EXPRESS: The effect of early list manipulations on the DRM illusion

The Deese-Roediger-McDermott (DRM) paradigm is widely used to study false memory in the laboratory. It tests memory for lists of semantically related words (correct list item memories) and their non-presented associates (false lure memories). Evidence suggests that early items in DRM lists could make an especially significant contribution to false memories of lures, as they may critically influence the underlying associative activation and/or gist extraction processes. The present study tested this suggestion by using two manipulations that were intended to affect processing of early DRM list items. The first was interpolation of a semantically unrelated distractor item among the list items (Experiments 1 and 2). The second was arranging for these items to be either the strongest or weakest associates of the lure (Experiment 2). In Experiment 1, a distractor item reduced both list item and lure recall when presented early in a DRM list, but selectively disrupted list item recall when presented late in the list. In Experiment 2, arranging for the early list items to be the weakest associates of the lure reduced false recall of the lure but had no effect on list item recall. The findings are discussed with respect to theories that explain false memory in the DRM protocol, including fuzzy trace theory (FTT) and activation monitoring theory (AMT). They are also discussed with respect to general theories of memory and the potential role of category/context information in generating false memories.

Tablet Assessment of Word Comprehension Reveals Coarse Word Representations in 18-20-month-old Toddlers

The present study explores the viability of using tablets in assessing early word comprehension by means of a two-alternative forced-choice task. Forty-nine 18-20-month-old Norwegian toddlers performed a touch-based word recognition task, in which they were prompted to identify the labelled target out of two displayed items on a touchscreen tablet. In each trial, the distractor item was either semantically related (e.g., dog-cat) or unrelated (e.g., dog-airplane) to the target. Our results show that toddlers as young as 18 months can engage meaningfully with a tablet-based assessment, with minimal verbal instruction and child–administrator interaction. Toddlers performed better in the semantically unrelated condition than in the related condition, suggesting that their word representations are still semantically coarse at this age. Furthermore, parental reports of comprehension, using the Norwegian version of the MacArthur Bates Communicative Development Inventories, predicted toddlers’ performance, with parent-child agreement stronger in the semantically unrelated condition, suggesting that parents declare a word to be known by their child if it is understood at a coarse representational level. This study provides among the earliest evidence that remote data collection in infants before their second birthday is viable, as comparable results were observed from both in-lab and online administration of the touch-screen recognition task.

ANALYTIC APPROACH OF RESPONSE PATTERN OF DIAGNOSTIC TEST ITEMS IN EVALUATING STUDENTS’ CONCEPTUAL UNDERSTANDING OF CHARACTERISTICS OF PARTICLE OF MATTER

This research aimed to evaluate the students’ conceptual understanding and to diagnose the students’ preconceptions in elaborating the particle characteristics of matter by development of diagnostic instrument as well as Rasch model response pattern analysis approach. Data were acquired by 25 multiple-choice written test items distributed to 987 students in North Sulawesi, Indonesia. Analysis on diagnostic test items response pattern was conducted in three steps: 1) conversion of raw score to a homogenous interval unit and effectiveness analysis of measurement instruments; 2) measurement of disparity of students’ conceptual understanding; and 3) diagnosis of students’ preconception by estimation of item response pattern. The result generated information on the diagnostic and summative measurement on students’ conceptual understanding in elaborating the topic; information also acts as empirical evidence on the measurement’s reliability and validity. Moreover, the result discovered a significant disparity between students’ conceptual understanding based on their educational level. It was found that the distractor item response pattern tended to be consistent, indicating a certain tendency of resistant preconception pattern. The findings are expected to be a recommendation for future researchers and educational practitioners that integrate diagnostic and summative measurement with Rasch model in evaluating conceptual understanding and diagnosing misconception. Keywords: conceptual understanding, item response, particle of matter, Rasch model

