Cognitive Psychology and Information processing in Computers

Information Processing

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Cognitive Psychology and Information Processing in ComputersRef-Saul McLeodPaper published2008

Information ProcessingAt the very heart ofcognitive psychologyis the idea of information processing.Cognitive psychology sees the individual as a processor of information, in much the same way that a computer takes in information and follows a program to produce an output.Cognitive psychology compares the human mind to a computer, suggesting that we too are information processors and that it is possible and desirable to study the internal mental / mediational processes that lie between the stimuli (in our environment) and the response we make. Theinformation processingparadigm of cognitive psychology views that minds in terms of a computer when processing information. However, there are important difference between humans and computers. The mind does not process information like a computer as computers dont have emotions or get tired like humans.

EnvironmentalStimuli

SensoryMemoryShort-term / WorkingMemoryLong-term Memory&KnowledgeCognitivePsychologyis concerned withwhat goes on in here.

Overt ResponseBehaviorInfo. Processing model

Cognitive PsychologyInformation processing approach decomposition of mental processesMulti-component memory systemAssumptions of Cog. Psych.Mental processes existPeople are active information processorsMental processes and structures can be revealed by time and accuracy measures

Basic AssumptionsThe information processing approach is based on a number of assumptions, including:(1) information made available by the environment is processed by a series of processing systems (e.g. attention, perception, short-term memory);(2) these processing systems transform or alter the information in systematic ways;(3) the aim of research is to specify the processes and structures that underlie cognitive performance;(4) information processing in humans resembles that in computers.

Computer - Mind AnalogyThe development of the computer in the 1950s and 1960s had an important influence on psychology and was, in part, responsible for the cognitive approach becoming the dominant approach in modern psychology (taking over from behaviorism).The computer gave cognitive psychologists a metaphor, or analogy, to which they could compare human mental processing. The use of the computer as a tool for thinking how the human mind handles information is known as the computer analogy.Essentially, a computer codes (i.e. changes) information, stores information, uses information, and produces an output (retrieves info). The idea of information processing was adopted by cognitive psychologists as a model of how human thought works.

Computer - Mind Analogy..(2)For example, the eye receives visual information and codes information into electric neural activity which is fed back to the brain where it is stored and coded. This information is can be used by other parts of the brain relating to mental activities such as memory, perception and attention. The output (i.e. behavior) might be, for example, to read what you can see on a printed page.Hence theinformation processing approachcharacterizes thinking as the environment providing input of data, which is then transformed by our senses. The information can be stored, retrieved and transformed using mental programs, with the results being behavioral responses.

Computer - Mind Analogy..(3)Cognitive psychology has influenced and integrated with many other approaches and areas of study to produce, for example, social learning theory,cognitive neuropsychology andartificial intelligence (AI).Information Processing & AttentionWhen we are selectively attending to one activity, we tend to ignore other stimulation, although our attention can be distracted by something else, like the telephone ringing or someone using our name.Psychologists are interested in what makes us attend to one thing rather than another (selective attention); why we sometimes switch our attention to something that was previously unattended (e.g. Cocktail Party Syndrome), and how many things we can attend to at the same time (attentional capacity).

Computer - Mind Analogy..(4)One way of conceptualizing attention is to think ofhumans as information processorswho can only process a limited amount of information at a time without becoming overloaded. Broadbent and others in the 1950's adopted amodel of the brainas alimited capacity information processing system, through which external input is transmitted.

The Information Processing SystemInformation processing models consist of a series of stages, or boxes, which represent stages of processing. Arrows indicate the flow of information from one stage to the next.*Inputprocesses are concerned with the analysis of the stimuli.* Storageprocesses cover everything that happens to stimuli internally in the brain and can include coding and manipulation of the stimuli.* Outputprocesses are responsible for preparing an appropriate response to a stimulus.

Critical EvaluationA number of models of attention within the Information Processing framework have been proposed including:Broadbent's Filter Model(1958),Treisman's Attenuation Model(1964) andDeutsch and Deutsch's Late Selection Model(1963).However, there are a number of evaluative points to bear in mind when studying these models, and the information processing approach in general.These include:1. The information processing models assume serial processing of stimulus inputs.Serial processingeffectively means one process has to be completed before the next starts.Parallel processingassumes some or all processes involved in a cognitive task(s) occur at the same time.

Critical EvaluationThere is evidence from dual-task experiments that parallel processing is possible. It is difficult to determine whether a particular task is processed in a serial or parallel fashion as it probably depends (a) on the processes required to solve a task, and (b) the amount of practice on a task. Parallel processing is probably more frequent when someone is highly skilled; for example a skilled typist thinks several letters ahead, a novice focuses on just 1 letter at a time.2. The analogybetween human cognition and computer functioning adopted by the information processing approach is limited. Computers can be regarded as information processing systems insofar as they:(i) combine information presented with stored information to provide solutions to a variety of problems, and(ii) most computers have a central processor of limited capacity and it is usually assumed that capacity limitations affect the human attentional system.

