/span>[4]:
</pre></div>
</div>
<div class="input_area highlight-ipython3 notranslate"><div class="highlight"><pre><span></span><span class="c1"># Similar to surface ref, we specify a volume reference, and extract the values needed</span>
<span class="n">vol_ref</span> <span class="o">=</span> <span class="n">VolRef</span><span class="p">(</span><span class="n">space</span><span class="o">=</span><span class="s1">'mni_1mm'</span><span class="p">,</span> <span class="n">parc</span><span class="o">=</span><spa