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.     

Process assessment: An examination of reinforcer effectiveness and predictive validity

This research describes an assessment procedure based on measures of actual learning. First-grade children (N = 120) learned five sight vocabulary words under feedback only, and were then assigned to one of five conditions where they learned five additional words either under feedback, praise, candy, praise and candy, or reproof. In a sixth condition (reciprocal to the first treatment), students learned the first five works under praise and the second five under feedback only. Although results indicated no differences in learning rate under different reinforcement conditions, learning measures under feedback accounted for approximately 39% of the variance in achievement (r = .62), with combined reinforcement learning measures slightly improving prediction (r = .68). The order of treatments had no effect on learning rate. Implications for this process approach to assessment are discussed. Directions for future research are suggested.     

Analyzing the random control procedure: Effects of paired and unpaired CSs and USs on autoshaping the chick's key peck with heat reinforcement

A series of five experiments using a total of 264 subjects investigated the effects of paired and unpaired key light (CS) and heat (US) stimuli on autoshaping the chick's key peck. Experiment 1 established that paired presentations of CS and US promoted a more rapid rise in key pecking than did randomly presented CSs and USs and that the specific sequence of stimuli under the random control procedure affected key pecking performance. Experiment 2 used a trace conditioning procedure to determine the role of the CS-US interval on autoshaping and to define empirically unpaired CSs and USs. Key pecking declined as the trace delay interval was increased from 0 to 25 sec; at 25 sec, no conditioning of key pecking occurred. Experiments 3–5 assessed the effects on autoshaped key pecking of (a) number of daily CS-US pairings, (b) added unpaired CS presentations, and (c) added unpaired US presentations, since paired and random control schedules differed in all of these respects. Reduction in the number of CS-US pairings slowed the acquisition of key pecking as did the concurrent addition of nonreinforced CSs and unsignaled USs. These results support theories of association formation that stress the effects of both paired and unpaired CSs and USs.     

Distraction effects in tasks of varying difficulty: Methodological issues in measuring development of distractibility

Effects of distraction on 5- and 8-year-old children's performance on a short-term memory task were examined. Tasks at three difficulty levels were employed to determine whether a floor effect could account for the lack of an age difference reported in an earlier study. A floor effect does not appear to be a key factor; the absolute amount of performance decrement was roughly equal for the two ages here regardless of task difficulty, and performance was well above chance under all conditions. The children adapted somewhat to the presence of distraction as shown in greater performance impairment for the first trial under distraction than for remaining trials. Use of a proportional, rather than an absolute, decrement index was considered, and the relevance of the present data to this issue was discussed.     

Auditory processing of relational information by young infants

The ability of 5-month-old infants to process relational information was assessed by means of a habituation-dishabituation paradigm with cardiac deceleration as the response measure. Infants were first habituated to a six-tone pattern and then shifted either to a transposition of the standard pattern or to a control pattern which comprised the elements of the transposed pattern in scrambled order. Dishabituation was not evident in the case of the transposed group but was clearly evident for the control group. These results indicate that infants can process relational information from tonal patterns.