The Effect Of Attention Control On Rhythmic Temporal Expectation

Many activities in our living environment are rhythmic,such as speech and music.The rhythm can be defined as a regular combination of multiple intervals.And the temporal expectation formed by using the rhythm time information is called rhythmic temporal expectation.Dynamic attending theory assumed that rhythmic temporal expectation is thought to be automatic,involuntary and independent of attention control.It provides a framework for explaining why rhythmic time context can predict the occurrence time of incoming events.That is the result of the time consistency between events and the synchronous oscillation between internal attenional energy and rhythmic structure.The theory is also known as the oscillator model,consisting of two important components: oscillators and attentional energy pulse.These two components make the distribution of attention resources in time not constant,but in the form of fluctuation.At different time points,attention resources have waxes and wanes with time's passing.The period and phase of the oscillator can be adaptively adjusted depending on the time structure of the events,gradually changing its own period and phase so that the peak of the attentional pulse(the time point with the most attentional resources)aligh with the time when the stimulus occurs.In other words,the adaptation process of the oscillator causes the attentional pulse to synchronize with the onset of external stimuli,eventually causing the concentration of attentional resources.This process is also called entrainment.If conditions permit,the oscillator will continue to adjust until the peak of the pulse is aligned with the expected time of the stimulus.The oscillatory selection hypothesis based on electrophysiological studies also supports the dynamic attending theory.Low-frequency neural oscillations has been shown to be related to the consequences for neural response elicited by stimulus events and behavioral performance.According to the external rhythmic structure,the low frequency neural oscillation adjusts its oscillation's period and phase,and thus synchronizes with the external time structure.Neural oscillation carries attentional resources.By adjusting its phase and period,the phases will be concentrated.The neural oscillations reflect the number of neurons that achieve synchronization in time.In turn,the extent of excitation synchronization of neurons is related to the degree of entrainment,and depends on the degree of temporal regularity of the stimulus sequence in the environment.The more regular,the higher the accuracy of entrainment,the more concentrated of attention resources.Continuing entrainmen is the internal mechanisms,by which the brain develop temporal expectations and promotes perception.The temporal regularity of sensory input leads to the generation of time expectation.As a result,the onset of event will be predicted.Although these two theoretical models are supported by numerous studies,there are two problems: first,the interval between stimuli in the stimulus sequence is mostly subsecond;second,because the auditory modality is superior to visual modality in processing time information.Researches is more likely using auditory materials.The range-synthetic model of time cognition emphasizes that the perception of time is segmented.The representations of different ranges of interval involve different processes,and are all influenced by multiple factors,such as physical characteristics of stimulation,cognitive factors,or personality.Therefore,whether or not the rhythmic temporal expectation is merely an automatic process requires an examination of the expectation formed by different sensory modalitys and different ranges of time intervals.In essence,time perception and the "perceived present" are the same.Researches often explore the the upper limit of "perceived present".Most of the studies were limited to the percetpion of duration within 5 seconds,during which information was integrated into a unity.Therefore,its main features are continuity and integrity.However,most of these studies explored a single time interval.Rhythm can be understood as a regular combination of multiple intervals.To study the effect of attention control on the rhythmic temporal expectation,it is firstly necessary to make sure the range of time interval,using which rhythmic temporal expectation can be developed.Vision and audition have differences in processing time information.The auditory is good at processing time information,while the visual is good at processing space and motion information.Therefore,Study 1 and Study 2 examine whether the rhythm information formed at different intervals from the auditory and visual respectively can form temporal expectation and examine whether there is a modality effects.Because the reaction time is an overall dependence variable index,including the early stage of percepion and motion preparation.Therefore,in Study 3,we used both response time and ERP components as dependent variable indicators to examine the effect of attentional control on the rhythmic temporal expectation at different rhythm rates.Audition is better than vision in recognizing and memorizing rhythm,and vision is better at processing motion and spatial information.However,previous studies often compare the visual rhythm consisting of flashes that appears in a fixed position with the auditory rhythm infomration.This contrast is not correct.Therefore,in study 4,visual materials are presented in the form of movements,examining the role of movement information in temporal prediction.furthermore,we explore the effects of attention control on this temporal ecpextation.In studies 1 and 2,we found that rhythmic temporal expecatation can be developed with ISI-700 ms,ISI-1500 ms,ISI-2500 ms in both auditory and visual modalities.Moreover,we also found that the paradigm that determines the expectation effect by operating the interval between the end of the stimulus sequence and the onset of the target is easily affected by the passage of time.Thus,the response time was the result of a combination of rhythmic temporal expectation and foreperiod effects.By changing the number of stimuli in the stimulus sequences,increasing the uncertainty of the appearance time of the target,the effect of temporal expectation can be further weakened.However,this weakening has different manifestations in the visual and auditory modality.In auditory modality,with the increasing of certainty of the time of appearance of the target,the role of the rhythmic time information is increasing.In the visual modality,the responses are more susceptible to the foreperiod effect.The studies also found that the paradigm is more stable by using a strictly periodic stimulus sequence that defines the rhythm as an isochronous sequence,and comparing it with a randomly sequence of inter-stimulus intervals to determine the rhythmic temporal expectancy.In study 3,we found that if response time is the dependent variable index,regardless of auditory or visual modality,rhythmic temporal expectation is not affected by the memory load with ISI-700 ms and ISI-1500 ms.However,when the rhythm information formed by the ISI-2500 ms,temporal exepctation is influenced by the memory load.Under high load conditions,there is no difference between the rhythmic sequence and the random sequence.This shows that the rhythmic temporal expectation is segmented.In details,temporal expectations developed by time interval below 2500 ms are more automatic,while those developed by intervals of 2500 ms or more are affected by cognitive control.Using the ERP components N1 and P3 as the dependent variable indicators,it was found that in the auditory modality,the ISI-700 ms and ISI-1500 ms intervals are not influenced by memory load,while in the ISI-2500 ms condition,memory load affected the rhythmic temporal expectation.The effect is shown by the fact that N1 potential has no difference in average amplitude under high load and low load conditions.However,the P3 component did not show significant differences under all conditions.In the visual modality,only the rhythmic temporal expectation formed at the interval of ISI-700 ms induces the N1 component.The rhythmic temporal expectation formed by the interval time of ISI-1500 ms and ISI-2500 ms did not induce significant N1 component,which Showing modality differences.in study 4,we found that movement information can significantly promote visual rhythmic temporal expectation with ISI-1500 ms and ISI-2500 ms.However,this requires participants to actively extract rhythmic information from the movement.When the subjects were asked to complete a working memory task at the same time,temporal expectation disappeared.This shows that visual rhythmic temporal expectation requires more attentional resources.In conclusion,this paper systematically discusses the effect of attention control on the rhythmic temporal expectation.Studies have shown that rhythmic temporal expectation is affected by the range of time interval between stimuli in the sequence,and show a difference in auditory and visual modalities.The rhythmic temporal expectation formed at the interval of ISI-2500 ms is expected to be affected by attention control.Furthermore,when the visual information has been carried in the form of movement,the expectation formed by the time interval of ISI-1500 ms or more is influenced by the attention control.The working memory task used in this study only includes the memory retention and recall processes.Future studies also need to use memory tasks that involving memory update and monitor,or perception load tasks to further examine the effect of attention control on rhythmic temporal expectation.