjunction of subjective time, autonoetic consciousness, and the experiencing self. Drawing on this last definition of the episodic memory, which lays an emphasis on the linkage to the self, Markowitsch has subsequently promoted the use of the construct “episodic-autobiographical” memory system. The episodic-autobiographical memory system features mental time travelling, an essential property that enables one individual to flexibly travel in subjective time in his/her past and, in addition, to flexibly project him/herself in the future. This property provides a “glue” for the self, supporting a coherent view of one's own person. According to Tulving and Markowitsch, it is unlikely that non-human animals possess the capacity for mental time travelling and the ability to “look into future” (“proscopy”). Furthermore, Tulving and Markowitsch had proposed that the ability for mental time travelling is dependent on age and intellect. Subsequent studies have confirmed that mental time travelling is one of the last features of the episodic- autobiographical memory system that achieves full functionality in humans and is the first one to be afflicted by old age, amnesia or neurodegenerative dementias (e.g., Alzheimer's dementia). At the brain level, the emergence of the capacity for mental time travelling is accompanied by ample structural and functional reorganization of elements of the brain networks supporting episodic-autobiographical memory, autonoetic consciousness, and self-referential processing.In human beings, damage to certain brain regions may alter the sense and consciousness of time in quite different ways. Herein, we have the goal to review changes in time perception and consciousness of time, which accompany different forms of amnesia. Patients with anterograde amnesia manifest an inability to consciously acquire new information for long-term storage and as a consequence are often “stuck in time”. ‘Chronotaraxis’ may accompany certain forms of preponderantly anterograde amnesia, as we aim to exemplify by drawing upon own cases, which were investigated medically, neuropsychologically, and with neuroimaging methods. Patients with retrograde amnesia manifest an inability to consciously retrieve already stored old mnemonic information, usually from the episodic-autobiographical memory domain. They lack the capacity to “ecphorize” old memories. Interestingly, the memory impairments are very similar in the patients with focal traumatic brain injuries and in those with psychogenic forms of amnesia: The patients are unable to engage in mental time traveling into their past. In addition, they show an impaired ability to imagine future personal events, being as a consequence trapped in a “noetic existence”. In psychogenic amnesia with pronounced retrograde memory impairments, we found (via functional neuroimaging) evidence of defective synchronization during retrieval between processing of affectively loaded personal events (that is presumed to preponderantly engage the right hemisphere) and fact-based processing (that is considered to preferentially recruit the left hemisphere). These data are relevant in the light of studies pointing to a right hemisphere bias for higher forms of consciousness. We conjecture that this synchronization abnormality not only leads to a memory blockade, but also to shrinkage of mental time traveling and loss of autonoetic consciousness in psychogenic or functional amnesic conditions.

Negative Emotional Outcomes Attenuate Sense of Agency over Voluntary Actions

Sense of agency (SoA) refers to the feeling that one's voluntary actions produce external sensory events [1, 2]. Several psychological theories hypothesized links between SoA and affective evaluation [3-6]. For example, people tend to attribute positive outcomes to their own actions, perhaps reflecting high-level narrative processes that enhance self-esteem [3]. Here we provide the first evidence that such emotional modulations also involve changes in the low-level sensorimotor basis of agency. The intentional binding paradigm [1] was used to quantify the subjective temporal compression between a voluntary action and its sensory consequences, providing an implicit measure of SoA. Emotional valence of action outcomes was manipulated by following participants' key-press actions with negative or positive emotional vocalizations [7], or neutral sounds. We found that intentional binding was reduced for negative compared to positive or neutral outcomes. Discriminant analyses identified a change in time perception of both actions and their negative outcomes, demonstrating that the experience of action itself is subject to affective modulation. A small binding benefit was also found for positive action outcomes. Emotional modulation of SoA may contribute to regulating social behavior. Correctly tracking the valenced effects of one's voluntary actions on other people could underlie successful social interactions.

Time perception impairs sensory-motor integration in Parkinson's disease.

It is well known that perception and estimation of time are fundamental for the relationship between humans and their environment. However, this temporal information processing is inefficient in patients with Parkinson’ disease (PD), resulting in temporal judgment deficits. In general, the pathophysiology of PD has been described as a dysfunction in the basal ganglia, which is a multisensory integration station. Thus, a deficit in the sensorimotor integration process could explain many of the Parkinson symptoms, such as changes in time perception. This physiological distortion may be better understood if we analyze the neurobiological model of interval timing, expressed within the conceptual framework of a traditional information-processing model called “Scalar Expectancy Theory”. Therefore, in this review we discuss the pathophysiology and sensorimotor integration process in PD, the theories and neural basic mechanisms involved in temporal processing, and the main clinical findings about the impact of time perception in PD.

