Comparing effects of perceptual and reflective repetition on subjective experience during later recognition memory

Using the Remember/Know procedure, we compared the impact of a reflective repetition by refreshing (i.e., briefly thinking of a just-seen item) and a perceptual repetition (i.e., seeing an item again) on subjective experience during recognition memory. Participants read aloud words as they appeared on a screen. Critical words were presented once (read condition), immediately repeated (repeat condition), or followed by a dot signalling the participants to think of and say the just-previous word (refresh condition). In Experiments 1 and 2, Remember responses benefited from refreshing a word (in comparison with reading it). In Experiment 2, this benefit disappeared when participants had to refresh one of three active items. Perceptual repetition increased Remember responses in Experiment 1, but not in Experiment 2 regardless of whether participants had just previously seen 1- or 3-items. These findings indicate that under some circumstances, reflective and perceptual repetition may have different consequences for later subjective experience during remembering, suggesting differences in their underlying functional mechanisms.     

Trait anxiety and impaired control of reflective attention in working memory

The present study investigated whether the control of reflective attention in working memory (WM) is impaired in high trait anxiety individuals. We focused on the consequences of refreshing—a simple reflective process of thinking briefly about a just-activated representation in mind—on the subsequent processing of verbal stimuli. Participants performed a selective refreshing task, in which they initially refreshed or read one word from a three-word set, and then refreshed a non-selected item from the initial phrase or read aloud a new word. High trait anxiety individuals exhibited greater latencies when refreshing a word after experiencing the refreshing of a word from the same list of semantic associates. The same pattern was observed for reading a new word after prior refreshing. These findings suggest that high trait anxiety individuals have difficulty resolving interference from active distractors when directing reflective attention towards contents in WM or processing a visually presented word.     

Two studies of visual search for word targets with controlled rates of presentation*

The two studies reported involve the visual search of word lists for a target item when the rate of presentation is controlled and the words are presented tachistoscopically. In the first study, the target is differentiated physically from the filler items by being capitalized. When the target is the last item in a list, it is readily identified at all presentation rates, but when it is the first word or is embedded in a list, recognition accuracy is inversely related to presentation rate. In the second study, the differentiation between target and filler items is in terms of the presence or absence of category membership. All Ss at all presentation rates do significantly better on lists with an animal word as a target and a set of unrelated words as filler items than on the converse arrangement.     

Mental rubbernecking to negative information depends on task context

We previously demonstratedmental rubbernecking during the simple cognitive act ofrefreshing a just activated representation. Participants saw two neutral and one negative word presented simultaneously and, 425 msec later, were cued to mentally refresh (i.e., think of) one of the no-longer-present words. They were slower to refresh a neutral word than the negative word (Johnson et al., 2005, Experiment 6A). The present experiments extended that work by showing mental rubbernecking when negative items were sometimes the target of refreshing, but not when negative items were present but never the target of refreshing, indicating that expectations influence mental rubbernecking. How expectations might modulate the impact of emotional distraction is discussed.     

Effect of study context on item recollection

We examined how visual context information provided during encoding, and unrelated to the target word, affected later recollection for words presented alone using a remember–know paradigm. Experiments 1A and 1B showed that participants had better overall memory—specifically, recollection—for words studied with pictures of intact faces than for words studied with pictures of scrambled or inverted faces. Experiment 2 replicated these results and showed that recollection was higher for words studied with pictures of faces than when no image accompanied the study word. In Experiment 3 participants showed equivalent memory for words studied with unique faces as for those studied with a repeatedly presented face. Results suggest that recollection benefits when visual context information high in meaningful content accompanies study words and that this benefit is not related to the uniqueness of the context. We suggest that participants use elaborative processes to integrate item and meaningful contexts into ensemble information, improving subsequent item recollection.     

When words collide: facilitation and interference in the report of repeated words from rapidly presented lists

Inhibited encoding is the basis of some accounts of repetition blindness--impaired report of the second occurrence of a repeated word in a rapidly presented word sequence. The author presents evidence for the claim that repetition effects arise from constructive processes of perception and memory that occur to some extent after the word sequence has been presented. Unpredictable postlist cues prompted subjects to report either the entire list or just the final word in the list. Repetition impaired the report of the second occurrence of a repeated word under full report but facilitated the report of such items when only the final word had to be reported. The author modulated this dissociation by presenting repeated words in sentences rather than unrelated word lists. The sensitivity of the effects of repetition to postlist cues supports a construction rather than an encoding inhibition account of repetition blindness.     

