Relation between intelligence and short-term memory

Several prior studies have concluded that the correlation between IQ and STM depends on differences in encoding or rehearsal strategies. Low IQ subjects use less effective strategies than high IQ subjects. One basis for these conclusions is that IQ exerts its greatest influence on the recall of early items in to-be-remembered lists, having little effect on the recall of recency items. The present study measured IQ/STM correlations in children, using probed serial recall of supraspan digit lists. The results showed the predictive power of IQ to range from a maximum in the case of recall for recency items to practically zero in the case of primacy items. Several explanations for the data are discussed, taking account of the possible roles of individual differences in rehearsal, in item persistence, and in the ability to access specified information in a short-term store.     

Recall and recognition of order and item information in probed running memory, as a function of IQ

Two experiments were designed to test the possibility that correlations between IQ and probed serial running memory depend on IQ-related individual differences in the retention of order information in short-term memory. In Experiment I, correlations were obtained regardless of whether instructions emphasized serial recall or free recall. In Experiment II, a significant correlation between IQ and performance was obtained in a recognition test for very recent item information, but not in a recognition test for very recent order information. These data together with a theoretical analysis of the operations involved in the tasks, led to the conclusion that the correlations reflected individual differences in the capacity to access specified sets of items in very short-term memory.     

Intelligence and short-term memory: A clandestine relationship

Five possible mechanisms are considered as being responsible for the systematic variation of serial STM with IQ, namely rehearsal maintenance, chunking, access, encoding of item and/or order information, and trace persistence. A STM/IQ correlational study is reported. It was concluded from analysis of a correlation matrix, and from earlier reported data, that the encoding of items-in-order into an already loaded store appears to be the critical mechanism in determining IQ-related individual differences in STM performance, at least in children. The implications of individual difference data for models of STM are also discussed.     

Critical processes in serial short-term memory: A developmental study

Two experiments are described which were designed to test the possible involvement of two operations in developmental auditory serial short-term memory (SSTM), namely rehearsal proficiency and item identification. The experiments provided mainly negative support for the notion that these operations are critical in developmental SSTM. As an alternative, the possibility that developmental differences in SSTM might have their origins in the processing of speech sound patterns was discussed.     

Memory in educable mentally retarded adults: Deficit in subject or experimenter?

Educable mentally retarded (EMR) and nonretarded adults free recalled lists of (a) words, (b) minitasks performed by the subjects (SPTs), (c) minitasks performed by the experimenter (EPTs), or (d) task instructions. The EMR subjects were significantly inferior to the nonretarded subjects in the immediate recall of words, EPTs and instructions, but not in the immediate recall of SPTs. This proficiency of the EMR subjects in SPT recall was attributed to the nonstrategic nature of this test. The EMR subjects were, however, inferior to the nonretarded subjects in a final free recall (recall of all lists) of all four types of item.     

Speeded recognition of ungrammaticality: Double violations

A model of sentence comprehension postulating that Subject-Verb-Object relations are specified prior to Noun-Adjective relations received support from a study of the speed at which sentences with various kinds of violations could be rejected. Compatible with the sequential model was the finding that Noun-Verb and Adjective-Noun double violations did not result in shorter RTs than Noun-Verb single violations — even though sentences with double violations were judged to be less acceptable.     

Short-term memory for time intervals

The effect of intertrial interval, preset interval, and retention interval on the performance of rats in a time estimation task was described. On each trial a signal was presented for a duration of 2 to 8 sec. Eighteen rats were trained to press one lever (the short response) if the signal was shorter than 4 sec, and another lever (the long response) if the signal was longer than 4 sec. When trials were massed (Experiment 1), the percentage long response was affected by the classification of the previous signal, but not by its actual duration. This suggests that the animals remembered the response made on the previous trial, but not the signal duration. If a response was not permitted on the previous trial (Experiment 2), the duration or classification of the previous signal had no effect on performance. This supports the conclusion from the first experiment and suggests that an animal can reset its internal clock in less than 2 sec. In Experiment 3, the difference limen of the psychophysical function increased with the duration of the retention interval, but the point of subjective equality did not change. This suggests that resetting of the internal clock occurs on a non-time dimension.     

Short-term memory in the pigeon with presentation time precisely controlled

Delayed matching-to-sample was studied in the pigeon using a procedure which precisely controlled the presentation time of the sample stimulus. Experiments 1 and 2 revealed that (a) accuracy of matching increased as a negatively accelerated function of presentation time, (b) accuracy declined when an interstimulus interval was introduced between successive presentations of the sample stimulus, and (c) the rate at which accurate matching was restored after an interstimulus interval was greatest when the initial presentation of the sample was short and the interval was long. It was concluded that a theory of STM based on the growth and decay of trace strength could account adequately for all of these findings. Experiment 3 studied trace interaction by presenting two sample stimuli first in succession and then simultaneously for choice. Predictions from trace competition theory about the specific lengths of presentation of these stimuli at which choice of the second stimulus should be 50% or deviate systematically below 50% were not supported. It appears that a recency mechanism in addition to competition is necessary to explain trace interaction effects.     

