Posted comment on ´Our humming brain help us learn rapidly` by Hitchings
published in New Scientist 2974 21st June 2014 p.16
Hitchings described work by Antzoulatos and Miller at the Massachusetts Institute of Technology who looked at brain waves of monkeys as they were taught to categorise patterns of dots into two groups. Initially, the monkeys learnt where the dots were, but then shifted to learning the rules of defining the groupings. This shift was observed in changes in brain waves patterns with the initial locating stage producing different brain wave frequencies in both prefrontal cortex and striatum leading to synchronisation of firing at a different frequency for each group of dots and between the two areas. This was recorded as the first report of synchronous firing linked to specific thoughts. According to Miller, the synchronisation occurs prior to physiological changes and gives the brain time to think about its options before recording in long-term memories.
The synchronisation of firing groups of neurons relevant to specific information inputted and recalled is known and the ´musical hum of brainwaves` reflects this synchronisation and frequency of the firing neuronal groups. As far as brain memory goes, these active neuronal groupings make up the sensory stores, short-term memories (held less than 10 minutes) and long-term memories (greater than 10 minutes). Whereas it is easier to imagine that the sensory stores and short-term memories represent groups of firing neurons in real-time and this firing leads to what is being perceived, it requires more thought as to how these neuronal groupings are remembered in order that memories can be evoked after a longer period of time. Establishing long-term stored groupings requires normally repetition of events (emotionally strong events being an exception) in order that mechanisms can be initiated that lead to observed physiological changes in those active cells. It is assumed that these physiological changes link the corresponding cells together in some way so that a real-time action is stored long-term. This may explain neuronal groupings within a brain area, but does not explain how other brain areas are linked. In my book ´Brain Memory: Outside the Box` (for more information see the link to the accompanying website) I discuss the topic of what I call this hypothetical connectivity which exists between cells from different areas and within areas. The study of Antzoulatos and Miller looks at this topic.
Antzoulatos and Miller said that previous studies have shown increased synchrony between the brain regions prefrontal cortex and striatum during learning and their study was the first to show specific patterns of synchrony linked to specific thoughts, ie it showed processing of information, but not specifically learning when working on the problem of discerning which group dots belong to. This view is supported by the functions of the prefrontal cortex and striatum known to take place in this type of task eg visual perception, processing using recalled memories in working memory, matching to groups, decision-making processes. Conscious awareness demonstrates a delay. Although a relatively simple task, the study of Antzoulatos and Miller show the vast number of processes going on simultaneously in order that it can be carried out and the need that all processes should be considered when interpreting the results.
Since we`re chatting about the topic…………………..
..would it be right to assume that if the experiment was performed with dots of different colours then the brain area activity and synchronicity associated with colour would be determined?
..if the striatum was lesioned and the experiment re-run we could see if the same results occur or if plasticity occurs and other brain areas compensate.
..if the speed of the experiment was increased so that conscious awareness was not possible, would any activity and synchrony observed be due to processing of unattended information compared to attended information in this experiment?