"It's hard to make predictions - especially about the future." — Robert Storm Petersen
Introduction
Until now
Developing from the information processing approach, today's cognitive psychology differs from classical psychological approaches in the methods they use as well as in the interdisciplinary connections to other sciences. Apart from rejecting introspection as a valid method to analyze mental phenomenon, cognitive psychology introduces further, mainly computer-based, techniques that had not been in the range of methods used by classical psychology so far.
Introducing new methods
By using imaging-techniques like fMRI scans cognitive psychology is able to analyze the relation between the physiology of the brain and mental processes. In the future cognitive psychology will even more concentrate on computer-related methods. Hereby it profits from improvements in this area. E.g. fMRI scans nowadays still have many possible error sources, which should be solved in the future. Thereby the approach becomes more powerful and precise. In addition to that the computer approach can be combined with the classical behavior approach, where one inferes a participant's mental states from the behavior that is shown.
Possible development
Apart from using the methods developed by other sciences cognitive psychology also collaborates with topic-related sciences like artificial intelligence, neuroscience, linguistics and philosophy. The different perspectives on the topic made it possible to confirm one's results as well as gaining new accesses to the study of the mind. Modern studies of cognitive psychology more and more critize the classical information processing approach. Instead of that other theories acquire more importance. E.g. the classical approach is modified to a parallel information processing approach, which more resembles the method of working of the mind. Furthermore different theories based on the different sciences concerned with the study of the mind come up.
Methods
In order to give an appropriate overview over the significant developments in the field of cognitive psychology in general first of all a we will focus on its subfields and their current approaches, problems and possible trends. Hereby hints of possible future developments should be given. Finally the method of converging operators is introduced which combines the different areas of cognitive psychology and
168 | Cognitive Psychology and Neuroscience
Present and Future of Research
furthermore areas that are related to it.
Experimental Cognitive Psychology
Psychological experimentation studies mental functions and it is done with indirect methods meaning reasoning. These studies are performed to find the cause and the consequence relation and the factors influencing the behavior. The researcher observes visible action and makes conclusions based on these observations. Variables are changed one at a time and the effect of it is observed. The benefits of experimental researching are that it is possible to find the causal relations and that the manipulated factors can be altered in the way the researcher wants.
In being the classical approach within the field of Cognitive Psychology the experimental approach has been the basis for the development of the multiple modern approaches within contempeorary Cognitive Psychology. Its empirical methods have been developed and verified over long periods of time and the so gained results contributed to the enhancements in many areas of psychology.
Taking the established character of experimental cognitive psychology into consideration one might suggest that the modifications in the way of working in this field are rather inconsiderable. In contrast to that in recent years a discussion was initiated concerning the question whether the findings of experimental cognitive psychology remain valid in the "real world" since the environment created in an experiment suppresses influencing factors that may affect the results. The resulting conditions of the experiment are artificial and may unintentionally cause the ignoration of facts and coherences (cf. Eysenck & Keane, Cognitive Psychology, pp.514-515).
A possible demonstrative example for this is the research concerning attention. Since the attention of the participant is mainly governed by the experimenter’s instructions, it’s focus is basically determined. Therefore "relatively little is known of the factors that normally influence the focus of attention." (ibid, p.514)
Beside this it turns out to be problematic that in experimental psychology mental phenomenons are often examined in isolation. While trying to make the experimental setup as concise as possible in order to get clearly interpretable results, one decouples the aspect at issue from adjacent and interacting mental processes. This tends to the situation that the results only turn out to be valid in the idealized experimental setting but not in “real life” where multiple mental phenomena interact and multiple outside stimuli influence the behavior of a mental process. The validity gained by such studies could only be characterized as an internal validity (which means that the results are valid in the special circumstances created by the experimenter) but not as an external validity (which means that the results stay valid in changed and more realistic circumstances) (cf. ibid, p.514).
Based on such objections concerning the approach of experimental cognitive psychology several experiments have been developed that refer closer to "real life". According to that experiments related to "real-world" phenomena like absent-mindedness, everyday memory or reading gain in importance.
Nevertheless the disscussion remains whether such experiments really deliver new information about mental processes. Accordingly whether such everyday phenomenon studies really become established or not in future experimental psychology will heavily depend on the results nowadays experiments of this field will deliver.
