Archive for the ‘short-term memory’ tag

Different values and approaches between disciplines and   no comments

Posted at 12:04 pm in Psychology


During the last week, I have continued reading the book “principles of cognitive psychology”. More specifically, I have focused on the chapters dealing with long and short-term memory including the study of forgetting. The theories themselves were quite interesting to read. However, since the book traces the different theories that were developed over time, I have found myself constantly struggling with new ideas and new theories all the time. This shift in believe of what is going on in our brain reminds me of our lectures on paradigms shift. Therefore, in this blog I will first of all summarise what I have read so far, and then discuss what I think of paradigms shift in the context of what I have read, followed by comparison with my own personal experience in the field of engineering. I will then conclude with a reflection on multidisciplinary research methods followed by plans for future reading.

Summary of cognitive psychology — long and short-term memory

Theories of short-term memory

One of the earlier models for short-term memory is called multi-store model. According to this model there are three types of memory store. They are sensory stores, short-term store, and long-term store. The sensory stores are modality specific, and hold information very briefly. The short-term store has very limited capacity. Information is lost from the store because of interference, diversion of attention, and decay. Evidence from brain-damaged patients supports the distinction between short-term and long-term memory stores. The memory stores differ with respect to temporal duration, storage capacity, and forgetting mechanism.

However, this model is thought to be oversimplified in its account of the unitary short-term and long-term stores, and the notion that access to long-term memory occurs only after information is processed in the short-term store. In addition, the role of rehearsal is also exaggerated.

In view of the shortcomings, a new theory was proposed — working memory. The working memory system consists of a central executive, a phonological loop, and a visuospatial sketchpad. Two tasks can be performed successfully together only when they use different components of the working memory system. A phonological loop consists of a passive phonological store and an articulatory process. Its primary function is to assist in the learning of new words. The visuospatial sketchpad consists of a visual cache and an inner scribe. It is possible that there are separate visual and spatial system rather than a single sketchpad. The central executive is involved in various functions such as switching of which revealed plans, time-sharing, selective attention, and temporary activation of long-term memory. There may be relatively separate verbal and spatial working memory systems. The working memory approach has the advantage over the multi-store model that it can be applied to most cognitive activities rather than only being of relevance to memory tasks.

Another interesting theory is the theory of levels of processing. According to this theory, long-term memory is better remembered when information is processed deeply or semantically at the time of learning. In addition, elaborate on this rehearsal improves long-term memory and maintenance rehearsal does not. Some evidence supports these theoretical assumptions. However, long-term memory depends on collaboration and distinctiveness of processing as well as on depth of processing. Long-term memory depends on the relevance of the stored information to the requirements of the memory test. The theory is more applicable to tests of explicit memory than to those of implicit memory. Finally, the theory provides a description rather than an explanation of certain memory phenomena. In an updated account of levels of processing theory, it was argued that depth of processing and transfer appropriate processing jointly determine long-term memory performance.

Theories of long-term memory

It has been argued that there is an important distinction between episodic and semantic memory. There is evidence from PET studies that Steve prefrontal cortex is much more involved in episodic memory and then in cemented memory. It remains unclear whether there is a fundamental distinction between episodic and cemented memory, in part because there are several similarities and interconnections between them. There is a major distinction between explicit and implicit memory. PET studies have reviewed that a rather different areas of the brain are activated in explicit and implicit memory tasks. There is increasing evidence that there are different types of implicit memory.

Theories of forgetting

The forgetting function is generally logarithmic with a few exceptions. The is evidence of a repression like repressors, and controversial evidence concerning recovered memories of childhood abuse. There is convincing evidence of the existence of proactive and retroactive interference. However, special conditions required for substantial interference effects to occur, and interference theory is relatively uninformative about the process involved in forgetting. Most of forgetting seems to be due to dependence, and is greater when the contextual information present at retrieval differs from the contextual information stored in memory.

Multidisciplinary issues: Paradigms shift

Overall, I have seen how one theory was proposed based on certain observations or experimentation results. It would appear that this theory stands as long as there are no contradictory observations proposed. That theory represents in the latest knowledge in the area of study. For example with short-term memory, the multi-store theory stood for a long time. However, with new information presented, new theories were proposed and the old ones replaced.

This cycle has happened quite a few times during my reading of this book. It is beginning to dawn on me that the nature of cognitive psychology is such that proposed theories can only be as it is theories. In other words, because we cannot open up the brain and start probing, we cannot be hundred percent sure how things work inside. Because of this very nature, we are forced to accept the theory that best represent our current knowledge and observations. Until such a time when a better model or theory is proposed, the older theory stands true.

This idea of paradigms shift just does not happen in the field of engineering. Therefore, this is a multidisciplinary issue. In engineering, we are predominantly concerned with creating a solution to a problem. It may be creating a new product, or improving the efficiency of a certain procedure. Whatever it may be, there will always be a final answer of right or wrong. For this reason, there is no such thing as paradigms shift.

For instance, the good old television may be using CRT whereas modern day TVs are probably LCD flatscreen. Just because there is a shift of consumer preference, designer preference and so on, the older theory still stands true. It is a case of preference, the old theory does not become wrong because of a preference shift. In the case of at least the part I have read in cognitive psychology, when the new theory replaces the old, the old is considered wrong, incomplete or un-usable. This is more than just a case of preference which is quite different to the field of engineering.

Moving on

Having read that much of the book I have tried to scan read what is left. Since I realise that detailed information therein is not of interest, and the original purpose of reading this book to understand the typical research methods in cognitive psychology has been fulfilled, I have decided not to continue with this book.

Instead, I have picked up from one of the guest lecturers and interesting sub branch of cognitive psychology called social cognition. I am not too sure exactly what it is about yet. However, a glance through of the table of contents seems interesting. It covers theoretical foundations of the subject including social perception, attitudes, attributions, self and identity, prejudice, and ideology.

Since I am interested in the web and education, I think this book will help me to identify how and why people behave on the online education environment.

Written by Mandy Lo on November 1st, 2011

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