What can I learn about memory and information processing throughout the life span? - Chapter 8

Retrograde amnesia stands for loss of memory of everything that happened before the incident that caused this. Anterograde amnesia stands for not being able to form new memories. Many forms of amnesia destroy explicit memory (as explained underneath) but leave implicit memory undamaged. 

What is the concept of memory?

When the computer came up, it was interesting to compare the workings of it to the workings of the human mind. The computer was the model for the information-processing approach to cognition. This approach emphasizes on the mental processes involved in attention, perception, memory and making decisions. Atkinson & Shiffrin came up with an information-processing framework with three memory components:

• sensory register. This really shortly holds the sensory information that is all around us.
• short-term memory. This holds a limited amount of information for a short period of time.
• long-term memory. This holds information quite permanently and seems unlimited.

To learn and remember something, you must first encode information and get it into the system. Then, information has to undergo consolidation, which means stabilizing and organizing the information so it can be stored in the long-term memory. This includes synaptic consolidation, occurring in the minutes or hours after initial learning, and system consolidation, taking place over a longer period. Sleep facilitates those processes and stress disturbs it. Also, relating new information with prior knowledge helps. Without consolidation, encoded information cannot get to the storage. The final step to the memory process is retrieval and stands for getting the information out when needed. This can happen through recognition memory (in a multiple choice test) or recall memory (in an open test). Between those is cued recall memory (when given a hint to facilitate retrieval). 

A more extensive model by Baddeley features a central executive which manages the short-term memory store, by controlling attention and information flow. This model also says there are three types of short-term memory: the phonological loop (for auditory information), the visual-spatial sketchpad (for visual and spatial information), and the episodic buffer (which integrates both of them and retains chronological order). Another thing is the introduction of the term working memory which is short-term memory actively used to achieve a goal. 

The long-term memory has two ways of responding to a task. The first is implicit memory (or nondeclarative memory), an unintentional, automatical way of responding, happening without awareness. The other is explicit memory (or declarative memory), involving deliberate and effortful recollection of events. Explicit memory can be subdivided into semantic memory (for general facts) and episodic memory (for specific experiences). 

Case studies showed that the hippocampus (part of the limbic system and located in the medial temporal lobe) is essential for creating new episodic memories. In the case of Henry Molaison, his entorhinal cortex (part of the temporal lobe) was removed, and this structure connected the hippocampus to other parts of the brain - when this was removed, episodic memories could not be formed again. Next to the hippocampus is the amygdala which involves in forming emotionally charged memories. Scans of the brain now show different parts are used for different forms of memory. Procedural memory (e.g. how to ride a bike, part of implicit memory) is mediated by the striatum, an area in the forebrain, and the basal ganglia and cerebellum. Explicit memory is mainly localized in the medial temporal lobe of the brain, which seems essential for consolidation. The storage and retrieval seems to take place in the area that encoded or was activated by the information. Implicit memory develops earlier than explicit memory, and they follow different developmental paths. Explicit memory capacity increases from infancy to adulthood and declines in later adulthood. Implicit memory capacity changes little. 

Some more added concepts to the model of memory are executive control processes (guiding the selection, organization, manpulation and interpretation if information) and parallel processing (carrying out multiple cognitive activities at the same time). With all of this, problem solving can happen. When problem solving does not succeed, this could be due to lack of attention, unability to hold all the information in working memory for enough time, lacking the strategies for transferring new information to the long-term memory or retrieving information from it, not having the stored knowledge to understand the problem, or not having the executive control processes needed. 

What does memory mean to the infant?

Several methods have been used to study the memory of infants:

• habituation. This means learning not to respond to a stimulus, like being "bored" with it: thus, it's evidence that the stimulus is familiar. Through habituation, fetuses can show that they can learn and remember. 
• operant conditioning. Conditioning an infant and then waiting a while to present the stimulus again, can show if the learned response is still remembered. It showed that infants can remember, and increasingly long as they age. Distributed practice and cued recall worked even better for infants to show they remember. In short this research showed that early memories are cue-dependent and context-specific, even a little change in context can remove the "remembering". 
• object search (like the A-not-B task by Piaget). Gets more succesful as the infants get older, and it shows 6-month old babies can show memory for the correct behavior.
• imitation. It seems even newborns can imitate some actions of a model. Moreover, infants as young as 6 months show deferred imitation which is the ability to imitate a novel act after a delay, and which gets better as infants age. Language helps memory performance. 

In sum, infants show recognition memory from birth and cued recall memory by about 2 months. More explicit memory appears to emerge toward the end of the first year. By age 2 it's clearer that infants can recall events that happened long ago, since they can use language to describe it.

Infants as young as 9 months old can solve a problem like dragging an object within reach. And when given hints, even younger infants could do it. When both hands need to be used, success occurs later in childhood. With 14 months, infants realize that adults can help them with problem-solving and act upon that. Simple problem-solving behavior improves over the first 2 years of life and will flourish in childhood.

What does memory mean to the child?

