Stimulus Items Research Articles

Why computational models are better than verbal theories: the case of nonword repetition

Tests of nonword repetition (NWR) have often been used to examine children's phonological knowledge and word learning abilities. However, theories of NWR primarily explain performance either in terms of phonological working memory or long-term knowledge, with little consideration of how these processes interact. One theoretical account that focuses specifically on the interaction between short-term and long-term memory is the chunking hypothesis. Chunking occurs because of repeated exposure to meaningful stimulus items, resulting in the items becoming grouped (or chunked); once chunked, the items can be represented in short-term memory using one chunk rather than one chunk per item. We tested several predictions of the chunking hypothesis by presenting 5-6-year-old children with three tests of NWR that were either high, medium, or low in wordlikeness. The results did not show strong support for the chunking hypothesis, suggesting that chunking fails to fully explain children's NWR behavior. However, simulations using a computational implementation of chunking (namely CLASSIC, or Chunking Lexical And Sub-lexical Sequences In Children) show that, when the linguistic input to 5-6-year-old children is estimated in a reasonable way, the children's data are matched across all three NWR tests. These results have three implications for the field: (a) a chunking account can explain key NWR phenomena in 5-6-year-old children; (b) tests of chunking accounts require a detailed specification both of the chunking mechanism itself and of the input on which the chunking mechanism operates; and (c) verbal theories emphasizing the role of long-term knowledge (such as chunking) are not precise enough to make detailed predictions about experimental data, but computational implementations of the theories can bridge the gap.

Poor phonemic discrimination does not underlie poor verbal short-term memory in Down syndrome

Individuals with Down syndrome tend to have a marked impairment of verbal short-term memory. The chief aim of this study was to investigate whether phonemic discrimination contributes to this deficit. The secondary aim was to investigate whether phonological representations are degraded in verbal short-term memory in people with Down syndrome relative to control participants. To answer these questions, two tasks were used: a discrimination task, in which memory load was as low as possible, and a short-term recognition task that used the same stimulus items. Individuals with Down syndrome were found to perform significantly better than a nonverbal-matched typically developing group on the discrimination task, but they performed significantly more poorly than that group on the recognition task. The Down syndrome group was outperformed by an additional vocabulary-matched control group on the discrimination task but was outperformed to a markedly greater extent on the recognition task. Taken together, the results strongly indicate that phonemic discrimination ability is not central to the verbal short-term memory deficit associated with Down syndrome.

Random effects structure for testing interactions in linear mixed-effects models

OPINION article Front. Psychol., 05 June 2013Sec. Quantitative Psychology and Measurement https://doi.org/10.3389/fpsyg.2013.00328

Can young children be more accurate predictors of their recall performance?

Preschoolers persistently predict that they will perform better than they actually can perform on a picture recall task. The current investigation sought to explore a condition under which young children might be able to improve their predictive accuracy. Namely, children were asked to predict their recall twice for the same set of items. Children’s second predictions were significantly less overconfident than their initial predictions for a set of items. However, between trials (when the stimulus items changed), children’s initial predictions remained persistently overconfident. Children appear to have some understanding that past performance can predict future performance when predicting for the same set of items, but they fail to apply this understanding to new sets of stimuli.

The Goldilocks effect: human infants allocate attention to visual sequences that are neither too simple nor too complex.

Human infants, like immature members of any species, must be highly selective in sampling information from their environment to learn efficiently. Failure to be selective would waste precious computational resources on material that is already known (too simple) or unknowable (too complex). In two experiments with 7- and 8-month-olds, we measure infants’ visual attention to sequences of events varying in complexity, as determined by an ideal learner model. Infants’ probability of looking away was greatest on stimulus items whose complexity (negative log probability) according to the model was either very low or very high. These results suggest a principle of infant attention that may have broad applicability: infants implicitly seek to maintain intermediate rates of information absorption and avoid wasting cognitive resources on overly simple or overly complex events.

