Nonballistic coincident timing

A nonballistic coincident timing task was used to assess to what extent retarded subjects could use spatial and temporal information to plan their movements. Subjects did not just respond to events but appeared able to modify/plan their responses, given sufficient time.     

The timing of meals

In most individuals, food intake occurs as discrete bouts or meals, and little attention has been paid to the factors that normally determine when meals will occur when food is freely available. On the basis of experiments using rats, the authors suggest that when there are no constraints on obtaining food and few competing activities, 3 levels of interacting controls normally dictate when meals will start. The first is the genetically determined circadian activity pattern on which nocturnal animals tend to initiate most meals in the dark. The second is the regularly occurring changing of the light cycle: These changes provide temporal anchors. The third relates to the size of the preceding meal, such that larger meals cause a longer delay until the onset of the next meal. Superimposed on these 3 are factors related to learning, convenience, and opportunity.     

Neural mechanisms of timing

A crucial step in timing research is to isolate clock components from other sources of temporal variability. Significant progress has been made both behaviorally and neurologically, using elaborate experimental designs that separate timing mechanisms from motoric sensory and mnemonic processes. Marked similarities between the temporal characteristics of the clock in perception and production tasks implicate a common timing system. Similar conclusions can be reached from clinical studies, indeed individuals with neocerebellar damage are impaired at discriminating and reproducing short intervals. However, other patient populations, especially those with disorders affecting the basal ganglia, also exhibit deficits in timing tasks. It therefore appears that temporal computation may be distributed throughout the brain with specific roles for different neural structures.     

The timing of appraisals

The appraisal process consists of the subjective evaluation that occurs during an individual's encounter with significant events in the environment, determining the nature of the emotional reaction and experience. Placed in the context of appraisal theories of emotion-elicitation and differentiation, the aim of the present research was to test empirically the hypothesis that the intrinsic pleasantness evaluation occurs before the goal conduciveness evaluation. In two studies, intrinsically pleasant and unpleasant images were used to manipulate pleasantness, and a specific event in a Pacman-type videogame was used to manipulate goal conduciveness. Facial EMG was used to measure facial reactions to each evaluation. As predicted, facial reactions to the intrinsic pleasantness manipulation were faster than facial reactions to the goal conduciveness manipulation. These results provide good empirical support for the sequential nature of the appraisal process.     

The effect of alcohol administration on human timing: a comparison of prospective timing, retrospective timing and passage of time judgements

Previous research suggests that human timing may be affected by alcohol administration. The current study aimed to expand on previous research by examining the effect of alcohol on prospective timing, retrospective timing and passage of time judgements. A blind between-subjects design was employed in which participants were either administered 0 g of alcohol per kilogramme of body weight (placebo), 0.4 g/kg (low dose) or 0.6 g/kg (high dose). Participants completed four types of temporal task; verbal estimation and temporal generalisation, a retrospective timing task and a passage of time judgement task. A high dose of alcohol resulted in overestimations of duration relative to the low dose and placebo group in the verbal estimation task. A high dose of alcohol was also associated with time passing more quickly than normal. Alcohol had no effect on retrospective judgements. The results suggest that a high dose of alcohol increases internal clock speed leading to over-estimations of duration on prospective timing tasks, and the sensation of time passing more quickly than normal. The absence of an effect of alcohol on retrospective timing supports the suggestion that retrospective judgements are not based on the output of an internal clock.     

Utterance timing and childhood stuttering

Articulatory speaking rate and response time latency are believed by many to be important factors in determining whether stuttering will occur in a given utterance. Currently, however, there is little empirical evidence to suggest that these measures of utterance timing are directly related to stuttering. This study examined the relationship between articulatory speaking rate and response time latency in the conversational speech of 12 boys who stutter (mean age = 55.2 months; SD = 8.8 months) who participated in 30-min conversational interactions with their mothers. Discriminant function analyses were conducted on 75 utterances drawn from each child's speech sample to determine if the articulatory speaking rate or response time latency of a specific utterance was related to the likelihood that the child would stutter on that utterance. No significant relationships between these measures of utterance timing and stuttering were found for any of the 12 subjects, and there were no significant relationships between these two measures of utterance timing. Findings do not provide support for many current theories of stuttering and suggest that the role of these measures of utterance timing in predicting the occurrence of stuttering in conversational speech in these theories may need to be reexamined.     

