A cognitive and psycholinguistic investigation of neologisms

Background: Jargon aphasia with neologisms (i.e., novel nonword utterances) is a challenging language disorder that lacks a definitive theoretical description as well as clear treatment recommendations (Marshall, 2006). Aim: The aims of this two part investigation were to determine the source of neologisms in an individual with jargon aphasia (FF), to identify potential facilitatory semantic and/or phonological cuing effects in picture naming, and to determine whether the timing of the cues relative to the target picture mediated the cuing advantage. Methods and Procedures: FF’s underlying linguistic deficits were determined using several cognitive and linguistic tests. A series of computerized naming experiments using a modified version of the 175 item-Philadelphia Naming Test (Roach, Schwartz, Martin, Grewal, & Brecher, 1996) manipulated the cue type (semantic versus phonological) and relatedness (related versus unrelated). In a follow-up experiment, the relative timing of phonological cues was manipulated to test the effect of timing on the cuing advantage. The accuracy of naming responses and error patterns were analyzed. Outcome and Results: FF’s performance on the linguistic and cognitive test battery revealed a severe naming impairment with relatively spared word and nonword repetition, auditory comprehension of words and monitoring, and fairly well preserved semantic abilities. This performance profile was used to evaluate various explanations for neologisms including a loss of phonological codes, monitoring failure, and impairments in semantic system. The primary locus of his deficit appears to involve the connection between semantics to phonology, specifically, when word production involves accessing the phonological forms following semantic access. FF showed a significant cuing advantage only for phonological cues in picture naming, particularly when the cue preceded or coincided with the onset of the target picture. Conclusions: When integrated with previous findings, the results from this study suggest that the core deficit of this and at least some other jargon aphasics is in the connection from semantics to phonology. The facilitative advantage of phonological cues could potentially be exploited in future clinical and research studies to test the effectiveness of these cues for enhancing naming performance in individuals like FF.

Dissociating mere exposure and repetition priming as a function of word type

The mere exposure effect is defined as enhanced attitude toward a stimulus that has been repeatedly exposed. Repetition priming is defined as facilitated processing of a previously exposed stimulus. We conducted a direct comparison between the two phenomena to test the assumption that the mere exposure effect represents an example of repetition priming. In two experiments, having studied a set of words or nonwords, participants were given a repetition priming task (perceptual identification) or one of two mere exposure (affective liking or preference judgment) tasks. Repetition printing was obtained for both words and nonwords, but only nonwords produced a mere exposure effect. This demonstrates a key boundary for observing the mere exposure effect, one not readily accommodated by a perceptual representation systems (Tulving & Schacter, 1990) account, which assumes that both phenomena should show some sensitivity to nonwords and words.

Understanding the relationship between repetition priming and mere exposure

Over the last two decades interest in implicit memory, most notably repetition priming, has grown considerably. During the same period, research has also focused on the mere exposure effect. Although the two areas have developed relatively independently, a number of studies has described the mere exposure effect as an example of implicit memory. Tacit in their comparisons is the assumption that the effect is more specifically a demonstration of repetition priming. Having noted that this assumption has attracted relatively little attention, this paper reviews current evidence and shows that it is by no means conclusive. Although some evidence is suggestive of a common underlying mechanism, even a modified repetition priming (perceptual fluency/attribution) framework cannot accommodate all of the differences between the two phenomena. Notwithstanding this, it seems likely that a version of this theoretical framework still offers the best hope of a comprehensive explanation for the mere exposure effect and its relationship to repetition priming. As such, the paper finishes by offering some initial guidance as to ways in which the perceptual fluency/attribution framework might be extended, as well as outlining important areas for future research.

Sentence repetition in adolescents with specific language impairments and autism: an investigation of complex syntax

Background: Recent studies have indicated that many children with autism spectrum disorders present with language difficulties that are similar to those of children with specific language impairments, leading some to argue for similar structural deficits in these two disorders. Aims: Repetition of sentences involving long-distance dependencies was used to investigate complex syntax in these groups. Methods & Procedures: Adolescents with specific language impairments (mean age = 15;3, n = 14) and autism spectrum disorders plus language impairment (autism plus language impairment; mean age = 14;8, n = 16) were recruited alongside typically developing adolescents (mean age = 14;4, n = 17). They were required to repeat sentences containing relative clauses that varied in syntactic complexity. Outcomes & Results: The adolescents with specific language impairments presented with greater syntactic difficulties than the adolescents with autism plus language impairment, as manifested by higher error rates on the more complex object relative clauses, and a greater tendency to make syntactic changes during repetition. Conclusions & Implications: Adolescents with specific language impairments may have more severe syntactic difficulties than adolescents with autism plus language impairment, possibly due to their short-term memory limitations.

