Part 2. Cognitive functions Text 1. Human memory

Read the text and describe human memory using the diagram below.

Memory refers to the processes that are used to acquire, store, retain and later retrieve information. There are three major processes involved in memory: encoding, storage and retrieval.

In order to form new memories, information must be changed into a usable form, which occurs through the process known as encoding. Once information has been successfully encoded, it must be stored in memory for later use. Much of this stored memory lies outside of our awareness most of the time, except when we actually need to use it. The retrieval process allows us to bring stored memories into conscious awareness.

There are generally three types of memory: sensory memory, short-term memory and long-term memory.

Sensory Memory. The sensory memories act as buffers for stimuli received through the senses. A sensory memory exists for each sensory channel: iconic memory for visual stimuli, echoic memory for aural stimuli and haptic memory for touch. Information is passed from sensory memory into short-term memory by attention, thereby filtering the stimuli to only those which are of interest at a given time.

Short-Term Memory acts as a scratch-pad for temporary recall of the information under process. For instance, in order to understand this sentence you need to hold in your mind the beginning of the sentence you read the rest.

There are typically six reasons why information is stored in our short term memory.

1. primacy effect - information that occurs first is typically remembered better than information occurring later.  When given a list of words or numbers, the first word or number is usually remembered due to rehearsing this more than other information.

2. recency effect - often the last bit of information is remembered better because not as much time has past; time which results in forgetting.

3. distinctiveness - if something stands out from information around it, it is often remembered better.  Any distinctive information is easier to remember than that which is similar, usual, or mundane.

4. frequency effect - rehearsal, as stated in the first example, results in better memory.  Remember trying to memorize a formula for your math class.  The more you went over it, the better you knew it.  

5. associations - when we associate or attach information to other information it becomes easier to remember.  Many of us use this strategy in our professions and everyday life in the form of acronyms.  

6. reconstruction - sometimes we actually fill in the blanks in our memory.  In other words, when trying to get a complete picture in our minds, we will make up the missing parts, often without any realization that this is occurring.

Short term memory decays rapidly (200 ms.) and also has a limited capacity. Chunking of information can lead to an increase in the short term memory capacity. That is the reason why a hyphenated phone number is easier to remember than a single long number. The successful formation of a chunk is known as closure. Interference often causes disturbance in short-term memory retention. This accounts for the desire to complete the tasks held in short term memory as soon as possible.

Long-Term Memory. Long-term memory is intended for storage of information over a long time. Information from the working memory is transferred to it after a few seconds. Unlike in working memory, there is little decay.

There are two types of long-term memory: episodic memory and semantic memory. Episodic memory represents our memory of events and experiences in a serial form. It is from this memory that we can reconstruct the actual events that took place at a given point in our lives. Semantic memory, on the other end, is a structured record of facts, concepts and skills that we have acquired. The information in semantic memory is derived from that in our own episodic memory, such that we can learn new facts or concepts from our experiences.

Long-Term Memory Processes. There are three main activities related to long term memory: storage, deletion and retrieval.

Information from short-term memory is stored in long-term memory by rehearsal. The repeated exposure to a stimulus or the rehearsal of a piece of information transfers it into long-term memory. Experiments also suggest that learning time is most effective if it is distributed over time. Deletion is mainly caused by decay and interference. Emotional factors also affect long-term memory.

However, it is debatable whether we actually ever forget anything or whether it becomes increasingly difficult to access certain items from memory. Having forgotten something may just be caused by not being able to retrieve it! Information may not be recalled sometimes but may be recognized, or may be recalled only with prompting. This leads us to the third process of memory: information retrieval.

The Organization of Memory. The ability to access and retrieve information from long-term memory allows us to actually use these memories to make decisions, interact with others, and solve problems. But how is information organized in memory? The specific way information is organized in long-term memory is not well understood, but researchers do know that these memories are arranged in groups.

Clustering is used to organize related information into groups. Information that is categorized becomes easier to remember and recall. For example, consider the following group of words:

Desk, apple, bookshelf, red, plum, table, green, pineapple, purple, chair, peach, yellow.

Spend a few seconds reading them, then look away and try to recall and list these words. How did you group the words when you listed them? Most people will list using three different categories: color, furniture and fruit.

One way of thinking about memory organization is known as the semantic network model. This model suggests that certain triggers activate associated memories. A memory of a specific place might activate memories about related things that have occurred in that place. For example, thinking about a certain campus building might trigger memories of attending classes, studying and socializing with peers.

(Abridged from: 1.Cемашко Л.А. Английский язык: Сборник текстов для студентов факультета психологии. – Челябинск: Изд-во ЮУрГУ, 2006. – 156 с., 2.http://psychology.about.com/od/cognitivepsychology/a/memory.htm, 3. http://allpsych.com/psychology101/memory.html)

Answer the questions below:

1. What are the three major processes involved in memory?

2. What are the three types of memory?

3. What are the six reasons why information is stored in our short term memory?