The attentional blink as an indicator of sexual interest

Using implicit measures in psychological assessment is new in research. The Attentional Blink is a widely supported phenomenon in the cognitive literature. It has been reported that emotionally salient stimuli, particularly those of a sexual nature, can produce it, leading to lower recall of a neutral target presented after the stimulus item. This study looked at the Attentional Blink as a measure of sexual interest. It also looked at the use of computer-generated (CG) images as an alternative to real images. Findings showed that nude images produced the largest Attentional Blink, real images are most effective, and CG images produced some effect. These finding are promising for the development of CG images of children for use in paedophile assessment.

Generalisation of personalised cueing to enhance word finding in natural settings

Background: Personalised cueing is a treatment method for naming deficits in patients with aphasia. As part of the treatment patients choose their own cues to help recall a target word. These cues usually include personally relevant semantic information, which is hypothesised to enhance long-term naming abilities. Previous research has shown that personalised cueing can improve long-term naming accuracy in persons with aphasia. However, no research has shown that personalised cueing carries over to improved naming in natural settings. Aims: The study aimed to examine the long-term generalisation of improved word finding using the personalised cueing method. Methods & Procedures: Three individuals participated in 12 training trials using the personalised cueing method; 40 unnamed stimulus items were chosen for each participant. Pre-training measures of the Sentence Production Task (SPT) and Message Exchange Task (MET) were administered for each participant. Of the 40 stimulus items, 20 were then trained using the personalised cueing method across 12 training sessions. Post-training measures of the SPT and MET were then collected, along with measures on a Caregiver Partner Rating scale to assess naming accuracy in natural settings. The 20 untrained stimulus items were also probed to assess generalisation to untrained stimuli. Outcomes & Results: Two of the three participants showed improvement in naming trained items in natural settings, but little improvement was noted on the untrained stimulus items. Results for these patients were consistent with other studies on the personalised cueing method. The third participant demonstrated a slight increase in naming accuracy over time. Shortly after this study that participant was diagnosed with Alzheimer's disease. Conclusions: Results suggest that personalised cueing is an effective method of improving naming in certain individuals with aphasia. It also suggests that the effects of personalised cueing are maintained over time and are evident in natural settings.

Generalisation of a novel implicit treatment for coarse coding deficit in right hemisphere brain damage: A single-participant experiment

Background: This manuscript reports generalisation effects of Contextual Constraint Treatment for an adult with right hemisphere brain damage (RHD). Contextual Constraint Treatment is designed to stimulate inefficient language comprehension processes implicitly, by providing linguistic context to prime, or constrain, the intended interpretations of treatment stimuli. The study participant had a coarse coding deficit, defined as delayed mental activation of particularly distant semantic features of words (e.g., rotten as a feature of “apple”). Treatment effects were expected to generalise to auditory comprehension of narrative discourse, and perhaps to figurative language interpretation, because coarse coding has been hypothesised and/or demonstrated to support these abilities. Aims: This treatment study aimed to induce generalisation of Contextual Constraint Treatment in an adult with RHD with inefficient coarse coding. Methods & Procedures: The participant in this study was a 75-year-old man with RHD and a coarse coding deficit. A single-participant experimental design across behaviours (stimulus lists) was used to document performance in baseline, treatment, and follow-up phases. Treatment consisted of providing brief, spoken context sentences to prestimulate, or constrain, intended interpretations of stimulus items. The participant made no explicit associations or metalinguistic judgements about the constraint sentences or stimulus words; rather these contexts served only as implicit primes. Probe tasks were adapted from prior work on coarse coding in RHD. The dependent measure was the percentage of responses that met predetermined response time criteria. There were two levels of contextual constraint, Strong and Moderate. Treatment for each item began with the provision of the Strong constraint context, to minimise the production or reinforcement of erroneous or exceedingly slow responses. Generalisation was assessed to a well-standardised measure of narrative discourse comprehension and to several metalinguistic tasks of figurative language interpretation. Outcomes & Results: Treatment-contingent gains, associated with respectable effect sizes, were evident after a brief period of treatment on one stimulus list. Generalisation occurred to untrained items, suggesting that the treatment was facilitating the underlying coarse coding process. Most importantly, generalisation was evident to narrative comprehension performance, for both overall accuracy and accuracy in answering questions about implied information, and all of these gains were maintained through three follow-up sessions. Conclusions: Although the results are still preliminary, this single-participant experimental design documents the potential for meaningful gains from a novel treatment that implicitly targets an underlying language comprehension process in an adult with RHD.