Why do learning and memory improve? There are 4 major hypotheses:

1. Changes in basic capacities. The "hardware" improves: the brain develops and so for instance working memory gets better. The storage capacity of long-term memory does not seem to change much across the life span and seems quite unlimited. The sensory register also works quite well from birth. Encoding and consolidation processes do improve over infancy and childhood as the brain matures. The speed of mental processes also improves, as neurons become myelinated. 
2. Changes in memory strategies. The "software" improves: children have learned and can use methods, like rehearsal (repeating of items they are learning), organization (classifying items into groups by making clusters or chunks), and elaboration (creating links between items), for putting information into long-term memory and retrieval. Rehearsal emerges first, then organization, and then elaboration. They can use encoding strategies (strategies applied at the time information is presented) or retrieval strategies (applied when retrieval is sought). Younger children use more external cues, like putting a toothbrush next to the pyjamas to remember brushing teeth. Younger children also have a tendency for perseveration errors (continuing to use the same strategy that was succesful in the past, despite the strategy not working in the current situation, similar to the A-not-B error.) By age 4 those errors decline. Initially, children also have mediation deficiency (they initally cannot spontaneously use strategies, even if taught how to use them). Even if they know a strategy, they do not consistently always apply it. There's also production deficiency in which children can use taught strategies but can not produce them on their own. And there is utilization deficiency in which children can spontaneously produce a strategy, but their task performance does not yet benefit from it. This could be due to the strategy taking a mental toll which influences other cognitive abilities, it is not yet a routine. 
3. Increased knowledge of memory. Older children know more about memory, like how long they must study and which strategy to use for a task. Metamemory is the knowledge of memory and the monitoring and regulating of your memory processes. It's an aspect of metacognition (the knowledge of the human mind and its range of cognitive processes). Metacognitive awareness is somewhat present at a young age, like at about 3 years, but there are significant improvements during childhood. Metamemory can help children choose strategies that fit them. 
4. Increased knowledge of the world. This makes material to learn more familiar, and makes it easier to learn and remember. The knowledge base affects learning and memory performance. When something is really familiar to you, that helps to learn or remember it. 

Episodic memories of personal events are called autobiographical memories. These help constitute our understanding of who we are. Childhood amnesia means that even though infants can store memories and chidren and andults can have many specific autobiographical events in their storage, older children and adults still have few autobiographical memories of events that happened during their first years of life. Age seems to be the lowest age limit for recall of early life events as an adult, and it's usually by 4 or 5 that the first memories come up. There are several reasons for this loss of early memories:

• Space in working memory. Infants may not have enough space to hold all the information that's needed to properly encode and consolidate. However, infants can remember to some degree, so this is not satisfactory.
• Lack of language. Autobiographical memory seems to rely heavily on language skills. A lack of good verbal skills in the first years of life may limit what we can recall from this period. However, we can also add verbal descriptions later, so still not completely satisfactory.
• Level of sociocultural support. It might be that whether the caregiver gives rich or non-rich elaborations of events, while talking to their child, influences the autobiographical memories. So there might be a big role for the parents in this phenomenon.
• Sense of self. Infants lack a good sense of self, which may have to do with it. This could be why the experiences aren't stored as personal, autobiographical memories. 
• Verbatim versus gist storage. This has to do with the fuzzy-trace theory. This theory says that children store verbatim and general accounts of an event separately. Verbatim information (like word-for-word recall of a lecture) is likely to be lost over time, while the gist (recall of the general points of the lecture) is easier to remember. Children go from storing mainly verbatim memories to storing more gist memories, and the earlier verbatim memories may be lost. 
• Neurogenesis. Neurogenesis, thus the birth of new cells, when happening in the hippocampus early in life, can refresh our memory store. After birth, the period with most neurogenesis is infancy so this could be why there are almost no memories from the infancy period. 

More research is needed to find out what constitutes childhood amnesia, but it is clear that the events of our early childhood do not seem to undergo the needed consolidation.

Children construct scripts or general event representations (GERs) for routine activities. This guides their behavior in these settings, like with going to a fastfood restaurant: waiting in line, then ordering, paying, going to the table, etc. Children as young as 3 use scripts, and usually report what happens in general than in a specific situation when asked. Scripts become more detailed with age and experience. Scripts affect memories of new experiences, and the recalling of past events. It can cause misremembering since something does not fit a script, which has implications for eyewitness memory (thus the reporting of experienced events). Information related to but coming to us after the event can also influence our memory of it. This shows memory is a reconstruction and not a replication.

Memories are critical to problem-solving skills as good working memory and also stored information is essential. Siegler's rule assessment approach determines what information about a problem children absorb and what rules they then formulate to account for this information. Thus the approach states children's problem-solving attempts are guided by rules, and they fail when they do not take in all the important aspects and have faulty rules. As children age they replace faulty rules with good ones and so their problem-solving skills improve. As people age, their accuracy in solving problems increases but sometimes their time needed does as well, since they are using a more complex strategy. Siegler also concluded that children do not move from one way of problem solving to another, but use multiple strategies rather than one. As they work they learn what strategies allow them to solve the task quicker. So success improves as we test out the multiple strategies and pick and develop the best ones. New ones will also come up as the working memory space allows it. Siegler says we shouldn't look at development as a series of stages, but as overlapping waves. 

