28 January 2013

Sleep and memory. Do they go together?

New study says yes.  A report in NY Times (Jan 27, 2013), "Aging in Brain Found to Hurt Sleep Needed for Memory" by Benedict Carey reports on new findings.
Previous research had found that the prefrontal cortex, the brain region behind the forehead, tends to lose volume with age, and that part of this region helps sustain quality sleep, which is critical to consolidating new memories. But the new experiment, led by researchers at the University of California, Berkeley, is the first to directly link structural changes with sleep-related memory problems.

The findings suggest that one way to slow memory decline in aging adults is to improve sleep, specifically the so-called slow-wave phase, which constitutes about a quarter of a normal night’s slumber.
Researchers are trying to use electrodes on the skull to help recreate the wave patterns that are associated with healthy sleep.

26 January 2013

How much are we truly aware of?

Not so much, according to David Eagleman's "Incognito", which describes how much flies under our conscious radar.  Overall I thought this book was quite good, a better introduction to these topics than several others I've read.

I won't write up too much about it, but there were a few points that I found new and worth noting.  First was this:  "Throughout the brain there is as much feedback as feed-forward" (p. 46).  This is described in reference to the visual system, with an example that the act of imagining a scene will cause the low-level visual system to light up with activity.  In this sense we create our visual world internally, and influence the processing of signals that come in via our eyes.  But I think the general principle is extremely important, that mental acts can cause all sorts of brain activity, and very likely "re-wire" neurons.

The other area that Eagleman is especially interested in has to do with personal responsibility and the legal system.  He argues that the quest to find blame is less useful than taking a more forward-oriented approach - will a person be likely to continue to be a danger to society, or is that a low likelihood.  He argues that there are all sorts of reasons why a person might have acted in a certain way, from contextual cues to biological reasons (for example a brain lesion could have eroded certain mental functions), but if the context is unlikely to recur, or the biological problem has been cured, then future behavior is unlikely to repeat the crime.  Obviously this then ties into drug addiction and our 'war on drugs' which has created such a large prison population.

Eagleman is apparently working on his next book on neuroplasticity, and I look forward to it.

08 January 2013

The Self Illusion - Bruce Hood (2012)

Quick review: typos, rehashes, some good points.

Bruce Hood is a UK professor in psychology, and he studies child development.  The Self Illusion is his 2012 book, subtitled 'How the Social Brain Creates Identity' - but unfortunately he doesn't actually spend all that much time directly focused on ideas of the 'social brain'.  Too much of the book tells of well-worn research findings from Libet, Milgram, Zimbardo, etc.  And the book feels rushed and a little sloppy due to the many typos (at least a dozen), along with the format which feels like a compendium of longish blog posts not fully tied together.

That said, there are a few things I felt worth covering from the book.  Hood makes it clear that his meaning of 'illusion' is not that there's nothing there, but that it is not what it seems.  The main point of the book seems to be that there is no truly singular, consistent 'self' - we all behave in different ways depending on the social & environmental context we find ourselves in, plus we are frequently driven by forces and incentives of brain processes that we aren't directly aware of.  However we all tend to feel that we are autonomous beings with some level of free will - and there appear to be very healthy psychological benefits from that mindset.

The information on certain aspects of child development were interesting.  Hood writes on p. 46 "So long as our interactions are timed to the babies' activity, they pay attention to us." In a sense babies are selecting the adults that are most attentive to them, those likely to be good care-givers.  There's also interesting material on critical periods of development, which can be devastating if not fulfilled.

There is a bit of coverage on split-brain patients, and I found the internal inconsistency of the book to be kind of typical, I'd say based on the mind/brain confusion.  On page 130 there's a section titled 'Being in Two Minds' that introduces the split-brain idea and research by Michael Gazzaniga.  But later on page 233 he notes "Gazzaniga has proposed that there are not two separate minds or selves in these split-brain patients."  I think this is an important point - if mind is the subjective experience, then even though communication between the lobes of the brain is incomplete, and behavior is not fully coordinated, the subjective mind experience is singular.

The book includes a chapter of musing about the impact of the internet and social media in particular.  It's probably too early to draw conclusions, but I think Hood is right to question how this context will influence the social development of people, and what it may do to one's sense of self.

Here's a short interview between Hood and Sam Harris.