Judgments of recency for long sequences of pictures: the absence of a developmental trend

Recency judgments were examined for four groups (N = 40 per group) aged 7, 8, 10, and 18 years. The Ss were required to choose either the near or far item on a series of test pairs embedded within a long sequence of single inspection items. No age effects were found. Performance was more accurate the longer the separation between the original presentation of the two test items and the shorter the lag from the most recently presented item to the test. Implications for general and developmental theories of memory were discussed. The data supported the hypothesis that tasks, which do not require deliberate mnemonic strategies, are not developmentally sensitive.     

Overshadowing in operant conditioning as a function of discriminability

Pigeons were trained in an operant, go/no-go, discrimination by successive presentations of discrete, positive and negative trials. In separate groups, the rate of discriminaion learning based on an auditory cue, on visual cues of different discriminability, and on combined auditory and visual cues was determined. The auditory cue was tone/no-tone, the visual cue was a difference in brightness level on the key. Following discrimination training, stimulus control was tested in extinction by presenting tone or notone at each of four key-brightness levels.Learning was more rapid with two cues than with either cue singly, demonstrating summation. The contribution made by the tone cue to the learning of the discrimination decreased with increasing discriminability of the light cue. The control exerted by the tone cue also decreased (i.e., the tone cue was overshadowed) with increasing discriminability of the light cue. In certain cases, the tone cue decreased control by brightness, showing that in two-cue discriminations each cue may reduce the control exerted by the other.     

Effects of list length and first-trial reward upon concurrent discrimination performance

Rhesus monkeys were given 2304 two-trial object discrimination problems that were presented as members of lists consisting of two, four, or eight problems. The problems within each list were presented concurrently, Trial 1 for all problems in the list being presented before initiation of Trial 2 for any problem. Each problem involved exposure of a single object on Trial 1, which was either rewarded or not rewarded, followed by presentation of the Trial 1 object along with a second object on Trial 2. Performance varied inversely with list length, and this effect became more prominent as a function of training. Performance after Trial 1 nonreward was substantially better than that after Trial 1 reward, and this effect became enhanced both with continued training and with increased list length. The findings were discussed in terms of Bessemer's short-term memory analysis of learning set.     

Children's decision strategies and their adaptation to task characteristics

Recent research has established decision making as an important type of strategic problem solving. From this perspective, the present paper examines strategic decision behavior in children and, in particular, the ability to adapt decision strategies to task characteristics. Twelve-year-olds' strategies were identified through analyses of information search patterns with different-sized matrices of information. Using a similar procedure, Payne (1976, Organizational Behavior and Human Performance, 16, 366–387) found that adults shifted to more efficient (but less “optimal”) strategies as task complexity increased. The present study indicates that, by 12 years of age, children understand many of the basic concepts of strategic decision making, such as compensation and elimination, and, like adults, they modify their strategies appropriately in response to complexity. However, their behavior differs from that reported for adults in that the distinctions among specific decision strategies are not clear cut, and there is frequent use of less demanding, cost-cutting strategies even with smaller decision tasks. Memory capacity and topic interest also affect decision strategy. The results support the feasibility of further developmental study of decision strategies. Analytical techniques developed here for use with children may profitably be applied in studies with adults as well.     

A case of literal alexia: evidence for a disconnection syndrome

We describe a patient with literal alexia, agraphia, and only minimal aphasia, resulting from a left occipito-parietal ischemic infarction. Neither impaired visual processing nor impaired oral output could explain the patient's letter reading deficit, since he retained the ability to match letters of mixed case, and remained able to spell aloud and to pronounce and comprehend orally spelled words. His residual word reading was characterized by better performance for nouns and highly imageable words than for functors , poorly imageable words, and nonwords. We propose that this patient's letter reading deficit was due to a partial disconnection of his visual from his linguistic systems, with residual word reading accomplished by a semantically mediated compensatory mechanism. We suggest, further, that the dissociations between word and letter reading observed in some alexic individuals may be attributed, in part, to a difference in the relative contributions of dorsal and ventral occipital structures to the reading process.     

Writing induces a right hemisphere linguistic advantage in dysphonetic dyslexic children: implications for attention and capacity models of laterality

An experiment demonstrated a complete hemispheric processing reversal in 10 male, dysphonetic dyslexic children that occurred during a dichotic listening test of their verbal working memory. Requiring a written response to dichotic digits produced a right hemisphere/left ear superiority in the dysphonetic dyslexics whereas normal subjects and other dyslexics maintained a left hemisphere/right ear advantage. This reversal was unaffected by changes in task difficulty. A second experiment assessed the influence on producing the reversal of concurrent manual interference with left hemisphere verbal processing (responding orally vs. manually) and selective right hemisphere priming (Forward Writing vs. Backward Writing). The dysphonetic children reverted to a strong left hemisphere superiority when recalling the dichotic digits orally. Backward writing produced no ear advantage in either direction. The findings suggest that dysphonetic dyslexia may be related to (1) left hemisphere processing demands that exceed capacity, (2) easily activated right hemisphere processing strategies and (3) failure to coordinate linguistic processing interhemispherically. The results supported a novel hybrid conceptualization of dyslexia consisting of a synthesis of selective activation, and dual processor-limited capacity, theories.     

Operant techniques used in stuttering therapy: A review

This article reviews research concerning the use of operant conditioning in stuttering therapy, and discusses the clinical implications of this literature. In order to be considered for this review, a report had to treat the findings of research specifically designed to use operant conditioning in the manipulation of speech disfluency. This body of experimental literature clearly indicates that operant management techniques can effectively reduce stuttering with punishment of disfluencies producing more notable results than reinforcement of fluent responses. Operant conditioning is an effective means of modifying stuttering behavior and should be more visible in terms of procedures used by speech therapists.     

Repetition and comprehension of spoken sentences by reading-disabled children

The language problems of reading-disabled elementary school children are not confined to written language alone. These children often exhibit problems of ordered recall of verbal materials that are equally severe whether the materials are presented in printed or in spoken form. Sentences that pose problems of pronoun reference might be expected to place a special burden on short-term memory because close grammatical relationships obtain between words that are distant from one another. With this logic in mind, third-grade children with specific reading disability and classmates matched for age and IQ were tested on five sentence types, each of which poses a problem in assigning pronoun reference. On one occasion the children were tested for comprehension of the sentences by a forced-choice picture verification task. On a later occasion they received the same sentences as a repetition test. Good and poor readers differed significantly in immediate recall of the reflexive sentences, but not in comprehension of them as assessed by picture choice. It was suggested that the pictures provided cues which lightened the memory load, a possibility that could explain why the poor readers were not demonstrably inferior in comprehension of the sentences even though they made significantly more errors than the good readers in recalling them.     

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.