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Vinsamlegast notið þetta auðkenni þegar þið vitnið til verksins eða tengið í það: http://hdl.handle.net/1946/28835

Titill: 
  • Titill er á ensku Effects of cycling speed on visual responses in the human sensory cortex
Námsstig: 
  • Bakkalár
Útdráttur: 
  • Útdráttur er á ensku

    Introduction: The behavioral state of an animal influences ongoing brain activity and is evident when brain responses of anesthetic animals are compared to alert animals. In recent years, interest has increased on what effect physical activity might have on these responses, with research suggesting that visual processing becomes more sensitive during locomotion. Single cell recordings in the sensory cortex of rodents show an increase in firing rate of feature selective neurons as a function of exercise and similar responses are seen in EEG recordings of the human visual cortex. An increase in responses to feature selective visual stimuli in the human sensory cortex is shown to be greatest when participants are cycling at a low level of resistance, compared to conditions where they are resting or cycling at a high level of resistance, suggesting possible inverted-U effects of exercise workload on sensitivity in cortex. The goal of the present study was to extend previous findings and test whether manipulating pedaling speed on the bike can also modulate neural responses in visual cortex.
    Methods: 11 adult volunteers (6 female, 5 male) took part in the study that was divided into two parts. Participants engaged in a visual orientation discrimination task in which they were presented with orientated gratings at one of nine different orientations and were required to detect a small rotation change. The gratings were flickered on and off at 15 Hz to generate a steady state response in cortex. The first part of the study involved determining a task difficulty level that the participant could perform at ~65% accuracy. In the second part, participants were positioned on a stationary exercise bike and completed the task at rest and during bouts of low (50 RPM) and high (70 RPM) speed pedaling. Each conditions lasted ~40 minutes. EEG, heart rate and pupil size were continuously recorded throughout each condition. An inverted encoding modeling (IEM) technique was applied to the EEG data to reconstruct estimated population-level neural response profiles.
    Results: Preliminary analyses revealed a significant difference in response profiles between rest vs. low cadence, [t(10) = 2.28, p=.045]. Furthermore, there was a significant difference in rest vs. high cadence in activity at 15 Hz, [t(10) = 2.32, p=.04].
    Discussion: The results seem to be trending in the same direction as the previous work, such that low-intensity exercise appeared to increase feature selective attention responses. The sample size of this study is currently rather low, but with more participants (n=18), we predict statistically significant differences in response profiles between rest and low-speed exercise conditions.

Samþykkt: 
  • 5.9.2017
URI: 
  • http://hdl.handle.net/1946/28835


Skrár
Skráarnafn Stærð AðgangurLýsingSkráartegund 
Asta_Gudrun_Sighvatsdottir_BSc.pdf957.51 kBOpinnHeildartextiPDFSkoða/Opna
Lokaverkefni - Yfirlýsing um meðferð(1).pdf50.84 kBLokaðurYfirlýsingPDF