Assessing model mimicry using the parametric bootstrap

We present a general sampling procedure to quantify model mimicry, defined as the ability of a model to account for data generated by a competing model. This sampling procedure, called the parametric bootstrap cross-fitting method (PBCM; cf. Williams (J. R. Statist. Soc. B 32 (1970) 350; Biometrics 26 (1970) 23)), generates distributions of differences in goodness-of-fit expected under each of the competing models. In the data informed version of the PBCM, the generating models have specific parameter values obtained by fitting the experimental data under consideration. The data informed difference distributions can be compared to the observed difference in goodness-of-fit to allow a quantification of model adequacy. In the data uninformed version of the PBCM, the generating models have a relatively broad range of parameter values based on prior knowledge. Application of both the data informed and the data uninformed PBCM is illustrated with several examples.     

Saccadic output is influenced by limb kinetics during eye-hand coordination

In several recent studies, saccadic eye movements were found to be influenced by concurrent reaching movements. The authors investigated whether that influence originates in limb kinematic or kinetic signals. To dissociate those 2 possibilities, the authors required participants (N = 6) to generate pointing movements with a mass that either resisted or assisted limb motion. With practice, participants were able to generate pointing responses with very similar kinematics but whose kinetics varied in a systematic manner. The results showed that saccadic output was altered by the amount of force required to move the arm, consistent with an influence from limb kinetic signals. Because the interaction occurred before the pointing response began, the authors conclude that a predictive signal related to limb kinetics modulates saccadic output during tasks requiring eye-hand coordination.     

A six-factor structure of personality-descriptive adjectives: solutions from psycholexical studies in seven languages

Standard psycholexical studies of personality structure have produced a similar 6-factor solution in 7 languages (Dutch, French, German, Hungarian, Italian, Korean, Polish). The authors report the content of these personality dimensions and interpret them as follows: (a) a variant of Extraversion, defined by sociability and liveliness (though not by bravery and toughness); (b) a variant of Agreeableness, defined by gentleness, patience, and agreeableness (but also including anger and ill temper at its negative pole); (c) Conscientiousness (emphasizing organization and discipline rather than moral conscience); (d) Emotionality (containing anxiety, vulnerability, sentimentality, lack of bravery, and lack of toughness, but not anger or ill temper); (e) Honesty-Humility; (f) Intellect/Imagination/Unconventionality. A potential reorganization of the Big Five factor structure is discussed.     

Stress priming in picture naming: an SOA study

This study investigates whether or not the representation of lexical stress information can be primed during speech production. In four experiments, we attempted to prime the stress position of bisyllabic target nouns (picture names) having initial and final stress with auditory prime words having either the same or different stress as the target (e.g., WORtel-MOtor vs. koSTUUM-MOtor; capital letters indicate stressed syllables in prime-target pairs). Furthermore, half of the prime words were semantically related, the other half unrelated. Overall, picture names were not produced faster when the prime word had the same stress as the target than when the prime had different stress, i.e., there was no stress-priming effect in any experiment. This result would not be expected if stress were stored in the lexicon. However, targets with initial stress were responded to faster than final-stress targets. The reason for this effect was neither the quality of the pictures nor frequency of occurrence or voice-key characteristics. We hypothesize here that this stress effect is a genuine encoding effect, i.e., words with stress on the second syllable take longer to be encoded because their stress pattern is irregular with respect to the lexical distribution of bisyllabic stress patterns, even though it can be regular with respect to metrical stress rules in Dutch. The results of the experiments are discussed in the framework of models of phonological encoding.     

The impact of semantic transparency of morphologically complex words on picture naming

We examined the contribution of semantic similarity to morphological priming effects, using the immediate (Exp. 1 and 3) and the delayed variant (Exp. 2) of picture-word interference. Distractor words were either compounds morphologically related to the picture name, but differing with respect to their semantic transparency (hummingbird, jailbird (Exp. 1); butterfly, butter dish (Exp. 3)), or form-related non-compound words (e.g., trombone). All three experiments revealed strong facilitation of picture naming due to morphologically related distractors. Form-related distractors facilitated picture naming in the immediate variant only, and to a lesser degree than compounds. Interestingly, the size of the morphemic effect was almost identical for semantically transparent and opaque complex words, which suggests that they share morphemic representations. These results suggest that morphological complexity in speech production is coded at the level of form representations, independent of semantic transparency.     

Verbal fluency output in children aged 7-16 as a function of the production criterion: qualitative analysis of clustering, switching processes, and semantic network exploitation

Developmental changes in children's verbal fluency were explored in this study. One hundred and forty children aged from 7 to 16 completed four verbal fluency tasks, each with a different the production criterion (letter, sound, semantic, and free). The age differences were analyzed both in terms of number of words produced, and clustering, switching, and semantic network exploration. Analysis of the number of words produced showed a larger difference between the 7-8- and the 9-10-year-olds in semantic than in letter fluency, but this difference gradually disappeared with increasing age for semantic fluency while remaining constant for letter fluency. In letter fluency production, age modified both the number of switches and clusters formed whereas in semantic fluency tasks, only cluster size changed with age. Concerning the semantic network exploration indicators derived from the supermarket fluency task, the number of categories sampled increased from 11 to 12 years, but efficient semantic exploitation occurred only after the age of 13-14 years. These results are discussed in terms of the development of strategic retrieval components and categorical knowledge.     

Verbal mediation of number knowledge: evidence from semantic dementia and corticobasal degeneration

Patients with corticobasal degeneration (CBD) appear to have impaired number knowledge. We examined the nature of their number deficit while we tested the hypothesis that comprehension of larger numbers depends in part on verbal mediation. We evaluated magnitude judgments and performance on number conservation measures rooted in Piagetian theory in nonaphasic patients with CBD (n=13) and patients with a fluent form of progressive aphasia known as semantic dementia (SD; n=15). We manipulated the numbers of the arrays and the visual-spatial properties of the stimuli being compared during magnitude judgments and Piagetian conservation measures. CBD patients were consistently impaired judging the magnitudes of larger numbers (4-9), while they had minimal difficulty with smaller numbers (magnitudes < or = 3). By comparison, SD patients performed all measures of number knowledge at a ceiling level regardless of number magnitude. Neither patient group was significantly impacted by manipulations of the spatial properties of the stimuli. CBD patients' impairment with larger numbers despite minimal aphasia, and SD patients' intact performance despite an aphasia, challenge the proposal that understanding larger numbers depends on verbal mediation.     

Liking and memory for musical stimuli as a function of exposure

Three experiments examined changes in liking and memory for music as a function of number of previous exposures, the ecological validity of the music, and whether the exposure phase required focused or incidental listening. After incidental listening, liking ratings were higher for music heard more often in the exposure phase and this association was stronger as ecological validity increased. After focused listening, liking ratings followed an inverted U-shaped function of exposure for the most ecologically valid stimuli (initial increases followed by decreases), but this curvilinear function was attenuated or nonexistent for less valid stimuli. In general, recognition improved as a function of previous exposure for focused listeners, but the effect was attenuated or absent for incidental listeners.     

Priming of non-speech vocalizations in male adults: the influence of the speaker's gender

Previous research reported a priming effect for voices. However, the type of information primed is still largely unknown. In this study, we examined the influence of speaker's gender and emotional category of the stimulus on priming of non-speech vocalizations in 10 male participants, who performed a gender identification task. We found a significant priming effect, which was greater for female than male vocalizations. In contrast, the emotional category of the stimuli did not appear to modulate the magnitude of priming. These data suggest that different aspects of the information conveyed in non-speech vocalizations may contribute differently to behavioral priming, possibly influenced by task relevance.