The Human Brain : From Neurone to Nervous System


  1. The Association Cortex consists of areas of cortex which combine many external and internal conscious processes to achieve a particular higher level function of the brain. These different high levels functions are localised in different parts of the brain and are interconneted by bundles of subcortical association fibres.

  2. All areas of the cortex are interconnected using subcortical axons. Higher level functions of the brain, i.e. these involving attention and thought, depend on sensory inputs of all types, memory, emotion, etc, in order to generate an appropriate response, be it movement, speech, or other output.

  3. Areas of the cortex concerned with specific higher level functions, such as conversational speech, depend on many factors, internal and external. For example, auditory inputs that need to be interpreted, and combined with an appreciation of three-dimensional space (where the sounds originate), facial recognition (of friends or foes?), auditory memory of dialects, accents, etc, memory of contexts, previous experience, etc, etc. Different parts of the brain are concerned with all of these separate functions and subcortical association fibres connect them, so that a mental image involving many senses, memory traces and emotions are combined almost simultaneously in order to produce a thoughtful reaction.

  4. Key Words: localisation of higher level functions of the brain, understanding words and speech, attention, emotion, thought, spatial awareness, behaviour, motivation, subcortical association fibres.