The effects of intersensory redundancy on attention and memory: Infants’ long-term memory for orientation in audiovisual events.

This research examined the effects of bimodal audiovisual and unimodal visual stimulation on infants’ memory for the visual orientation of a moving toy hammer following a 5-min, 2-week, or 1-month retention interval. According to the intersensory redundancy hypothesis (L. E. Bahrick & R. Lickliter, 2000; L. E. Bahrick, R. Lickliter, & R. Flom, 2004) detection of and memory for nonredundantly specified properties, including the visual orientation of an event, are facilitated in unimodal stimulation and attenuated in bimodal stimulation in early development. Later in development, however, nonredundantly specified properties can be perceived and remembered in both multimodal and unimodal stimulation. The current study extended tests of these predictions to the domain of memory in infants of 3, 5, and 9 months of age. Consistent with predictions of the intersensory redundancy hypothesis, in unimodal stimulation, memory for visual orientation emerged by 5 months and remained stable across age, whereas in bimodal stimulation, memory did not emerge until 9 months of age. Memory for orientation was evident even after a 1-month delay and was expressed as a shifting preference, from novelty to null to familiarity, across increasing retention time, consistent with Bahrick and colleagues’ four-phase model of attention. Together, these findings indicate that infant memory for nonredundantly specified properties of events is a consequence of selective attention to those event properties and is facilitated in unimodal stimulation. Memory for nonredundantly specified properties thus emerges in unimodal stimulation, is later extended to bimodal stimulation, and lasts across a period of at least 1 month. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The impact of stress on mothers' memory of a natural disaster.

The effects of stress on mothers' recall for a major hurricane were studied. Stress was objectively defined as low, moderate, or high according to the severity of home damage. This study of 96 mothers was conducted concurrently with L. E. Bahrick, J. F. Parker, R. Fivush, and M. Levitt (1998), allowing the authors to compare child and adult recall as a function of the same stressor. There was a quadratic relationship between storm severity and total recall for adults, similar to their children. Mothers' recall increased from low to moderate severity, but recall at moderate severity did not differ from high severity. These findings help clarify the effects of stress on the amount and type of information adults recall in retrospective accounts of naturalistic, temporally extended events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retention of Spanish vocabulary over 8 years.

Thirty-five individuals who had learned and relearned 50 English-Spanish word pairs were tested for recall and recognition after an interval of 8 years. Two variables, the spacing between successive relearning sessions and the number of presentations required to encode individual word pairs, are excellent predictors of the likelihood of achieving permastore retention. Optimum recall occurs for words encoded in 1–2 presentations and accessed at intervals of 30 days. Both variables yield monotonic retention functions that account for a range of variation from 0% to 23% recall. These variables also have very significant effects on the recognition of unrecalled words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic memory content in permastore: Fifty years of memory for Spanish learned in school.

Tested retention of Spanish among 587 Ss who had studied the language in high school or college 1–50 yrs previously. Also tested were 146 Ss currently studying Spanish and 40 who had never studied Spanish. Tests of reading comprehension, recall, recognition vocabulary, and grammar were administered together with a questionnaire to determine the level of original training, the grades received, and rehearsals during the retention interval in the form of reading, writing, speaking, or listening to Spanish. Analysis showed that retention throughout the 50-yr period was predictable on the basis of the level of original training. Data reveal no significant rehearsal effects. The analysis yielded memory curves that declined exponentially for the 1st 3–6 yrs of the retention interval. After that, retention remained unchanged for up to 30 yrs before showing a final decline. Large portions of the originally acquired information remained accessible; the portion of the information in a "permastore" state was a function of the level of original training, the grades received in Spanish courses, and the method of testing (recall vs recognition). (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detection of intermodal proprioceptive–visual contingency as a potential basis of self-perception in infancy.

Four studies investigated 29 3-mo-old (Exp IV) and 60 5-mo-old (Exps I–III) infants' capacity to detect proprioceptive–visual relations uniting self-motion with a visual display of that motion. Previous research has shown that 5-mo-old infants can detect the invariant relationship between their own leg motion and a video display of that motion. The 1st 3 experiments showed that the 5-mo-olds discriminated between a perfectly contingent live display of their own leg motion and a noncontingent display of self or a peer. They showed this discrimination by preferential fixation of the noncontingent display. This effect was evident even when an S's direct view of his/her own body was occluded, eliminating video image discrimination on the basis of an intramodal visual comparison between the sight of self-motion and the video display of that motion. These results suggest that the contingency provided by a live display of one's body motion is perceived by detecting the invariant intermodal relationship between proprioceptive information for motion and the visual display of that motion. The detection of these relations may be fundamental to the development of self-perception in infancy. Although 3-mo-olds did not show significant discrimination of the contingent and noncontingent displays in Exp IV, they did show significantly more extreme looking proportions to the 2 displays than did the 5-mo-olds. This may reflect the infant's progression from a self- to a social orientation. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of infant intersensory perception: Advantages of a comparative convergent-operations approach.

