Incidental visual memory for objects in scenes

Three experiments were conducted to investigate the existence of incidentally acquired, long-term, detailed visual memory for objects embedded in previously viewed scenes. Participants performed intentional memorization and incidental visual search learning tasks while viewing photographs of real-world scenes. A visual memory test for previously viewed objects from these scenes then followed. Participants were not aware that they would be tested on the scenes following incidental learning in the visual search task. In two types of memory tests for visually specific object information (token discrimination and mirror-image discrimination), performance following both the memorization and visual search conditions was reliably above chance. These results indicate that recent demonstrations of good visual memory during scene viewing are not due to intentional scene memorization. Instead, long-term visual representations are incidentally generated as a natural product of scene perception.     

Does relocating information in text depend on verbal or visuospatial abilities? An individual-differences analysis

In this individual-differences study, we evaluated the prevalent view that relocating information in a previously read text depends primarily on visuospatial abilities. Participants read a text, answered fillin-the-blank test questions, and identified which page and line in the original text contained the sentence in each question. They also completed a battery of verbal and visuospatial tasks. Performance on verbal tasks was highly predictive of the accuracy of both page and line identifications, and this correlation remained significant even after we controlled for performance on visuospatial tasks. In contrast, performance on visuospatial tasks was not predictive of either page or line identification accuracy, once verbal abilities were controlled for. These results suggest an important role for verbal abilities in relocation of text information and a lesser role for visuospatial abilities than has previously been assumed.     

Advance visual information, awareness, and anticipation skill

The authors examined 13 skilled, 13 recreational, and 11 novice players' awareness of the advance visual information that they used to judge tennis serve direction. Participants viewed video clips of serve actions under 5 conditions of spatial occlusion. The authors assessed participants' awareness by comparing the different groups' confidence associated with correct and incorrect judgments and by conducting a postexperiment free-recall test. The results indicated that information from the ball toss and the arm + racquet region underpinned players' anticipation skill and that greater expertise was accompained by increasing awareness of the information on which judgments were based. The authors discuss the implications of the present results for researchers' use of confidence ratings to assess awareness in perceptual-judgment tasks.     

Proactive interference from items previously stored in visual working memory

This study investigates the fate of information that was previously stored in visual working memory but that is no longer needed. Previous research has found inconsistent results, with some showing effective release of irrelevant information and others showing proactive interference. Using change detection tasks of colors or shapes, we show that participants tend to falsely classify a changed item as "no change" if it matches one of the memory items on the preceding trial. The interference is spatially specific: Memory for the preceding trial interferes more if it matches the feature value and the location of a test item than if it does not. Interference results from retaining information in visual working memory, since it is absent when items on the preceding trials are passively viewed, or are attended but not memorized. We conclude that people cannot fully eliminate unwanted visual information from current working memory tasks.     

Influence of visual guidance on braille recognition: Low lighting also helps touch

This study was an attempt to clarify the mechanisms responsible for the benefits of visual guidance in tactual braille recognition. Subjects touched +90° tilted braille under normal room lighting, or with low lighting, with or without visual guidance. Both visual information about finger angle and spatial reference information were manipulated with stained glass and light-emitting diodes. The provision of visual information about finger angle alone was no help to braille recognition, and performance was low. Adding visual spatial reference information to vision of finger angle raised performance. However, recognition accuracy was also substantially improved by low lighting. The benefits of darkness for haptics did not generalize to the reading of upright, two-letter braille words. It was proposed that extraneous visual information may distract sighted subjects in haptic tasks that require mental rotation of visual images.     

Do conversational hand gestures communicate?

In 5 experiments, male and female undergraduates viewed gestures and tried to select the words that originally accompanied them; read interpretations of gestures' meanings and tried to select the words that originally had accompanied them; tried to recognize gestures they previously had seen, presented either with or without the accompanying speech; and assigned gestures and the accompanying speech to semantic categories. On all 4 tasks, performance was better than chance but markedly inferior to performance when words were used as stimuli. Judgments of a gesture's semantic category were determined principally by the accompanying speech rather than gestural form. It is concluded that although gestures can convey some information, they are not richly informative, and the information they convey is largely redundant with speech.     

