A flowchart of the nested spectral analysis as described in the text.

<p>A flowchart of the nested spectral analysis as described in the text.</p

Regular song spectrograms versus Rhythm spectrograms.

<p>A. A regular song spectrogram using a 10msec sliding window, showing power up to several kHz. B. Rhythm spectrograms display longer time scales. These are computed by estimating the dynamic spectrum of an appropriate song feature (amplitude in the above example). Each column of the rhythm spectrogram represents the averaged spectrum of song features sung during an hour long interval. C. Rhythm spectrograms that were generated using a point process that marks the onsets of syllables.</p

A spectrogram of an adult zebra finch song.

<p>This song has three repetitions of the motif. An occurrence of song is called a bout.</p

The relations of motif durations and the fundamental frequency of the rhythm spectrogram.

<p>Changes in the motif duration show up as changes in the fundamental frequency of the rhythm spectrogram as described in the text.</p

Rhythm of juvenile songs.

<p>The rhythm of juvenile song can be identified early during development, as described in the text.</p

Spatial preference for a fly in the circular Open Field arena.

<p>(a) The joint probability distribution <i>p(r,</i>̂<i>)</i> obtained using a bin size of 1° in ̂, 0.05 cm in <i>r</i>. There appeared to be little angular preference, but the preference for the arena wall (<i>r</i> = 7.5 cm) is evident. (b) Marginal radial probability distribution <i>p(r)</i>. The histogram was obtained by binning <i>r²</i> in bins of size 1.13 cm² (50 total bins). This estimate suggests defining a boundary between a Rim Zone and Central Zone at approximately <i>r</i> = 7.3 cm.</p

Speed distributions in each spatial ‘zone.’

<p>(a) Speed distribution in the Central Zone, obtained using a bin size of 0.1 cm² in <i>v</i>². Two visible behavioral components are seen in the plot, near-zero speed segments, marked by the tail descending from the zero speed bin, and finite speed segments, marked by the peak in the distribution at a non-zero, finite velocity (∼1.48 cm/s). A transition between these two segments can be estimated at about 0.75 cm/s. The first bin, which contains stops, is not shown in the figure. (b) Speed distribution in the Rim Zone, obtained using a bin size of 0.033 cm in <i>v.</i> Bins containing stops are not shown in the figure. Similar to the Central Zone distribution, this distribution has a peak at finite velocity (∼1.14 cm/s), but the near-zero segments do not show the large tail descending from zero seen in (a). A transition between the two segments in this zone can be estimated at about 0.4 cm/s.</p

Distribution of the time between entrance into and exit from the Central Zone and the Rim Zone (bottom).

<p>This can also been interpreted as the “length of stay.” A bin size of 4 seconds has been used to bin the data.</p

Position and speed characteristics of a fly moving in a circular Open Field arena.

<p>(a) The trajectory obtained from tracking a fly for two hours using the setup shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0001083#pone-0001083-g001" target="_blank">Fig. 1</a>. (b) The speed of the fly between 1150 and 1200 s, calculated by taking a numerical derivative of the smoothed position data. The stop-start behavior characteristic of fly locomotor activity is evident.</p

Experimental setup for characterization of locomotor behavior of <i>Drosophila</i> in the Open Field.

<p>Experimental setup for characterization of locomotor behavior of <i>Drosophila</i> in the Open Field.</p