Biomedical subjects

Markus F Damian

Publications and source records attributed to Markus F Damian.

12 recordsLinked to original sources

PubMed2006

Effects of childhood hearing loss on organization of semantic memory: typicality and relatedness.

OBJECTIVE: The purpose of this research was to study how early childhood hearing loss affects development of concepts and categories, aspects of semantic knowledge that allow us to group and make inferences about objects with common properties, such as dogs versus cats. We assessed category typicality and out-of-category relatedness effects. The typicality effect refers to performance advantage (faster reaction times, fewer errors) for objects with a higher number of a category's characteristic properties; the out-of-category relatedness effect refers to performance disadvantage (slower reaction times and more errors) for out-of-category objects that share some properties with category members. DESIGN: We applied a new children's speeded category-verification task (vote "yes" if the pictured object is clothing). Stimuli were pictures of typical and atypical category objects (e.g., pants, glove) and related and unrelated out-of-category objects (e.g., necklace, soup). Participants were 30 children with hearing impairment (HI) who were considered successful hearing aid users and who attended regular classes (mainstreamed) with some support services. Ages ranged from 5 to 15 yr (mean = 10 yr 8 mo). Results were related to normative data from . RESULTS: Typical objects consistently showed preferential processing (faster reaction times, fewer errors), and related out-of-category objects consistently showed the converse. Overall, results between HI and normative groups exhibited striking similarity. Variation in speed of classification was influenced primarily by age and age-related competencies, such as vocabulary skill. Audiological status, however, independently influenced performance to a lesser extent, with positive responses becoming faster as degree of hearing loss decreased and negative responses becoming faster as age of identification/amplification/education decreased. There were few errors overall. CONCLUSIONS: The presence of a typicality effect indicates that 1) the structure of conceptual representations for at least one category in the HI group was based on characteristic properties with an uneven distribution among members, and 2) typical objects with a higher number of characteristic properties were more easily accessed and/or retrieved. The presence of a relatedness effect indicates that the structure of representational knowledge in the HI group allowed them to appreciate semantic properties and understand that properties may be shared between categories. Speculations linked the association 1) between positive responses and degree of hearing loss to an increase in the quality, accessibility, and retrievability of conceptual representations with better hearing; and 2) between negative responses and age of identification/amplification/education to an improvement in effortful, postretrieval decision-making proficiencies with more schooling and amplified auditory experience. This research establishes the value of our new approach to assessing the organization of semantic memory in children with HI.

Adolescent↗

PubMed2005

What's in a name? Typicality and relatedness effects in children.

We studied how category typicality and out-of-category relatedness affect speeded category verification (vote "yes" if pictured object is clothing) in typically developing 4- to 14-year-olds and adults. Stimuli were typical and atypical category objects (e.g., pants, glove) and related and unrelated out-of-category objects (e.g., necklace, soup). Typical and unrelated out-of-category objects exhibited preferential processing (faster reaction times and fewer errors). Variations in typicality and relatedness disproportionately influenced children's performance, with developmental improvement associated with both verbal and nonverbal factors. Underextension versus overextension errors seemed to be associated with independent factors, namely multifaceted maturational factors versus receptive vocabulary skill, respectively. Errors were infrequent, suggesting spontaneous taxonomic classification by all participants. An experiment with printed words in adults replicated results, indicating that typicality and relatedness effects reflected organizational principles of the semantic system, not picture-related processes. This research establishes the viability of an online approach to assessing automatic components of semantic organization in children.

Adolescent↗

PubMed2005

Long-lasting semantic context effects in the spoken production of object names.

A number of recent studies have found that objects are named more slowly in the context of same-category items than in the context of items from various semantic categories. Several experiments reported here indicated that this semantic effect is relatively persistent because it was essentially unaffected by the presence of interspersed filler items. The authors suggest that the effect is specific to the retrieval of lexical-semantic codes and characterize mechanisms that could support the effect at this processing level, such as incremental learning in the links between conceptual and lexical codes and the temporary increase of lexical resting levels. The results underscore the necessity of incorporating mechanisms of long-term adaptation into current models of spoken production.