THE EFFECTS OF BEHAVIOR SKILLS TRAINING ON CORRECT TEACHER IMPLEMENTATION OF NATURAL LANGUAGE PARADIGM TEACHING SKILLS AND CHILD BEHAVIOR

Natural Language Paradigm (NLP) is a naturalistic teaching strategy for children with autism that increases immediate and delayed imitative utterances, spontaneous utterances and new words, and production of utterances. NLP includes increasing child choice, varying stimulus items, loose shaping contingencies for communicative attempts, and providing reinforcers with a direct relationship to the response. Only one previous study investigated the effects of behavioral skills training (BST) on staff acquisition and generalization of implementation of NLP and child behavior. A BST package of instructions, modeling rehearsal and feedback, was used to train teachers to implement NLP teaching procedures with three pre‐school children with autism spectrum disorder. Training increased correct teacher performance systematically across all three teachers during NLP teaching sessions and with children for whom teachers did not directly receive training. Correct teacher performance increased appropriate child vocalizations and decreased maladaptive behavior for four of six children. BST is effective in quickly training teachers in the generalized implementation of complex NLP teaching procedures across children. Copyright © 2012 John Wiley & Sons, Ltd.

Sources of illusion in consonant cluster perception

Previous studies have shown that listeners have difficulty discriminating between non-native CC sequences and licit alternatives (e.g. Japanese [ebzo]-[ebuzo], English [bnif]-[bənif]) (Berent et al., 2007; Dupoux et al., 1999). Some have argued that the difficulty in distinguishing these illicit–licit pairs is due to a “perceptual illusion” caused by the phonological system, which prevents listeners from accurately perceiving a phonotactically unattested consonant cluster. In this study, we explore this and other sources of perceptual illusion by presenting English listeners with non-native word-initial clusters paired with various modifications, including epenthesis, deletion, C1 change, and prothesis, in both AX and ABX discrimination tasks (e.g. [zmatu]-[zəmatu], [matu], [smatu], or [əzmatu]). For English listeners, fricative–initial sequences are most often confused with prothesis, stop–nasal sequences with deletion or change of the first consonant, and stop–stop sequences with vowel insertion. The pattern of results across tasks indicates that in addition to interference from the phonological system, sources of perceptual illusion include language-specific phonetic knowledge, the acoustic similarity of the stimulus items, the task itself, and the number of modifications to illicit sequences used in the experiment.

A COMPARISON OF TWO FLASH-CARD METHODS FOR IMPROVING SIGHT-WORD READING

Flash cards have been shown to be useful for teaching sight-word reading. To date, the most effective flash-card instruction method is incremental rehearsal (IR). This method involves the instructor interspersing unknown stimulus items into the presentation of known stimulus items. In this study, we compared IR to a modified IR procedure-strategic incremental rehearsal (SIR)-to determine whether the effects of IR might be improved by incorporating variables likely to increase word acquisition. These included increased opportunities to respond to unknown stimuli, using learner responding as a basis for changing instructional items, and systematic prompting methods. An A-B-A-B design was used to compare the effects of IR and SIR for increasing sight-word reading with 4 elementary school students. Results indicated that students read more words correctly with SIR than with IR. In addition, similar patterns of responding were seen at a 2-week follow-up.

Technology-based programs to promote walking fluency or improve foot-ground contact during walking: Two case studies of adults with multiple disabilities

These two case studies assessed technology-based programs for promoting walking fluency and improving foot-ground contact during walking with a man and a woman with multiple disabilities, respectively. The man showed breaks during walking and the woman presented with toe walking. The technology used in the studies included a microprocessor with specific software, an MP3 with the recordings of preferred stimulus items, and optic sensors. Both studies were carried out according to an ABAB design. In Study I, the optic sensors were activated when the man crossed small marks distributed along the travel routes. At each sensor's activation, the man received a brief period of preferred stimulation. In Study II, the woman received preferred stimulation when the sensors at the toe and the heel of her shoes were activated in close time proximity. The man walked virtually without breaks and improved his mood (with an increase in indices of happiness) during the intervention phases of the study. The woman largely increased her percentages of steps with adequate foot-ground contact, which reached a mean of about 80 during the second intervention phase. The results were discussed in terms of rehabilitation implications and technology demands.