Another issue concerning experimental setups in cognitive psychology is the way individual differences are handled. In general the results from an experiments are generated by an analysis of variance. Thereby different results which are due to individual differences are averaged out and accordingly are not taken into consideration. Such a procedure seems highly questionable especially against the background of an investigation of Bowers in 1973 which showed that over 30% of the variance in such studies are due to individual differences or their interaction with the current situation (cf. ibid, p.515). Based on such facts one challenge for future experimental cognitive psychology is the analysis of individual differences and the finding of a way to include the knowledge about such differences in general studies.
Cognitive Neuropsychology
Cognitive Neuropsychology maps the connection between brain functions and the cognitive behavior. Patients with brain damages have been the most important source of research in neuropsychology. Neuropsychology also examines dissociation (“forgetting”), double dissociation and associations (connection between two things formed by cognition). Neuropsychology uses technological reseach methods to create images of the brain functioning. There are many differences in techniques to scan the brain. The most common ones are EEG (Electroencephalography), MRI and fMRI (functional Magnetic Resonance Imaging) and PET (Positron Emission Tomography).
Cognitive Neuropsychology became very popular because it delivers good evidence. Theories developed for normal individuals can be verified by patients with brain damages. Apart from that new theories could have been established because of the results of neuropsychological experiments.
Nevertheless certain limitations to the approach as it is today have to be taken into consideration. First of all the fact that people having the same mental disability often do not have the same lesion needs to be pointed out (cf. ibid, pp.516-517). In such cases the researchers have to be careful with their interpretation. In general it could only be concluded that all the areas that the patients have injured could play a role in the mental phenomenon. But not which part really is decisive. Based on that future experiments in this area tend to make experiments with a rather small number of people with pretty similar lesion respectively compare the results from groups with similar syndroms and different lesions.
In addition to that the situation often turns out to be vice versa. Some patients do have pretty similar lesions but show rather different behaviour (cf. ibid, p.517). One probable reason therfor is that the patients differ in their age and lifestyle (cf. Banich, Neuropsychology, p.55). With better technologies in the future one will be better able to distinguish the cases in which really the various personalities make the difference and in which cases the lesions only on the first look seem to be equal. In addition to that the indiviual brain structures which may cause the different reactions to the lesions will become a focus of research.
Another problem for Cognitive Neuropsychology is that their patients are rare. The patients which are interesting for such research have lesions of an accident or suffered during war. It would be highly philosophical the suggest whether the amount of possible patients increases or decreases in future. But in addition there are differences in the manner of the lesion. Often multiple brain regions are damaged which makes it very hard to determine which of the is responsible for the examined phenomenon. The dependency on chance whether there are patients available for the studies will remain in future. Thereby predictions concerning this aspect of the research are not very reliable.
Apart from that it is not possible to localise some mental processes in the brain. Creative thought or organisational planning could not have been unitised (cf. Eysenck & Keane, Cognitive Psychology, p.517). A possible outcome of the research is that those activities rely on parallel processing. This would support the idea of the modification of the information processing theory that will be discussed later on. But if it shows up that a lot of mental processes depend on such parallel processing it would turn out to be a big drawback for Cognitive Psychology since its core is the modularization of the brain and the according phenomena.
In this context the risk of overestimation and underestimation has to be mentioned. The latter occurs because Cognitive Psychology often only identifies the most important brain region for the mental task. Other regions that are related thereto could be ignored. This could turn out to be fundamental if really parallel processing is crucial to many mental activities. Overestimation occurs when fibers that only pass the damaged brain region are lesioned, too. The researcher concludes that the respective brain region play an important role in the phenomenon he analyses even though only the deliverance of the information passed that region (cf. ibid). Modern technologies and experiments here have to be developed in order to provide valid and precise results.
Cognitive Science
Cognitive science is multidisciplinary science. It comprises areas of cognitive psychology, linguistics, neuroscience, artificial intelligence, cognitive anthropology, computer science and philosophy. Cognitive sciences concentrates to study the intelligent behavior of humans, which includes perception, learning, memory, thought and language. Research in cognitive sciences are based on naturalistic research methods such as cognitive neuropsychology, introspection, psychological experimentation, mathematical modeling and philosophical argumentation.
In the beginning of the cognitive sciences the most common method was introspection. It meant that the test subject evaluated his/her own cognitive thinking. In these experiments the researchers were using experienced subjects because they had to analyze and report their own cognitive thinking. Problems can occur when the results are interpreted and the subject has different reports from the same action. In the research should be clearly separated the matters that can be studied by introspection and the ones that are not to be studied with this method.