Executive control in set switching: residual switch cost and task-set inhibition.

Executive processes necessary for flexibly switching between different tasks were studied using a set switching paradigm that requires participants to rapidly switch between different tasks across consecutive trials. Switch cost reflects poorer performance for task-switch trials than for consecutive same-task trials. Significant switch cost was observed even with considerable preparation time before a task-switch, an effect known as residual switch cost. This study tested the hypothesis that one process underlying residual switch cost is inhibition of the previous task-set. We used semantic categorization tasks to compare switch cost between alternating task series (ABA) and nonalternating series (ABC) in order to test the generality of a task-set inhibition effect previously observed with perceptual judgment tasks (Mayr & Keele, in press). The results yielded significant switch cost only for alternating tasks, in both response times and errors resulting from performance of the wrong task. Thus, resolving inhibition associated with previously abandoned task-sets may be the main process underlying residual switch costs, suggesting that task-set inhibition is an important executive control process.     

Famous people knowledge and the right and left temporal lobes

It is generally accepted that the anterior temporal lobes support knowledge of famous people. The specific roles of the right and left temporal lobe remain a subject of debate, with some studies suggesting differential roles based on modality (visual versus verbal information) and others category (person knowledge versus general semantics). The present study re-examined performance of semantic dementia patients with predominantly right and predominantly left temporal lobe atrophy on famous face, famous name and general semantic tasks, with the specific aim of testing the hypothesis that the right temporal lobe has a privileged role for person knowledge and the left temporal lobe for general semantic knowledge. Comparisons of performance rankings across tasks showed no evidence to support this hypothesis. By contrast, there was robust evidence from naming, identification and familiarity measures for modality effects: right-sided atrophy being associated with relatively greater impairment for faces and visual tasks and left-sided atrophy for names and verbal tasks. A double dissociation in test scores in two patients reinforced these findings. The data present a challenge for the influential `semantic hub' model, which views the anterior temporal lobes as an area of convergence in which semantic information is represented in amodal form.     

Do emotional stimuli enhance or impede recall relative to neutral stimuli? An investigation of two “false memory” tasks

Many eyewitness memory situations involve negative and distressing events; however, many studies investigating “false memory” phenomena use neutral stimuli only. The aim of the present study was to determine how both the Deese–Roediger–McDermott (DRM) procedure and the Misinformation Effect Paradigm tasks were related to each other using distressing and neutral stimuli. Participants completed the DRM (with negative and neutral word lists) and viewed a distressing or neutral film. Misinformation for the film was introduced and memory was assessed. Film accuracy and misinformation susceptibility were found to be greater for those who viewed the distressing film relative to the neutral film. Accuracy responses on both tasks were related, however, susceptibility to the DRM illusion and Misinformation Effect were not. The misinformation findings support the Paradoxical Negative Emotion (PNE) hypothesis that negative stimuli will lead to remembering more accurate details but also greater likelihood of memory distortion. However, the PNE hypothesis was not supported for the DRM results. The findings also suggest that the DRM and Misinformation tasks are not equivalent and may have differences in underlying mechanisms. Future research should focus on more ecologically valid methods of assessing false memory.     

Division of attention: The single-channel hypothesis revisited

Two experiments are reported in which subjects performed two forced-paced serial reaction time tasks separately and together at their maximum sustainable rates of information processing. Experiment 1 investigated the effects on the relationship between single- and dual-task performance of using tasks with the same or different input and output modality characteristics; an additional condition tested the effects on this relationship of using tasks with higher S-R compatibility. Experiment 2 investigated the effects on the relationship between single- and dual-task performance of varying information load (number of S-R alternatives). No significant differences were found in subjects' capacities to process information in single- and dual-task conditions. This finding was unaffected by: (a) the absolute information levels of the tasks, (b) whether inputs and/or outputs involved the same or different modalities, or (c) the level of S-R compatibility. The data from both experiments provide strong support for the single-channel hypothesis.     

