We asked whether the ability to keep in working memory the binding between a visual object and its spatial location changes with development across the life span more than memory for item information. Paired arrays of colored squares were identical or differed in the color of one square and, in the latter case, the changed color was unique on that trial (item change) or was duplicated elsewhere in the array (color-location binding change). Children (8-10 and 11-12 years old) and older adults (65-85 years old) showed deficits relative to young adults. These were only partly simulated by dividing attention in young adults. The older adults had an additional deficiency, specifically in binding information, which was evident only when item-and binding-change trials were mixed together. In that situation, the older adults often overlooked the more subtle, bindingtype changes. Some working-memory processes related to binding undergo life-span development in an inverted U shape, whereas other, bias-and salience-related processes that influence the use of binding information seem to develop monotonically.Older adults have a memory deficiency compared to young adults, specifically in the retention of binding information. When items are presented in pairs, the items can be remembered normally but there is difficulty in remembering which ones were paired with which others. This appreciable decline occurs for the binding of focal items to contextual elements (Bayen, Phelps, & Spaniol, 2000;Chalfonte & Johnson, 1996 Chalfonte & Johnson (1996), suggested an associative deficit hypothesis, which focuses on the distinction between memory for single units and memory for associations among units. The present study examines the generality of the associative deficit hypothesis for children as well as the older adults, and for a task examining working memory rather than long-term memory. In this task, two arrays of colored squares must be compared, with the arrays sometimes identical and sometimes differing in the color of a single square. This task has been extensively researched in young adults (Luck & Vogel, 1997; Morey & Cowan, 2004, in press;Todd & Marois, 2004;Vogel & Machizawa, 2004;Vogel, Woodman, & Luck, 2001) and has been examined in infants (Ross-Sheehy, Oakes, & Luck, 2003) and children (Cowan et al., in press).In our version of the task, haphazardly-placed squares of different colors form a sample array that is soon replaced by a blank interval and then a test array identical to the sample array or differing in the color of a single square. A circle surrounding one square in the test array indicates which square changed color, if any square did, and the required response is a judgment as to whether a color change occurred. Inasmuch as colors are selected for the sample array

Previous studies have established an associative deficit hypothesis (Naveh-Benjamin, 2000), which attributes part of older adults' deficient episodic memory performance to their difficulty in creating cohesive episodes. In this article, the authors further evaluate this hypothesis, using ecologically relevant materials. Young and old participants studied name-face pairs and were then tested on their recognition memory for the names, faces, and the name-face pairs. The results extend the conditions under which older adults exhibit an associative deficit. They also show that reduced attentional resources are not the sole mediator of this deficit.Studies show that memory abilities decline in old age (e.g., Craik & Jennings, 1992;Salthouse, 1991). This decline, however, seems to be differential, characterizing only some memory functions, with episodic memory being particularly vulnerable to the effects of age (e.g., Craik, 1999;Light, 1991). Past research has tried to explain the mechanisms underlying the age-related decline in episodic memory, and several hypotheses have been advanced to explain this decline in memory performance in old age (see Light, 1991, for a review).Recently, Chalfonte and Johnson (1996) and Mitchell, Johnson, Raye, Mather, and D'Esposito (2000) suggested a binding deficit hypothesis, showing that older adults have a particular deficit in memory that requires the binding of information to contextual elements. Naveh-Benjamin (2000) extended this suggestion and proposed an associative deficit hypothesis (ADH), which focuses on the distinction between memory for single units and memory for the associations between these units. The ADH claims that older adults' deficiency in creating and retrieving links between single units of information is one of the main factors that leads to poorer episodic memory. The degree to which a given memory task requires the creation or use of such associations is a significant determinant of old people's memory performance.Naveh-Benjamin (2000) used procedures that allow the independent assessment of memory for component and for associative information (Humphreys, 1976; see the Methods section). The results of four studies provided support for the ADH by showing that older adults exhibit an associative deficit for different types of relationships, including interitem (word-word or nonword-word), as well as intraitem ones (a word and the font in which it was presented). Naveh-Benjamin, Hussain, Guez, and Bar-On (2003) have recently replicated some of these results by using item and associative recognition tests. In the Naveh-Benjamin et al. (2003) study, older adults were shown to be particularly deficient in memory tests that require associations. In addition, older adults showed an associative deficit even when pictures, which usually are remembered well by older adults, are used. Finally, the results of that study supported a prediction made by an ADH, namely, that older adults will show less of an associative deficit when the components of the episodes used are ...