Non-word repetition in adolescents with Specific Language Impairment and Autism plus Language Impairments: a qualitative analysis

Non-word repetition (NWR) was investigated in adolescents with typical development, Specific Language Impairment (SLI) and Autism Plus language Impairment (ALI) (n = 17, 13, 16, and mean age 14;4, 15;4, 14;8 respectively). The study evaluated the hypothesis that poor NWR performance in both groups indicates an overlapping language phenotype (Kjelgaard & Tager-Flusberg, 2001). Performance was investigated both quantitatively, e.g. overall error rates, and qualitatively, e.g. effect of length on repetition, proportion of errors affecting phonological structure, and proportion of consonant substitutions involving manner changes. Findings were consistent with previous research (Whitehouse, Barry, & Bishop, 2008) demonstrating a greater effect of length in the SLI group than the ALI group, which may be due to greater short-term memory limitations. In addition, an automated count of phoneme errors identified poorer performance in the SLI group than the ALI group. These findings indicate differences in the language profiles of individuals with SLI and ALI, but do not rule out a partial overlap. Errors affecting phonological structure were relatively frequent, accounting for around 40% of phonemic errors, but less frequent than straight Consonant-for-Consonant or vowel-for-vowel substitutions. It is proposed that these two different types of errors may reflect separate contributory mechanisms. Around 50% of consonant substitutions in the clinical groups involved manner changes, suggesting poor auditory-perceptual encoding. From a clinical perspective algorithms which automatically count phoneme errors may enhance sensitivity of NWR as a diagnostic marker of language impairment. Learning outcomes: Readers will be able to (1) describe and evaluate the hypothesis that there is a phenotypic overlap between SLI and Autism Spectrum Disorders (2) describe differences in the NWR performance of adolescents with SLI and ALI, and discuss whether these differences support or refute the phenotypic overlap hypothesis, and (3) understand how computational algorithms such as the Levenshtein Distance may be used to analyse NWR data.

Effect of phonetic complexity on word reading and repetition in deep dyslexia

This investigation moves beyond the traditional studies of word reading to identify how the production complexity of words affects reading accuracy in an individual with deep dyslexia (JO). We examined JO’s ability to read words aloud while manipulating both the production complexity of the words and the semantic context. The classification of words as either phonetically simple or complex was based on the Index of Phonetic Complexity. The semantic context was varied using a semantic blocking paradigm (i.e., semantically blocked and unblocked conditions). In the semantically blocked condition words were grouped by semantic categories (e.g., table, sit, seat, couch,), whereas in the unblocked condition the same words were presented in a random order. JO’s performance on reading aloud was also compared to her performance on a repetition task using the same items. Results revealed a strong interaction between word complexity and semantic blocking for reading aloud but not for repetition. JO produced the greatest number of errors for phonetically complex words in semantically blocked condition. This interaction suggests that semantic processes are constrained by output production processes which are exaggerated when derived from visual rather than auditory targets. This complex relationship between orthographic, semantic, and phonetic processes highlights the need for word recognition models to explicitly account for production processes.

Immediate auditory repetition of words and nonwords: An ERP study of lexical and sublexical processing

ERPs were elicited to (1) words, (2) pseudowords derived from these words, and (3) nonwords with no lexical neighbors, in a task involving listening to immediately repeated auditory stimuli. There was a significant early (P200) effect of phonotactic probability in the first auditory presentation, which discriminated words and pseudowords from nonwords; and a significant somewhat later (N400) effect of lexicality, which discriminated words from pseudowords and nonwords. There was no reliable effect of lexicality in the ERPs to the second auditory presentation. We conclude that early sublexical phonological processing differed according to phonotactic probability of the stimuli, and that lexically-based redintegration occurred for words but did not occur for pseudowords or nonwords. Thus, in online word recognition and immediate retrieval, phonological and/or sublexical processing plays a more important role than lexical level redintegration.

Habituation and dishabituation to speech and office noise

The authors examined whether background noise can be habituated to in the laboratory by using memory for prose tasks in 3 experiments. Experiment 1 showed that background speech can be habituated to after 20 min exposure and that meaning and repetition had no effect on the degree of habituation seen. Experiment 2 showed that office noise without speech can also be habituated to. Finally, Experiment 3 showed that a 5-min period of quiet, but not a change in voice, was sufficient to partially restore the disruptive effects of the background noise previously habituated to. These results are interpreted in light of current theories regarding the effects of background noise and habituation; practical implications for office planning are discussed.