Humans↗

PubMed2005

Refractory effects in picture naming as assessed in a semantic blocking paradigm.

In the cyclic semantic blocking paradigm participants repeatedly name sets of objects with semantically related names (homogeneous sets) or unrelated names (heterogeneous sets). The naming latencies are typically longer in related than in unrelated sets. In Experiment 1 we replicated this semantic blocking effect and demonstrated that the effect only arose after all objects of a set had been shown and named once. In Experiment 2, the objects of a set were presented simultaneously (instead of on successive trials). Evidence for semantic blocking was found in the naming latencies and in the gaze durations for the objects, which were longer in homogeneous than in heterogeneous sets. For the gaze-to-speech lag between the offset of gaze on an object and the onset of the articulation of its name, a repetition priming effect was obtained but no blocking effect. Experiment 3 showed that the blocking effect for speech onset latencies generalized to new, previously unnamed lexical items. We propose that the blocking effect is due to refractory behaviour in the semantic system.

Association Learning↗

PubMed2004

Age-of-acquisition effects in visual word recognition: evidence from expert vocabularies.

Three experiments assessed the contributions of age-of-acquisition (AoA) and frequency to visual word recognition. Three databases were created from electronic journals in chemistry, psychology and geology in order to identify technical words that are extremely frequent in each discipline but acquired late in life. In Experiment 1, psychologists and chemists showed an advantage in lexical decision for late-acquired/high-frequency words (e.g. a psychologist responding to cognition) over late-acquired/low-frequency words (e.g. a chemist responding to cognition), revealing a frequency effect when words are perfectly matched. However, contrary to theories that exclude AoA as a factor, performance was similar for the late-acquired/high-frequency and early-acquired/low-frequency words (e.g. dragon) even though their cumulative frequencies differed by more than an order of magnitude. This last finding was replicated with geologists using geology words matched with early-acquired words in terms of concreteness (Experiment 2). Most interestingly, Experiment 3 yielded the same pattern of results in naming while controlling for imageability, a finding that is particularly problematic for parallel distributed processing models of reading.

Adult↗

PubMed2004

Asymmetries in the processing of Arabic digits and number words.

Numbers can be represented as Arabic digits ("6") or as number words ("six"). The present study investigated potential processing differences between the two notational formats. In view of the previous finding (e.g., Potter & Faulconer, 1975) that objects are named slower, but semantically categorized faster, than corresponding words, it was investigated whether a similar interaction between stimulus format and task could be obtained with numbers. Experiment 1 established that number words were named faster than corresponding digits, but only if the two notation formats were presented in separate experimental blocks. Experiment 2 contrasted naming with a numerical magnitude judgment task and demonstrated an interaction between notation and task, with slower naming but faster magnitude judgment latencies for digits than for number words. These findings suggest that processing of the two notation formats is asymmetric, with digits gaining rapid access to numerical magnitude representations, but slower access to lexical codes, and the reverse for number words.

Attention↗

PubMed2003

Articulatory duration in single-word speech production.

Three different speech production paradigms assessed C. T. Kello, D. C. Plaut, and B. MacWhinney's (2000) claim that the characteristics of speech production flexibly vary between staged and cascaded modes depending on task demand. All experiments measured response latencies and durations of single words without and with a response deadline. Experiment 1 used a picture-word interference task; Experiment 2 blocked pictures either by semantic category or by word-initial overlap; and Experiment 3 used a Stroop paradigm. In all cases, systematic effects of semantic and form relatedness were obtained on latencies but not on response durations. These results support the assumption that articulation, as assessed by response duration, is never influenced by central cognitive processes once a response has been initiated.

