The effects of mediated word lists on false recall and recognition

False memory effects were explored using unrelated list items (e.g., slope, reindeer, corn) that were related to mediators (e.g., ski, sleigh, flake) that all converged upon a single nonpresented critical item (CI; e.g., snow). In Experiment 1, participants completed either an initial recall test or arithmetic problems after study, followed by a final recognition test. Participants did not falsely recall CIs on the initial test; however, false alarms to CIs did occur in recognition, but only following an initial recall test. In Experiment 2, participants were instructed to guess the CI, followed by a recognition test. The results replicated Experiment 1, with an increase in CI false alarms. Experiment 3 controlled for item effects by replacing unrelated recognition items from Experiment 1 with both CIs and list items from nonpresented lists. Once again, CI false alarms were found when controlling for lexical characteristics, demonstrating that mediated false memory is not due simply to item differences.     

A comparison of lexical-semantic impairments in left hemisphere stroke and Alzheimer's disease

Patients with aphasia due to left hemisphere stroke and patients with Alzheimer's disease, who were matched for severity of naming impairment, were compared on tests of lexical-semantic processing. The results suggest that the lexical-semantic impairments in both groups are due to a combination of impaired access to, and loss of, lexical-semantic information, but that impaired access is more prominent in stroke patients, whereas Alzheimer's disease patients suffer a greater loss of information. The results are discussed in terms of a brain model of the storage and processing of lexical-semantic information, and with respect to implications for treatment strategies.     

Representation of dynamic spatial configurations in visual short-term memory

Locations of multiple stationary objects are represented on the basis of their global spatial configuration in visual short-term memory (VSTM). Once objects move individually, they form a global spatial configuration with varying spatial inter-object relations over time. The representation of such dynamic spatial configurations in VSTM was investigated in six experiments. Participants memorized a scene with six moving and/or stationary objects and performed a location change detection task for one object specified during the probing phase. The spatial configuration of the objects was manipulated between memory phase and probing phase. Full spatial configurations showing all objects caused higher change detection performance than did no or partial spatial configurations for static and dynamic scenes. The representation of dynamic scenes in VSTM is therefore also based on their global spatial configuration. The variation of the spatiotemporal features of the objects demonstrated that spatiotemporal features of dynamic spatial configurations are represented in VSTM. The presentation of conflicting spatiotemporal cues interfered with memory retrieval. However, missing or conforming spatiotemporal cues triggered memory retrieval of dynamic spatial configurations. The configurational representation of stationary and moving objects was based on a single spatial configuration, indicating that static spatial configurations are a special case of dynamic spatial configurations.     

DynAOI: A tool for matching eye-movement data with dynamic areas of interest in animations and movies

Analyzing gaze behavior with dynamic stimulus material is of growing importance in experimental psychology; however, there is still a lack of efficient analysis tools that are able to handle dynamically changing areas of interest. In this article, we present DynAOI, an open-source tool that allows for the definition of dynamic areas of interest. It works automatically with animations that are based on virtual three-dimensional models. When one is working with videos of real-world scenes, a three-dimensional model of the relevant content needs to be created first. The recorded eye-movement data are matched with the static and dynamic objects in the model underlying the video content, thus creating static and dynamic areas of interest. A validation study asking participants to track particular objects demonstrated that DynAOI is an efficient tool for handling dynamic areas of interest.     

Spatial updating of dynamic scenes: Tracking multiple invisible objects across viewpoint changes

Research on dynamic attention has shown that visual tracking is possible even if the observer’s viewpoint on the scene holding the moving objects changes. In contrast to smooth viewpoint changes, abrupt changes typically impair tracking performance. The lack of continuous information about scene motion, resulting from abrupt changes, seems to be the critical variable. However, hard onsets of objects after abrupt scene motion could explain the impairment as well. We report three experiments employing object invisibility during smooth and abrupt viewpoint changes to examine the influence of scene information on visual tracking, while equalizing hard onsets of moving objects after the viewpoint change. Smooth viewpoint changes provided continuous information about scene motion, which supported the tracking of temporarily invisible objects. However, abrupt and, therefore, discontinuous viewpoint changes strongly impaired tracking performance. Object locations retained with respect to a reference frame can account for the attentional tracking that follows invisible objects through continuous scene motion.     

Age-related differences in guessing on free and forced recall tests

This study examined possible age-related differences in recall, guessing, and metacognition on free recall tests and forced recall tests. Participants studied categorised and unrelated word lists and were asked to recall the items under one of the following test conditions: standard free recall, free recall with a penalty for guessing, free recall with no penalty for guessing, or forced recall. The results demonstrated interesting age differences regarding the impact of liberal test instructions (i.e., forced recall and no penalty) relative to more conservative test instructions (i.e., standard free recall and penalty) on memory performance. Specifically, once guessing was controlled, younger adults’ recall of categorised lists varied in accordance with test instructions while older adults’ recall of categorised lists did not differ between conservative and liberal test instructions, presumably because older adults approach standard free recall tests of categorised lists with a greater propensity towards guessing than young adults.     

The effects of initial testing on false recall and false recognition in the social contagion of memory paradigm

In three experiments, participants studied photographs of common household scenes. Following study, participants completed a category-cued recall test without feedback (Exps. 1 and 3), a category-cued recall test with feedback (Exp. 2), or a filler task (no-test condition). Participants then viewed recall tests from fictitious previous participants that contained erroneous items presented either one or four times, and then completed final recall and source recognition tests. The participants in all conditions reported incorrect items during final testing (a social contagion effect), and across experiments, initial testing had no impact on false recall of erroneous items. However, on the final source-monitoring recognition test, initial testing had a protective effect against false source recognition: Participants who were initially tested with and without feedback on category-cued initial tests attributed fewer incorrect items to the original event on the final source-monitoring recognition test than did participants who were not initially tested. These data demonstrate that initial testing may protect individuals’ memories from erroneous suggestions.     

Visual target detection is impaired at event boundaries

Boundaries between meaningful events are key moments in comprehending human action. At these points, viewers may focus on the event's contents at the expense of other information. We tested whether visual detection was impaired at those moments perceivers judged to be boundaries between events. Short animated football clips were used as stimulus material, and event boundaries were imposed by having the ball change possession. In a first experiment, we found that possession changes were perceived to be event boundaries. In a second experiment, participants were asked to keep track of 4 of 10 players and to watch for 120 ms probes appearing either at an event boundary or a nonboundary. Probe detection was less accurate at event boundaries. This result suggests that the segmentation of ongoing activity into events corresponds with the regulation of attention over time.