Pietro Spataro

The relationship between divided attention and implicit memory: A meta-analysis

This article reports a meta-analysis comparing the size of repetition priming in full and divided-attention (DA) conditions. The main analysis included 38 effect sizes (ES) extracted from 21 empirical studies, for a total of 2074 (full-attention) and 2148 (divided-attention) participants. The mean weighted ES was 0.357 (95% CI=0.278-0.435), indicating that divided attention produced a small, but significant, negative effect on implicit memory. Overall, the distinction between identification and production priming provided the best fit to empirical data (with the effect of DA being greater for production tests), whereas there was no significant difference between perceptual and conceptual priming. A series of focused contrasts suggested that word-stem completion might be influenced by lexical-conceptual processes, and that perceptual identification might involve a productive component. Implications for current theories of implicit memory are discussed.

Divided attention can enhance memory encoding: the attentional boost effect in implicit memory.

Distraction during encoding has long been known to disrupt later memory performance. Contrary to this long-standing result, we show that detecting an infrequent target in a dual-task paradigm actually improves memory encoding for a concurrently presented word, above and beyond the performance reached in the full-attention condition. This absolute facilitation was obtained in 2 perceptual implicit tasks (lexical decision and word fragment completion) but not in a conceptual implicit task (semantic classification). In the case of recognition memory, the facilitation was relative, bringing accuracy in the divided attention condition up to the level of accuracy in the full attention condition. The findings follow from the hypothesis that the attentional boost effect reflects enhanced visual encoding of the study stimulus consequent to the transient orienting response to the dual-task target.

Attention and Implicit Memory

The distinction between identification and production priming assumes that tasks based on production processes involve two distinct stages: the activation of multiple solutions and the following selection of a final response. Previous research demonstrated that divided attention reduced production but not identification priming. However, an unresolved issue concerns whether the activation of candidate solutions is sufficient to account for the enhanced request of attentional resources, independently from the contribution of selection processes. The present paper investigated this question by using a version of the lexical decision task (LDT) in which the target words had either many or few orthographic neighbors. Two experiments showed that the effects of divided and selective attention were equivalent in both conditions, suggesting that the inclusion of a process of generation of multiple solutions in the LDT is not sufficient to increase the amount of cognitive resources needed to achieve full priming to the levels of production tasks.

Typical and Delayed Lexical Development in Italian

PURPOSE The Language Development Survey (LDS; Rescorla, 1989) was used to compare Italian and English lexical development. The authors addressed the issue of universal versus language-specific aspects of lexical development by testing language, age, and gender effects on vocabulary scores and by comparing vocabulary composition across languages. They addressed the issue of delay versus deviance by comparing vocabulary composition in late talkers and younger vocabulary-size-matched children. METHOD Participants were 398 Italian and 206 U.S. children ages 18-35 months. RESULTS Vocabulary size did not differ significantly by language, and age and gender effects on vocabulary size were not moderated by language. The Italian-English Q correlation for percentage word use scores was .55, lower than the within-language concordance of .90 and above. Cross-linguistic concordance declined as age and vocabulary size increased. Many cross-linguistic word matches (63 words) were found among the top 100 words. Italian late talkers were similar to younger vocabulary-size-matched Italian children in vocabulary composition, consistent with findings for English, Greek, and Korean. CONCLUSIONS In both languages, the early lexicons of late talkers and typical talkers contained many of the same words, indicating considerable universality in young childrens lexical development. These common words are therefore good targets for clinical intervention.

Working memory and individual differences in the encoding of vertical, horizontal and diagonal symmetry

Previous studies, using a modified version of the sequential Corsi block task to examine the impact of symmetry on visuospatial memory, showed an advantage of vertical symmetry over non-symmetrical sequences, but no effect of horizontal or diagonal symmetry. The present four experiments investigated the mechanisms underlying the encoding of vertical, horizontal and diagonal configurations using simultaneous presentation and a dual-task paradigm. Results indicated that the recall of vertically symmetric arrays was always better than that of all other patterns and was not influenced by any of the concurrent tasks. Performance with horizontally or diagonally symmetrical patterns differed, with high performing participants showing little effect of concurrent tasks, while low performers were disrupted by concurrent visuospatial and executive tasks. A verbal interference had no effect on either group. Implications for processes involved in the encoding of symmetry are discussed, together with the crucial importance of individual differences.

