Adult Age Differences in Conscious and Unconscious Influences on Memory for Novel Associations

Forty-eight younger and 48 older adults generated sentences under self-paced conditions for semantically unrelated word pairs. Then they completed word + word stem pairs under inclusion and exclusion instructions for items that appeared in the same or different context relative to study. Performance on the inclusion and exclusion tasks was transformed into estimates of conscious and unconscious influences on memory by a series of equations as specified by Jacoby's (1991) Process Dissociation Procedure (PDP). Three notable findings were obtained. First, younger and older adults displayed a context effect when conscious, but not unconscious, influences on memory were considered. Second, age invariance in the strength of unconscious influences on memory was observed when data analysis was performed on the entire subject sample. In contrast, the estimated strength of unconscious contributions to memory was stronger for younger than older adults when data analysis was restricted to participants who made errors on the exclusion task. Third, conscious influences on memory were stronger for younger than older adults regardless of which method of data analysis was used. Taken together, these findings shed light on previous research which has examined the complex relationship between age, test awareness, and the implicit retention of novel verbal associations. They also highlight some of the methodological issues regarding the use of the PDP to measure age-related differences in the strength of unconscious memory processes.     

Conscious and unconscious influences of memory for object location

The process-dissociation procedure was used to investigate conscious and unconscious influences of memory for object location. In two experiments, subjects worked with drawings of household objects and rooms of a house depicted on a computer monitor to simulate placing objects in various locations. Memory for object locations was tested by having subjects search for those objects. A double dissociation was obtained between estimates of conscious and unconscious influences of memory computed from equations that assumed independence between these two influences: Age-related differences were found in the estimate of conscious influences, but not in the estimate of unconscious influences, whereas manipulation of habit strength affected the unconscious estimate, but not the conscious estimate. These results were closely fit by a multinomial model assuming independence between conscious and unconscious influences of memory.     

Effects of Age and Divided Attention on Memory Components Derived for the Category Exemplar Generation Task

ABSTRACT

Age differences in memory performances on a conceptually driven task, the category exemplar generation (CEG) test, were investigated. Thirty-six younger adults and 36 healthy older adults studied word lists in full and divided attention conditions. Recall was tested with category names. The process-dissociation procedure was used to derive estimates of controlled and automatic memory. Old-old adults (70–84 years) exhibited poorer conscious recollection than both younger (18–24) and young-old adults (59–69). In contrast, no age differences were found in estimates of automatic memory. For the younger and older adults, the divided encoding manipulation reduced both the consciously controlled and automatic estimates of memory. The results suggest that the few prior findings of age deficits in priming on the CEG may have been an artifact of contamination from conscious retrieval processes. They also indicate that the opportunity for greater semantic processing enhances the conceptual priming of both younger and older adults.     

Executive function across the life span

The development and determinants of executive function (EF) were studied in children (mean age=8.8 years), young adults ( M= 22.3 years), and elderly adults (M = 7 years). EF was indexed by perseverative responding on two bidimensional sorting tasks (Visually Cued Color-Shape task and Auditorily Cued Number-Numeral task), and age-related changes in EF were considered in relation to estimates of conscious vs. unconscious memory that were obtained using the process dissociation procedure (PDP). Results revealed the rise and fall of EF across the life span, with significant quadratic trends found for performance on both sorting tasks and for the conscious recollection component (C) of the PDP task. Regression analyses indicated that PDP estimates of conscious memory accounted for variation in performance on the visual sorting task, but not on the auditory sorting task. The findings are discussed in terms of their implications for hierarchical models of EF and its development.     

Effects of age and divided attention on memory components derived for the category exemplar generation task

Age differences in memory performances on a conceptually driven task, the category exemplar generation (CEG) test, were investigated. Thirty-six younger adults and 36 healthy older adults studied word lists in full and divided attention conditions. Recall was tested with category names. The process-dissociation procedure was used to derive estimates of controlled and automatic memory. Old-old adults (70-84 years) exhibited poorer conscious recollection than both younger (18-24) and young-old adults (59-69). In contrast, no age differences were found in estimates of automatic memory. For the younger and older adults, the divided encoding manipulation reduced both the consciously controlled and automatic estimates of memory. The results suggest that the few prior findings of age deficits in priming on the CEG may have been an artifact of contamination from conscious retrieval processes. They also indicate that the opportunity for greater semantic processing enhances the conceptual priming of both younger and older adults.     

