Jonathan Guez

Effects of Divided Attention on Encoding and Retrieval Processes in Human Memory: Further Support for an Asymmetry

Despite a tradition in cognitive psychology that views encoding and retrieval processes in human memory as being similar, F. I. M. Craik, R. Govoni, M. Naveh-Benjamin and N. D. Anderson (1996) have recently shown that notable differences exist between the 2 when divided-attention manipulations are used. In this article, the authors further examined this asymmetry by using several manipulations that changed task demands at encoding and retrieval. The authors also used a secondary-task methodology that allowed a microlevel analysis of the secondary-task costs associated with encoding and retrieval. The results illustrated the resiliency of retrieval processes to manipulations involving different task demands. They also indicated different loci of attention demands at encoding and retrieval. The authors contend that whereas encoding processes are controlled, retrieval processes are obligatory but do require attentional resources for their execution.

Divided Attention in Younger and Older Adults: Effects of Strategy and Relatedness on Memory Performance and Secondary Task Costs.

Divided attention at encoding leads to a significant decline in memory performance, whereas divided attention during retrieval has relatively little effect; nevertheless, retrieval carries significant secondary task costs, especially for older adults. The authors further investigated the effects of divided attention in younger and older adults by using a cued-recall task and by measuring retrieval accuracy, retrieval latency, and the temporal distribution of attentional costs at encoding and retrieval. An age-related memory deficit was reduced by pair relatedness, whereas strategy instructions benefited both age groups equally. Attentional costs were greater for retrieval than for encoding, especially for older adults. These findings are interpreted in light of notions of an age-related associative deficit (M. Naveh-Benjamin, 2000) and age-related differences in the use of self-initiated activities and environmental support (F. I. M. Craik, 1983, 1986).

The effects of divided attention at encoding on item and associative memory

Divided attention at encoding is well known to have adverse effects on episodic memory performance (e.g., Naveh-Benjamin & Greg, 2000). This article attempts to determine whether these effects are a result of the interruption of encoding of associative information among the components of an episode. Five experiments, using different types of episodes and episodes components, were conducted. Participants studied information under either full or divided attention and were then tested on their memory for both the episodes’ components and the associations between them. Divided attention did not produce a differential deficit in memory for associative information; memory for the components suffered to the same degree as memory for the associations among the components. The cause of the divided-attention effect at encoding lies somewhere other than in the associative processes that are engaged.

Effects of divided attention on encoding and retrieval processes: assessment of attentional costs and a componential analysis.

Recent research has shown that divided attention at retrieval, in contrast to encoding, affected memory performance only minimally. This immunity at retrieval was associated with a significant secondary task cost. In this article the authors further investigated these effects employing a cued-recall task and a multimeasure approach with accuracy, latency, overall attentional costs, and the temporal distribution of attentional costs associated with the encoding and retrieval of low- and high-frequency words. The results of 2 experiments yielded a complex pattern of both similarities and differences between encoding and retrieval. Simultaneous inspection of the different measures of performance was instrumental in identifying 3 major types of retrieval (unsuccessful, slow, and fast), as well as different phases of the retrieval process, each of which was characterized by a different demand for attentional resources.

Older adults' associative deficit in episodic memory: Assessing the role of decline in attentional resources

In this study, we evaluated an associative deficit hypothesis. This hypothesis suggests that the deficit seen in the episodic memory performance of older adults is due, in considerable part, to older adults’ difficulty in binding together unrelated components of an episode into a cohesive entity (Naveh-Benjamin, 2000). The study extended the conditions under which older adults show a differential deficit in tests requiring associations among the episode components to situations in which the item and the associative recognition tests are equated on the response mode used and on the amount of information displayed. In addition, we tested the potential role of a decrease in attentional resources in the associative deficit of older adults by comparing their performance to that of younger adults under conditions of reduced attentional resources. The results of the study, which indicate that younger adults under divided attention do not show an associative deficit, are interpreted as indicating that the associative deficit of older adults is due to factors other than depleted attentional resources.

Traumatic stress is linked to a deficit in associative episodic memory

Individuals with posttraumatic stress disorder (PTSD) are haunted by persistent memories of the trauma, but ironically are impaired in memories of daily life. The current set of 4 experiments compared new learning and memory of emotionally neutral content in 2 groups of patients and aged- and education-matched controls: 20 patients diagnosed with chronic posttraumatic stress disorder (C-PTSD) and 20 patients diagnosed with acute stress disorder (ASD). In all experiments, participants studied a list of stimuli pairs (words or pictures) and were then tested for their memory of the items, or for the association between items in each pair. Results indicated that both types of patients showed associative memory impairment compared to a control group, although their item memory performance was relatively intact. Potential mechanisms underlying such associative memory deficits in posttraumatic patients are discussed.

