Age-related differences in encoding-retrieval similarity and their relationship to false memory

Typical aging is associated with increases in false memory rates among older adults. Such errors are frequently associated with differential neural activity during encoding and retrieval in older compared to younger adults within visual cortices, hippocampus, and front-parietal regions. It remains unknown how pattern similarity reductions relate to false memories in healthy aging. Using encoding-retrieval similarity (ERS) analyses in a sample of younger and older adults, we examined how the similarity of neural patterns between memory phases associated with target and lure objects was impacted by age and contributed to false memory rates. Single-item ERS for targets and lures was reduced by age throughout much of the ventral visual stream and the posterior hippocampus. Furthermore, ERS associated with perceptual lures within the visual stream maintained differential relationships with false memory. Finally, a global ERS metric accounted for age deficits in single-item ERS, but did not contribute to false memory rates. These findings highlight the contribution of age-related reductions in ERS across multiple representational levels to false memories in healthy aging.

Age effects on category learning and their relationship to deficits in memory specificity

Age deficits in memory for individual episodes are well established. Less is known about how age affects another key memory function: the ability to form new conceptual knowledge. Here we studied age differences in concept formation in a category-learning paradigm with face-blend stimuli, using several metrics: direct learning of category members presented during training, generalization of category labels to new examples, and shifts in perceived similarity between category members that often follow category learning. Age deficits in categorization were compared to metrics of memory specificity (recognition, cued-recall) for the same set of stimuli. We found that older adults were impaired in direct learning of training examples, but there was no generalization deficit above-and-beyond the deficit in direct learning. We also found that category learning affected the perceived similarity between members of the same versus opposing categories, and age did not significantly moderate this effect. When comparing categorization to memory specificity, we found that categorization deficits were smaller than deficits in recall and comparable to deficits in recognition, showing that categorization deficits are smaller than some of the largest known age-related memory deficits. Lastly, we compared traditional category learning to categorization after a learning task in which a category label (shared last name) was presented alongside stimulus-specific information (unique first names that individuated category members). We found that simultaneously learning stimulus-specific and category information resulted in decreased category learning in both age groups, and that this decrement was not disproportionate in older adults.

Influences of complexity on decision making in young and older adults

Leading theory hypothesizes that age deficits in decision making may rise as the complexity of decision-related information increases. This suggests that older adults would benefit relative to young adults from simplification of information used to inform decision making. Participants indicated political, nutritional and medical preferences and then chose between politicians, foods and medicines. The amount of information presented was systematically varied but age differences were largely similar for simple and complex trials. Paradoxically, the data showed that decisions based on simpler information could be less aligned with participant’s preferences than decisions based on more complex information. Further analyses suggested that participants may have been responding purely on the basis of their most valued preferences and that when information about those preferences was not presented, decision making became poorer. Contrary to our expectations, simplification of information by exclusion may therefore hinder decision making and may not particularly help older adults.