Liquid matrix deposition on conductive hydrophobic surfaces for tuning and quantitation in UV-MALDI mass spectrometry

With its highly fluctuating ion production matrix-assisted laser desorption/ionization (MALDI) poses many practical challenges for its application in mass spectrometry. Instrument tuning and quantitative ion abundance measurements using ion signal alone depend on a stable ion beam. Liquid MALDI matrices have been shown to be a promising alternative to the commonly used solid matrices. Their application in areas where a stable ion current is essential has been discussed but only limited data have been provided to demonstrate their practical use and advantages in the formation of stable MALDI ion beams. In this article we present experimental data showing high MALDI ion beam stability over more than two orders of magnitude at high analytical sensitivity (low femtomole amount prepared) for quantitative peptide abundance measurements and instrument tuning in a MALDI Q-TOF mass spectrometer. Samples were deposited on an inexpensive conductive hydrophobic surface and shrunk to droplets <10 nL in size. By using a sample droplet <10 nL it was possible to acquire data from a single irradiated spot for roughly 10,000 shots with little variation in ion signal intensity at a laser repetition rate of 5-20 Hz.

Synthesis and properties of polyaromatic dendrimers possessing a repetitive amide-ester coupling sequence

A series of novel polyaromatic dendrimers that feature tris-(2-ethylamino)amine as the central core unit has been synthesized up to the third generation by employing a convergent growth strategy. The building blocks 1,3-diamino-2-hydroxypropane and 4-carboxybenzaldehyde were used for dendron construction, a process that involved the cyclic repetition of esterification, oxidation and selective amidation steps. Molecular modelling of this class of dendrimers has been used to predict potential solution state conformations employing molecular mechanics and molecular dynamic simulations. In addition, the results of preliminary metal binding studies using the first generation dendritic system are also outlined. (C) 2003 Elsevier Science Ltd. All rights reserved.

Neural mechanisms of visual object priming: evidence for perceptual and semantic distinctions in fusiform cortex

Previous functional imaging studies have shown that facilitated processing of a visual object on repeated, relative to initial, presentation (i.e., repetition priming) is associated with reductions in neural activity in multiple regions, including fusiforin/lateral occipital cortex. Moreover, activity reductions have been found, at diminished levels, when a different exemplar of an object is presented on repetition. In one previous study, the magnitude of diminished priming across exemplars was greater in the right relative to the left fusiform, suggesting greater exemplar specificity in the right. Another previous study, however, observed fusiform lateralization modulated by object viewpoint, but not object exemplar. The present fMRI study sought to determine whether the result of differential fusiform responses for perceptually different exemplars could be replicated. Furthermore, the role of the left fusiform cortex in object recognition was investigated via the inclusion of a lexical/semantic manipulation. Right fusiform cortex showed a significantly greater effect of exemplar change than left fusiform, replicating the previous result of exemplar-specific fusiform lateralization. Right fusiform and lateral occipital cortex were not differentially engaged by the lexical/semantic manipulation, suggesting that their role in visual object recognition is predominantly in the. C visual discrimination of specific objects. Activation in left fusiform cortex, but not left lateral occipital cortex, was modulated by both exemplar change and lexical/semantic manipulation, with further analysis suggesting a posterior-to-anterior progression between regions involved in processing visuoperceptual and lexical/semantic information about objects. The results are consistent with the view that the right fusiform plays a greater role in processing specific visual form information about objects, whereas the left fusiform is also involved in lexical/semantic processing. (C) 2003 Elsevier Science (USA). All rights reserved.

Processing of wh-questions in a case of posterior cortical atrophy

Posterior cortical atrophy (PCA) is a type of dementia that is characterized by visuo-spatial and memory deficits, dyslexia and dysgraphia, relatively early onset and preserved insight. Language deficits have been reported in some cases of PCA. Using an off-line grammaticality judgement task, processing of wh-questions is investigated in a case of PCA. Other aspects of auditory language are also reported. It is shown that processing of wh-questions is influenced by syntactic structure, a novel finding in this condition. The results are discussed with reference to accounts of wh-questions in aphasia. An uneven profile of other language abilities is reported with deficits in digit span (forward, backward), story retelling ability, comparative questions but intact abilities in following commands, repetition, concept definition, generative naming and discourse comprehension.