Strategy selection and aging: impact of item concreteness in paired-associate task

The aim of this study was to examine the effect of aging on strategy selection in a paired-associate word task. Twenty-eight younger adults (mean age = 20.68 years) and 28 older adults (mean age = 68.46 years) studied 39 pairs of concrete, middle and abstract words. The concreteness level was manipulated in order to modify the benefit of imagery and sentence strategies in relation to task characteristics. The results showed an age difference in strategy selection in relation to concreteness level. Older adults showed less adaptive strategy selection for the imagery strategy but not for the sentence strategy. Change in strategy selection did not seem to be explained by better efficiency of sentence than imagery, so this study suggests a partial reduction of strategy adaptivity during aging.     

Strategy selection and aging: Impact of item concreteness in paired-associate task

ABSTRACT

The aim of this study was to examine the effect of aging on strategy selection in a paired-associate word task. Twenty-eight younger adults (mean age = 20.68 years) and 28 older adults (mean age = 68.46 years) studied 39 pairs of concrete, middle and abstract words. The concreteness level was manipulated in order to modify the benefit of imagery and sentence strategies in relation to task characteristics. The results showed an age difference in strategy selection in relation to concreteness level. Older adults showed less adaptive strategy selection for the imagery strategy but not for the sentence strategy. Change in strategy selection did not seem to be explained by better efficiency of sentence than imagery, so this study suggests a partial reduction of strategy adaptivity during aging.     

The concreteness effect: evidence for dual coding and context availability

The term concreteness effect refers to the observation that concrete nouns are processed faster and more accurately than abstract nouns in a variety of cognitive tasks. Two models have been proposed to explain the neuronal basis of the concreteness effect. The dual-coding theory attributes the advantage to the access of a right hemisphere image based system in addition to a verbal system by concrete words. The context availability theory argues that concrete words activate a broader contextual verbal support, which results in faster processing, but do not access a distinct image based system. We used event-related fMRI to detect the brain regions that subserve to the concreteness effect. We found greater activation in the lower right and left parietal lobes, in the left inferior frontal lobe and in the precuneus during encoding of concrete compared to abstract nouns. This makes a single exclusive theory unlikely and rather suggests a combination of both models. Superior encoding of concrete words in the present study may result from (1) greater verbal context resources reflected by the activation of left parietal and frontal associative areas, and (2) the additional activation of a non-verbal, perhaps spatial imagery-based system, in the right parietal lobe.     

Adult age differences in temporal and item memory

Three experiments tested whether the relationship between age differences in temporal and item memory depends on the degree to which the item memory measure relies on memory for context. The authors predicted a stronger relationship of temporal memory to free recall than to recognition memory. Results showed that age differences in temporal memory could be eliminated after controlling for free recall but not recognition memory performance. Under some conditions recognition memory accounted for a significant portion of age-related variance in temporal memory. These results challenge past research that has interpreted age differences in temporal and item memory as independent and suggest that a generalized decline in context memory may underlie reduced performance in older adults on all types of memory tests.     

Effects of drawing on children's item recall

In four experiments, we used item recall tasks to investigate recent claims that young children's event recall can be facilitated by drawing. In Experiments 1 to 3, children of ages 5 to 8 years were tested 4 h after presentation for recall of a set of 25 items that had been presented in groups on a colored, segmented board. In Experiment 1, recall was enhanced by replacement of the objects on the board as they were recalled, but not by drawing them. In Experiments 2 and 3, drawing the board and objects concurrently with or just prior to verbal recall not only failed to facilitate recall, but significantly reduced the number of items reported by 5- to 6-year-olds. In Experiment 4, drawing again impaired recall of items that had been presented as paired associates. Overall, results indicate that under some conditions drawing can impair children's recall rather than facilitate it, as reported in several recent studies.     

Effects of concreteness and semantic relatedness on composite imagery ratings and cued recall

Day and Bellezza (1983) rejected a dual coding imagery explanation for the superior recall of concrete words because unrelated concrete pairs were rated lower in composite imagery but were still remembered better than related abstract pairs. We show that dual coding theory explains their results and our new findings using the same paradigm. In Experiment 1, 120 subjects rated imagery or relatedness for 108 pairs that varied in concreteness, pair relatedness, and associative strength. Incidental cued recall followed. Relatedness and strength affected imagery ratings, as did concreteness, and very low relatedness partly accounted for the low composite imagery ratings for unrelated concrete pairs. Concreteness and relatedness also affected recall, and suporior recall for unrelated concrete pairs occurred consistently under imagery but not under relatedness instructions. In Experiment 2, 40 subjects rated imagery value and recalled 24 pairs. Subsequent questioning indicated that composite images were retrieved better given stimuli from unrelated concrete than from related abstract pairs. These findings and Day and Bellezza’s original results are explained in terms of (1) imaginal and verbal associative processes, which jointly influence composite imagery ratings and recall, and (2) the critical role of stimulus concreteness during image retrieval and recall (i.e., the conceptual peg hypothesis).     