Effects of divided attention in the word-fragment completion task with unique and multiple solutions

The Identification-Production Hypothesis predicts that the effect of divided attention (DA) at encoding should be larger when priming tasks involve divergent search processes through many different competitors, because they are supposed to place heavier attentional demands on frontal lobe functions (Gabrieli, Vaidya, Stone et al., 1999). This hypothesis was tested in two experiments using the Word Fragment Completion (WFC) task with unique solutions (which relies on convergent lexical search towards single appropriate representations: the identification version of the WFC) or multiple solutions (which implies a competition between equally plausible responses: the production version of the WFC). In Experiment 1 the two versions of the completion task were found to be equally unaffected by the imposition of a short-term memory load at encoding. In Experiment 2 the reduction of target words’ study time (from 2.5 to 1 s), and the use of a blocked (rather than mixed) design, significantly diminished the level of priming in the DA condition: However, contrary to the predictions, the degree of impairment was not greater for multiple-solution fragments. Results are in line with recent failures to support the identification–production hypothesis in normal adults (Geraci, 2006; Prull, 2004).

Individual differences in the prevalence of words and gestures in the second year of life: developmental trends in Italian children.

This longitudinal study investigated individual differences in the relationship between words and representational gestures in a sample of 104 Italian children between 12 and 23 months of age, using two parent-report questionnaires. Multivariate analyses reached three main conclusions. First, a high gesture frequency did not enhance language development when word production was equated and children showing a prevalence of words over gestures outperformed those showing a prevalence of gestures over words at all ages. Second, an early predominance of gestures at 12 months did not hamper the acquisition of verbal abilities, while the persistence of a gestural advantage at 16 and 20 months was related to a slower language development at 23 months. Finally, for infants with small gestural repertoires at 12 months, a high frequency of gesture use benefitted the process of lexical learning. These findings support the hypothesis that representational gestures bridge the transition from pre-linguistic to symbolic communication. However, they also suggest that the role of representational gestures might be less critical than previously proposed, being mostly evident in the earlier phases of the second year of life.

A longitudinal examination of early communicative development: Evidence from a parent-report questionnaire

The present research employed a longitudinal design to assess the verbal and non-verbal communicative abilities of a sample of 104 children, using two different parent-report instruments: the Questionnaire for Communication and Early Language (QCEL) development at 12, 16, and 20 months, and the Italian adaptation of the MacArthur-Bates Communicative Development Inventories: Words and Gestures at 23 months. The results supported and extended previous data about the validity of the QCEL, by showing that: (1) both verbal and non-verbal variables predicted the level of language development at 23 months; (2) children classified as at-risk with the QCEL had reduced vocabulary size and a lower number of sentences at 23 months; (3) early individual differences in the use of words and gestures were associated with later differences in linguistic abilities. It is concluded that the longitudinal use of the QCEL questionnaire can provide useful information about language development.

Children's Acquisition of Nouns and Verbs in Italian: Contrasting the Roles of Frequency and Positional Salience in Maternal Language.

Because of its structural characteristics, specifically the prevalence of verb types in infant-directed speech and frequent pronoun-dropping, the Italian language offers an attractive opportunity to investigate the predictive effects of input frequency and positional salience on childrens acquisition of nouns and verbs. We examined this issue in a sample of twenty-six mother-child dyads whose spontaneous conversations were recorded, transcribed, and coded at 1;4 and 1;8. The percentages of nouns occurring in the final position of maternal utterances at 1;4 predicted childrens production of noun types at 1;8. For verbs, childrens growth rates were positively predicted by the percentages of input verbs occurring in utterance-initial position, but negatively predicted by the percentages of verbs located in the final position of maternal utterances at 1;4. These findings clearly illustrate that the effects of positional salience vary across lexical categories.

The attentional boost effect with verbal materials.

Study stimuli presented at the same time as unrelated targets in a detection task are better remembered than stimuli presented with distractors. This attentional boost effect (ABE) has been found with pictorial (Swallow & Jiang, 2010) and more recently verbal materials (Spataro, Mulligan, & Rossi-Arnaud, 2013). The present experiments examine the generality of the ABE with verbal materials and critically assess the perceptual encoding hypothesis, the notion that the memory benefits are due to enhanced encoding of the perceptual properties of the study stimulus. Experiments 1 and 3 demonstrated an ABE with visual study items, comparable in size whether the recognition test was visual or auditory. Experiments 2 and 3 established an ABE for auditory study stimuli that was again equivalent for auditory and visual recognition tests. Experiments 4 and 5 found an ABE on the test of free recall. Finally, the ABE was greater for high-frequency than low-frequency words. The results demonstrate the generality of the ABE over study and test modality, and over memory tests (recognition and free recall), while also documenting a moderating factor (word frequency). Importantly, the representational basis for the ABE with verbal materials appears to be abstract, or amodal, rather than modality specific.