内隐记忆的证明逻辑与加工分离说（PDP）的修正模型

讨论了内隐记忆的证明逻辑和内隐与外显测验中的意识和无意识影响问题。间接证明内隐记忆的逻辑应用在功能分离实验中。它的前提假设是记忆测验都是＂纯净＂的。直接证明逻辑应用在匹配比较实验中。它认为测验中的意识和无意识影响是并存的,Ｊａｃｏｂｙ等人近期提出的加工分离说（ＰＤＰ）在匹配比较法的基础上,将测验中的意识和无意识影响进行了分离,并借用经典测验理论的公式计算这两种影响。作者认为,按照概率论关于两个随机独立事件之和与积的运算法则,必须把包含测验（ｉｎｃｌｕｓｉｏｎｔｅｓｔ）的公式修正为Ｉｎｃｌｕｓｉｏｎ＝Ｒ（１－ａ）＋Ａ（１－Ｒ）。修正过的ＰＤＰ由四个方程组成。它不仅考虑了原ＰＤＰ忽视的外显条件下的无意识缺失（１－ａ）,而且可以更加确切地估计回忆概率（Ｒ）。这在数学理论上已找到了证据。     

Conscious and unconscious processes: the effects of motivation

The process-dissociation procedure has been used in a variety of experimental contexts to assess the contributions of conscious and unconscious processes to task performance. To evaluate whether motivation affects estimates of conscious and unconscious processes, participants were given incentives to follow inclusion and exclusion instructions in a perception task and a memory task. Relative to a control condition in which no performance incentives were given, the results for the perception task indicated that incentives increased the participants' ability to exclude previously presented information, which in turn both increased the estimate of conscious processes and decreased the estimate of unconscious processes. However, the results also indicated that incentives did not influence estimates of conscious or unconscious processes in the memory task. The findings suggest that the process-dissociation procedure is relatively immune to influences of motivation when used with a memory task, but that caution should be exercised when the process-dissociation is used with a perception task.     

Unconscious influences revealed. Attention, awareness, and control.

Recent findings of dissociations between direct and indirect tests of memory and perception have renewed enthusiasm for the study of unconscious processing. The authors argue that such findings are heir to the same problems of interpretation as are earlier evidence of unconscious influences--namely, one cannot eliminate the possibility that conscious processes contaminated the measure of unconscious processes. To solve this problem, the authors define unconscious influences in terms of lack of conscious control and then describe a process dissociation procedure that yields separate quantitative estimates of the concurrent contributions of unconscious and consciously controlled processing to task performance. This technique allows one to go beyond demonstrating the existence of unconscious processes to examine factors that determine their magnitude.     

Older adults show a self-reference effect for narrative information

The self-reference effect (SRE), enhanced memory for information encoded through self-related processing, has been established in younger and older adults using single trait adjective words. We sought to examine the generality of this phenomenon by studying narrative information in these populations. Additionally, we investigated retrieval experience at recognition and whether valence of stimuli influences memory differently in young and older adults. Participants encoded trait adjectives and narratives in self-reference, semantic, or structural processing conditions, followed by tests of recall and recognition. Experiment 1 revealed an SRE for trait adjective recognition and narrative cued recall in both age groups, although the existence of an SRE for narrative recognition was unclear due to ceiling effects. Experiment 2 revealed an SRE on an adapted test of narrative recognition. Self-referential encoding was shown to enhance recollection for both trait adjectives and narrative material in Experiment 1, whereas similar estimates of recollection for self-reference and semantic conditions were found in Experiment 2. Valence effects were inconsistent but generally similar in young and older adults when they were found. Results demonstrate that the self-reference technique extends to narrative information in young and older adults and may provide a valuable intervention tool for those experiencing age-related memory decline.     

FOK与情节记忆、语义记忆和内隐记忆关系的研究

实验采用R/K判断和PDP测量技术,研究了FOK判断与情节记忆、语义记忆和内隐记忆关系及其监测强度.实验结果表明FOK判断的准确性程度为R判断＞K判断,即对情节记忆监测的准确性要大于对语义记忆监测的准确性.FOK对于自动加工的预测准确性差异不显著,说明FOK监测对内隐记忆的作用是微弱的,由此推测无记忆是意识最高层面的活动.对记忆监测水平强度是由意识--无意识逐渐减弱的.FOK判断对意识性水平较高的记忆活动监测的准确性较强.     

