22 Sep 2013

Aakom rebooted

A quick glance at the dates on this blog's posts will reveal that it has been idle for about 3 years. During that time, I've been teaching and, most recently, have been ill. To paraphrase Iain Banks, I am unofficially (as few care) rather poorly. But this enforced physical idleness has rekindled interest in some of my blogs that have been languishing in cyber-storage: Aakom is one such blog.

7 Apr 2010

Direct recording shows brain signal active even in dreamless sleep

Neuroscientists at Washington University School of Medicine in St. Louis have taken one of the first direct looks at one of the human brain's most fundamental "foundations": a brain signal that never switches off and may support many cognitive functions. The results, appearing online this week in the Proceedings of the National Academy of Sciences, are an important step forward for efforts to outline what neuroscientists call the functional architecture of the brain. Better understanding of this architecture will aid efforts to treat brain injury and mental disorders.

6 Apr 2010

Are Vision and Consciousness Intimately Related?

In my article on brain waves and consciousness I looked at some research associating gamma wave activity with consciousness. This is, however, a controversial area in that other researchers have found that such gamma activity is also correlated with eye movements known as saccades: these are the small eye movements that the brain edits out so that we do not perceive the world as a blur as we switch focus. So, are brain gamma waves merely a byproduct of saccadic movements or are they correlated with consciousness or, potentially, both?

28 Mar 2010



The European Society for the Study of Science And Theology (ESSSAT)
& The Science Religion Forum (SRF)
present the
XIIIth European Conference on Science and Theology, Edinburgh, UK,
April 7-11, 2010

Transient Induced Gamma-Band Response in EEG as a Manifestation of Miniature Saccades

The induced gamma-band EEG response (iGBR) recorded on the scalp is widely assumed to reflect synchronous neural oscillation associated with object representation, attention, memory, and consciousness. The most commonly reported EEG iGBR is a broadband transient increase in power at the gamma range not, vert, similar200–300 ms following stimulus onset. A conspicuous feature of this iGBR is the trial-to-trial poststimulus latency variability, which has been insufficiently addressed. Here, we show, using single-trial analysis of concomitant EEG and eye tracking, that this iGBR is tightly time locked to the onset of involuntary miniature eye movements and reflects a saccadic “spike potential.” The time course of the iGBR is related to an increase in the rate of saccades following a period of poststimulus saccadic inhibition. Thus, whereas neuronal gamma-band oscillations were shown conclusively with other methods, the broadband transient iGBR recorded by scalp EEG reflects properties of miniature saccade dynamics rather than neuronal oscillations.

Transient Induced Gamma-Band Response in EEG as a Manifestation of Miniature Saccades

The above link to the article also has links to the exchanges that followed about whether gamma waves as recorded by EEG are intimately linked to consciousness or results of electrical signals from microsaccades, or possibly both.
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