The Perceptual Interaction between Schwa Deletion and English Phonotactic Constraints

This study explored the perceptual interaction between schwa deletion and English phonotactic constraints by conducting syllable-count experiments on native English and Korean and Japanese learners of English, using English nonce word stimuli. The results of both response accuracy and latency showed that English were abel to discriminate between legal and illegal onset clusters in English resulting from schwa deletion, regardless of the number of the syllables of the stimuli. However, Korean and Japanese learners of English were not sensitive to English phonotactic constraints on legal vs. illegal onset sequences created by schwa deletion. Similarly, English speakers perception of illegal onsets resulting from schwa deletion conformed to the predictions of the sonority-based onset markedness in that their perception of onsets of sonority rises was more accurate and faster than sonority levels and falls in order. On the contrary, Korean and Japanese learners of English displayed a partial sensitivity to the onset-markedness, as the mean accuracy of sonority plateaus was higher than that of sonority rises and as the number of the syllables of the stimulus items also affected the general results. Overall, the results indicate that English phonotactic restrictions as well as the sonority-driven onset-markedness play a role in the perception of onset sequences resulting from schwa deletion. The implications of the results for speech perception, markedness, and lexical representation were further discussed.

Attention does more than modulate suppressive interactions: attending to multiple items

Directing attention to a visual item enhances its representations, making it more likely to guide behavior (Corbetta et al. 1991). Attention is thought to produce this enhancement by biasing suppressive interactions among multiple items in visual cortex in favor of the attended item (e.g., Desimone and Duncan 1995; Reynolds and Heeger 2009). We ask whether target enhancement and modulation of suppressive interactions are in fact inextricably linked or whether they can be decoupled. In particular, we ask whether simultaneously directing attention to multiple items may be one means of dissociating the influence of attention-related enhancement from the effects of inter-item suppression. When multiple items are attended, suppressive interactions in visual cortex limit the effectiveness with which attention may act on their representations, presumably because "biasing" the interactions in favor of a single item is no longer possible (Scalf and Beck 2010). In this experiment, we directly investigate whether applying attention to multiple competing stimulus items has any influence on either their evoked signal or their suppressive interactions. Both BOLD signal evoked by the items in V4 and behavioral responses to those items were significantly compromised by simultaneous presentation relative to simultaneous presentation, indicating that when the items appeared at the same time, they interacted in a mutually suppressive manner that compromised their ability to guide behavior. Attention significantly enhanced signal in V4. The attentional status of the items, however, had no influence on the suppressive effects of simultaneous presentation. To our knowledge, these data are the first to explicitly decouple the effects of top-down attention from those of inter-item suppression.

Effects of semantic elaboration and typicality on picture naming in Alzheimer disease

Purpose Individuals with probable Alzheimer disease (pAD) are frequently impaired at picture naming. This study examined whether a semantic elaboration task would facilitate naming in pAD, and whether training either semantically typical or atypical stimulus items facilitated generalized improvement in picture naming and category generation tasks. Methods Twelve adults with mild-moderate pAD participated in the study. Participants performed an experimental semantic elaboration training task using a subset of typical items from one category and atypical items from another category. The third category, acted as a control (i.e., no items were trained). The study assessed change in category generation and a picture naming within the three target categories. Results Individuals showed significantly improved category generation and naming, but changes were not limited to trained categories. Naming of trained atypical items improved significantly. Participants showed significantly improved naming of untrained typical items from categories trained with typical items. Conclusions Semantic elaboration of typical items within a semantic category can lead to generalized improvement in other typical items in the category in mild-moderate pAD. This is consistent with theories postulating that typical category items share overlapping distributed representations. Further exploration of the effects of semantic elaboration on word-finding in pAD is warranted, especially the possibility of within-category generalization. Learning outcomes: After reading this article, the reader will be able to: (1) explain how word-finding is affected by probable Alzheimer disease; (2) identify ways word finding is usually assessed in Alzheimer's disease; (3) describe the effects of training typical versus atypical items from a category in people with aphasia; and (4) describe the effects of training people with Alzheimer's disease on typical versus atypical items from a category.