Accuracy of temporal coding: Auditory-visual comparisons

Three experiments were designed to decide whether temporal information is coded more accurately for intervals defined by auditory events or for those defined by visual events. In the first experiment, the irregular-list technique was used, in which a short list of items was presented, the items all separated by different interstimulus intervals. Following presentation, the subject was given three items from the list, in their correct serial order, and was asked to judge the relative interstimulus intervals. Performance was indistinguishable whether the items were presented auditorily or visually. In the second experiment, two unfilled intervals were defined by three nonverbal signals in either the auditory or the visual modality. After delays of 0, 9, or 18 sec (the latter two filled with distractor activity), the subjects were directed to make a verbal estimate of the length of one of the two intervals, which ranged from 1 to 4 sec and from 10 to 13 sec. Again, performance was not dependent on the modality of the time markers. The results of Experiment 3, which was procedurally similar to Experiment 2 but with filled rather than empty intervals, showed significant modality differences in one measure only. Within the range of intervals employed in the present study, our results provide, at best, only modest support for theories that predict more accurate temporal coding in memory for auditory, rather than visual, stimulus presentation.     

Effects of divided attention and word concreteness on correct recall and false memory reports

Lists of thematically related words were presented to participants with or without a concurrent task. In Experiments 1 and 2, respectively, English or Spanish word lists were either low or high in concreteness (concrete vs abstract words) and were presented, respectively, auditorily or visually for study. The addition of a concurrent visual or auditory task, respectively, substantially reduced correct recall and doubled the frequency of false memory reports (nonstudied critical or theme words). Divided attention was interpreted as having reduced the opportunity for participants to monitor successfully their elicitations of critical associates. Comparisons of concrete and abstract lists revealed significantly more recalls of false memories for abstract than concrete word lists. Comparisons between two levels of attention, two levels of word concreteness, and two presentation modalities failed to support the "more is less" effect by which enhanced correct recall is accompanied by increased frequencies of false memories.     

Effects of aging and IQ on item and associative memory

The effects of aging and IQ on performance were examined in 4 memory tasks: item recognition, associative recognition, cued recall, and free recall. For item and associative recognition, accuracy and the response time (RT) distributions for correct and error responses were explained by Ratcliff's (1978) diffusion model at the level of individual participants. The values of the components of processing identified by the model for the recognition tasks, as well as accuracy for cued and free recall, were compared across levels of IQ (ranging from 85 to 140) and age (college age, 60-74 years old, and 75-90 years old). IQ had large effects on drift rate in recognition and recall performance, except for the oldest participants with some measures near floor. Drift rates in the recognition tasks, accuracy in recall, and IQ all correlated strongly. However, there was a small decline in drift rates for item recognition and a large decline for associative recognition and cued recall accuracy (70%). In contrast, there were large effects of age on boundary separation and nondecision time (which correlated across tasks) but small effects of IQ. The implications of these results for single- and dual-process models of item recognition are discussed, and it is concluded that models that deal with both RTs and accuracy are subject to many more constraints than are models that deal with only one of these measures. Overall, the results of the study show a complicated but interpretable pattern of interactions that present important targets for modeling.     

Effects of emotion-induced self-focused attention on item and source memory

Motivation and Emotion - Affective states are closely linked to attention to internal aspects of the self (i.e., self-focused attention). We investigated how self-focused attention induced by...     

Word concreteness and encoding effects on context-dependent discrimination

In three experiments, we investigated the effects of word concreteness and encoding instructions on context-dependent discrimination in verbal contexts, using Murnane, Phelps, and Malmberg's (1999) ICE (item, context, ensemble) theory as the framework Word concreteness was manipulated within participants, and encoding was manipulated between participants. It was hypothesized that the magnitude of context-dependent discrimination would be affected by both concreteness and encoding instructions. Imagery instructions resulted in context-dependent discrimination for both concrete and abstract word pairs across all the experiments. Context-dependent discrimination was observed under rote instructions for concrete and abstract words, particularly when the same context word was paired multiple times with the targets. The results indicated that context-dependent discrimination is not dependent solely on the use of interactive imagery instructions or on word concreteness.     