What does memory mean to the adolescent?

In adolescence, strategies are more deliberaty used, and new learning and memory strategies emerge, relevant for school learning too. The memory strategy of elaboration is fully mastered and they can ignore irrelevant information better. Working memory improves as well because of developments in the brain. Obviously, the knowledge base improves and metacognition too. For instance, they regulate how they should plan their study time: more for a difficult test and less for an easier one. Girls, and adolescents with higer SES, use more metacognitive strategies than boys and lower SES adolescents. And possibly due to all of this, problem-solving improves as well.

What does memory mean to the adult?

It shows that adults function best cognitively in their fields of expertise. However, this is domain-specific knowledge and domain-specific information-processing strategies occur, meaning that their excellence in one field does not really carry over into other domains. 

What determines whether an event will probably be recalled later on (through autobiographical memories)? There are four factors that may influence this:

• Personal significance. People think that meant a lot to you will probably be stored. However, the personal significance of an event, rated at the time of happening, has little effect on someone's ability to recall it later on. This could be due to something becoming less meaningful to you over time. So, as long as something is still personally significant it might influence memory, but when it's not anymore it will probably also not be easy to recall it.
• Distinctiveness. The more unique the event, the easier to recall a detailed memory of it later. Common experiences are often recalled as multiple experiences lumped together as one. 
• Emotional intensity. Events with very negative or very positive emotions are recalled better. This enhanced memory for emotional events occurs, even though the emotion may have faded away later. This is probably due to the arousal the emotions cause, and with that comes greater neural activity, especially in the amygdala.
• Life phase of the event. People recall more from their teens and 20s than from any other time, except the near present. This is called the reminiscence bump and may occur because memories from adolescence and early adulthood are easier accessible than memories from other periods. This could be because of their distinctiveness, and the effort applied to understanding the meaning of certain events, since a lot of important things happen in this period. All the events in your life form your life script, a story we tell over and over and which is biased towards positive events. Telling this life script makes sure that major life events are secured in our memory system. 

The elderly almost all suffer from difficulty with remembering, however there is variability. It usually starts from the 70s and gets worse with aging from then. Timed memory tasks are especially difficult, and unfamiliar topics as well. There is a large gap, as in basically every other age, between recognition ability and recall ability: showing that the information is encoded and stored, but not easy to retrieve without cues. The semantic memory stays greater than the episodic memory, just like implicit memory stays greater than explicit memory. 

Age-related loss can be prevented or even reversed by reducing stress, since stress elevates cortisol in the brain, which impedes memory. Physical fitness, mental activity, and a sense of control over life events predict good memory. 

Knowledge base is still good for elderly and thus is not a cause of the memory problems. Gains in knowledge can even help compensate the decrease of information-processing efficiency. Metamemory also remains well, but there may be some weaker areas. Elderly also have a more negative attitude about their memory than younger people. People's beliefs about elderly can even predict the presence of memory loss. Next, the use of spontaneous strategies seems to decrease. However elderly can benefit from mental exercise and training. The biggest cause of memory problems is probably the changes in basic processing capacities that come with aging. And elderly can not ignore irrelevant stimuli as good as younger people. In the brain of older people, underactivity (e.g. due to a deficiency of the hardware of the brain, or the software and thus the strategy) can occur or overactivity (the brain compensating for age-related losses). Slow neural transmission and too much or too little of certain proteins may be what causes the limitations in working memory in old age. 

Many researchers have a contextual perspective on learning and memory. They don't believe in an universal decline and say that performance on learning and memory tasks is the product of interaction between characteristics of the learner, characteristics of the task and situation, and characteristics of the broader environment, including the cultural context. Cohort differences can explain the presumed age differences and the cross-sectional design can have a lot of influence, since longitudinal designs show different and more positive results. The truth is probably somewhere between the basic processing capacity view (emphasizing a general decline, thus nature) and the contextual view (emphasizing nurture). 

Older adults do not do very good on traditional problem-solving tasks in the laboratory. For instance, they do not adapt the good strategy of asking constraint-seeking questions (questions that will rule out more than one item) when trying to find the thing that the researcher has in mind. Instead they ask specific questions like is it a pig?. When the task is made familiar, they do way better, so it depends on the context. However, generally, there is still a decline in problem-solving skills in the elderly. 

It seems like older adults approach problems different than younger ones. They generate less possible solutions, but their solutions are more goal-focused and selective. Thus, quality over quantity. In addition, a framework has been found and named selective optimization with compensation, and this is about understanding how elderly may cope with and compensate for their decreasing cognitive abilities. Three processes are involved: selection (focus on a limited set of goals and the needed skills), optimization (practicing those skills) and compensation (develop ways around the needed skills that are not there). Applying SOC improves their life.