Cognitive psychology explores cognitive processes such as perception, problem solving, and memory, usually making use of behavioural data. Methodologically, cognitive psychology marked a clear break with behaviourism in once again making the mind a legitimate focus of study in psychology, instead of insisting on observing only external behaviours. Cognitive psychologists felt that higher cognitive processes such as language and thinking could not be given satisfactory explanations simply in terms of stimulus-response relationships (no matter how complex). Learning depends not just on the kind of experiences we have, but also on our own abilities to process the information we receive, and link it to previous knowledge. While attempting to keep the behaviourist insistence on careful, replicable experimental methodology, cognitive psychologists developed ingenious new methods of gathering data.
Cognitive psychology can be seen as a subset of 'cognitive science', which comprises any discipline that studies cognition scientifically. This can include linguistics, psychology, and Artificial Intelligence (AI) as well as other disciplines. Cognitive science can be contrasted with neuroscience, in that cognitive science can be seen as essentially trying to map the brain's software (e.g. computer programs), with neuroscience examining the brain's hardware (e.g. the electronic circuitry in a computer). This computer metaphor is an appropriate one, as it is not an accident that cognitive psychology arose at about the same time as rapid developments in computing technology (and some associated theoretical developments in mathematics, such as Claude Shannon's pioneering work in information theory). Computers provided an irresistible metaphor for the workings of the mind (much as at-the-time cutting-edge technologies such as hydraulics had done for Freud 70 or more years earlier), helping introduce an information processing approach to studying psychology. Many researchers found their thinking greatly stimulated by the presence of this machine metaphor (and some of its associated mathematics). Some researchers, however, go a step further, arguing that people literally are machines of a certain sort. In the memorable phrase of the AI researcher Marvin Minsky, the brain can be seen as a 'computer made of meat'. In the cognitive perspective, information is assumed to be received via senses (such as sight, hearing, or touch). This information is further processed in various ways, with the resulting outputs used to guide future action and behaviour.
Cognitive psychologists try to describe what is 'in the head' (i.e., what is called the mind) in terms of function (i.e. what the mind does) and process (how the mind does what it does) often without specifying in detail how these functions and processes are physically represented in terms of actual brain structure. For example, memory could be described in terms of what is (and what isn't) remembered, and factors influencing this. Perception could be described in terms of what people perceive, when they perceive it, and issues such as how prior knowledge influences what we perceive. Our everyday practical use and understanding of complex systems like computers, televisions and cars is mostly based at these levels of function and process. As I write this document now, I know exactly how to change the format or the typeface, but have little idea of how the underlying electronic pathways of the computer produce these functions. Nor do I need to know this, to operate the word-processing function effectively. Similarly, even a four year old child could know how to use the computer for certain purposes, but have virtually no understanding of how this function is physically achieved. This is not necessary, in order to be effective (though such knowledge may be very useful if the computer breaks down in some way! It is neuropsychology/neuropsychiatry that helps in the diagnosis, and sometimes the cure, of organic brain disorders, seen in this metaphor as 'hardware' problems. However, it should also be added that some cognitive psychologists are also interested in the underlying neural structures [e.g. the role of the hippocampus in episodic memory ).
Cognitive psychology's strategy of trying to understand the mind in terms of its functions and processes is therefore not so far removed from our level of understanding of other complex systems. As well as studying processes such as perception and memory, at the level of the individual, some cognitive psychologists turned towards the study of social cognition(e.g. how human beings use cognitive processes to make sense of social situations). A particular impetus for this came from the work of the cognitive psychologist Ulric Neisser, who suggested that cognitive psychologists shouldn't just confine themselves to (possibly quite artificial) laboratory-based studies, but should 'understand cognition as it occurs in the ordinary environment and in the context of natural purposeful activity' (Neisser, 1976, 'Cognition and Reality' p 7). Neisser argued that cognitive psychologists should undertake research which had much higher 'ecological validity', i.e. was much more relevant to the everyday lives of people in the real world (and the kinds of information and cognitive processing that arose in such contexts). Such research now plays a much more central role within cognitive psychology.