Item-specific processing reduces false recognition in older and younger adults: Separating encoding and retrieval using signal detection and the diffusion model

Our study examined processing effects in improving memory accuracy in older and younger adults. Specifically, we evaluated the effectiveness of item-specific and relational processing instructions relative to a read-only control task on correct and false recognition in younger and older adults using a categorized-list paradigm. In both age groups, item-specific and relational processing improved correct recognition versus a read-only control task, and item-specific encoding decreased false recognition relative to both the relational and read-only groups. This pattern was found in older adults despite overall elevated rates of false recognition. We then applied signal-detection and diffusion-modeling analyses, which separately utilized recognition responses and the latencies to those responses to estimate contributions of encoding and monitoring processes on recognition decisions. Converging evidence from both analyses demonstrated that item-specific processing benefits to memory accuracy were due to improvements of both encoding (estimates of d′ and drift rate) and monitoring (estimates of lambda and boundary separation) processes, and, importantly, occurred similarly in both younger and older adults. Thus, older and younger adults showed similar encoding-based and test-based benefits of item-specific processing to enhance memory accuracy.     

Aging, memory and visual search

Potential age-related differences in the memory processes that underlie visual search are examined in the present study. Using a dynamic, gaze-contingent search paradigm developed to assess memory for previously examined distractors, older adults demonstrated no memory deficit. Surprisingly, older adults made fewer refixations compared to their younger counterparts, indicating better memory for previously inspected objects. This improved memory was not the result of a speed-accuracy trade-off or larger Inhibition-of-Return effects for older than for younger adults. Additional analyses suggested that older adults may derive their benefit from finer spatial encoding of search items. These findings suggest that some of the memory processes that support visual search are relatively age invariant.     

Conscious and unconscious influences of memory: temporal dynamics

Changes in the conscious and unconscious influences of memory over time were assessed in two experiments by using a variant of the process-dissociation procedure. In both experiments, performance on a stem-completion task was measured under both inclusion and exclusion instructions. Across the two experiments, there were four different retention intervals: 2 minutes, 2 days, 2 weeks, and 2 months. The results indicated that conscious influences decreased systematically across retention interval. In contrast, unconscious influences of memory in the absence of conscious influences increased between 2 minutes and 2 days, and then remained relatively stable from 2 days to 2 weeks to 2 months. These results stand in apparent contrast to those of McBride and Dosher (1999), which showed equal rates of forgetting for conscious and unconscious influences of memory on performance. The implications for models of the relation between conscious and unconscious influences of memory on performance are discussed.     

The impact of different directed forgetting instructions on implicit and explicit memory: New evidence from a modified process dissociation procedure

In contrast to previous research on directed forgetting, the present studies adopted a recent modification of the process dissociation procedure (Jacoby, 1991; Richardson-Klavehn & Gardiner, 1995) to accommodate the cross-contamination of memory test performance by implicit and explicit memorial factors. In Experiment 1, 120 subjects were compared in global directed forgetting, item-by-item directed forgetting, and control conditions on estimates of voluntary conscious memory, involuntary conscious memory, and involuntary unconscious memory performance. In Experiment 2, 80 subjects were compared in specific directed forgetting and control conditions on estimates of voluntary conscious memory, involuntary conscious memory, and involuntary unconscious memory performance. Subjects showed significant decrements in voluntary and involuntary conscious memory performance following instructions for directed forgetting in all conditions. None of the directed forgetting conditions showed a decrement in involuntary unconscious memory performance. Results suggest that, regardless of instruction type, directed forgetting prevents the conscious expression of memorial information (both voluntary and involuntary) while leaving unconscious memory intact.     

The role of interference in memory span

In two experiments, we investigated the possibility that susceptibility to proactive interference (PI) affects performance on memory span measures. We tested both younger and older adults (older adults were tested because of the suggestion that they are differentially susceptible to PI). We used two different span measures and manipulated testing procedures to reduce PI for these tasks. For older adults, span estimates increased with each PI-reducing manipulation; for younger adults, scores increased when multiple PI manipulations were combined or when PI-reducing manipulations were used in paradigms in which within-task PI was especially high. The findings suggest that PI critically influences span performance. We consider the possibility that interference-proneness may influence cognitive behaviors previously thought to be governed by capacity.     

