Timing and trajectory in rhythm production

The Wing-Kristofferson movement timing model (A. M. Wing & A. B. Kristofferson, 1973a, 1973b) distinguishes central timer and motor implementation processes. Previous studies have shown that increases in interresponse interval (IRI) variability with mean IRI are due to central timer processes, not motor implementation. The authors examine whether this is true with IRI duration changes in binary rhythm production. Ten participants provided IRI and movement data in bimanual synchronous tapping under equal (isochronous) and alternating (rhythm) interval conditions. Movement trajectory changes were observed with IRI duration (300, 500, or 833 ms) and for 500-ms IRIs produced in rhythm contexts (300/500 ms, 500/833 ms). However, application of the Wing-Kristofferson model showed that duration and context effects on IRI variability were attributable largely to timer processes with relatively little effect on motor processes.     

Anticipation across modalities in children and adults: Relating anticipatory alpha rhythm lateralization,reaction time,and executive function

The development of the ability to anticipate—as manifested by preparatory actions and neural activation related to the expectation of an upcoming stimulus—may play a key role in the ontogeny of cognitive skills more broadly. This preregistered study examined anticipatory brain potentials and behavioral responses (reaction time; RT) to anticipated target stimuli in relation to individual differences in the ability to use goals to direct action (as indexed by measures of executive function; EF). A cross-sectional investigation was conducted in 40 adults (aged 18–25 years) and 40 children (aged 6–8 years) to examine the association of changes in the amplitude of modality-specific alpha-range rhythms in the electroencephalogram (EEG) during anticipation of lateralized visual, tactile, or auditory stimuli with inter- and intraindividual variation in RT and EF. Children and adults exhibited contralateral anticipatory reductions in the mu rhythm and the visual alpha rhythm for tactile and visual anticipation, respectively, indicating modality and spatially specific attention allocation. Variability in within-subject anticipatory alpha lateralization (the difference between contralateral and ipsilateral alpha power) was related to single-trial RT. This relation was more prominent in adults than in children, and was not apparent for auditory stimuli. Multilevel models indicated that interindividual differences in anticipatory mu rhythm lateralization contributed to the significant association with variability in EF, but this was not the case for visual or auditory alpha rhythms. Exploratory microstate analyses were undertaken to cluster global field power (GFP) into a distribution-free temporal analysis examining developmental differences across samples and in relation to RT and EF. Anticipation is suggested as a developmental bridge construct connecting neuroscience, behavior, and cognition, with anticipatory EEG oscillations being discussed as quantifiable and potentially malleable indicators of stimulus prediction.     

EEG alpha rhythm, ocular activity and basal skin resistance.

Most hypotheses about the origin of the occipital alpha rhythm stress the specific influence of ocular activity.In this study, the influence of eye-movement frequency and extreme upward deviation of the eyeballs (enlarging the corneo-retinal potential) on occipital alpha activity and basal skin resistance is investigated. Eye-movement frequency did not significantly influence alpha activity and basal skin resistance. On the other hand, extreme upward deviation of the eyeball resulted in alpha activity enhancement and BSR increase. A white noise stimulus, given while the eyeballs were in an extreme upward position lead to a significant decrease in both alpha activity and BSR. However, the influence of the white noise condition was relatively larger on BSR than on alpha activity.The results of this study lead to the hypothesis that the extreme deviation of the eyeballs effects occipital alpha activity in two different ways; one is a direct influence from the eyes, along a low conductance pathway to the occipital region, according to Ennever; secondly, it is proposed that, during the extreme upward deviation of the eyeballs, inhibitory impulses from extra-ocular muscle receptors are sent down to the reticular formation leading to alpha activity increase (e.g. cortical arousal decrease).     

Cortical alpha rhythm, biofeedback, and the determinants of subjective state

A critical assumption in the rationale for the clinical application of voluntary control over central nervous system (CNS) activity is that there exists a direct relationship between specific CNS activities and specific subjective mood states. The experiment reported here was based on the idea that a joint manipulation of both cognitive and physiological (i.e., alpha electroencephalographic [EEG]) variables would provide information required for an explication of the processes involved in subjective mood change. Three main variables were considered in the present experiment. First, the instructions were designed to induce a "set" or expectations for either positive or negative changes in subjective mood. Second, the type of feedback (alpha or not alpha) was varied. Those in the not-alpha feedback condition received feedback contingent on the absence of alpha activity, whereas those in the alpha feedback condition received feedback contingent on the presence of alpha activity. Third, an estimate of each individual's baseline alpha density was obtained, and on this basis subjects were classified as high-baseline or low-baseline subjects. Baseline alpha density, alpha density during training, and subjective mood were all considered as continuous variables. The results of the present study indicate that biofeedback of the cortical alpha rhythm is neither a sufficient nor a necessary condition for changes in subjective mood. In addition, the type of instructions designed to set subjects for positive or negative alterations in subjective states is predictive of changes in subjective state reported during alpha biofeedback training as well as of success at controlling and changing EEG during feedback training. The data presented here permit a direct examination of the actual relationship of EEG changes to changes in subjective mood state. Similar shifts in subjective mood state can be obtained with either increases or decreases in alpha activity. Further, both positive and negative subjective experiences can be associated with increases in alpha activity.     