Computational modeling in cognitive science means that the mind is seen as a machine. This modeling seeks to express theoretical ideas through computational modeling that generate behavior similar to humans. Mathematical modeling is based on flow charts. The quality of the modeling is very important to ensure the equivalence of the input and results.
Nowadays the researchers in cognitive sciences use often theorizing and computational modeling.
"This does not exclude their primary method of experimentation with human participants. In cognitive sciences it is also important to bring the theories and the experimenting together. Because it comprises so many fields of science it is important to bring together the most appropriate methods from all these fields. The psychological experiments should be interpreted through a theory that expresses mental representations and procedures. The most productive and revealing way to perform research in cognitive sciences is to combine different approaches and methods together. This ensures overall picture from the research area and it comprises the viewpoints of all the different fields." (Thagard, Cognitive Science)
Nevertheless Cognitive Science has not yet managed to succeed in bringing the different areas together. Nowadays it is criticized for not establishing a science on its own. Rather few scientist really address themselves as cognitive scientist. Furthermore the basic metaphor of the brain functioning like a computer is challenged as well as the distinctions between their models and nature (cf. Eysenck & Keane, Cognitive Psychology, pp. 519-520).
Here a lot of work has to be done in future. Cognitive Science has to work on better models that explain natural processes and that are reliably able to make predictions. Furthermore these models have to combine multiple mental phenomenon. In addition to that a general "methodology for relating a computational model's behaviour to human behaviour" has to be worked out. Hereby the strength of such models can be increased. Apart from that Cognitive Science needs to establish an identity with prominent researchers that avow themself to Cognitive Science. And finally its biggest goal the creation of a general unifying theory of human cognition (see Theory Part) has to be reach (cf. ibid, p. 520). If Cognitive Science fails on too much of these challenges the danger arises that it becomes labeled as a deadend. Therefor the highest rate to development can be expected in the field of Cognitive Science.
Cognitive Neuroscience
Another approach to get a better understanding of human cognition is from cognitive neuroscience. Cognitive neuroscience lies at the interface between traditional cognitive psychology and the brain sciences. Cognitive neuroscience is a science with approach chatacterized by attempts to derive cognitive level theories from a variety types of information, such as computational properties of neural circuits, patterns of behavioral damage as a result of brain injury, measures of brain activity during the performance of cognitive tasks (cf. www.psy.cmu.edu). Cognitive neuroscience helps to get the understanding of how the human brain supports thought, perception, affection, action, social process and other aspects of cognition and behaviour, including how such processes develop and change in the brain and through time (cf. www.nsf.gov).
Cognitive neuroscience has emerged in the last decade as an intensely active and influential discipline, forged from interactions among the cognitive sciences, neurology, neuroimaging, physiology, neuroscience, psychiatry, and other fields. Of particular importance for this discipline have been new methods for non-invasive functional neuroimaging of humans performing psychological tasks (cf. www.nsf.gov). The findings from cognitive neuroscience are directed toward enabling basic scientific understanding of a broad range of issues involving brain, cognition and behavior. One example non-invasive functional neuroimaging, this includes: positron emission tomography (PET), functional magnetic resonance imaging (fMRI), magnetoencephalography (MEG), optical imaging (near infrared spectroscopy or NIRS), anatomical MRI, and diffusion tensor imaging (DTI) (cf. www.nsf.gov).
Cognitive neuroscience becomes a very important approach to understand human cognition, since findings from cognitive neuroscience can elucidate functional brain organization, such as the operations performed by a particular brain area and the system of distributed, discrete neural areas supporting a spesific cognitve representation. These findings can reveal the effect on brain organization of individual differences (including even genetic variation) (cf. www.psy.cmu.edu, www.nsf.gov).
Another importance of cognitive neuroscience is that cognitive neuroscience provides some ways that allow us to "obtain detailed information about the brain structures involved in different kind of cognitive processing" (Eysenck & Keane, Cognitive Psychology, p. 521). Techniques such as MRI and
CAT scans have proved of particular value when used on patients to discover which brain areas are damaged. Before non-invansive methods of cognitive neuroscience were developed, examination to know the location of "brain damage could only be established by postmortem examination" (ibid). Knowing which brain areas related to which cognitive process would surely lead to obtain a clearer view of brain region, hence, in the end would help in better understanding for human cognition process.