Obstetric and perinatal outcomes in women with eating disorders.

BACKGROUND We wished to investigate whether women with a history of eating disorders have an increased risk for adverse obstetric and perinatal outcomes. STUDY DESIGN A retrospective study was conducted comparing pregnancy complications in patients with and without eating disorders. Deliveries occurred during the years 1988-2009 in a tertiary medical center. Women lacking prenatal care and with multiple gestations were excluded from the study. Stratified analyses were performed using multivariable logistic regression models. Odds ratios (OR) and their 95% confidence interval (CI) were computed. A p value<0.05 was considered statistically significant. RESULTS During the study period, of 117,875 singleton deliveries, 122 (0.1%) occurred in patients with eating disorders. Eating disorders were significantly associated with fertility treatments (5.7% vs. 2.8%, p=0.047), intrauterine growth restriction (7.4% vs. 2.3%, p<0.001), term low birth weight (<2500 g) (7.4% vs. 2.8%, p=0.002), preterm delivery (15.6% vs. 7.5%, p=0.002), and cesarean delivery (25.4% vs. 15.0%, p=0.001). Using multivariable analyses, low birth weight (OR 2.5, 95% CI 1.3-5.0), preterm delivery (OR 2.2, 95% CI 1.4-3.6), and cesarean section (OR 1.9, 95% CI 1.3-2.9) were significantly associated with eating disorders. CONCLUSIONS Eating disorders are associated with increased risk of adverse pregnancy outcomes. Accordingly, careful surveillance is needed for early detection of possible complications.

Associative memory impairment in acute stress disorder: Characteristics and time course

Stress and episodic memory impairment have previously been associated. Acute stress disorder (ASD) is a maladaptive stress response, which develops in some individuals following traumatic life events. Recently, the authors demonstrated a specific deficit in associative memory for emotionally neutral stimuli in ASD and posttraumatic stress disorder (PTSD). This study further tested the relationship between this memory impairment and the course of ASD. We assessed new learning and memory for item and associative information in patients diagnosed with ASD (n=14) and matched trauma naïve controls (n=14). Memory performance and posttraumatic symptoms were examined for approximately 1 and 10 week periods following the traumatic experience. In the two experiments, participants studied a list of stimuli pairs (verbal or visual) and were then tested for their memory of the items (item recognition test), or for the association between items in each pair (associative recognition test). In both experiments, ASD patients showed a marked associative memory deficit compared to the control group. After 10 weeks, ASD symptoms were resolved in most patients. Interestingly, their performance on associative recognition for verbal stimuli improved, while the associative deficit for visual stimuli remained unchanged. Potential mechanisms underlying such an associative memory deficit in post-trauma patients are discussed.

Divided attention at encoding and retrieval for once- and thrice-presented items: A micro-level analysis of attentional costs

Several recent studies have indicated that retrieval, unlike encoding, is only minimally affected by dividing attention, but is associated with significant secondary task costs. The reported experiment further investigated the effects of divided attention at encoding and retrieval on recall by manipulating the number of presentations of word pairs and using a cued-recall paradigm and a multimeasure approach. This allowed the assessment of accuracy and latency of retrievals of once- and thrice-presented items, as well as of overall attentional costs and the temporal distribution of attentional costs incurred by these retrievals. The results obtained show that providing episodic enhancement to the cue–target relationships, by presenting word pairs three times during the study phase, increases both the probability of retrieval success and the speed of the retrieval. In addition, repetition leads to retrieval which requires less attentional resources. In particular, repeated items require fewer attentional resources during the cue-elaboration/search component. This effect seems to be mediated by a change in the nature of retrievals of the thrice-presented pairs, which seem to mostly bypass the search process, making it faster and less dependent on attentional resources.

The effects of divided attention on encoding processes under incidental and intentional learning instructions: underlying mechanisms?

Divided attention (DA) at encoding has been shown to significantly disrupt later memory for the studied information. However, what type of processing gets disrupted during DA remains unresolved. In this study, we assessed the degree to which strategic effortful processes are affected under DA by comparing the effects of DA at encoding under intentional and pure incidental learning instructions. In three experiments, participants studied list of words or word pairs under either full or divided attention. Results of three experiments, which used different methodologies, converged to show that the effects of DA at encoding reduce memory performance to the same degree under incidental and intentional learning. Secondary task performance indicated that encoding under intentional learning instructions was more effortful than under incidental learning instructions. In addition, the results indicated enhanced attention to the initial appearance of the words under both types of learning instructions. Results are interpreted to imply that other processes, rather than only strategic effortful ones, might be affected by DA at encoding.