Neurons which are missing the protein Staufen2 have less synapses, and the signal transmission between them is disturbed. "An important notice on that, is that Staufen 2 for the education of functioning Synapses is crucial", says Kiebler ( researcher).
If what we have learned is forgotten, long-term connections become out of contact of the connection points. German Neurobiologist worked on the correlation between the outgrowing of the connections of cells, the so-called "thorns" and the building of functioning synapses.
In order to be able to follow the outgrowing of thorns, the cells in the near surrounding area of the stimuli were observed using a high resolution two-Photon-microscope. An electron microscope was used in order to review whether the variations in the nerve cells actually led to the origin of new synapses.
Within few minutes after the current impulse, the encouraged nerve cells opened the gate to a new discovery. These thin thorns do not grow spontaneously (as they thought), but rather grow towards possible contact partners. Within the first eight hours no piece of information can be exchanged between the newly emerged cell contacts. Not until the following hours it is decides whether a connection remains exist or disappears.
For sure, those contacts, that are still available after 24 hours, have fully functioning synapses which can transfer information and have a good chance to exist after several days. Then the reconstruction in the brain is locked evidently.
Which parts of the brain remember which type of memory?
The Psychology behind memory
It is generally accepted that there are three different memory systems:
- sensory memory
- short term memory
- long term memory
These distinctions were first defined by Atkinson and Shiffrin (1971).
Sensory memory
Is that which holds information from the senses for up to several seconds at the most.
Short-term memory
Is whatever we are thinking about at any given moment and has a relatively rapid input and retrieval. Miller (1965) argued that human short term memory has a span of approximately seven items, plus or minus two.
Long term memory
Is the permanent memory system which has a virtually unlimited capacity but takes longer to retrieve and to store (Baddeley, 1990).
Evidence suggests that short-term memory is primarily phonological involving an articulatory loop of rehersal in working memory (Baddeley, 1990), whereas long term memory relies primarily on the semantic code (Baddeley, 1990).
It is well known that there is both a primacy and a recency effects in short term memory. This means that there is an improved recall of words at both the start and at the end of the presentation list whereas there will be more information lost from the middle of the presentation.
There are two theories concering the loss of information in short term memory. The decay theory proposes that loss is the result of trace decay, e.g. the simple automatic fading of the memory. Whereas the inference theory proposes that the forgetting is caused by other information getting in the way. One of the main ways to assess this has been to impose a distraction technique during or after the items which are to be memorized. For example Wolach and Pratt (2000) studied the effects of both phonological and noise distracters on short term momory recall and showed that both distracters negatively affected the memorization process. The stronger that the distracter was to the material to be memorised than the more severe this effect was.
The recency effect is greater for auditory than visually presented material. This is called the modality effects. It has been shown that if an irrelevant item is spoken at the end of a list, the recency effect is reduced for auditory but not for visually presented lists. This is called the suffix effect.
Many other factors can adversely affect short term memory recall. For example, Banbury, Macken, Tremblay and Jones (2001) studied the effects verbal distractions on short term memory. The degree of interference was related to the properties of the sound specifically and even quiet background sounds have a negative effect upon recall. The word frequency and the rate of presentation are also influential in short term memory recall as is presentation type. For example Frankish (1985) found that there was a substantial recall advantage for grouped lists with auditory but not with visual presentation.
Individuals with defective short terms memory systems have told us a lot about memory and illustrate the need for continued research in this field. An example is that of a patient referred to as HM, who developed an incapacity learn new material (Milner 1966). HM underwent surgery to remove portions of his temporal lobes to stop the seizures he had suffered from since a child. The surgery was successful in this respect but afterwards HM could not maintain normal short term memory for more than a minute despite a perfectly good long term memory for events which happened before the surgery. Specifically he lacked the ability to transfer new short term memories into long term ones. He could repeat information for many minutes, but if distracted, even briefly, he would forgot. HM is not an isolated case and thus the role of the temporal lobes is clearly essential in human memory.
This study therefore aims to assess the effects of using imagery associated to the word. It is hypothesised that chunked items without a distraction will facilitate greater recall than chunked items followed by a distraction. In addition it is hypothesised that chunked items without distraction will result in greater recall than non chunked items with a distraction. Overall, chunked items will be more successful in terms of recall then non chunked items and the presence of the distracter will result in a deterioration in recall.
Until now the Hippocampus counted as a key region of the long-term memory. That Bonn study suggests very that it plays a role in the short time memory.
The short time memory consists of electric excitement patterns, that are maintained from a second up to a minute long. As soon as they fade away, the memory is gone. Therefore we mumble phone number before us there until we entered it. How however do we actually remember things?
This is was the test subject of a study carried out at Bonn. During participants where a shown a pictures shown different pictures and after a short while they where given the same pioctures and they had to recall wheather they had seen this picture before. During this activity they took a closer look at the brain waves. The researchers on the Hippocampus, (a structure in the temple rag whose electric activity changes) noticed that the wave "swings" simultaneously in different frequencies. The so-called Theta volume about swings with four to eight Hertz clearly more slowly than the gamma volume, that comes on 25 to 100 Hertz.
The swigin of frequencies in the Hippocampus comes to and end and the short time memory becomes active. Then the Theta drum takes over and plays the tac before the gamma drum. Within this tact, the gamma drum then starts to join the theta drum by playing a “note”. "We assume that the memory of is freshened up the different faces sequentiell, znd to be sure each face to its specific moment in the Theta cycle."
In order to remember the picture: the gamma drum strikes the first quarter, the excitement pattern is freshened up of face one, follows is locked on the second quarter no. two – at the end of the tact the complete memory cycle. The Theta tact is there the time span that is available the short time memory refreshing of all faces to the. For this thesis speaks: The Theta oscillation became slower the more faces the test subjects should notice themselves.
Method:
Participants were 20 male and female sixth form students, aged between 16-18 years who participated voluntarily. Each participant completed each condition once.
There were two types of recall stimuli used within this study. Participants will be shown a list of words. Each word will be displayed for 5 seconds. After that participants had to count back in twos from 500 for 30 seconds to avoid recency effect. Then another group was shown the same list but with images associated to the word. They had to count backwards from 500 in twos again to avoid recency effect.
There were two lists in each category each of which contained 10 items, thus the maximum score it was possible to gain in each condition was 20
Each list was presented visually for a total of 50 timed seconds. The order of presentation of these lists was also counterbalanced to avoid the possibility of presentation effects. Following presentation participants were asked to recall as many of the items as they could utilising a free recall design. i.e. in any order they like. Participants were given one minute to recall as many items as possible in written form.
Equipments
The list of words (or the list of word with pictures) was presented to the participant over a power point presentation. This allowed me to set the time for how long I want a picture to be displayed. O chose to use 5 seconds per slide. I also used a stop watch with which I timed 30 second when they count back. Participants were provided with pencil and paper to write down their result.
Pilot test:
Morning-list without pictures morning- with pictures
Afternoon-list without pictures Afternoon- with pictures
A pilot test was carried out prior to the actual. 6 students we asked to take part in a memory test in the morning and afternoon
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Morning list Morning Picture
Afternoon list Afternoon- picture