Despite impressive demonstrations of human infants' intersensory capabilities over the past several decades, there has been little focus on the contributions of prenatal and postnatal experience or the specific developmental processes underlying the emergence of intersensory functioning. Research with nonhuman animals has, however, provided a number of advances in understanding early intersensory perception. The authors explore the value of a comparative, convergent-operations approach to the study of early intersensory perception and examine how this approach has highlighted the study of (a) prenatal factors, (b) brain–behavior relations, and (c) context and experience variables contributing to infants' intersensory responsiveness. The authors review the conceptual frameworks guiding most theory and research in the area of human infant intersensory development over the past 30 yrs. Examples of how human and animal research programs can cross-fertilize one another in their attempts to understand developmental processes underlying intersensory perception are considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intersensory redundancy guides attentional selectivity and perceptual learning in infancy.

This study assessed an intersensory redundancy hypothesis, which holds that in early infancy information presented redundantly and in temporal synchrony across two sense modalities selectively recruits attention and facilitates perceptual differentiation more effectively than does the same information presented unimodally. Five-month-old infants' sensitivity to the amodal property of rhythm was examined in 3 experiments. Results revealed that habituation to a bimodal (auditory and visual) rhythm resulted in discrimination of a novel rhythm, whereas habituation to the same rhythm presented unimodally (auditory or visual) resulted in no evidence of discrimination. Also, temporal synchrony between the bimodal auditory and visual information was necessary for rhythm discrimination. These findings support an intersensory redundancy hypothesis and provide further evidence for the importance of redundancy for guiding and constraining early perceptual learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intersensory redundancy facilitates prenatal perceptual learning in bobwhite quail (Colinus virginianus) embryos.

Information presented redundantly and in temporal synchrony across sensory modalities (intersensory redundancy) selectively recruits attention and facilitates perceptual learning in human infants. This comparative study examined whether intersensory redundancy also facilitates perceptual learning prenatally. The authors assessed quail (Colinus virginianus) embryos' ability to learn a maternal call when it was (a) unimodal, (b) concurrent but asynchronous with patterned light, or (c) redundant and synchronous with patterned light. Chicks' preference for the familiar over a novel maternal call was assessed 24 hr following hatching. Chicks receiving redundant, synchronous stimulation as embryos learned the call 4 times faster than those who received unimodal exposure. Chicks who received asynchronous bimodal stimulation showed no evidence of learning. These results provide the first evidence that embryos are sensitive to redundant, bimodal information and that it can facilitate learning during the prenatal period. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptions of past research.

Publication records were determined for 17 research topics in learning, memory, and perception. Topics varied in the initial and median years of publications, longevity, and size and shape of the distributions of publications. A total of 237 research scholars indicated their knowledge, perceptions, and evaluations of the issues. Familiarity with a problem depended on its age and when one was trained: Earlier PhDs were more familiar with older issues, and later PhDs with more recent issues. Topics perceived as the demonstration of a phenomenon were judged as less important, and those perceived as the investigation of a cognitive process as more important. Problems viewed as resolved were accorded more significance, and those abandoned because of paradigm shifts or intractability as less significance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fifty years of memory of college grades: Accuracy and distortions.

One to 54 years after graduating, 276 alumni correctly recalled 3,025 of 3,967 college grades. Omission errors increased with the retention interval, and better students made fewer errors. Accuracy of recall increased with confidence in recall. Eighty-one percent of commission errors inflated the actual grade. Distortions occur soon after graduation, remain constant during the retention interval, and are greater for better students and for courses students enjoyed most. Confidence in recall is unrelated to distortion. Courses that were not freely recalled, but had to be cued, were recalled less accurately and with less distortion. The data support a supplementary theory of memory distortion. The theory assumes that forgetting and distorting memory content are relatively independent processes, that relevant generic memories are used to fill in gaps after episodic memory fails, that systematic distortions affect autobiographical content that is emotionally and motivationally valenced, and that most individuals supplement with content that is emotionally more gratifying than the veridical content. The data conflict with dynamic displacement theories according to which screen memories actively block access to unpleasant veridical content. (PsycINFO Database Record (c) 2010 APA, all rights reserved)