The influence of semantic relationships on older adult map memory

Research has shown that nonspatial features, including semantic categories, can bias younger adults' spatial location memory. For example, semantically related information is remembered as being closer in space than semantically unrelated information (Hirtle & Mascolo, 1986). These findings suggest that verbal information is concurrently encoded with spatial information and influences younger adults' spatial information retrieval. The present study explored whether older adults have a similar dependency between verbal and spatial information. In Experiment 1, older and younger adults learned maps depicting semantically categorizable landmarks. After learning, participants completed landmark free recall and distance estimation tasks. Younger adults recalled more landmarks from semantically organized maps compared with older adults. In addition, younger adults were more likely to underestimate the distance between semantically related landmarks than were older adults. Experiment 2 examined whether supportive instructions would influence older adults' use of verbal information when learning maps. When given instructions that encouraged semantic feature use, older adults remembered more landmarks, were more likely to cluster landmarks semantically, and demonstrated biases in distance estimation based on semantic relationships. These findings suggest that verbal influences on spatial/map learning in older adults depends on explicit instructions or environmental support at encoding. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Use of relational and item-specific information in remembering by older and younger adults

The applicability to older adults of predictions from the integrated memory model, that optimal memory results from concurrent availability of relational and item-specific information, was assessed. In Experiment 1, older adults (M = 69 years) encoded related or unrelated words using rating, sorting, or both tasks. Using both tasks produced better recall than either separate task. Rating facilitated recall for related items, but sorting did not facilitate unrelated items. In Experiment 2, younger (M = 20) and older (M = 74) adults sorted or rated lists comprising categories of varying sizes. Young adults' free recall conformed to predictions, but older adults again showed facilitation mainly from rating larger categories. The stronger effects for younger adults imply that specific combinations of encoding and retrieval manipulations and materials must be considered in predicting older adults' performance.     

Naturalistic assessment of executive function and everyday multitasking in healthy older adults

ABSTRACT

Everyday multitasking and its cognitive correlates were investigated in an older adult population using a naturalistic task, the Day Out Task. Fifty older adults and 50 younger adults prioritized, organized, initiated, and completed a number of subtasks in a campus apartment to prepare for a day out (e.g., gather ingredients for a recipe, collect change for a bus ride). Participants also completed tests assessing cognitive constructs important in multitasking. Compared to younger adults, the older adults took longer to complete the everyday tasks and more poorly sequenced the subtasks. Although they initiated, completed, and interweaved a similar number of subtasks, the older adults demonstrated poorer task quality and accuracy, completing more subtasks inefficiently. For the older adults, reduced prospective memory abilities were predictive of poorer task sequencing, while executive processes and prospective memory were predictive of inefficiently completed subtasks. The findings suggest that executive dysfunction and prospective memory difficulties may contribute to the age-related decline of everyday multitasking abilities in healthy older adults.     

Fear of falling and falls in older adults with mild cognitive impairment and Alzheimer’s disease

ABSTRACT

The purpose of this study was to explore the influence of social importance on prospective remembering in younger and older adults as a possible factor contributing to the age-prospective memory paradox. Using a between-subjects design, 40 younger and 40 older adults worked on a time-based prospective memory task in which social importance was varied. Overall, younger adults outperformed older adults in the prospective memory task. Importantly, in contrast to younger adults, older adults' prospective memory performance was significantly better in the social importance condition than in the standard condition. This interaction was not reflected in participants' time-monitoring behaviour. Findings are discussed in the context of recent prospective memory theories.     

Age-Related Deficits in Face Recognition are Related to Underlying Changes in Scanning Behavior

ABSTRACT

Previous studies demonstrating age-related impairments in recognition memory for faces are suggestive of underlying differences in face processing. To study these differences, we monitored eye movements while younger and older adults viewed younger and older faces. Compared to the younger group, older adults showed increased sampling of facial features, and more transitions. However, their scanning behavior was most similar to the younger group when looking at older faces. Moreover, while older adults exhibited worse recognition memory than younger adults overall, their memory was more accurate for older faces. These findings suggest that age-related differences in recognition memory for faces may be related to changes in scanning behavior, and that older adults may use social group status as a compensatory processing strategy.