Citrine (colour) than it is today and could be "reddish or brownish yellow; or orange; or amber (distinguished from yellow)". In today's English citrine as a colour is mostly confined to the contexts of (1) gemstones, including quartz, and (2) some animal and plant names. E.g., the citrine wagtail ("Motacilla citreola"), an Asian bird species with golden-yellow plumage, or the citrine warbler, citrine canary-flycatcher, citrine forktail, etc. Citrine (colour) Citrine is a colour, the most common reference for which is certain coloured varieties of quartz which are a medium deep shade of golden yellow. Citrine has been summarized at various times as
Colour centre cannot track the actual firing of neurons, which happen on a millisecond timescale, but it can track the haemodynamic response, which happens on a seconds timescale. This method is ideal for tracking colour selective neurons because colour perception results in a visual after-image that can be observed in the neurons, which lasts about 15 seconds. Sakai et al. used fMRI to observe whether activation of the fusiform gyrus correlated with the perception of colour and the after image. The subjects in the Sakai study were placed in the fMRI machine and were subsequently subjected to various visual stimuli. A series