by Fiona Nicholson, Science Writer

IN LAST MONTH’S issue of iScot, we saw a good description of the ‘elephant rope’, a story based on the theory of ‘learned helplessness’. What scientists now know however, is that the neuronal cells or neurons, in the brain never recover from the consequences of negative or aversive learning. The brains of all mammals are composed of broadly similar structures. The ancient brain which is common to all mammals, includes the brain stem which directs most of the automatic functions in the body such as breathing and heart rate, and the limbic system which deals primarily with emotions. The limbic system includes the hippocampus, the hypothalamus and the amygdala, two tiny almond-shaped structures sitting below the hippocampus. The hypothalamus responds to signals from the amygdala and throughout the body mainly through release of hormones such as dopamine in the ‘reward’ pathways. The higher brain is more developed in humans than other mammals, and the main part of this is the neocortex where logic, analysis and parts of memory are located. Neural signals which are sent directly to the hippocampus and hypothalamus are very rapid, causing reflex responses, such as jumping out of the path of a speeding car. Logical processing, analysis and cognitive processes take place in the higher brain and take longer to effect.