Executive function

(1976). Genetic dissection of the photoreceptor system in the compound eye of Drosophila melanogaster. (1978). A Drosophila mutant with a temperature-sensitive block in nerve conduction. synonymous with those behaviours and abilities. At an abstract level of processing, least tied to routine behaviour, are flexible representations of goals and intentions. Such 'higher-level' representations are often contrasted with 'lower-level' cognitive processes involved in analysing specific perceptual inputs (such as visual processing of stimuli such as 'BLUE') and generating specific motor outputs (such as vocal responses). According to most theories, executive function entails the modulation of lower-level processes by those at a higher level. Depending on our current goal, we are able to modulate lower-level perceptual-analysis and speech-output processes in order to produce appropriate behaviour. In different contexts we might ignore the word, read it out, or name its colour, even though we are presented with the same perceptual input in each case. Thus, executive functions allow us to behave flexibly, rather than being slaves to our environment and always behaving in a stereotyped manner when particular events occur. This equips us with the ability to adapt to novel, or changing, situations. The modulation of various cognitive, perceptual, and motor processes according to abstract goals and intentions is commonly referred to as 'top-down control'. However, this should not imply a strict unidirectional influence from higher-level to lower-level processes. Instead, the role of executive function in cognition is probably more accurately considered in terms of continual interaction between higher-and lower-level processes. Higher-level processes are commonly triggered in everyday life by conflicts between representations or inputs at lower levels, for instance when something unexpected occurs or when behaviour does not have the usual consequences. Paradigms in executive function research Historically, a major obstacle to progress in research into executive function has been the difficulty of quantifying the processes supported by the human frontal lobes, a problem compounded by the variety of cognitive, social, and emotional changes that have been reported to occur as a consequence of damage to this region. Methodological and Executive functions are the high-level cognitive processes that facilitate new ways of behaving, and optimise one's approach to unfamiliar circumstances. As many situations in everyday life are not exactly the same as ones that we have encountered before, it follows that the operation of executive processes accompanies a very wide range of behaviours. But we particularly engage such processes when, for instance, we …