Bistable Perception Is Biased by Search Items but Not by Search Priming

During visual search, selecting a target facilitates search for similar targets in the future, known as search priming. During bistable perception, in turn, perceiving one interpretation facilitates perception of the same interpretation in the future, a form of sensory memory. Previously, we investigated the relation between these history effects by asking: can visual search influence perception of a subsequent ambiguous display and can perception of an ambiguous display influence subsequent visual search? We found no evidence for such influences, however. Here, we investigated one potential factor that might have prevented such influences from arising: lack of retinal overlap between the ambiguous stimulus and the search array items. In the present work, we therefore interleaved presentations of an ambiguous stimulus with search trials in which the target or distractor occupied the same retinal location as the ambiguous stimulus. Nevertheless, we again found no evidence for influences of visual search on bistable perception, thus demonstrating no close relation between search priming and sensory memory. We did, however, find that visual search items primed perception of a subsequent ambiguous stimulus at the same retinal location, regardless of whether they were a target or a distractor item: a form of perceptual priming. Interestingly, the strengths of search priming and this perceptual priming were correlated on a trial-to-trial basis, suggesting that a common underlying factor influences both.

Combined Electrophysiological and Behavioral Evidence for the Suppression of Salient Distractors

Researchers have long debated how salient-but-irrelevant features guide visual attention. Pure stimulus-driven theories claim that salient stimuli automatically capture attention irrespective of goals, whereas pure goal-driven theories propose that an individual's attentional control settings determine whether salient stimuli capture attention. However, recent studies have suggested a hybrid model in which salient stimuli attract visual attention but can be actively suppressed by top–down attentional mechanisms. Support for this hybrid model has primarily come from ERP studies demonstrating that salient stimuli, which fail to capture attention, also elicit a distractor positivity (PD) component, a putative neural index of suppression. Other support comes from a handful of behavioral studies showing that processing at the salient locations is inhibited compared with other locations. The current study was designed to link the behavioral and neural evidence by combining ERP recordings with an experimental paradigm that provides a behavioral measure of suppression. We found that, when a salient distractor item elicited the PD component, processing at the location of this distractor was suppressed below baseline levels. Furthermore, the magnitude of behavioral suppression and the magnitude of the PD component covaried across participants. These findings provide a crucial connection between the behavioral and neural measures of suppression, which opens the door to using the PD component to assess the timing and neural substrates of the behaviorally observed suppression.

Attention-Related Modulation of Sensory-Evoked Brain Activity in a Visual Search Task

When subjects are explicitly cued to focus attention on a particular location in visual space, targets presented at that location have been shown to elicit enhanced sensory-evoked activity in recordings of event-related brain potentials (ERPs). The present study sought to determine if this type of sensory facilitation also occurs during visual search tasks in which a feature conjunction target must be identified, presumably by means of focal attention, within an array of distractor items. In this experiment, subjects were required to discriminate the shape of a distinctively colored target item within an array containing 15 distractor items, and ERPs were elicited by task-irrelevant probe stimuli that were presented at the location of the target item or at the location of a distractor item on the opposite side of the array. When the delay between search-array onset and probe onset was 250 msec, the sensory-evoked responses in the latency range 75-200 msec were larger for probes presented at the location of the target than for probes presented at the location of the irrelevant distractor. These results indicate that sensory processing is modulated in a spatially restricted manner during visual search, and that focusing attention on a feature conjunction target engages neural systems that are shared with other forms of visual-spatial attention.

Combining Expectancies

Five experiments examine the combined effects of spatial and non-spatial cues on the latency of an orientation judgement. In Experiment 1 an interaction between position and form expectancies is observed: There is an unusual delay in response time (RT) when expectancies mismatch—that is, when an unexpected (uncued) form appears at an expected (cued) position or an expected (cued) form appears at an unexpected (uncued) position. This interaction is inconsistent with the spatial spotlight model's prediction that position and form expectancy effects will be additive. The position-form interaction is eliminated when target position discriminability is made difficult by adding a distractor item at the location not containing a target (Experiment 2) or by decreasing the validity of the positional cue (Experiment 3). Decreasing the validity of the form cue has no effect on the interaction. The mismatching expectancy interaction is not unique to combinations of position and form—it is also observed when temporal (Experiment 4) and colour (Experiment 5) expectancies are combined with form expectancies. The effects of advance knowledge of position therefore suggest no special status for location compared to other stimulus attributes. Thus, at least for combined expectancies, the notion of a uniquely spatial mental spotlight seems unjustified. It is hypothesized that expectancy interactions may reflect a hierarchical crosstalk relation between dimensions of encoding.