Taxonomic and thematic organisation of proper name conceptual knowledge.

We report the investigation of the organisation of proper names in two aphasic patients (NBC and FBI). The performance of both patients on spoken word to written word matching tasks was inconsistent, affected by presentation rate and semantic relatedness of the competing responses, all hallmarks of a refractory semantic access dysphasia. In a series of experiments we explored the semantic relatedness effects within their proper name vocabulary, including brand names and person names. First we demonstrated the interaction between very fine grain organisation and personal experience, with one patient with a special interest in the cinema demonstrating higher error rates when identifying the names of actors working in a similar film genre (e.g. action movies: Arnold Schwarzenegger, Bruce Willis, Sylvester Stallone, Mel Gibson) than those working in different genres (e.g. Arnold Schwarzenegger, Gregory Peck, Robin Williams, Gene Kelly). Second we compared directly two potential principles of semantic organisation – taxonomic and thematic. Furthermore we considered these principles of organisation in the context of the individuals' personal knowledge base. We selected topics matching the interests and experience of each patient, namely cinema and literature (NBC) and naval history (FBI). The stimulus items were arranged in taxonomic arrays (e.g. Jane Austen, Emily Bronte, Agatha Christie), thematic arrays (e.g. Jane Austen, Pride and Prejudice, Mr Darcy), and unrelated arrays (e.g. Jane Austen, Wuthering Heights, Hercule Poirot). We documented that different patterns of taxonomic and thematic organisation were constrained by whether the individual has limited knowledge, moderate knowledge or detailed knowledge of a particular vocabulary. It is suggested that moderate proper name knowledge is primarily organised by taxonomy whereas extensive experience results in a more detailed knowledge base in which theme is a powerful organising principle.

Taxonomic and Thematic Organisation of Proper Name Conceptual Knowledge

We report the investigation of the organisation of proper names in two aphasic patients (NBC and FBI). The performance of both patients on spoken word to written word matching tasks was inconsistent, affected by presentation rate and semantic relatedness of the competing responses, all hallmarks of a refractory semantic access dysphasia. In a series of experiments we explored the semantic relatedness effects within their proper name vocabulary, including brand names and person names. First we demonstrated the interaction between very fine grain organisation and personal experience, with one patient with a special interest in the cinema demonstrating higher error rates when identifying the names of actors working in a similar film genre (e.g. action movies: Arnold Schwarzenegger, Bruce Willis, Sylvester Stallone, Mel Gibson) than those working in different genres (e.g. Arnold Schwarzenegger, Gregory Peck, Robin Williams, Gene Kelly). Second we compared directly two potential principles of semantic organisation – taxonomic and thematic. Furthermore we considered these principles of organisation in the context of the individuals' personal knowledge base. We selected topics matching the interests and experience of each patient, namely cinema and literature (NBC) and naval history (FBI). The stimulus items were arranged in taxonomic arrays (e.g. Jane Austen, Emily Bronte, Agatha Christie), thematic arrays (e.g. Jane Austen, Pride and Prejudice, Mr Darcy), and unrelated arrays (e.g. Jane Austen, Wuthering Heights, Hercule Poirot). We documented that different patterns of taxonomic and thematic organisation were constrained by whether the individual has limited knowledge, moderate knowledge or detailed knowledge of a particular vocabulary. It is suggested that moderate proper name knowledge is primarily organised by taxonomy whereas extensive experience results in a more detailed knowledge base in which theme is a powerful organising principle.

Action and object processing in brain-injured speakers of Chinese.