Stimulus similarity decrements in children's working memory span

Two experiments investigated the impact of the relationship between processing and storage stimuli on the working memory span task performance of children aged 7 and 9 years of age. In Experiment 1, two types of span task were administered (sentence span and operation span), and participants were required to recall either the products of the processing task (sentence-final word, arithmetic total) or a word or digit unrelated to the processing task. Experiment 2 contrasted sentence span and operation span combined with storage of either words or digits, in tasks in which the item to be remembered was not a direct product of the processing task in either condition. In both experiments, memory span was significantly greater when the items to be recalled belonged to a different stimulus category from the material that was processed, so that in sentence span tasks, number recall was superior to word recall, and in operation span tasks, word recall was superior to number recall. Explanations of these findings in terms of similarity-based interference and response competition in working memory are discussed.     

Single-item memory, associative memory, and the human hippocampus

We tested recognition memory for items and associations in memory-impaired patients with bilateral lesions thought to be limited to the hippocampal region. In Experiment 1 (Combined memory test), participants studied words and then took a memory test in which studied words, new words, studied word pairs, and recombined word pairs were presented in a mixed order. In Experiment 2 (Separated memory test), participants studied single words and then took a memory test involving studied word and new words. In a separate test, they studied word pairs and then took a memory test involving studied word pairs and recombined word pairs. In both experiments, patients were impaired at memory for single items as well as memory for associations, suggesting that the hippocampus is important for both of these memory functions. In Experiment 1, patients appeared to be more impaired at associative memory than item memory. In Experiment 2, patients were similarly impaired at associative memory and item memory. These different findings are considered, including the fact that in Experiment 1 the results depended on the fact that controls produced unexpectedly low false-alarm rates to recombined pairs. We discuss single-item and associative memory from the perspective that the hippocampus and adjacent cortex work cooperatively to signal recognition and that simple dichotomies do not adequately describe the division of labor within the medial temporal lobe.     

Phonemic-analysis training helps children benefit from spelling-sound rules

It has been frequently suggested that the ability to analyze spoken words into phonemes facilitates children’s learning of spelling-sound rules. This research attempts to demonstrate that link by showing that phonemic-analysis training helps children take advantage of spelling sound rules in learning to read. In two experiments, preschool and kindergarten prereaders participated in an analysis condition and a control condition on each of 4 test days. In the analysis condition, children learned to segment (and in Experiment 2, also to blend) selected spoken syllables. In the control condition, they merely repeated syllables. Children were then introduced to printed items that corresponded to the spoken syllables with which they had worked. The pronunciation of the “related” item could be deduced from those of other printed items in the set; the pronunciation of the “unrelated” item could not be so deduced. Both experiments revealed a significant interaction between condition (analysis vs. control) and item type (related vs. unrelated). In the control condition, children tended to make more errors on the related item than on the unrelated item; in the analysis condition, they tended to make fewer errors on the related item than on the unrelated item. These results suggest a causal link between the ability to analyze spoken syllables and the ability to benefit from spelling-sound relations in reading.     

The time course of competition for attention: attention is initially labile

Competition for attention between 2 written words was investigated by presenting the words briefly in a single stream of distractors (Experiment 1) or in different streams (Experiment 2-6), using rapid serial visual presentation at 53 ms/item. Stimulus onset asynchrony (SOA) was varied from 0 to 213 ms. At all SOAs there was strong competition, but which word was more likely to be reported shifted markedly with SOA. At SOAs in the range of 13-53 ms the second word was more likely to be reported, but at 213 ms, the advantage switched to the first word, as in the attentional blink. A 2-stage competition model of attention is proposed in which attention to a detected target is labile in Stage 1. Stage 1 ends when one target is identified, initiating a serial Stage 2 process of consolidation of that target.     

Imagery encoding and false recognition errors: Examining the role of imagery process and imagery content on source misattributions

Imagery encoding effects on source-monitoring errors were explored using the Deese-Roediger-McDermott paradigm in two experiments. While viewing thematically related lists embedded in mixed picture/word presentations, participants were asked to generate images of objects or words (Experiment 1) or to simply name the items (Experiment 2). An encoding task intended to induce spontaneous images served as a control for the explicit imagery instruction conditions (Experiment 1). On the picture/word source-monitoring tests, participants were much more likely to report "seeing" a picture of an item presented as a word than the converse particularly when images were induced spontaneously. However, this picture misattribution error was reversed after generating images of words (Experiment 1) and was eliminated after simply labelling the items (Experiment 2). Thus source misattributions were sensitive to the processes giving rise to imagery experiences (spontaneous vs deliberate), the kinds of images generated (object vs word images), and the ways in which materials were presented (as pictures vs words).     