Critical Evaluation2. The analogybetween ....system.BUT-(i) the human brain has the capacity for extensive parallel processing and computers often rely on serial processing;(ii) humans are influenced in their cognitions by a number of conflicting emotional and motivational factors.3. The evidencefor the theories/models of attention which come under the information processing approach is largely based on experiments under controlled, scientific conditions. Most laboratory studies are artificial and could be said tolack ecological validity.In everyday life, cognitive processes are often linked to a goal (e.g. you pay attention in class because you want to pass the examination), whereas in the laboratory the experiments are carried out in isolation form other cognitive and motivational factors. Although these laboratory experiments are easy to interpret, the data may not be applicable to the real world outside the laboratory. More recent ecologically valid approaches to cognition have been proposed (e.g. the Perceptual Cycle, Neisser, 1976).

Critical EvaluationAttention has been studied largely in isolationfrom other cognitive processes, although clearly it operates as an interdependent system with the related cognitive processes of perception and memory. The more successful we become at examining part of the cognitive system in isolation, the less our data are likely to tell us about cognition in everyday life.4. The Models proposed by Broadbent and Treisman are 'bottom-up' or stimulus driven models of attention.Although it is agreed that stimulus driven information in cognition is important, what the individual brings to the task in terms of expectations/past experiences are also important. These influences are known as 'top-down' or 'conceptually-driven' processes. For example, read the triangle below:Expectation (top-down processing) often over-rides information actually available in the stimulus (bottom-up) which we are, supposedly, attending to. How did you read the text in the triangle above?

Component of ModelSensory memory input deviceWhat info is sent to the processorShort-term / Working memoryCentral processor, actively processes infoLong-term memory / KnowledgeLibrary of programs, algorithms, data, and experiences that are stored for useNote similarities to computer!

Sternberg ParadigmTest of how info is processed Subjects (Ss) memorize list of digits{4, 6, 5, 9, 3, 2}Given recognition test9?Yes/NoMeasure both accuracy and reaction time (Msec.)Some trials were false (8?)Some were true (9?)

Think in terms of Memory system!9659324

LTM

STM / WM--+---Decision

Results

Perceive StimulusGenerate responseMake decision9=9?9=3?9=6?9=2?

Perceive StimulusGenerate responseMake decision7=9?7=3?7=6?7=2?

6, 9, 3, 29?7?What would happen if the search string were 6 items?What would happen if degraded the probe?What would happen if we biased the decision process?

Time to respond was linear function of size of search stringEach element added 38 msec to search timeSerial position did not matter!Thus, search is exhaustiveSternbergs conclusion: Ss engaged in serial matching process

Goal of Cognitive Psychology: to explain basic processes of thoughtSimple example:

Cognitive perspectiveThink about what had to happen in order for you to answer that question.

How many handsdid Aristotle have?

Speech Interpretation

Speech interpretationSegmentation--where are the breaks between words?Where are the breaks between phonemes?Variability in phoneme production between speakers



Interpretation ofquestion

Interpretation of questionWord order dramatically changes sentences. Compare John wished he had jumped higher and He wished John had jumped higherSurrounding context also matters: Compare He smiled and He slowly took out the gun. He smiled.




Find answerin memory

Find answer in memory




Find answerin memoryMake decision:answer or not?

Answer or notHow confident am I that I know the answer?What happens if I dont answer?Is this a trick? (Psych. Classes are full of tricks.)





Phrase theanswer

Phrase the answer*TwoHe had two handsIm not sure, but Im guessing twoTwo--whats it to you?





Phrase theanswerCreate motorcommands to lips, tongue, etc

Create motor commandsDegrees of freedom problemSerial order problem

Summary: this shows basics of cognitive perspectiveEmphasizes information and how it is transformedThink in terms of stages in which information is transformedStages communicate with one another, but one stage doesnt know what the other is doing.Like Computer Science there is Algorithm ,but unlike Algorithm it varies from person to person and the frame of mind an Individual is.

Critical EvaluationReferencesBroadbent, D. (1958).Perception and Communication.London: Pergamon Press.Deutsch, J. A., & Deutsch, D. (1963). Attention: Some Theoretical Considerations.Psychological Review, 70, 8090Neisser, U. (1967).Cognitive Psychology. New York: Appleton-Century-Crofts.Treisman, A. (1964). Selective attention in man.British Medical Bulletin, 20, 12-16

Cognitive Psychology and Information processing in Computers

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