Another strength of cognitive neuroscience is that it serves as a tool to demonstrate the reality of theoretical distinctions. For example, it has been argued by many theorists that implicit memory can be diveded into perceptual and conceptual implicit memory; support for that view has come from PET studies, which show that perceptual and conceptual priming tasks affected different areas of the brain (cf. ibid, pp. 521-522).
However, cognitive neuroscience is not that perfect as a science to be able to stand alone and answer all questions dealing with human cognition. Cognitive neuroscience has some limitations, dealing with data collecting and data validity. In most neuroimaging studies, data are collected from several individuals and then averaged. Some concern has arose about such averaging because of the existence of significant individual differences. The problem was answered by Raichle (1998), who stated that the differ in individual brain should be appreciated, however general organizing principles emerge that transcend these differences (cf. ibid, p. 522).
Converging operations
The four approaches of experimental cognitive psychology, cognitive neuropsychology, cognitive science and cognitive neuroscience differ in their strengths and weaknesses. Because of this reason, it is clear that no science can stand alone in answering the questions dealing with human cognition, also for future researches. We should use and combine the knowledge, and use the method of converging operations "in order to maximize our understanding of human cognition" (ibid, p. 523). The method of converging operations involves making use of a variety approaches to consider any given issue from different perspectives (cf. ibid).
An example for such a procedure is Davachi's memory experiment(2003). First the participants one of the words place and read, then they saw an adjective which they had to mentally pronounce backwards if the previous word was read or they had to imagine a scene that could be described by that adjective if the previous word was place. After learning a list of words in the described manner the participants got a list with the learned words and the same number of new words the next day. Their task now was to decide whether a presented word was new or one of them learned the day before. The experiment showed that the words learned by the place method were remembered better.
So far the experiment seems to be a normal behavioral experiment characteristically for the experimental approach. But while learning the words Davachi used an fMRI on the participants in order to determine the activated brain regions. It became obvious that the perirhinal cortex only was activated during the place task but not during the read task. According to that it could be concluded that memory is better when the perirhinal cortex is activated during learning (cf. Goldstein, Cognitive Psychology, pp. 16-19). In this case the physiological approach in this experiment explained the results gained by the behavioral.
When the method of converging operations is applied, there are two possible outcomes: first, the findings obtained are broadly comparable. The second is that the "findings differ significantly"
(Eysenck & Keane, Cognitive Psychology, p. 523). When the findings from two approaches are similar, this increases the confidence in the validity of the findings and in the usefulness of both approaches. When the findings are different, this indicates the need of further research to clarify what happens. Thus, the method of converging operations helps to prevent researchers from drawing incorrect conclusions on the basis of limited findings from a single approach (cf. ibid, p. 523).
Theory
The field Cognitive Psychology derived from an analogy between the mind and a computer. The idea that the mind works on the brain just as a programm does work on a computer nowadays is know as the information-processing theory. Thereby existed an identical theoretical basis for all subfields of Cognitive Psychology. Nevertheless in practical application when explaining concrete phenomenon researcher tended to establish models that only focused on their subfield. Some examples handled in this book are Baddeley's model of working memory or Pylyshyn's and Kosslyn's different theories about imagery. Hereby a fragmentation of Cognitive Psychology emerged. In 1972 Allen Newell criticised this tendency in his paper "You can't play 20 questions with nature and win". He stated:
"Suppose that in the next thirty years we continued as we are now going. Another hundred phenomena, give or take a few dozen, will have been discovered and explored. [...] It seems to me that clarity is never achieved. Matters simply become muddier and muddier as we go down through time. Thus, far from providing the rungs of a ladder by which psychology gradually climbs to clarity, this form of conceptual structure leads rather to an ever increasing pile of issues, which we weary of or become diverted from, but never really settle." (Anderson, The Atomic Components of Thought, pp. 1-2)
Over thirty years later several attempts to create a unified theory which should avert Newell's prediction were presented. But a widely accepted unified theory that includes at least most of the mental phenomena still could not have been established. So the main focus of theoretical development in Cognitive Psychology still lays on the constitution of such an overarching and unifing model. Possible ways of reaching this goal will be discussed in the following.
Unifying Theories
Newell's own solution to the dilemma he described was based on a production system. Such a system consist of a set of conditions and actions. Based on the given data an action is performed if the corresponding condition is fulfilled. Hereby the data structure is changed and new conditions are generated. The system stops either when no conditions are fulfilled or when an action includes a stop operation. The theory Newell developed from his approach is called Soar theory of human cognition (cf. ibid, pp. 2-3). Apart from that several other theories based on production systems exist. Here primarily Anderson's ACT-R theory has to be mentioned since it has been partially validated against behavioral timing data and fMRI brain localizations and timing data.