Variations in hand position, cerebral lateralization, and reading ability among right-handed children

A group of 121 right-handed children between the ages of 7 and 9 with a range of hand positions between normal and inverted were assessed for verbal and visuospatial lateralization and reading comprehension. Results indicate that (a) children with a normal hand position tended to be more verbally lateralized than children with nonnormal positions, although the effect was not strong or always consistent, (b) the closer the child was to the normal position, the higher the child's reading scores, and (c) poor readers were as lateralized for verbal and visuospatial functions as were good readers. Coupled with the results of previous research, these findings suggest that hand position indexes both maturation and lateralization, and that the relationship between hand position and reading is primarily mediated by the former.     

Developmental changes in memory: The effects of processing time and rehearsal instructions

An overt rehearsal procedure was used to investigate the relationship between children's rehearsal strategies and free recall performance. Previous work has shown that developmental differences in rehearsal content, rather than rehearsal frequency, affect recall performance. This experiment investigated the effects of increased processing time and rehearsal training upon recall. Third-grade girls (age 8) were able to use additional processing time to increase the activity of their rehearsal, and they showed corresponding improvement in recall. In contrast, third-grade boys (age 8) and sixth-grade boys and girls (age 12) did not take advantage of a slower presentation rate to rehearse more actively, and their recall did not change. Further, even without additional processing time, both the third-grade boys and girls were able to use an instructed active rehearsal strategy to facilitate their recall. The direct manipulation of rehearsal activity and the resulting improvement in recall provide experimental support for the proposed relationship between rehearsal content and recall from long-term memory store.     

Memory and rehearsal characteristics of profoundly deaf children

This study examined whether a deficiency in spontaneous strategy use accounts for deaf children's verbal short-term memory performance. Various colors were presented for 3 s each, followed by a 15-s recall delay. The delay was either unfilled, or subjects were induced to rehearse or were prevented from rehearsing. Sixty-four deaf students from oral and total communication settings, 5 to 15 years of age, were tested. The spontaneous rehearsal of both deaf samples seemed to emerge later than the hearing sample's, and it was both inefficiently implemented and less effective in mediating recall than hearing children's. However, when rehearsal was prevented or was induced in all samples, the deaf recalled as well as, or better than, the hearing. Implications discussed include the need to compare both spontaneous and controlled strategy use in developmental memory studies, and the need to provide additional training for deaf children in the strategies of remembering, as opposed to the content material.     

Differences in the search rate of children and adults in short-term memory

When people recognize a test item as belonging or not belonging to a previously presented set, recognition latency increases with the number of items in the set. Although some evidence suggests otherwise, it is currently held that the rate of this increase is the same for children and adults. In contrast, the present experiments indicated a much slower search rate for second graders (mean age = 7.33 years) than for seventh (mean age = 12.50 years) and twelfth graders (mean age = 17.25 years). Moreover, search rate for second graders was invariant under instructions which did or did not emphasize speed and with presentation of the memory set in either the auditory or visual modality. Experiment II showed that the slow search rate for children was not due to differences in encoding between children and adults.     

Developmental differences in recall and recognition: The relationship between rehearsal and memory as test expectation changes

An overt rehearsal procedure was used to study the relationship between children's rehearsal strategies and their memory performance under different conditions of test expectation. Previous work has shown that developmental differences in rehearsal content affect recall performance. This study was designed to address the question of why active rehearsal content results in superior recall performance. The equivalence of recognition-memory performance for third- (age 9) and sixthgraders (age 12) suggests that developmental differences in recall are due to the effects of rehearsal content on item retrieval from permanent memory. In addition, the data indicate that third- and sixth-graders can differentiate between expected recall and recognition tests and, with the exception of the sixth-grade boys, use this information to modify their rehearsal content. These differences in rehearsal content, as a function of the type of test expected, corresponded to changes in recall performance.     

Analysis of memory codes and cumulative rehearsal in observational learning

The present study examined the influence of memory codes varying in meaningfulness and retrievability and cumulative rehearsal on retention of observationally learned responses over increasing temporal intervals. Symbolic codes combining meaningfulness with retrievability produced superior memory performances, but responses were poorly retained in symbolic representations containing only one of these properties. Individual response analysis further confirmed that the more meaningful the codes incorporating retrieval guides the better are modeled responses learned and retained. Cumulative rehearsal had differential effects on memory performances depending upon the serial input position of the responses and the form into which the modeled behavior was encoded. Code rehearsals facilitated retention of early and intermediate responses which were repeated more than later ones, but this was true mainly for codes vulnerable to loss. The overall findings provide further corroborative evidence that memory performances are governed more by information coding than by associative strengthening processes.     