Assessing the concreteness of relational representation

Research has shown that people's ability to transfer abstract relational knowledge across situations can be heavily influenced by the concrete objects that fill relational roles. This article provides evidence that the concreteness of the relations themselves also affects performance. In 3 experiments, participants viewed simple relational patterns of visual objects and then identified these same patterns under a variety of physical transformations. Results show that people have difficulty generalizing to novel concrete forms of abstract relations, even when objects are unchanged. This suggests that stimuli are initially represented as concrete relations by default. In the 2nd and 3rd experiments, the number of distinct concrete relations in the training set was increased to promote more abstract representation. Transfer improved for novel concrete relations but not for other transformations such as object substitution. Results indicate that instead of automatically learning abstract relations, people's relational representations preserve all properties that appear consistently in the learning environment, including concrete objects and concrete relations.     

Working memory for item and temporal information in younger and older adults

Two experiments examined age differences in mechanisms hypothesized to affect activation of item and temporal information in working memory. Activation levels were inferred from the ability to reject n-back lures matching items in different temporal positions. Information with the least decay had a performance advantage over less recent information, but was susceptible to the same temporal context errors found in all adjacent-to-target lure positions. Lures most distant from the current item showed a performance rebound. The pattern of increased magnitudes of age effects at adjacent-to-target positions indicated a reduction in older adults' working memory for temporal context information above and beyond item memory declines. Results overall support the emphasis on context information as a critical factor in working memory and cognitive aging.     

Repetition blindness under minimum memory load: Effects of spatial and temporal proximity and the encoding effectiveness of the first item

Repetition blindness (RB) refers to the reduced performance in reporting a repeated as opposed to a nonrepeated item in rapid serial visual presentation. In Experiment 1, we found RB for two-item stimuli in uncertain locations. The magnitude of RB decreased significantly with increases in interstimulus interval, but not with increases in spatial separation, indicating that RB is determined primarily by temporal factors. In Experiment 2, we found RB when subjects were required to report only the second of two successively presented items. The magnitude of RB increased with the duration of the first item, indicating that RB is determined by the encoding effectiveness of the first item. The results of this study collectively indicate that RB is not a memory or a sensory phenomenon, but rather a perceptual phenomenon occurring at the stage of identity encoding. The findings also undermine the arguments (Kanwisher, 1987) that have been offered in favor of the type-token binding failure hypothesis and indicate instead that type-node refractoriness may be the cause of RB.     

Effects of multiple versus chained schedules on stereotypy and item engagement

We evaluated rates of automatically reinforced stereotypy and item engagement for 2 children with autism under multiple and chained schedules in a multielement design. Each schedule included components during which stereotypy was blocked (S–) or allowed (S+), and we used colored cards as schedule‐correlated stimuli. We report rates of stereotypy and item engagement during S– and S+ components, as well as the percentage of component time that elapsed before the first instances of stereotypy and item engagement. We observed less stereotypy and more consistent item engagement during chained‐schedule sessions, and stimulus control of stereotypy and item engagement was established with the chained schedule. A subsequent concurrent‐chains analysis revealed participant preference for the chained schedule. These results highlight the importance of contingent access to stereotypy when therapists attempt to gain stimulus control of stereotypy and increase functional item engagement.     

Effects of same-category and different-category extraneous memory sets on item recognition

In a study designed to distinguish between parallel and serial models of performance on Sternberg’s item recognition task, Krueger (1975) presented subjects with a memory set (the “added” set) followed by a second (“core”) set, a probe to the core set, and finally a probe to the added set. Response latency (RT) to both the core- and added-set probes initially increased with the size of the extraneous set. Over successive blocks of trials, the effect of the size of the extraneous set diminished. In Experiment 1 of the present study, Krueger’s basic procedures were replicated with results similar to those he reported for early trials. Experiment 2 was a variation on the added-set procedure. Rather than the memory sets’ being drawn from different categories (letters and digits), both sets consisted of digits. On half of the negative trials for both the core and the added tasks, the probe was drawn from the extraneous set, forcing the subjects to separate the two sets. Although RT on the core task did not increase with the size of the added set, there was an increase in RT to the added set with increases in core-set size, a finding inconsistent with the serial search model     

Sparse but not 'grandmother-cell' coding in the medial temporal lobe

Although a large number of neuropsychological and imaging studies have demonstrated that the medial temporal lobe (MTL) plays an important role in human memory, there are few data regarding the activity of neurons involved in this process. The MTL receives massive inputs from visual cortical areas, and evidence over the last decade has consistently shown that MTL neurons respond selectively to complex visual stimuli. Here, we focus on how the activity patterns of these cells might reflect the transformation of visual percepts into long-term memories. Given the very sparse and abstract representation of visual information by these neurons, they could in principle be considered as 'grandmother cells'. However, we give several arguments that make such an extreme interpretation unlikely.