Length Of Retention Interval Research Articles

Effects of length of retention interval on proactive interference in short-term visual memory.

Effects of length of retention interval on proactive interference in short-term visual memory.

The Serial-Position Effect in Short-Term Motor Retention

The existence of inter-item interference was demonstrated in an experiment investigating proactive inhibition in motor short-term memory. Blindfolded subjects moved a slide to a stop and then attempted to replace the slide in the correct (criterion) location with the stop removed. Independent variables were positions recalled in addition to the criterion (zero or four) and retention interval length (5 or 50 sec). While retention loss on the criterion position was found only for the group with four additional positions and a 50-sec retention interval, analysis of recall error at each position for subjects given a five-item sequence and a 5-sec retention interval indicated a serial-position effect. Implications of the findings for the role of cognitive processes in motor short-term memory were discussed.

Irrelevance of retention interval length and distractor-task similarity to schizophrenic cognitive interference.

Irrelevance of retention interval length and distractor-task similarity to schizophrenic cognitive interference.

Effect of amount of interpolated learning and length of retention interval upon retroactive inhibition in a serial search task.

Effect of amount of interpolated learning and length of retention interval upon retroactive inhibition in a serial search task.

Free recall of trigrams following their presentation in a short-term memory task

Ss free recalled items they had previously separately verbally recalled in a standard short-term memory task. Free recall was examined as a function of: (1) order of item presentation, (2) length of retention interval, (3) presence or absence of an instructional set to recall all items, and (4) activity during the intertrial interval. Significant effects due to order of item presentation, intertrial-interval activity, and interactions between order of presentation and intertrial-interval activity and between presentation order and instructions were found. A recency effect appeared in all instances, but a primacy effect was obtained only when Ss were forewarned of free recall. The effect of intertrial-interval activity was most evident with the last item. Rehearsal of the item produced better recall than either counting or doing nothing, but counting produced better recall than doing nothing.

The effect of duration of item exposure on recall in a short-term memory paradigm

Ss were tested for recall of six consonant trigrams at retention intervals of 0, 3, and 18 sec with a 2,000-, 500-, or 200-msec duration of item exposure. As duration was reduced, retention at 3- and 18-sec within- and between-exposure durations declined for all items, and the interaction between length of retention interval and number of items was significantly reduced for the initial and middle items. The results were interpreted in terms of increased proactive interference as item exposure was reduced.

Response latency and task difficulty in recognition memory

Changes in response latency were examined under conditions where task difficulty was varied by manipulating length of retention interval and formal similarity of test alternatives. The task was to select a previously shown CVC from five alternatives having 0–2 letters in common. Retention interval was varied by having S count backwards for 3.75 sec from each of 0–5 successively presented 3-digit numbers. Eighty-four Ss were each tested on all 42 combinations of six retention intervals and seven degrees of similarity. Results indicated that correct recognitions decreased and latencies of correct recognitions increased with increasing length of retention interval and degrees of similarity. The data were discussed in terms of available information and search and decision processes.

Influence of amount of training and retention interval length on long-term perceptual memory in normal and educable-retarded children.

The influence of perceptual memory on the perception of apparent movement was found to be the same for educable-retarded children and normals of the same MA following a short retention interval. However, in order for the memory effects to endure 24 hr., the EMRs needed much more training than did normals. The results are discussed with respect to those reported in an earlier paper (Raskin, 1969b) and interpreted in terms of association perceptual learning.

Auditory and visual short-term memory with successive syllable presentation in both modalities

Three groups of 20 Ss processed CCC trigrams by the Peterson and Peterson method. The consonants were presented successively for 0.5 sec each, the input being visual for one group and auditory for another. The third group received half of their trigrams in a visual mode and half in an auditory mode. Recall was a decreasing function of length of retention interval, with materials presented in the auditory mode being better recalled than those in the visual mode, especially at the shorter retention intervals. In light of these and other findings, it was concluded that the more pronounced recency effect for the auditory modality is a stable phenomenon, being obtainable under successive as well as under simultaneous visual presentation and being invariant with respect to choice of experimental design.