Self-instructions: Effects of cognitive level and active rehearsal

This research examined the effects of a self-instruction intervention on the relationship between cognitive level and conceptual tempo. Preoperational and concrete operational children received the Matching Familiar Figures Test prior to and after serving in either a no training control group, a content only control group, or a self-instruction group. Children in the content only control group received the same set of self-guiding strategy statements as those in the self-instruction group but without overt rehearsal of the statements. Cognitive level and conceptual tempo were strongly related; preoperational children tended to be classified as impulsive, concrete operational chidlren, as reflective. Although cognitive level predicted overall performance, with concrete operational children being more successful and more reflective than preoperational children, the influence of training was similar for both groups. On posttest, children in the self-instruction groups made more correct responses and were more reflective than children in the other two training groups.     

Component processes of an overt rehearsal strategy in young children

The locus of facilitation due to rehearsal was investigated in three experiments with first-grade children. Several different overt acquisition strategies in a four-item sequential memory task were compared, including ordered repetition, item repetition, item labeling, and free strategy conditions. Experiment 1 showed that ordered repetition yields most of the facilitation due to rehearsal, and Experiment 2 demonstrated that the facilitation cannot be attributed to spaced practice. Experiment 3 showed that retrieval practice during study may improve memory performance but that the facilitation due to ordered repetition and retrieval practice is relatively short term. Mere repetition and labeling were not found to be significant component processes of rehearsal in any of the experiments. These results were discussed in terms of their relevance to rehearsal training studies and a differentiation between maintenance and elaborative rehearsal.     

Self-assessment,self-enhancement,and task preference

If task choice depends on a person's interest in the accurate assessment of his or her abilities, task attractiveness should be positively related to the diagnosticities of all performance outcomes with regard to one's ability level. In contrast, the view that people are primarily interested in maximizing pride or mininizing shame would predict that task attractiveness is positively related to the diagnosticity of success but negatively related to the diagnosticity of failure. To test these predictions, subjects were presented with tasks that varied orthogonally in the extent to which success was diagnostic of high ability level and the extent to which failure was diagnostic of low ability level. Consistent with the self-assessment view, task attractiveness increased both with the diagnosticity of success and with the diagnosticity of failure. Furthermore, both effects were more pronounced for high achievement motive subjects than for low achievement motive subjects. This result lends support to the self-assessment view, which assumes that high achievement motive subjects are more interested in attaining the ability-relevant information contained in any performance outcome.     

Locus of control,field dependence and the conditions arousing objective vs subjective self-awareness

Observations of persons engaged in quasievaluative situations revealed that the greater amounts of body movement characterized as tension reducing were exhibited by persons holding internal control as opposed to external control expectancies. Conceptualizing situations as varying in the degree to which they allow one to become task involved (subjective self-awareness) or self-conscious (objective self-awareness) it was hypothesized that the latter would be more disruptive to internals, the former to externals. Body movement exhibited during introspection and personal reminiscence supported this hypothesis though no support was found in another task involving the completion of moral dilemma stories. In the latter task field dependent subjects proved to be more affected by self-awareness conditions, writing more normative stories when cues for objective self-awareness were more prominent.     

Cognitive flexibility-rigidity, repetition effects, and memory

This experiment examined the role of cognitive flexibility-rigidity in memory. On the basis of several personality tests, subjects were classified as flexible, intermediate, or rigid, using a postexperimental blocking procedure. All subjects were given a perceptual grouping task, which masks the meaningful structure of the material. Subjects have the option of discovering the more meaningful structure consisting of word pairs, or alternatively, processing less meaningful chunks of letters. Results were that flexible subjects recalled substantially more items than intermediate and rigid subjects, in that order. In addition, subjects given different (varied) groupings of the letter chunks recalled substantially more than subjects given repeated presentations of the same grouping structure. Transfer tests indicated that subjects acquired different coding strategies under varied and constant input. Repetitious input led subjects to adopt inefficient strategies in processing the material to be remembered, whereas varied input led subjects to adopt efficient encoding strategies.     

Evidence for a developmental shift in the basis for memory organization

Using a false recognition procedure, either with or without instructions to facilitate Synonym or Antonym encoding, 128 second- and sixth-grade boys and girls were tested. The results indicated that there were no grade or sex differences in generalization errors to synonyms or antonyms under neurtral learning instructions, but that facilitative instructions interacted with grade level. Under instructions to facilitate synonym encoding, second graders showed a marked increase in synonym errors. On the other hand, under instructions to facilitate antonym encoding, sixth graders showed an increase in antonym errors. In addition, association strength was directly related to the magnitude of the generalization errors in both grades. The results are discussed in terms of age-related shifts in the basis underlying the organization of verbal memories.