Emergence of Frequency-Dependent Motor Variability Within Supra-Second Auditory Cueing.

Motor variability (MV) is an essential feature of the sensory motor system, and it plays an important role in sensory-motor learning. MV facilitates motor adaptation during auditory-motor synchronization (AMS). In AMS, individuals receive a series of similar auditory stimuli that come in a periodic manner at a fixed interval called an inter-stimulus interval (ISI). Peri-second ISI (1 second range) and supra-second ISI (>1 second) are differently processed, since these intervals involve different amount of cognitive resources. Supra-second ISI involves more top-down attention as compared to peri-second ISI. In this study we examined the effect of tone frequency (perceptual property of auditory stimuli) on predictive tapping and MV under peri-second and supra-second ranges. We examined the effect of tone frequency (a perceptual property of auditory stimuli) on predictive tapping and motor variability (MV) under short (peri-second) and long (supra-second) inter-stimulus intervals. Among 30 healthy participants (aged 18-35 years, M = 24.6 years), we randomly assigned equal numbers of these two inter-stimulus conditions to isochronous sound sequences. In their attempt to synchronize their motor responses with the tone, participants reproduced the ISI in their inter-tap intervals (ITIs). We analyzed their predictive tapping in terms of negative asynchrony (in which the tap occurs before the tone) and small positive asynchrony (0-100 ms), whereas we analyzed MV using the coefficient of variation (CV) of the ITI. We found that participants showed predictive tapping under short ISI, irrespective of the tone frequency. Moreover, their MV was unaffected by tone frequency. These findings imply that participants expressed MV in a predictive rather than reactive manner under short, but not long, ISI. Under long ISI, tone frequency had a significant effect on MV such that there was higher MV with the low-frequency than with the high-frequency tone. Thus, low-frequency tones are most suitable for auditory-motor learning in the supra-second range.

Less effortful auditory-motor synchronization with low-frequency tones in isochronous sound sequence.

In music aided rehabilitation therapies like Rhythmic auditory stimulation (RAS), it is important for a subject to engage with isochronous sound sequence for efficient auditory-motor synchronization (AMS). This engagement will depend upon listening effort (which is the amount of cognitive resources needed to comprehend and synchronize with the isochronous sound sequence). Less effort will lead to more engagement. Frequency of tone and inter-stimulus interval (ISI) are two main elements of sound sequence which are likely to affect the synchronization accuracy and listening effort. This study examines the motor response of the participants to the tone and their listening effort involved in performing continuous tapping task. The emphasis is how the effect of frequency of the tone and inter-stimulus interval (ISI) affect synchronization error and listening effort in isochronous sound sequence. Thirty participants (aged, 18-35 years, M = 24.6 years) took part on a voluntary basis in this study. Their finger tapping responses and listening efforts were measured. Pupillary dilation was recorded using Tobii tx-30 eye tracker in order to analyze listening effort. The results suggest that the frequency of tone plays a crucial role in tapping performance and listening effort. In summary, this study demonstrates that there is better temporal alignment to low-frequency tones with lesser listening effort as compared to high-frequency tones.

Wound healing potential of methanolic extract of Trichosanthes dioica Roxb (fruits) in rats.

AIM OF THE STUDY: The present study provides a scientific evaluation for the wound healing potential of methanolic (MeOH) extract of TDR fruits. MATERIALS AND METHODS: Excision and incision wounds were inflicted upon three groups of six rats each. Group I was assigned as control (ointment base), Group II was treated with standard silver sulfadiazine (0.01%) cream. Group III was treated with 5% MeOH extract ointment. The parameters observed were percentage of wound contraction, epithelialization period, hydroxyproline content, tensile strength including histopathological studies. RESULTS: It was noted that the effect produced by the extract ointment showed significant (P<0.01) healing in both the wound models when compared with control group. All parameters such as wound contraction, epithelialization period, hydroxyproline content, tensile strength and histopathological studies showed significant changes when compared to control. CONCLUSION: The result shows that TDR extract ointment demonstrates wound healing potential in both excision and incision models.