Informational primacy of visual dimensions: specialized roles for luminance and chromaticity in figure-ground perception

Three experiments were conducted to examine the distinct contributions of two visual dimensions to figure-ground segregation. In each experiment, pattern identification was assessed by asking observers to judge whether a near-threshold test pattern was the same or different in shape to a high-contrast comparison pattern. A test pattern could differ from its background along one dimension, either luminance (luminance tasks) or chromaticity (chromaticity tasks). In each task, performance in a baseline condition, in which the test pattern was intact, was compared with performance in each of several degradation conditions, in which either the contour or the surface of the figure was degraded, using either partial occlusion (Experiment 1) or ramping (Experiments 2 and 3) of figure-ground differences. In each experiment, performance in luminance tasks was worst when the contour was degraded, whereas performance in chromaticity tasks was worst when the surface was degraded. This interaction was found even when spatial frequencies were fixed across test patterns by low-pass filtering. The results are consistent with a late (postfiltering) dual-mechanism system that processes luminance information to extract boundary representations and chromaticity information to extract surface representations.     

Informational primacy of visual dimensions: Specialized roles for luminance and chromaticity in figure-ground perception

Three experiments were conducted to examine the distinct contributions of two visual dimensions to figure-ground segregation. In each experiment, pattern identification was assessed by asking observers to judge whether a near-threshold test pattern was the same or different in shape to a high-contrast comparison pattern. A test pattern could differ from its background along one dimension, either luminance (luminance tasks) or chromaticity (chromaticity tasks). In each task, performance in a baseline condition, in which the test pattern was intact, was compared with performance in each of several degradation conditions, in which either the contour or the surface of the figure was degraded, using either partial occlusion (Experiment 1) or ramping (Experiments 2 and 3) of figure-ground differences. In each experiment, performance in luminance tasks was worst when the contour was degraded, whereas performance in chromaticity tasks was worst when the surface was degraded. This interaction was found even when spatial frequencies were fixed across test patterns by low-pass filtering. The results are consistent with a late (postfiltering) dual-mechanism system that processes luminance information to extract boundary representations and chromaticity information to extract surface representations.     

幼儿心理理论表现的任务特异性分析

研究以90名3～5岁幼儿为被试,采用相同材料和标准评估幼儿外表-事实的区分和错误信念认识,考察幼儿表现的任务特异性及材料刺激的影响。结果表明;幼儿的表现仍存在任务特异性,并且实验材料对儿童的外表-事实区分和错误信念认识具有重要影响。在解释这些结果时,特殊领域知识习得观似乎优于表征缺失理论。     

The influence of affective statements on performance on implicit and explicit memory tasks

Consumers are often exposed to brand names presented concurrently with information such as brand claims and warnings, prior to making product choices. As implicit memory has been implicated in the consumer choice process, two experiments were conducted to assess the influence of additional information, namely simple positive and negative statements, on implicit and explicit memory tasks. In Experiment 1, the mere presence of additional statements at study significantly reduced performance on a two‐alternatives forced recognition task. However, the same manipulation had no effect on implicit preference judgement task performance. The valence of the accompanying information had no effect on either task. In Experiment 2, using modified implicit and explicit choice tasks, performance on the former was unaffected by statement valence, whereas the latter task was. Hence, positive priming was obtained for brand names previously shown with negative information. The results of the experiments are discussed in relation to both implicit memory and consumer choice. Copyright © 2002 John Wiley & Sons, Ltd.     

Memory and frequency estimation processes in a decision task

Two experiments examined the role of information storage and frequency estimation processes in a simple decision task. On each trial from one to five simultaneous sequences of information were presented, and subjects were required to monitor and respond to each sequence. In one study independent groups of subjects gave decisions, recognition responses. or frequency judgments. In a second study recall responses were obtained from subjects as part of the decision and frequency judgment tasks. Changes in performance as the number of simultaneous sequences increased suggested an independence of decisions from memory for specific information. Performance on the decision and frequency judgment tasks exceeded at times that which was possible on the basis of specific information available. Other data suggested that subjects in the frequency estimation tasks maintained an accurate frequency count when possible, but in the decision task kept little more than a record of their currently favored hypothesis. When direct counting was prevented in the second experiment. performance in the two tasks was not significantly different, suggesting that the two processes are very similar under such conditions.     