Cognition↗

PubMed2003

Semantic priming in the name retrieval of objects and famous faces.

Researchers interested in face processing have recently debated whether access to the name of a known person occurs in parallel with retrieval of semantic-biographical codes, rather than in a sequential fashion. Recently, Schweinberger, Burton, and Kelly (2001) took a failure to obtain a semantic context effect in a manual syllable judgment task on names of famous faces as support for this position. In two experiments, we compared the effects of visually presented categorically related prime words with either objects (e.g. prime: animal; target: dog) or faces of celebrities (e.g. prime: actor; target: Bruce Willis) as targets. Targets were either manually categorized with regard to the number of syllables (as in Schweinberger et al.), or they were overtly named. For neither objects nor faces was semantic priming obtained in syllable decisions; crucially, however, priming was obtained when objects and faces were overtly named. These results suggest that both face and object naming are susceptible to semantic context effects.

Adult↗

PubMed2003

Locus of semantic interference in picture-word interference tasks.

Picture-word interference studies typically show that semantically related distractor words embedded within a picture slow picture-naming responses, relative to unrelated ones. This semantic interference effect is commonly interpreted as arising from the competition of lexical-semantic (e.g., Schriefers, Meyer, & Levelt, 1990) or lexical-phonological (e.g., Starreveld & La Heij, 1996) codes. The experiment reported here tests a crucial assumption shared by these accounts--namely, that the effect reflects a lexical, rather than a nonverbal, conceptual conflict. Pictures were named while participants attempted to ignore embedded distractors that were in either verbal or pictorial format. The presence of both words and pictures substantially interfered with naming responses, but only words, not pictures, were found to induce semantic interference. These findings support the claim that for semantic interference to arise, both target picture and distractor have to be lexicalized. Consequently, a general conceptual locus of the effect can be excluded, and the claim that semantic interference is based on a lexical conflict is confirmed.

Adolescent↗

PubMed2002

Semantic distance effects on object and action naming.

Graded interference effects were tested in a naming task, in parallel for objects and actions. Participants named either object or action pictures presented in the context of other pictures (blocks) that were either semantically very similar, or somewhat semantically similar or semantically dissimilar. We found that naming latencies for both object and action words were modulated by the semantic similarity between the exemplars in each block, providing evidence in both domains of graded semantic effects.

Humans↗

PubMed2002

Semantic and syntactic forces in noun phrase production.

Three experiments investigated semantic and syntactic effects in the production of phrases in Dutch. Bilingual participants were presented with English nouns and were asked to produce an adjective + noun phrase in Dutch including the translation of the noun. In 2 experiments, the authors blocked items by either semantic category or grammatical gender. Participants performed the task slower when the target nouns were of the same semantic category than when they were from different categories and faster when the target nouns had the same gender than when they had different genders. In a final experiment, both manipulations were crossed. The authors replicated the results of the first 2 experiments, and no interaction was found. These findings suggest a feedforward flow of activation between lexico-semantic and lexico-syntactic information.

Adult↗

PubMed2002

A third route for reading? Implications from a case of phonological dyslexia.

Models of reading in the neuropsychological literature sometimes only include two routes from print to sound, a lexical semantic route and a sublexical phonological route. Other researchers hypothesize an additional route that involves a direct connection between lexical orthographic representations and lexical phonological representations. This so-called 'third route' has been invoked to account for the preserved oral reading of some patients who show severe semantic impairments and a disruption of the sublexical phonological route. In their summation hypothesis, Hillis and Caramazza proposed that reading in these cases could result from a combination of partial lexical semantic information and partial sublexical phonological information, thus obviating the need for the third route. The present study examined the case of a phonological dyslexic patient (ML) who exhibited preserved word reading, even for items he could not name, along with a non-word reading impairment. The relationship between ML's naming and reading, and the influence of semantic variables on his reading were examined. The results of this examination are interpreted as supporting the existence of the third route.

Dyslexia↗