ACT-R is a cognitive architecture. It is constructed based on actual assumptions of the functioning of human cognition. It can be used to fulfill different tasks related with human cognition like language comprehension or the Towers of Hanoi. Apart from that researchers are able to modify the programm in order to add their own assumptions. Here ACT-R functions quite similar to a programming language. Thereby it is possible to compare the results gained by the model with results from human
participants and to verify respectively to correct the model (cf. act-r.psy.cmu.edu and http://www.carleton.ca/ics/ccmlab/actr/).
In addition to that EPIC from Meyer and Kieras and 3CAPS from Just and Carpenter are production system theories with potential (cf. Anderson, The Atomic Components of Thought, p. 3). But the fact that several candidates for such an overarching theory have to be referred to makes it obvious that none of the systems really managed to be accepted from most of the researchers in Cognitive Psychology. So far the goal to create a unifying theory has not been reached. Some possible theories exist but the future development has to show if one of them really manages to become globally established.
Parallel Processing
Another possibility how to reach a reunification of the field is to create a new theory. In this case the analogy with the computer which was already the basis for the whole cognitive psychological approach seems to be the attempt with the best chances. It has to be taken into considertation that the information processing theory already developed over time. The traditional theory e.g. was only able to explain bottom-up processes (like used in Atkinson's and Shiffrin's memory theory) based on its sequential structure. But it failed to give an appropriate explanation for top-down processing which occurs e.g. when one has certain expectations based on the circumstances and context (cf. Eysenck & Keane, Cognitive Psychology, p. 2).
This limitation could have been overcome by keeping track with the developments in computer science and thereby with a modification of the analogy. As more and more parallel processing computer were build one changed the theory from sequential working to parallel processing. Thereby one was able to explain both bottom-up and top-down processes. Furthermore the highly parallel activation of the brain was integrated in the theory.
These developments in the theoretical view of the functioning of the brain may also give a hint to future changes. As computer science moves on the analogy may have to be modified again. Based on that new theories could be developed which maybe reach the goal to become an overarching theory that includes all human cognitive abilities and that is globally accepted.
Levels of Analysis
The realization that there are important links between brain activity and cognitive functions is the key assumption for present and future research. Complete psychological accounts of cognitive functioning require considerations of the computational level, algorithmic level (implementation of the computational theory, representation of the input and the algorithm of the transformation) and the brain levels, about how the representation and the algorithm be realized physically (cf. ibid, pp. 523-524).
Here a possible reason for the differences in the theories shows up. Some of these might occur because the descriptions used in the different theories refer to different levels of analysis. In order to avoid misunderstandings an overarching theory therefor has to include all of these levels.
Conclusion
Today's work in the field of Cognitive Psychology gives several hints how future work in this area may look like. In practical applications improvements will probably mainly be driven by the limitations one faces today. Here in particular the newer subfields of Cognitive Psychology will develop quick. How such changes look like heavily depends on the character of future developments in technology. Especially improvements in Cognitive Neuropsychology and Cognitive Neuroscience depend on the advancements of the imaging techniques.
In addition to that the theoretical framework of the field will be influenced by such developments. The parallel processing theory may still be modified according to new insights in computer science. Thereby or eventually by the acceptance of one of the already existing overarching theories the theoretical basis for the current research could be reunified.
But if it takes another 30 years to fulfill Newell's dream of such a theory or if it will happen rather quick is still open. As a rather young science Cognitive Psychology still is subject to elementary changes. All its practical and theoretical domains are steadily modified. Whether the trends mentioned in this chapter are just deadends or will cause a revolution of the field could only be predicted which definitely is hard.
References
• E. Br. Goldstein, Cognitive Psychology, Wadsworth, 2004
• M. W. Eysenck, M. T. Keane, Cognitive Psychology - A Student's Handbook, Psychology Press Ltd, 2000
• Thagard, Paul, Cognitive Science in Edward N. Zalta (ed.), The Stanford Encyclopedia of Philosophy, 2004
• Banich, Marie T., Neuropsycology - The Neural Bases of Mental Function, Hougthon Mifflin Company, 1997
• Anderson, John R., Lebiere, Christian, The Atomic Components of Thought, Lawrence Erlbaum Associates, 1998
Links
• http://www.psy.cmu.edu/home/research/index.html
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