O10.3. EARLY CHILDHOOD DEVELOPMENT AND LATER PSYCHOTIC EXPERIENCES: FINDINGS FROM THE RAINE STUDY

Background Early childhood development is considered to be the most critical developmental phase throughout the lifespan. Cognitive and motor dysfunction are hallmark features found along the psychosis spectrum and have also been shown in young people who report subclinical psychotic experiences (PE). Whether such deficits can be detected in infancy is not yet known. The aim of the present research was to examine early childhood developmental skills and their association with PE in childhood and adolescence. Methods Data was taken from the Western Australia Pregnancy Cohort (Raine) Study, a pregnancy cohort study in which 2,868 infants were enrolled. Early childhood development was measured at age 1, 2 and 3 using the Infant Monitoring Questionnaire (IMQ; now the Ages and Stages questionnaire. Outcome of interest: PE was measured at age 10 via parent-report, and at age 14 and 17 via self-report by the participants using the 2 items (‘hearing things’ and ‘seeing things’) from the Child Behaviour Checklist (CBCL)/Youth Self-Report (YSR) thought problems subscale. The PE group included any participant who endorsed either or both of the items at any of the 3 time-points. The PE group was further subdivided into those who endorsed transient PE (one time-point) or recurring PE (2 or more time-points). Random effects logistic regression models were performed to investigate the relationship between early childhood development and later risk. Developmental time specific investigations (at age 1, 2 and 3 years of age separately) were also conducted using logistic regressions. Cumulative risk based on category specific deficits at age 3 was also calculated. This analysis was also applied to compare the PE group vs. controls, the transient PE group vs. controls and the recurring PE group vs. controls. Results In the first 3 years of life, lower scores in communication (adjusted OR = 1.32, 95% CI = 1.01–1.72, p = 0.05) and adaptive (problem-solving) (adjusted OR = 1.26, 95% CI = 1.01–1.59, p = 0.048) skills were found to be predictive of PE in childhood and/or adolescence. For the age specific analysis, adaptive skill deficits specifically at 1 year of age predicted PE (adjusted OR = 1.18, 95% CI = 1.03–1.35, p = 0.017), while at 2 years of age, deficits in communication (adjusted OR = 1.35, 95% CI = 1.18–1.54, p<0.001) and adaptive skills (adjusted OR = 1.25, 95% CI = 1.08–1.45, p<0.005) predicted PE. Importantly, at 3 years of age, deficits in any of the 5 categories (communication, gross motor, fine motor, adaptive and personal social) were predictive of PE. Deficits (lowest 10th percentile) in 1–2 categories at 3 years of age led to an almost a 2-fold increase risk of having a PE (adjusted OR = 1.94, 95% CI = 1.38–2.71, p < 0.001), while deficits in 3–5 categories led to a 3-fold increased risk of having a PE (adjusted OR = 3.02, 95% CI = 1.65–5.50, p = <0.001). When subdividing PE into those with transient and recurring PE, different patterns emerged, in which motor deficits in the first 3 years of life were more associated with the recurring PE group. Discussion The present research suggests that lower scores in early childhood developmental skills in the first 3 years of life are strongly associated with childhood and adolescent PE. Results showed that deviances in communication and problem-solving abilities during the first 3 years of life are particularly associated. At age 3 specifically, deficits in all domains of development are predictive of PE, and the greater the number of category deficits, the greater the risk. Differing patterns of development emerge for the transient PE and recurring PE groups. The findings enlighten the understanding of the neurodevelopmental origins of early onset PE for a proportion of individuals.

Age-Related Decline in Learning Deterministic Judgment-Based Sequences

Objectives Because sequence learning is integral to cognitive functions across the life span, the present study examined the effect of healthy aging on deterministic judgment-based sequence learning. Methods College-aged, younger–old (YO), and older–old (OO) adults completed a judgment-based sequence learning task which required them to learn a full sequence by chaining together single stimulus–response associations in a step-by-step fashion. Results Results showed that younger adults outperformed YO and OO adults; older adults were less able to acquire the full sequence and committed significantly more errors during learning. Additionally, higher sequence learning errors were associated with advancing age among older adults, even when controlling for other factors known to contribute to sequence learning abilities. Such impairments were selective to learning sequential information, because adults of all ages performed equivalently on postlearning probe trials, as well as on learning simple stimulus–response associations. Discussion This pattern of age deficits during deterministic sequence learning challenges past reports of age preservation. Though the neural processes underlying learning cannot be determined here, our patterns of age deficits and preservation may reflect different brain regions that are involved in the task phases, adding behavioral evidence to the emerging hypothesis of frontostriatal declines despite spared hippocampal function with age.

On Attentional Control and the Aging Driver

Theories of cognitive aging suggest diminished frontal lobe function and reduced attentional control could contribute to age-related changes in driving a motor vehicle. To address this possibility, the authors investigated the interrelationship among age, attentional control, and driving performance. Using a high-fidelity simulator, they measured individual differences in participants’ abilities to maintain a prescribed following distance behind a lead vehicle, as well as their reaction time to press a brake pedal when this lead vehicle braked. Consistent with the literature on age-related changes in driving, following distance elongated with increased age, and brake reaction time slowed. Furthermore, regression analyses revealed the increase in following distance and the slowing in brake reaction time both co-varied with age deficits in attentional control. These results provide a novel demonstration of the inherent value of cognitive theory when applied to naturalistic settings, sharpening our understanding of the relevance of age-related deficits in attentional control for complex, real-world tasks like driving.