This supports the assumption that integrated objects, not merely single features are stored in visual short term memory. We obtained comparable results in a second experiment using real objects in composed scenes. Estimates approach the “magic number” of 4, especially for longer strings at slower SOAs. A visual memory capacity can be estimated by multiplying overall accuracy by the length of the string of cues. There was no significant “primacy” effect favoring the item cued first. However, performance was above chance even for items that were early in strings of 8 Cues.
Results show a strong “recency effect” with the last two cued items recalled more accurately than the other cued items. Ss responded at chance levels to the 10% of uncued probed items but at above chance level at all cued locations. On 90% of trials, the probed item was chosen from the cued set. After the cue sequence, a single item was masked and subjects were asked to make a 5AFC decision about the color of the now hidden item. Items were cued, one after another, every 50, 150 or 300 ms. On each trial, 3, 6, or 8 of these spots were cued by a luminance increment. In Experiment One, subjects viewed 20 colored spots.
SERIAL POSITION EFFECT SERIAL
We looked for serial position effects in this type of memory by endogenously cueing a subset of items and then probing for memory of one of those items. When they are at the beginning or at the end of the list, they are not surrounded by as many words that could interfere with them words in the middle, on the other hand, must compete for space in working memory with more words around them.After being briefly presented with an array of simple items, observers seem to be able to retain a small number of these (∼4) in a visual short-term memory (e.g. Words in a list tend to interfere with one another. Second, short-term memory involves keeping some information in active, working memory this information is likely to be the most recently presented stimuli. First, the primacy and recency effects occur because items at the beginning and the end of the list are distinct or isolated from the other stimuli due to their positions.
The serial position effect occurs due to three factors: distinctiveness, constraints of short-term memory, and inhibition.
SERIAL POSITION EFFECT FREE
When a learner must use serial recall, or recall of the stimuli in their order of presentation, the items appearing first and last on the list still show an advantage over those in the middle, but the items at the beginning of the list are recalled more often than items at the end of the list, a reversal of the pattern in free recall. (The tendency for retrieving words from the beginning of a list is called the primacy effect.) Recall will be poorest for items in the middle of the list, unless a stimulus has special characteristics and stands out. This tendency for the best memory for recently presented items is referred to as the recency effect. As a rule, if free recall is engaged, the words that are best remembered are those from the end of the list, and they are also likely to be the first to be recalled.
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