Inter- and intra-individual variation in immediate free recall: an examination of serial position functions and recall initiation strategies

Serial position functions in immediate free recall have been historically noted for their bowed shape, where items presented at the beginning (primacy) and end (recency) of a list are better remembered than those presented in the middle. While extensive work has examined these effects, researchers typically ignore the systematic differences among individuals that likely contribute, but are lost when using an aggregate function. In the current study, inter- and intra-individual differences in serial position functions and differences in recall strategies were examined. Participants performed a free recall task on multiple lists. Three groups of participants were derived based on the relative profiles in their serial position functions. These groups differed in the extent that they output mainly primacy items, recency items, or both primacy and recency items. Performance on immediate free recall and on cognitive ability tasks was compared between these three groups. Systematic inter- and intra-individual variation in recall strategies led to differential profiles of performance in immediate free recall, which was also related to the additional cognitive ability measures. Performance on a task can be due to the utilisation of a variety of control processes that emphasise various components of that task over other components.     

“You Have to Sit and Explain it All,and Explain Yourself.” Mothers’ Experiences of Support Services for Their Offspring with a Rare Genetic Intellectual Disability Syndrome

The experiences of mothers of adult offspring with Angelman, Cornelia de Lange, or Cri du Chat syndrome have not been previously explored in research. The current study focuses on experiences with social and medical services and the impact the rareness of an adult offspring’s syndrome has on the experiences of mothers. Eight mothers of adults with Angelman, Cornelia de Lange, or Cri du Chat syndrome were interviewed. Thematic Content Analysis was used to interpret the interviews. Four themes emerged from the analysis: (i) The rarity of their offspring’s syndrome, (ii) Uneven medical and social care service provision, (iii) The inertia of social care services, and (iv) Mothers as advocates. Mothers felt that the rareness of their offspring’s syndrome did not affect experiences with social care services, but did affect access to medical services and some aspects of day-to-day living. Accessing appropriate social care services was reported to be a lengthy and complex process. These data may help inform care service providers about how best to support adults with rare genetic syndromes and their families.     

Reconstructing alcohol-induced memory blackouts

Many people who drink alcohol have experienced a blackout; whereby they are unable to recall events that occurred during a period of intoxication. Following these blackout episodes individuals may attempt to reconstruct what happened to them. Blackouts therefore afford an excellent opportunity to study the strategies people use to reconstruct forgotten experiences. We conducted a survey of university students to explore how people choose to reconstruct blackouts, and the likely accuracy of these reconstructions. Our findings add to the growing research literature on people's strategies for validating their past experiences, and highlight the important role of external sources in the reconstruction process. The data show that people's desire to "fill in the blanks" can lead them to rely on rather unreliable sources, and may also encourage them to adopt weaker source-monitoring criteria. Indeed, in at least some cases reconstructing blackouts appears to lead to the development of false beliefs or memories.     

Ontogeny and adult behavior of mice with congenital neural tube defects

Effects of abnormal neural tube development were studied in immature and adult mice. The behavior of affected adult mice was found to resemble that of mice that exhibit the "waltzer syndrome." Behavioral ontogenetic studies indicate that effected mice are deficient in labyrinthine responses as shown by the late development or lack of negative geotaxic behaviors and the delayed loss of pivoting behavior. Retarded maturation of neural responses was indicated by a delay in the appearance of the startle response. Evidence that circling behavior in adult mice of the "waltzer syndrome" may be a result of central nervous system disorders alone, or in concert with abnormalities of the inner ear, was provided by the fact that open field activity was increased in affected mice that exhibit circling behavior as adults.     

Individual differences in working memory capacity and episodic retrieval: examining the dynamics of delayed and continuous distractor free recall

Two experiments explored the possibility that individual differences in working memory capacity (WMC) partially reflect differences in the size of the search set from which items are retrieved. High- and low-WMC individuals were tested in delayed (Experiment 1) and continuous distractor (Experiment 2) free recall with varying list lengths. Across both experiments low-WMC individuals recalled fewer items than high-WMC individuals, recalled more previous list intrusions than high-WMC individuals, and recalled at a slower rate than high-WMC individuals. It is argued that low-WMC individuals' episodic retrieval deficits are partially due to the fact that these individuals search through a larger set of items than high-WMC individuals. Simulations based on a random search model were consistent with these general conclusions.     

Investigating the role of emotion during the search process in free recall

Typically, research has shown that emotional words are remembered better than neutral words; however, most studies have reported only the mean proportion of correctly recalled words. The present study looked at various dependent measures used by search models to determine whether emotion can influence the search process as well. The results from Experiment 2 showed that when emotionality was made salient, participants were able to utilize emotional associations, in addition to temporal associations, to cue retrieval of additional emotional words during subsequent sampling but relied mainly on temporal context when the emotional information was not made salient (Experiment 1). Additionally, both experiments showed that emotional words were more likely to be output earlier in the recall sequence, which would suggest that emotion also serves to boost relative strength during initial sampling. Overall, the results suggest that emotion contributes to enhanced memory dynamically by influencing the probability of sampling an item during the search process—specifically, by boosting relative strength and strengthening interitem associations.     

The growth of reading skills in children with Down Syndrome

There appears to be a close and probably causal relationship between early variations in phoneme skills and later reading skills in typically developing children, though the pattern in children with Down Syndrome is less clear. We present the results of a 2-year longitudinal study of 49 children with Down Syndrome (DS) and 61 typically developing (TD) control children with similar initial levels of reading skill. Phoneme awareness and vocabulary were strong concurrent predictors of initial levels of reading skill in both groups. However, longitudinally phoneme awareness was a predictor of the growth of reading skills in TD children but not in children with DS. There was a very high degree of longitudinal stability in reading skills in children with DS, and initial levels of reading skills seemed to be highly constrained by general language skills, as indexed by vocabulary knowledge, in this population. We conclude that reading development in children with DS shows similarities and differences to the pattern observed in TD children and that phoneme awareness appears to be a less powerful influence on the development of reading skills in children with DS.