Timing during interruptions in timing

Duration and location of breaks in time interval production were manipulated in various conditions of stimulus presentation (Experiments 1-4). Produced intervals shortened and then stabilized as break duration lengthened, suggesting that participants used the break as a preparatory period to restart timing as quickly as possible at the end of the break. This interpretation was supported in Experiment 5, in which similar results were obtained with a reaction time response executed at the end of the break. In all experiments, produced intervals lengthened as the break occurred later during the interval. The authors conclude that varying break location and duration reveal, respectively, the influence of attentional time-sharing before the interruption and of preparatory processes taking place during the break.     

Speech timing of grammatical categories

A series of experiments was performed to determine how the duration of a word spoken in a sentence is influenced by: (1) the grammatical category to which it belongs, and (2) the position of the word in a constituent. Experiment I contained Noun-Verb homophones (e.g. “I saw the coach…” — noun; “I saw him coach…” — verb), in sentences matched for phonetic environment and stress pattern. Results support the notion that Nouns are longer than Verbs in typical sentences. Experiment II, however, demonstrated that the duration of Noun-Verb homophones in matched clause-final position is approximately equal. Experiment III contained transitive and intransitive Verbs in matched sentences. The results of Experiments II and III provided support for a lengthening account based on constituent-final position, while ruling out an account based on a debatable deletion site. Results of Experiment IV generalized the account of constituent-final lengthening for Nouns and Verbs to additional major categories, by comparing the duration of the phrase-initial Adjective two with the phrase-final Adverb too. Finally, Experiment V tested the distinction between minor and major categories. Results demonstrated that the Preposition to is shorter than the Adjective two by approximately 50 percent. Taken in sum, these findings indicate that it is sufficient to make a binary distinction between major and minor categories for purposes of a theory of speech timing and speech synthesis. Durational effects traditionally ascribed to differences within the class of major categories can be accounted for solely in terms of constituent boundaries, already required in the theory to account for three other classes of phenomena.     

Occasion setting of timing behavior

Rats were trained on a temporal switching discrimination, with 2 features, A and B, signaling 2 target conditioned stimuli, x and y; feature offset and target onset were separated by a 5-s feature-target interval, and all target stimulus presentations terminated in a food pellet. The target conditioned stimuli were either short or long (6 or 30 s): Specifically, when signaled by A, x was 6 s and y 30 s, but when x and y were signaled by B, x was 30 s and y 6 s. Trials with 6-s and 30-s targets were termed short and long trials, respectively. Probe tests indicated that the animals correctly anticipated when food was to be delivered on these 2 types of trials. In further testing, the interval between feature offset and target onset was lengthened, to investigate the precise mechanism underlying this behavior. This manipulation did not have a substantial effect on discrimination performance. These results are discussed with reference to theories of occasion setting, timing, and configural learning.     

The timing of interresponse intervals

Analogs of models of duration discrimination are here related to the timing of discrete motor responses. The measure of interest is the variability in duration of intervals collected in short interval reproduction tasks. For data from a Morse key-tapping task, it is shown that, taken separately, neither of the models described can completely account for the relation between the mean and the variance of the interresponse intervals.     

Counting processes in human timing

A subject reproducing a long duration, t, may time out either a single interval of duration t or a succession of n intervals, each of duration t/n. It is shown that a class of timing models obeying Weber’s law predicts the variance of reproductions of t to be a decreasing function of the number of subdivisions, n. In contrast, a second class of proportional variance models, which includes Creelman’s pulse counter model (1962), predicts no change in the variance as a function of n. Data are presented from a duration reproduction experiment in which subjects counted silently at a specified rate up to a given number and then responded. Several statistics involving the variance of the reproduced durations are shown to be predicted significantly better by the Weber’s law class of models than by the proportional variance class of models.     