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The present experiments investigated whether the observed associative deficit in older adults' episodic memory is mediated by a reduction of attentional resources. Using a dual-task procedure, younger and older participants studied lists of word pairs either under full attention or while performing a concurrent task. Both experiments showed that dividing attention did not cause a greater impairment to memory for associations than to memory for items in either age group. Furthermore, an analysis of concurrent task performance revealed that older adults' attentional costs for both learning and binding items were not larger than for learning items alone, relative to younger adults. These data provide support for a multicausal interpretation of older adults' memory deficits in which common, depleted attentional resources may be a mechanism that reduces memory for components of an episode in both older and younger adults under divided attention at encoding. In addition, older adults have a unique deficit in memory for the associations between the components, which does not seem to be resource dependent.

Although aging causes relatively minor impairment in recognition memory for components, older adults' ability to remember associations between components is typically significantly compromised, relative to that of younger adults. This pattern could be associated with older adults' relatively intact familiarity, which helps preserve component memory, coupled with a marked decline in recollection, which leads to a decline in associative memory. The purpose of the current study is to explore possible methods that allow older adults to rely on pair familiarity in order to improve their associative memory performance. Participants in 2 experiments were repeatedly presented with either single items or pairings of items prior to a study list so that the items and the pairs were already familiar during the study phase. Pure pair repetition (the effects of pair repetition after the effects of item repetition are taken into account) increased associative memory for older and younger adults. Findings based on remember and know judgments suggest that familiarity but not recollection is involved in mediating the repetition effect.

Several studies have demonstrated that divided attention at encoding significantly reduces memory performance, whereas divided attention at retrieval affects memory performance only minimally. However, the possibility exists that retrieval processes have shown such resilience because the concurrent tasks used have often not been very demanding. To assess this possibility, we used independent manipulations of the concurrent task during either encoding or retrieval that included stimulus-response compatibility and participant-versus experimenter-controlled pace. In addition, we manipulated the distribution of practice that the participants received with the primary and the concurrent tasks. The results replicated and extended those recently reported by Rohrer and Pashler (2003), indicating that although memory performance is negatively affected by divided attention at retrieval, especially with noncompatible stimulus-response mapping in the concurrent task, this effect was much smaller than that at encoding, in line with the asymmetry notion. Furthermore, experimenter versus participant control of the concurrent task had no effect on memory retrieval. Finally, under conditions of equal practice with both the memory and the concurrent tasks, memory retrieval was affected only to a small degree. In contrast to encoding processes, the processes involved in retrieval accuracy appear, in many cases, to be less interrupted by divided attention, although this protection requires substantial resources.

We assessed the contribution of two hypothesized mechanisms to impaired memory performance of older adults in an immediate serial recall task: decreased temporary information storage in a capacity-limited mechanism, such as the focus of attention, and a deficit in binding together different components into cohesive chunks. Using a method in which paired associations between words were taught at varying levels to allow an identification of multiword chunks (Cowan, Chen, & Rouder, 2004), we found that older adults recalled considerably fewer chunks and, on average, smaller chunks than did young adults. Their performance was fairly well simulated by dividing attention in younger adults, unlike what has been found for long-term associative learning. Paired-associate knowledge may be used in an implicit manner in serial recall, given that younger adults under divided attention and older adults use it well despite the relatively small chunk capacities displayed by these groups.

Although older adults have lower working memory spans on average than young adults, we demonstrate in five experiments one way in which older adults paradoxically resemble higher-capacity young adults. Specifically, in a selective-listening task, older adults almost always failed to notice their names presented in an unattended channel. This is an exaggeration of what high-span young adults show, and the opposite of what low spans show. This striking finding in older adults remained significant after controlling for working memory span and for noticing their names in an attended channel. The findings were replicated when presentation rate was made slower and when the ear in which the unattended name was presented was controlled. These results point to an account of older adults’ performance involving not only an inhibition factor, which allows high-span young adults to suppress the channel to be ignored, but also an attentional capacity factor, with more unallocated capacity allowing low-span young adults to notice their names much more often than older adults with comparably low spans.