Effects Of Foreperiod Duration Research Articles

Effect of Foreperiod Duration and Handedness on Simple and Choice Auditory Reaction Time Among the Older People

Effect of Foreperiod Duration and Handedness on Simple and Choice Auditory Reaction Time Among the Older People

Effects of foreperiod duration on anticipatory postural adjustments: determination of an optimal preparation in standing and sitting for a raising arm movement

The purpose of the present experiment was to examine the motor and postural preparation processes evolving during the foreperiod (known to be optimal at 500 ms in sitting) in a voluntary upper limb movement executed while standing. The foreperiod duration (300, 500, 700 and 900 ms) and the postural conditions (sitting versus standing) were manipulated using a priming procedure. Two types of prime were provided: (1) a prime giving valid information on the side of the raising arm movement to execute, and (2) a prime giving non-valid information (prime opposite to the required side). In a sitting and standing condition, eight normal subjects performed a raising arm movement with a 1 kg load at the level of the wrist. Premotor time and acceleration of arm movement were recorded in the two postural conditions. In the standing condition, anticipatory postural adjustments (APAs) were also quantified using the relative latency of electromyographic (EMG) data and the centre of foot pressure (CoP) displacements. Results (1) showed that the optimal foreperiod duration (i.e., leading to the shortest premotor time) increased as a function of postural conditions (500 versus 700 ms in the sitting and standing conditions, respectively), and (2) emphasized the existence of a temporal modulation in the central organization of the postural and focal commands according to the foreperiod duration.

Independence of reaction time and response force control during isometric leg extension

In this study, we examined the relative control of reaction time and force in responses of the lower limb. Fourteen female participants (age 21.2±1.0 years, height 1.62±0.05 m, body mass 54.1±6.1 kg; mean±s) were instructed to exert their maximal isometric one-leg extension force as quickly as possible in response to an auditory stimulus presented after one of 13 foreperiod durations, ranging from 0.5 to 10.0 s. In the ‘irregular condition’ each foreperiod was presented in random order, while in the ‘regular condition’ each foreperiod was repeated consecutively. A significant interactive effect of foreperiod duration and regularity on reaction time was observed (P < 0.001 in two-way ANOVA with repeated measures). In the irregular condition the shorter foreperiod induced a longer reaction time, while in the regular condition the shorter foreperiod induced a shorter reaction time. Peak amplitude of isometric force was affected only by the regularity of foreperiod and there was a significant variation of changes in peak force across participants; nine participants were shown to significantly increase peak force for the regular condition (P < 0.001), three to decrease it (P < 0.05) and two showed no difference. These results indicate the independence of reaction time and response force control in the lower limb motor system. Variation of changes in peak force across participants may be due to the different attention to the bipolar nature of the task requirements such as maximal force and maximal speed.

Specification of direction and duration during programming of discrete sliding movements

Two experiments on duration programming of a discrete sliding movement in choice reactions are reported. In the first experiment it was examined whether duration of movement might be preprogrammed when varied across sessions. The result suggested that programming of movement duration is dependent on direction uncertainty. Experiment 2 used the movement precue technique in an attempt to further examine programming of movement duration and direction. Movement duration, movement direction, movement form and foreperiod duration were manipulated. When duration was not precued, a duration effect was found, while precueing resulted in disappearance of the duration effect, demonstrating that duration of sliding movements can be preprogrammed. Moreover, (pre)programming duration was independent of direction uncertainty, supporting an independent order notion of programming of these response variables. Evidence that motor preparation comprises different processing stages was derived from the additive effects of foreperiod duration and of the movement variables duration and direction.

Positive and negative effects of stimulus intensity in auditory reaction tasks: Further studies on immediate arousal

Effects of foreperiod duration and preknowledge about stimulus intensity were examined in auditory reaction time (RT) tasks in which stimulus intensity was varied between 50 and 110 dB (SPL). Long foreperiods of about 30 sec considerably lengthened RT in comparison with the 2 sec foreperiod. In addition, long foreperiod durations reduced the detrimental effect of intense stimuli ( > 70 dB) on choice RT that was obtained at short foreperiods. Preknowledge produced a general time gain of about 10 msec without affecting the RT/intensity curves in all but the simple RT condition of experiment 2, where the RT/intensity gradient was somewhat steepened. The present results are consistent with the view that size and direction of immediate arousal as exerted by intense stimuli are regulated by foreperiod duration as well as by the demands placed upon the response choice mechanism. The view is defended that immediate arousal can be identified with a defensive reflex (DR), conceived as a motor facilitating system (Graham 1979), rather than with an orientation reflex (OR).

On ego regression and prior time information effect in schizophrenia.

Process schizophrenics, reactive schizophrenics, neurotics, and alcoholics (N = 80) estimated the duration of a dark dot that followed an auditory warning signal of variable duration. The duration of the warning signal constituted foreperiod (FP). The effect of FP duration on time estimation (TE) was an increasing one for all Ss, and schizophrenics were indistinguishable from nonschizophrenics. Similarly, there was no group difference with respect to the effect of preceding foreperiod (PFP). Prior time information (TI) in terms of the correlation between the pitch of the warning signal and FP duration eliminated the effects of FP and FP change for schizophrenics. As for neurotics, such prior TI accentuated the effect of decrease of FP duration and attenuated the effect of increase of FP duration. The multi-level conceptualization of time is proposed in order to establish the distinction between regression in time and regression of time. Neurosis is regarded as involving regression in time; schizophrenia is regarded as involving regression on time.

Binocular locus of prior time information effect in schizophrenia.

Schizophrenics and alcoholic controls estimated the duration of a single dark dot, which followed an auditory warning signal of variable duration that functioned as foreperiod duration. The effect of foreperiod duration on time estimation was an increasing one for both schizophrenics and alcoholics alike. Elimination of such foreperiod effect by prior time information in terms of correlation between pitch of the warning signal and foreperiod duration, was shown to be unique to schizophrenics. However, this prior time information effect was demonstrated only when the dot was viewed binocularly, not when viewed monocularly. This binocular locus of time expectancy in schizophrenia reflects the tendency toward spatialization of prior time information.

The relation between physical stimulus properties and the effect of foreperiod duration on reaction time.

Seven subjects were used in an experiment on the relation between signal modality and the effect of foreperiod duration (EP) on RT. With visual signals the usually reported systematic increase of RT as a function of FP duration (1, 5 and 15 s) was confirmed; with auditory signals no difference was found between FP's of 1 and 5 s while the effect at 15 s was equivalent to that found at 5 s with the visual signal. The results suggest that besides factors such as time uncertainty the FP effect is also largely dependent on the arousing quality of the signal.