Selective and nonselective transfer: positive and negative priming in a multiple-task environment

Processing of a probe stimulus can be affected either positively or negatively by presenting a related stimulus immediately before it. According to structural accounts, such effects occur because processing of the prime activates or inhibits the mental representation of the probe before it is presented. In contrast, transfer-appropriate processing accounts suggest that success in processing a probe depends on resources made available by earlier experiences of related stimuli. The authors manipulated the similarity between the prime and probe on color, lexical status, and orthographic structure, requiring either lexical decision or color identification on each. The authors observed a complex pattern of positive and negative transfer that cannot easily be explained through activation-inhibition of mental structures. Instead, that pattern provides evidence in favor of transfer-appropriate processing.     

Sex Differences in Social Support and Self-Efficacy Within a Recovery Community

This study examined similarities and differences in social support and self-efficacy for abstinence between women and men recovering from substance addiction. The sample consisted of 87 residents of Oxford House (OH) self-run, community-based recovery homes. Analyses revealed similarities between women and men in terms of the composition and utilization of support networks and abstinence self-efficacy. Also, for both sexes, length of residency in OH was significantly related to decreased social support for alcohol and drug use and increased self-efficacy for abstinence. However, multiple-group SEM analyses demonstrated that social support for alcohol/drug use fully mediated the link between length of residency and abstinence self-efficacy for women, but not for men. Findings suggest that the process of gaining self-efficacy to remain abstinent is distinct for women and men, and that social support plays a different role in women's recovery than it does in men's.     

On the relationship between effort toward an ongoing task and cue detection in event-based prospective memory

In recent theories of event-based prospective memory, researchers have debated what degree of resources are necessary to identify a cue as related to a previously established intention. In order to simulate natural variations in attention, the authors manipulated effort toward an ongoing cognitive task in which intention-related cues were embedded in 3 experiments. High effort toward the ongoing task resulted in decreased prospective memory only when the cognitive processing required to identify the cue was similar to the cognitive processing required to complete the ongoing activity. When the required processing was different for the 2 tasks, cue detection was not affected by manipulated effort, despite there being an overall cost to decision latencies in the ongoing tasks from possessing the intention. Resource allocation policies and factors that affect them are proposed to account for ongoing vs. prospective memory task performance.     

Revisiting the role of recollection in item versus forced-choice recognition memory

Many memory theorists have assumed that forced-choice recognition tests can rely more on familiarity, whereas item (yes-no) tests must rely more on recollection. In actuality, several studies have found no differences in the contributions of recollection and familiarity underlying the two different test formats. Using word frequency to manipulate stimulus characteristics, the present study demonstrated that the contributions of recollection to item versus forced-choice tests is variable. Low word frequency resulted in significantly more recollection in an item test than did a forced-choice procedure, but high word frequency produced the opposite result. These results clearly constrain any uniform claim about the degree to which recollection supports responding in item versus forced-choice tests.     

Acetylcholine release in the hippocampus and striatum during place and response training

These experiments examined the release of acetylcholine in the hippocampus and striatum when rats were trained, within single sessions, on place or response versions of food-rewarded mazes. Microdialysis samples of extra-cellular fluid were collected from the hippocampus and striatum at 5-min increments before, during, and after training. These samples were later analyzed for ACh content using HPLC methods. In Experiment 1, ACh release in both the hippocampus and striatum increased during training on both the place and response tasks. The magnitude of increase of training-related ACh release in the striatum was greater in rats trained on the response task than in rats trained on the place task, while the magnitude of ACh release in the hippocampus was comparable in the two tasks. Experiment 2 tested the possibility that the hippocampus was engaged and participated in learning the response task, as well as the place task, because of the availability of extra-maze cues. Rats were trained on a response version of a maze under either cue-rich or cue-poor conditions. The findings indicate that ACh release in the hippocampus increased similarly under both cue conditions, but declined during training on the cue-poor condition, when spatial processing by the hippocampus would not be suitable for solving the maze. In addition, high baseline levels of ACh release in the hippocampus predicted rapid learning in the cue-rich condition and slow learning in the cue-poor condition. These findings suggest that ACh release in the hippocampus augments response learning when extra-maze cues can be used to solve the maze but impairs response learning when extra-maze cues are not available for use in solving the maze.     

Perceptual functions in prosopagnosia

Some patients with prosopagnosia may have an apperceptive basis to their recognition defect. Perceptual abnormalities have been reported in single cases or small series, but the causal link of such deficits to prosopagnosia is unclear. Our goal was to identify candidate perceptual processes that might contribute to prosopagnosia, by subjecting several prosopagnosic patients to a battery of functions that may be necessary for accurate facial perception. We tested seven prosopagnosic patients. Three had unilateral right occipitotemporal lesions, two had bilateral posterior occipitotemporal lesions, and one had right anterior-to-occipital temporal damage along with a small left temporal lesion. These lesions all included the fusiform face area, in contrast to one patient with bilateral anterior temporal lesions. Most patients had impaired performance on face-matching tests and difficulty with subcategory judgments for non-face objects. The most consistent deficits in patients with lesions involving the fusiform face area were impaired perception of spatial relations in dot patterns and reduced contrast sensitivity in the 4 to 8 cycles deg(-1) range. Patients with bilateral lesions were impaired in saturation discrimination. Luminance discrimination was normal in all but two patients, and spatial resolution was uniformly spared. Curvature and line-orientation discrimination were impaired in only one patient, who also had the most difficulty with more basic-level object recognition. We conclude that deficits in luminance, spatial resolution, curvature, line orientation, and contrast at low spatial frequencies are unlikely to contribute to apperceptive prosopagnosia. More relevant may be contrast sensitivity at higher spatial frequencies and the analysis of object spatial structure. Deficits in these functions may impair perception of subtle variations in object shape, and may be one mechanism by which the recognition defect in prosopagnosia can extend to other classes of object subcategorization.     

The effect of midazolam on implicit and explicit memory in category exemplar production and category cued recall

Transfer-appropriate processing theory (Roediger, Weldon, & Challis, 1989) proposes that dissociations between performance on explicit and implicit memory tests arise because these tests often rely on different types of information processing (e.g., perceptual processing vs conceptual processing). This perspective predicts that implicit and explicit memory tasks that rely primarily on conceptual processing should show comparable results, not dissociations. Numerous studies have demonstrated such similarities. It is, however, possible that these results arise from explicit memory contamination of performance on implicit memory tasks. To address this issue, an experiment was conducted in which participants were administered the sedative midazolam prior to study. Midazolam is known to create a temporary, but dense, period of anterograde amnesia. The effects of blocking stimulus materials by semantic category at study and generation at study were investigated on category exemplar production and category-cued recall. The results of this study demonstrated a dissociation of the effects of midazolam on category exemplar production and category-cued recall. Specifically, midazolam reduced the effect of blocking stimulus materials in category-cued recall, but not in category exemplar production. The differential effect of midazolam on explicit and implicit memory is at odds with transfer-appropriate processing theory and suggests that theories of memory must distinguish the roles of different types of conceptual processing on implicit and explicit memory tests.     

Visual skills in airport-security screening

Abstract— An experiment examined visual performance in a simulated luggage-screening task. Observers participated in five sessions of a task requiring them to search for knives hidden in x-ray images of cluttered bags. Sensitivity and response times improved reliably as a result of practice. Eye movement data revealed that sensitivity increases were produced entirely by changes in observers' ability to recognize target objects, and not by changes in the effectiveness of visual scanning. Moreover, recognition skills were in part stimulus-specific, such that performance was degraded by the introduction of unfamiliar target objects. Implications for screener training are discussed.