Short-term memory in autism spectrum disorder

Three experiments examined verbal short-term memory in comparison and autism spectrum disorder (ASD) participants. Experiment 1 involved forward and backward digit recall. Experiment 2 used a standard immediate serial recall task where, contrary to the digit-span task, items (words) were not repeated from list to list. Hence, this task called more heavily on item memory. Experiment 3 tested short-term order memory with an order recognition test: Each word list was repeated with or without the position of 2 adjacent items swapped. The ASD group showed poorer performance in all 3 experiments. Experiments 1 and 2 showed that group differences were due to memory for the order of the items, not to memory for the items themselves. Confirming these findings, the results of Experiment 3 showed that the ASD group had more difficulty detecting a change in the temporal sequence of the items.     

The effects of lexical and semantic information on same-different visual comparison of words

Previous research has indicated that phonemic and orthographic factors cannot account for the fact that words (clear/clear) are responded to more rapidly than orthographically legal nonwords (creal/creal) in a same-different visual comparison task. However, the role of semantic and lexical factors is less certain. The effects of semantic similarity on both same and different judgments were evaluated in several experiments. In the first experiment, subjects were not any slower on semantically related (rang/rung) than on unrelated (rang/rank) different judgments even with a 3,000-msec interval between the first and second word. In Experiment 2, subjects based their judgments on whether or not the first letter of each word was visually identical. Same judgments were not any faster for semantically related than unrelated items even though other evidence indicated that subjects were processing the whole word and not just the first letter. Experiment 3 showed that the word/orthographically legal nonword difference could be replicated with the first-letter visual comparison task employed in Experiment 2. These and related results were discussed with reference to the idea that the word/orthographically legal nonword difference is due to the facilitating effects of a lexical entry upon the encoding, but not the comparison of an item.     

Language access and language selection in professional translators

Two experiments were conducted measuring self-paced reading to study language access and language selection in professional translators and bilinguals when they understood sentences randomly presented in their first language (L1, Spanish) and second language (L2, English). These sentences contained a critical cognate word or a control matched word. The effect of cognate words was considered an index of between-language activation while the inhibition of the non-target language was examined with the asymmetrical switching cost. In Experiment 1, participants read and repeated sentences while in Experiment 2 participants read sentences without repeating them after reading. The results indicated that lexical processing depended on the experience of participants in professional translation and the demands imposed by the understanding task (reading and repeating or only reading).     

Capturing conceptual implicit memory: The time it takes to produce an association

Conceptual implicit memory is demonstrated when, in the absence of explicit retrieval, performance on a task requiring conceptual processing benefits more from prior conceptual encoding than from prior nonconceptual encoding. In the present study, we sought to provide an improved measure of conceptual implicit memory by minimizing contamination from explicit retrieval. On a modified word association test, participants free-associated to the actually studied items, with response time to produce any associate serving as the dependent measure. Experiment 1 varied whether words were read or generated at study and showed that generated words were associated to more quickly than were read words. Experiment 2 varied level of processing at study and showed that words processed semantically were associated to more quickly than were words processed nonsemantically. With modifications to ensure its implicit nature, a conceptual implicit test can be consistently affected by the same encoding manipulations as those that affect conceptual explicit memory tests.     

Lexical competition and the acquisition of novel words

Three experiments examined the involvement of newly learnt words in lexical competition. Adult participants were familiarized with novel nonsense sequences that overlapped strongly with existing words (e.g. cathedruke, derived from cathedral) through repeated presentation in a phoneme-monitoring task. Experiment 1 looked at the immediate effects of exposure to these sequences, with participants showing familiarity with the form of the novel sequences in a two-alternative forced choice task. The effect of this exposure on lexical competition was examined by presenting the existing words (e.g. cathedral) in a lexical decision task. The immediate effect of the exposure was facilitatory, suggesting that the novel words had activated the representation of the closest real word rather than developing their own lexical representations. In Experiment 2, inhibitory lexical competition effects emerged over the course of 5 days for offset-diverging (e.g. cathedruke-cathedral) but not onset-diverging (e.g. yothedral-cathedral) novel words. Experiment 3 disentangled the roles of time and level-of-exposure in the lexicalization process and assessed the generality of the observed lexical inhibition using pause detection. A single, concentrated exposure session was used, which resulted in good recognition performance soon after. Lexicalization effects were absent immediately after exposure but emerged 1 week later, despite no intervening exposure to the novel items. These results suggest that integrating a novel word into the mental lexicon can be an extended process: phonological information is learnt swiftly, but full integration with existing items develops at a slower rate.     