The effect of stress on the suppression of erroneous competing responses

Abstract Evidence exists that the intention to perform certain cognitive tasks activates, unintentionally, competing responses and computations that intrude on the performance of the intended tasks. For the intended task to be performed effectively, such intrusions must be controlled. Two experiments were carried out to test the hypothesis that stress heightens the difficulty of exercising effective control over erroneous competing responses, a possible explanation of decrements in the performance of cognitive tasks under stress. Participants performed four tasks, which contained features that could potentially prime or activate erroneous responses. The results demonstrated that the interference of these features with performance was more pronounced among stressed than among less-stressed participants. The need for a more comprehensive theory of the effects of stress on information processing is discussed.     

Processing of temporal duration information in working memory after frontodorsal tumour excisions

This study aimed to test the hypothesis that impairments of temporal duration processing after frontal lobe lesions reflect deficits in executive monitoring functions rather than a domain-specific deficit in the maintenance of duration information in working memory. Patients with frontodorsal lesions, clinical controls with post-central lesions, and healthy controls performed recognition and classification tasks, which should allow for testing maintenance and monitoring functions, respectively. Results showed mild non-selective impairments of the frontal patients on both temporal and spatial recognition tasks, but a marked selective degradation on temporal classification while performance on spatial classification was unimpaired. This suggests that maintenance of duration information in working memory after frontal lesions is basically preserved but that, depending on executive task characteristics, there is a specific deficit in the strategic organization of this type of information.     

A computational model of anterior cingulate function in speeded response tasks: effects of frequency,sequence, and conflict

A growing body of evidence from functional neuroimaging and computational modeling studies indicates that the anterior cingulate cortex (ACC) detects the presence of response conflict and conveys this information to other brain regions, enabling subsequent adjustments in cognitive control. The present study examined previous empirical findings of increased ACC for low-frequency stimuli across three distinct speeded response tasks (two-alternative forced choice, go/no-go, and oddball). Simulations conducted in a neural network model incorporating sequential priming mechanisms (developed in Cho et al., 2002) confirmed that a computational measure of response conflict was higher on low-frequency trials across all three tasks. In addition, the model captured detailed aspects of behavioral reaction time and accuracy data, predicted the dynamics of ACC activity related to trial sequence effects, and provided evidence for the functional role of conflict information in performance monitoring and optimization. The results indicate that the conflict-monitoring hypothesis, augmented by mechanisms for encoding stimulus history, can explain key phenomena associated with performance in sequential speeded response tasks.     

Fruitful visual search: Inhibition of return in a virtual foraging task

Inhibition of return (IOR) has long been viewed as a foraging facilitator in visual search. We investigated the contribution of IOR in a task that approximates natural foraging more closely than typical visual search tasks. Participants in a fully immersive virtual reality environment manually searched an array of leaves for a hidden piece of fruit, using a wand to select and examine each leaf location. Search was slower than in typical IOR paradigms, taking seconds instead of a few hundred milliseconds. Participants also made a speeded response when they detected a flashing leaf that either was or was not in a previously searched location. Responses were slower when the flashing leaf was in a previously searched location than when it was in an unvisited location. These results generalize IOR to an approximation of a naturalistic visual search setting and support the hypothesis that IOR can facilitate foraging. The experiment also constitutes the first use of a fully immersive virtual reality display in the study of IOR.     

Perceiving patterns in dynamic action sequences: Investigating the processes underpinning stimulus recognition and anticipation skill

We examined whether skilled and less‐skilled participants process dynamic sequences comprised of numerous elements using relational information or specific display features. Moreover, the processes underpinning anticipation and recognition judgments were compared. Participants viewed dynamic film sequences showing multiple display features and anticipated what would happen next. New and previously viewed action sequences were then presented in film or point‐light display format. Participants attempted to recognize previously viewed sequences. Skilled participants demonstrated superior anticipation skill and were more sensitive in discriminating previously viewed and novel clips than their less‐skilled counterparts. Skilled participants fixated more locations than less‐skilled participants, implying that they process dynamic scenes as a series of relations between display features. The patterns of eye fixation measures differed between the anticipation and recognition tasks suggesting that different processes underpin these two types of judgments. Copyright © 2009 John Wiley & Sons, Ltd.