Impaired pitch production and preserved rhythm production in a right brain-damaged patient with amusia

Pre- and postmorbid singing of a patient with amusia due to a right-hemispheric infarction was analyzed acoustically. This particular patient had a premorbid tape recording of her own singing without accompaniment. Appropriateness of pitch interval and rhythm was evaluated based on ratios of pitch and duration between neighboring notes. The results showed that melodic contours and rhythm were preserved but individual pitch intervals were conspicuously distorted. Our results support a hypothesis that pitch and rhythm are subserved by independent neural subsystems. We concluded that action-related acoustic information for controlling pitch intervals is stored in the right hemisphere.     

The effects of expertise and age on rhythm production: adaptations to timing and sequencing constraints.

We investigate age- and expertise-related individual differences in component processes of rhythmic timing. To this end we apply analysis of covariance structure and symbolic dynamics to time series obtained from performances of two bimanual rhythm tasks at different tempos. Results show similar effects for peripheral motor implementation and timekeeper execution in young and older amateur pianists. Older participants show specific problems with temporal sequencing processes (specification of different target intervals). Expert pianists show lower variability in both motor implementation and timekeeper execution and they accommodate to the sequencing demands of different tempos by selectively relying on integrated or parallel timing. We argue that the observed timing control characteristics reflect individuals' adaptations to internal processing limitations and performance constraints.     

Effect of drugs on human discrimination ability

The effects of phenobarbital, nitrazepam, diazepam, medazepam, chlordiazepoxide, phenytoin, carbamazepine, thioridazine and caffeine on the detail discrimination ability of healthy subjects were compared with those of a placebo by means of the d2-test and the Bourdon-Wiersma test. The impairment of performance induced by phenobarbital, thioridazine and diazepam varied with dosage. The improved performance yielded by caffeine was related to both dose and time. Both deletion tests yielded the same results. They are suitable for detecting the effects of drugs and have proved useful for clinicopharmacological and clinicopharmacological and clinicopsychopharmacological studies.     

Television production feature effects on children's comprehension of time

Children's temporal comprehension was assessed after viewing a television program containing a flashback that shifted the events to a much earlier time. The flashback was marked or not marked with sound effects, and time relations were visually represented with either dreamy camera dissolves or abrupt camera cuts. Sixty-four children, equally distributed by grades kindergarten and first versus fourth and fifth, participated in individual viewing sessions. After viewing, children answered questions to assess comprehension on the flashback. Older children understood the flashback better than did the younger children. Children who saw dreamy visual dissolves understood temporal concepts presented in the flashback better than those who saw camera cuts, particularly at young ages. The results suggest that formal production features affect children's comprehension of complex temporal concepts presented via television.     

A matter of time: actual time and the production of the past

In psychoanalytic theory, space metaphors are frequently used to describe the psychic apparatus. As for time, it is traditionally invoked under the heading of timelessness of the unconscious, more aptly described as the resistance of the repressed to wearing away with time. This paper examines how the insertion of time into psychic events and structural differentiation form a single process. After looking into the parallelism between phenomenological and psychoanalytic views of time and differentiation, the author draws a distinction between two time categories: chronological versus actual. A clinical example is presented.     

Comparison of the effect of hard and easy mental arithmetic upon blocking of the occipital alpha rhythm

The intensity of blocking of the alpha rhythm of the EEG induced by the solution of five Hard mental multiplications has been compared with the intensity of blocking induced by five Easy mental multiplications in 36 normal subjects. From predictions derived from the application of two hypotheses concerning the intensity of blocking, it would be anticipated, firstly, that blocking would be more intense in the Hard tasks, if their solution required increased mental concentration and, secondly, that insofar as “higher thought” processes are more extensively required in the solution of Hard tasks, then blocking would be less intense in Hard tasks than in Easy tasks. However, the findings of the experiment have been that blocking is of the same intensity in tasks of both kinds. Possible reasons for this are discussed.

Hard tasks differed from Easy tasks, with regard to the relation of EEG changes and performance. It is thought that different mechanisms may underly the solution of the two types of task.     

Effect of diazepam on visuomotor reaction time

20 male and 10 female adult, normal, healthy subjects, whose mean age was 26.34 yr., participated in a double-blind study of the effect of a single dose (0.2 mg./kg. of body weight) of diazepam on visuomotor reaction time. Reaction time was measured before drug administration, and 60 min., and 120 min. after administration. Separate reaction times for the dominant and nondominant hand were recorded. There were no significant differences between the diazepam and placebo group at each of the three time intervals. Diazepam in the single dose employed does not appear to affect adversely visuomotor reaction time of relatively young, normal, healthy adults. For both groups the difference in visuomotor reaction time between the dominant hand and the nondominant hand was statistically significant as expected.     

Preferred rates of repetitive tapping and categorical time production

In a constrained finger-tapping task, in which a subject attempts to match the rate of tapping responses to the rate of a pacer stimulus, interresponse interval (IRI) was a nonlinear function of interstimulus interval (ISI), in agreement with the results of Collyer, Broadbent, and Church (1992). In an unconstrained task, the subjects were not given an ISI to match, but were instructed to tap at their preferred rate, one that seemed not too fast or too slow for comfortable production. The distribution of preferred IRIs was bimodal rather than unimodal, with modes at 272 and 450 msec. Preferred IRIs also tended to become shorter over successive sessions. Time intervals that were preferred in the unconstrained task tended to be intervals that were overproduced (IRI > ISI) when they were used as ISIs in the constrained task. A multiple-oscillator model of timing developed by Church and Broadbent (1990) was used to simulate the two tasks. The nonlinearity in constrained tapping, termed theoscillator signature, and the bimodal distribution in unconstrained tapping were both exhibited by the model. The nature of the experimental results and the success of the simulation in capturing them both provide further support for a multiple-oscillator view of timing.