Short Term Motor Retention as a Function of Response-Similarity

The present study examined short-term retention in a simple leverpositioning task. The basic variables were the degree of similarity of prior responses about a target (± 5 deg., ± 15 deg., and ± 25 deg.) and the length of retention interval (5, 15, and 50 sec.). It was found that the absolute errors at recall were inversely related to the similarity of the prior responses about the target position. In all conditions, forgetting was found to be an increasing function of the retention interval. The loss of retention over short periods of time was interpreted as being consistent with verbal short-term memory studies. The results on the similarity of responses were in direct opposition to the findings usually observed in verbal tasks. Comparisons with verbal responses are difficult to make since the nature of retention measurement is different in verbal tasks.

Postural set as a factor in short-term motor memory

The present study attempted to differentiate between a set vs an interference explanation of the decrements in recall when activities are included in the retention interval. Using a lever-positioning task with three retention intervals (12, 22, and 37 sec) and two types of activity during the retention interval, it was found that movement caused a significant overestimation of the target position using algebraic error, and that a movement by retention interval interaction was not significant. Since the decrements in recall were independent of the retention interval length, the results indicated that the effect of movement was to reduce S’s postural set. No differences were found when using absolute errors.

Proactive inhibition of descriptive prose as a function of the length of retention interval.

Proactive inhibition of descriptive prose as a function of the length of retention interval.

Effects of formal interitem similarity and length of retention interval on proactive inhbition of short-term memory.

Effects of formal interitem similarity and length of retention interval on proactive inhbition of short-term memory.

Effects of incentive and incentive-cue position on short-term retention

Ss recalled CCC trigrams differing in incentive value, temporal position of incentive cue, and length of retention interval. Recall varied as a function of incentive and retention interval, but was unrelated to cue position. Additional evidence suggested that differential learning and covert rehearsal may mediate the facilitative effects of incentive.

Short-term retention in normal and retarded children

To test certain predictions from the Ellis (1963) “stimulus trace” theory, retarded children and equal-MA normals were compared for the short-term retention of digits where length of retention interval (LRI) and amount of retroactive interference (RI) were varied. A Low-IQ deficit as well as an RI effect was demonstrated. There were no reliable IQ by LRI or IQ by RI interactions. Implications for the Ellis theory were discussed.

Proactive inhibition in short-term retention of single items

Summary Three experiments were performed to determine the relationship between certain variables influencing proactive inhibition in long-term retention of lists of verbal items and the influence of these variables on short-term retention of single items. More particularly, retention of single items over 18 sec. should, if the laws of long-term retention are applied, decrease with number of previous items to which S has been exposed. In addition, amount of forgetting should be a direct joint function of number of previous items and length of the retention interval. In Exp. 1 each S was presented consonant syllables singly, with retention being measured after 3, 9, and 18 sec. Forgetting of the first item presented (T-1) was less than for the second (T-2) or third (T-3) item, but forgetting of the latter (T-2 vs. T-3) did not differ. On all three tests forgetting was directly related to length of retention interval, but no interaction was evident between number of previous items and length of retention interval. In Exp. 2 a higher degree of initial learning of the items was achieved. Forgetting increased directly as a function of number of previous items presented. The predicted interaction was indeterminate since retention was essentially 100% on T-1 for all retention intervals. Experiment 3 tested retention of six successive items over 3- and 18-sec. intervals. Retention after 3 sec. showed an initial drop and then a rise over the six tests, the rise suggesting a practice effect. Forgetting over 18 sec. increased directly from T-1 to T-6 and there was no indication that a constant amount of proactive interference had been reached. The interaction between length of retention interval and number of potential proactively interfering items was very evident. The results were interpreted to mean that proactive inhibition in short-term memory of single items follows the same laws as proactive inhibition in long-term memory of lists of items.