Hierarchical coding in speech timing

The analysis of syllable and pause durations in speech production can provide information about the properties of a speaker's grammatical code. The present study was conducted to reveal aspects of this code by analyzing syllable and pause durations in structurally ambiguous sentences. In Experiments 1–6, acoustical measurements were made for a key syllabic segment and a following pause for 10 or more speakers. Each of six structural ambiguities, previously unrelated, involved a grammatical relation between the constituent following the pause and one of two possible constituents preceding the pause. The results showed lengthening of the syllabic segments and pauses for the reading in which the constituent following the pause was hierarchically dominated by the higher of the two possible preceding constituents in a syntactic representation. The effects were also observed, to a lesser extent, when the structurally ambiguous sentences were embedded in disambiguating paragraph contexts (Experiment 7). The results show that a single hierarchical principle can provide a unified account of speech timing effects for a number of otherwise unrelated ambiguities. This principle is superior to a linear alternative and provides specific inferences about hierarchical relations among syntactic constituents in speech coding.     

The timing of bar-pressing behaviour

The time spent by a rat in a bar-pressing situation is made up of active time spent n pressing, eating time, and extra time spent in other activities. With a well trained rat, active time and extra time are small, and eating time mainly determines the rate of reward delivery. Active time is affected by a change of weight on the bar, the time between reward deliveries is affected by the amount of reward, and the extra time is affected by extinction conditions.

There is not a one-to-one correspondence between periods of activity at the knob and rewards.

The term “response” and some variables based on it are given empirical referents, which show that much research and theorizing on bar-pressing behaviour has been concerned with only a small selection of the rat's bar-pressing activities. Some reasons for this restriction are the use of the simple weighted bar, the lack of a rationale for bar-pressing research, and the practice of not watching the rat during an experiment.     

Pure timing in temporal differentiation

Temporal control appears to depend on whether the critical durations are those of stimuli or those of responses. Stimulus timing (temporal discrimination) supports Weber's law, whereas response timing (temporal differentiation) indicates decreasing relative sensitivity with longer time intervals. The two types of procedure also yield different conclusions in scaling experiments designed to study the functional midpoint of two or more durations (temporal bisection procedures). In addition, the fractional-exponent power relation between emitted and required duration usually found with animals in differentiation experiments conflicts with deductions from formal analyses. The experiment reported here derived from considering differentiation arrangements as schedules of reinforcement. When analyzed from this perspective, the procedures are tandem schedules involving a required pause followed by a response, and it is the pause alone that involves temporal control. A choice procedure separated timing from responding, and enabled observations of pause timing in isolation. Pure temporal control in differentiation consisted of linear overestimation of the standard duration, and Weber's law described sensitivity. These results indicate that the two problems, the fractional-exponent power relations and the apparently different nature of sensitivity in differentiation and discrimination, disappear when temporal control is observed alone in differentiation.     

Age-specific problems in rhythmic timing

The authors investigated performance in 2 rhythm tasks in young (M = 23.8 years) and older (M = 71.4 years) amateur pianists to test whether slowing of a central clock can explain age-related changes in timing variability. Successive keystrokes in the rhythm tasks were separated by either identical (isochronous) time intervals or varying (anisochronous) intervals. Variability was comparable for young and older adults in the isochronous task; pronounced age effects were found for the anisochronous rhythm. Analyses of covariances between intervals rule out slowing of a central clock as an explanation of the findings, which instead support the distinction between target specification, timekeeper execution, and motor implementation proposed by the rhythm program hypothesis (D. Vorberg & A. M. Wing, 1996). Age stability was found at the level of motor implementation, but there were age-related deficits for processes related to target-duration specification.     

Testing the accuracy of timing reports in visual timing tasks with a consumer-grade digital camera

This study tested the accuracy of a visual timing task using a readily available and relatively inexpensive consumer grade digital camera. A visual inspection time task was recorded using short high-speed video clips and the timing as reported by the task’s program was compared to the timing as recorded in the video clips. Discrepancies in these two timing reports were investigated further and based on display refresh rate, a decision was made whether the discrepancy was large enough to affect the results as reported by the task. In this particular study, the errors in timing were not large enough to impact the results of the study. The procedure presented in this article offers an alternative method for performing a timing test, which uses readily available hardware and can be used to test the timing in any software program on any operating system and display.