Heya!

[Tank]

May the saints preserve us... I/we have sorely missed Silver for a long time now. 

Please visit when ever you can, dear lady.

Hear hear!

[xSilverPhinx]

What a lovely surprise, xSilverPhinx. Please tell us what you've been up to.

Hey, Hermes!

Not much, not much! Biggest thing that happened was I spent 6 months in Houston last year trying to learn how to use a miniscope (really cool stuff, I got to see individual neurons shine) but now I'm back trying to finish my PhD on time (insert excessively nervous laughter here).

Bloody well done on the PhD front! Would any of us understand any of it?

Thanks! Yes, I'm certain you all would!

Memories change with time, right? Autobiographical memories can be divided into semantic memory, which is memory for facts, and episodic memory, which is memory for life events. So basically what happens is episodic memories can become less detailed with time and become more semantic.

For instance, if you think back on your school days, you certainly learnt facts such as "the molecular formula for water is H2O". But do you remember who taught you that? The color of clothes that teacher was wearing? What was the weather like that day? Probably not, but you remember the fact that H2O means water.

(Obviously this is an oversimplified exsmple as school facts can be taught repeatedly and memories interfere with each other, but you get the idea  )

So in the brain the hippocampus is important for consolidating recent episodic memories, and with time other "higher-up" cortical structures become important for remembering. As this shift from the hippocampus to cortex happens, episodic memories can become semantic. In the case of pathological and robust fear memories, that can result in mental health problems such as PTSD, because the traumatic memory becomes progressively stripped of context that surrounded that event, loses what anchors it to defined environments and situations and so can be triggered by reminders that are not part of the traumatic experience. For instance, fireworks triggering strong memories of war in a veteran during New Year celebrations, far from any war zone.

So, for my dissertation I'm comparing these processes between male and female rats and how they're modulated by sex hormones.

In Houston the idea was to see fluorescent activity of individual neurons in awake animals using a miniscope.    Whenever a neuron is electrically stimulated enough to communicate with another neuron it would shine The goal is to implement that technology here (which is relatively cheap and open source) to analyse that shift from the hippocampus to other brain structures as these memories are recalled.

[Tank]

I understood that!     

[Dark Lightning]

That's interesting!

[hermes2015]

What you said about memory made me think that it was similar to constructive interference. An example is astrophotography, where the image of a star is enhanced if one adds together many exposures. The background noise, because it is random, cancels out, while the image of the star becomes clearer as one adds more and more exposures. Another example is in environmental and forensic chemical analysis, where the sensitivity of your detector is less important than the signal to noise ratio (S/N). Ultimately, it is the S/N. not the absolute sensitivity of your sensor, that allows you to reach very low limits of detection.