To see whether action and object processing across different tasks and modalities differs in brain-injured speakers of Chinese with varying fluency and lesion locations within the left hemisphere. Words and pictures representing actions and objects were presented to a group of 33 participants whose native and/or dominant language was Mandarin Chinese: 23 patients with left-hemisphere lesions due to stroke and 10 language-, age- and education-matched healthy control participants. A set of 120 stimulus items was presented to each participant in three different forms: as black and white line drawings (for picture-naming), as written words (for reading) and as aurally presented words (for word repetition). Patients were divided into groups for two separate analyses: Analysis 1 divided and compared patients based on fluency (Fluent vs. Nonfluent) and Analysis 2 compared patients based on lesion location (Anterior vs. Posterior). Both analyses yielded similar results: Fluent, Nonfluent, Anterior, and Posterior patients all produced significantly more errors when processing action (M = 0.73, SD = 0.45) relative to object (M = 0.79, SD = 0.41) stimuli, and this effect was strongest in the picture-naming task. As in our previous study with English-speaking participants using the same experimental design (Arévalo et al., 2007, Arévalo, Moineau, Saygin, Ludy, & Bates, 2005), we did not find evidence for a double-dissociation in action and object processing between groups with different lesion and fluency profiles. These combined data bring us closer to a more informed view of action/object processing in the brain in both healthy and brain-injured individuals.

A nonverbal phoneme deletion task administered in a dynamic assessment format

PurposeThe purpose of the project was to design a nonverbal dynamic assessment of phoneme deletion that may prove useful with individuals who demonstrate complex communication needs (CCN) and are unable to communicate using natural speech or who present with moderate–severe speech impairments. MethodA nonverbal dynamic assessment of phoneme deletion with a systematic prompting and scoring system was developed and compared to the same measure administered using a traditional “static” format. Both versions were administered to 64 typically developing children ranging in age from 6 to 8;5. The dynamic phoneme deletion task was designed so that no verbal response was required. Children were asked to point to pictures representing each stimulus item. The same stimulus items were administered to children in a traditional static format, without the use of pictures. For example, in the dynamic assessment task, children were asked to point to 1 of 4 pictures (e.g., ice) to indicate their response when asked to delete “m” from “mice.” In the static format, children were asked to “say” the real word left over after deleting “m” from “mice.” Correlations between phoneme deletion tasks and word-level reading tasks were calculated. ResultsInternal reliability for the nonverbal dynamic phoneme deletion task was α=.88 for the total sample. Correlations between the dynamic and static formats were high (r=.84) as were correlations between the deletion tasks and the measure of word-level reading (dynamic; r=.54, static; r=.53). ConclusionsThese preliminary findings suggest that the nonverbal dynamic phoneme deletion task holds promise for use with children for whom speech output is compromised. Implications for use with children who use AAC or who have significant speech impairments and recommendations for future research are discussed.Learning outcomes: Readers will learn about a nonverbal dynamic assessment of phoneme deletion that may prove useful for measuring phoneme awareness for children who are unable to communicate using natural speech or who present with moderate–severe speech impairments. Readers will learn about the importance of accurate measurement of phoneme awareness for children with complex communication needs. Readers will also learn about how to develop and utilize reliable and valid measures of phoneme awareness for this population of children with communication impairments.

Paranormal Encounters as Eyewitness Phenomena: Psychological Determinants of Atypical Perceptual Interpretations

Many people who report paranormal sightings (e.g., Bigfoot and UFO aliens) are apparently sincere. This places many such sightings in the category of eyewitness errors, rather than of deliberate deception. Recent research has supported this idea; in an earlier paper, we demonstrated that paranormal beliefs are facilitated by tendencies toward attention deficit hyperactive disorder, dissociation, and depression. These characteristics predicted specific patterns of beliefs in several paranormal phenomena. The present research addressed the question of whether such psychological tendencies would tend to create bias in perception and interpretation as well as in belief- in whether a person’s identification of a given stimulus as paranormal in nature would be influenced by the same factors previously demonstrated to influence paranormal beliefs. This hypothesis was supported. Specifically, those with dissociative tendencies were significantly more likely to identify given stimulus items as paranormal in nature than were those with lower dissociation scores. Dissociation was further shown to be related to paranormal beliefs, consistent with earlier findings. Results are discussed in terms of the reconfigurative dynamics known to operate in areas of human cognition such as eyewitness identification, and in terms of the generality of those effects to the realm of paranormal sightings.