When moving without volition: Implied self-causation enhances binding strength between involuntary actions and effects

The conscious awareness of voluntary action is associated with systematic changes in time perception: The interval between actions and outcomes is experienced as compressed in time. Although this temporal binding is thought to result from voluntary movement and provides a window to the sense of agency, recent studies challenge this idea by demonstrating binding in involuntary movement. We offer a potential account for these findings by proposing that binding between involuntary actions and effects can occur when self-causation is implied. Participants made temporal judgements concerning a key press and a tone, while they learned to consider themselves as the cause of the effect or not. Results showed that implied self-causation (vs. no implied self-causation) increased temporal binding. Since intrinsic motor cues of movement were absent, these results suggest that sensory evidence about the key press caused binding in retrospect and in line with the participant's sense of being an agent.

Cognitive abilities explaining age-related changes in time perception of short and long durations

The current study investigated how the development of cognitive abilities explains the age-related changes in temporal judgment over short and long duration ranges from 0.5 to 30 s. Children (5- and 9-year-olds) as well as adults were given a temporal bisection task with four different duration ranges: a duration range shorter than 1 s, two duration ranges longer than 3 s (4–8 s and >15 s), and an intermediate duration range (1.25–2.5 s). Their cognitive abilities were also assessed using a series of neuropsychological tests. The results showed that temporal sensitivity improved with age for each duration range but that this improvement occurred earlier for the short durations than for the long durations. Furthermore, the results revealed that the age-related improvement in time sensitivity for the durations shorter than 1 s was explained by the development of short-term memory span, whereas that for long durations was explained by the development of attention/executive functions. To summarize, the development of the abilities required to process long durations seems to be explained mainly by the development of attentional resources.

The manifestation of musical time in Italian ballatas around 1400: the case of Andrea da Firenze'sNon più doglie ebbe Dido

ABSTRACTThe changes in time perception that emerged in the late Middle Ages have not only left their mark on musical notation or the isorhythmic motet, but also on the composition of polyphonic songs. This article proposes an analytical approach to late Trecento songs that takes these changes into account. A case study of Andrea da Firenze's ballataNon più doglie ebbe Didoreveals how the temporal structures of the text and the music interact.

Intentional binding and higher order agency experience

Recent research has shown that human instrumental action is associated with systematic changes in time perception: The interval between a voluntary action and an outcome is perceived as shorter than the interval between a physically similar involuntary movement and an outcome. The study by, Ebert and Wegner (2010) suggests that this change in time perception is related to higher order agency experience. Notwithstanding certain issues arising from their study, which are discussed, we believe it offers validation of binding as a measure of sense of agency.

Time perception, depression and sadness

This study examined changes in time perception as a function of depressive symptoms, assessed for each participant with the Beck Depression Inventory (BDI). The participants performed a temporal bisection task in which they had to categorize a signal duration of between 400 and 1600 ms as either as short or long. The data showed that the bisection function was shifted toward the right, and that the point of subjective equality was higher in the depressive than in the non-depressive participants. Furthermore, the higher the depression score was, the shorter the signal duration was judged to be. In contrast, the sensitivity to time was similar in these two groups of participants. These results thus indicate that the probe durations were underestimated by the depressive participants. The sadness scores assessed by the Brief Mood Inventory Scale (BMIS) also suggest that the emotional state of sadness in the depressive participants goes some way to explaining their temporal performance. Statistical analyses and modeling of data support the idea according to which these results may be explained by a slowing down of the internal clock in the depressive participants.

The effect of changes in perception of time on demographic processes

The paper first analyses the new changes of demographic processes that have taken place in the past decades, next a point of consideration, namely changes in the perception of time, is presented with the help of which one may get closer to an explanation of this social phenomenon threatening the future of industrially developed countries. The present paper studies what effects are produced by the difference in the perception of time on the number of births and on the struggle for extending life, and, finally, how this difference influences the shape of the population pyramid and the future of the entire society. After having presented the newest research results it is worth calling attention to the fact that the consideration of time as finite has acquired a ‘dominant’ position in the majority of industrially developed countries, the expression used by T. Kuhn in his work on the change of paradigm. This worldview primarily based on rationality has had a significant role in that the number of births declined in these countries, for as D.A. Coleman put it in his keynote speech at the European Congress on Demography in 1998, ‘it is not so obvious why rational and educated people should have children’. Research results dealing with this issue show that as a result of pushing sacral considerations into the background the stability of marriages (and partnerships) decreases and the number of children also declines. For people accepting and following a finite perception of time death will be more terrible. This fear of death is a strong incentive for pushing the limits of narrowed time as far as possible. This is why the struggle for lengthening life has such an important role in scientific research, in medical practice as well as in the life of modern people. Medical science tries to meet this strong social expectation, which, besides several other factors, contributes to the growth of life expectancy at birth and, as a result, the number of births is declining. The consequences of the change of paradigm in perceiving time have modified the shape of the population pyramid: its upper part has become ‘stronger’, the lower part has been significantly ‘weakened’, and its long-term stability has been continuously weakening. And if these efforts become general, this threatens the future of the entire society.