Physical and conceptual priming effects on picture and word identification

In the study phase of these experiments, subjects were asked to think of an item suggested by the omission in an incomplete sentence, and then look at a picture or word describing an item and say whether it was the same as theirs. In the test phase, they were asked to identify studied and nonstudied items presented briefly in either picture or word form. Subjects were then required to recall the words or pictures shown in the study phase. Experiment 1, with a within-subjects design, revealed that the studied pictures were identified more readily than studied words and nonstudied pictures. This indicates a physical priming effect. In word identification, studied words were identified more readily than nonstudied words; however, there was no difference between studied words and studied pictures, and the performance for studied pictures and nonstudied items were largely the same. The physical priming effect on picture identification was also shown in Experiment 2, with a between-subjects design. Different processing mechanisms in picture and word identification are discussed.     

Examining the Response Competition Hypothesis of Age Effects in Implicit Memory

ABSTRACT

Age reductions in priming have been explained by differences in processing demands across implicit memory tests. According to one hypothesis, older adults show reduced priming relative to younger adults on implicit tests that require production of a response because these tests typically allow for response competition. In contrast, older adults do not show reductions in priming on identification tests that contain little response competition. The following experiments tested the specific role of response competition in mediating age effects in implicit memory. In Experiment 1, younger and older adults studied a list of words and were then given an implicit test of word stem completion. They studied a second list of words and were given an implicit test of general knowledge. Each implicit test contained items with unique solutions (the low response competition condition) and items with multiple solutions (the high response competition condition). In Experiment 2, younger and older adults were given explicit versions of the word stem completion and the general knowledge tests. Results showed an effect of age on explicit memory (Experiment 2), but no effect of age or response competition on priming (Experiment 1). Results are inconsistent with the theory that response competition leads to age effects on production tests of implicit memory.     

Backward recall and the word length effect

The word length effect, the finding that words that have fewer syllables are recalled better than otherwise comparable words that have more syllables, is one of the benchmark effects that must be accounted for in any model of serial recall, and simulation models of immediate memory rely heavily on the finding. However, previous research has shown that the effect disappears when participants are asked to recall the items in strict backward order. The present 2 experiments replicate and extend that finding by manipulating the participant's foreknowledge of recall direction (Experiment 1) and by giving the participant repeated practice with one direction by blocking recall direction (Experiment 2). In both experiments, a word length effect obtained with forward but not backward recall. The results are problematic for all models that currently have an a priori explanation for word length effects. The finding can be accounted for but is not predicted by Scale-Independent Memory, Perception, and Learning (SIMPLE), a model in which item and order information are differentially attended to in the 2 recall directions.     

The influence of consistency, frequency, and semantics on learning to read: an artificial orthography paradigm

Two experiments explored learning, generalization, and the influence of semantics on orthographic processing in an artificial language. In Experiment 1, 16 adults learned to read 36 novel words written in novel characters. Posttraining, participants discriminated trained from untrained items and generalized to novel items, demonstrating extraction of individual character sounds. Frequency and consistency effects in learning and generalization showed that participants were sensitive to the statistics of their learning environment. In Experiment 2, 32 participants were preexposed to the sounds of all items (lexical phonology) and to novel definitions for half of these items (semantics). Preexposure to either lexical phonology or semantics boosted the early stages of orthographic learning relative to Experiment 1. By the end of training, facilitation was restricted to the semantic condition and to items containing low-frequency inconsistent vowels. Preexposure reduced generalization, suggesting that enhanced item-specific learning was achieved at the expense of character-sound abstraction. The authors' novel paradigm provides a new tool to explore orthographic learning. Although the present findings support the idea that semantic knowledge supports word reading processes, they also suggest that item-specific phonological knowledge is important in the early stages of learning to read.