Dynamics of assessments of time intervals by patients with heroin addiction

The perception of 12-sec time intervals time by patients with heroin addiction was assessed in 10 trials with precision of up to 0.1 sec. A total of 82 patients with heroin addiction were studied in the withdrawal and post-withdrawal periods. The results obtained in patients were comparable to measurements obtained in 52 healthy subjects. The time interval estimated by patients as an overall group was shorter than that in healthy subjects during the first two days of in-patient treatment (during development of withdrawal syndrome); the 12-sec period was reproduced accurately at 5-6 days, after which the period was exceeded; perception of time again became accurate on days 15-16 (the post-withdrawal period). Changes in the subjective perception of time were found to depend on the duration of addiction and the individual characteristics of interhemisphere brain asymmetry.

The Time of Your Life: One Thousand Moons

AbstractThe present work deals with four themes that relate to the problem of aging and time. They include questions of allometric scaling, the novelty of experience, the change in perception of time with age, and the certainty of death. Featured in each of these themes is the prominence of time and the manner in which poetic, scientific, and technologic facets of each theme are interwoven. The overall argument serves to dispel the chronometric dominance of time versus its behavioral reality.

Benefits of music therapy as an adjunct to chest physiotherapy in infants and toddlers with cystic fibrosisResearch conducted at the Royal Children's Hospital, Victoria, Australia.Copies of the recorded music and questionnaires used in this study are available from the corresponding author.

Routine chest physiotherapy (CPT) is an important component of prophylactic therapy in children with cystic fibrosis (CF) and requires a significant commitment of time and energy. It is important, therefore, to establish CPT as a positive experience. In this study, we evaluated the effect of recorded music as an adjunct to CPT. Specifically, we compared the use of newly composed music, familiar music, and the family's usual routine on children's and parents' enjoyment of CPT and the parents' perception of time taken to complete CPT. Enjoyment and perception of time were evaluated via questionnaires designed specifically for this study. Participants were caregivers of one or more children with CF who were aged between 4½ months and 24 months at the commencement of the clinical trial and required CPT on a daily basis. Participants were randomly allocated into control and treatment groups. Control group participants experienced two conditions consecutively: no audiotape (NT; control) and familiar music tape (FT; placebo control). Treatment group participants were given the treatment music tape (TT), which was composed and compiled by a music therapist. After baseline assessment, evaluation occurred at two 6-weekly intervals. Children's enjoyment increased significantly after use of the TT (+1.25 units) compared to NT (−0.5 units; P = 0.03), as did parents' enjoyment (+1.0 vs. 0.0 units, P = 0.02). Children's enjoyment did not change significantly after use of the FT (+0.75 units) compared to NT (n.s.). Likewise, parents' enjoyment did not change significantly after use of the FT (+1.0 units, n.s.). There was no change in perception of time after use of the TT (−4.5 vs. +0.2 min, n.s.) or the FT (+3.3 min, n.s.). These results indicate that children's and parents' enjoyment of CPT significantly increased after the use of specifically composed and recorded music as an adjunct. We therefore recommend that recorded music, such as that provided in this study, be given to parents to use as an adjunct to CPT when their young children are diagnosed with CF, in order to assist the establishment of a positive routine. Pediatr Pulmonol. 2000; 29:371–381. © 2000 Wiley-Liss, Inc.

Perception, production, and imitation of time ratios by skilled musicians.

We have described our exploration of the judgment, production, and imitation of fractions of a beat by skilled musicians, illustrating our findings with data from violinist and conductor Paul Zukofsky. For small fractions we found systematic and substantial errors. In the judgment task small stimulus fractions are associated with names that are too large (overestimation). In both production and imitation tasks the fractions produced were too large (overproduction, overimitation). A summary of our findings and of the expectations they violate is provided in Figure 7. The temporal patterns we used are perhaps the simplest that qualify as rhythms, incorporating just a beat interval and a fraction. The phenomena we discovered in relation to these simple patterns, and their implications for underlying mechanisms, must be considered in attempts to understand the perception and production of more complex rhythms, as in actual music. We explored and rejected several plausible explanations for the overestimation and overproduction of small fractions. Although we have as yet no satisfactory explanations of the errors themselves, relations among the errors have powerful implications for human timing mechanisms. The relation between the errors in judgment and production requires us to reject a feedback model of production, in which a subject uses the same processes as in the judgment task to evaluate and adjust his performance in the production task. An explanation of the inconsistency between judgment and production seems most likely to lie in a change in time perception induced by the production task. Together with the existence of systematic errors in judgment, the equality of the errors in production and imitation argues that imitation is not accomplished by concatenating all the processes used in judgment and production. Our results are instead consistent with a model containing four internal transformation processes, in which judgment and production share no process, but do involve the same internal-fraction representation, and in which imitation shares one process with judgment and another with production.