The Attentional Boost Effect in Older Adults: Examining the Vulnerable Boost Hypothesis.

INTRODUCTION: The Attentional Boost Effect (ABE) occurs whenever participants recognize stimuli paired earlier with to-be-responded targets better than stimuli earlier paired with to-be-ignored distractors or presented on their own (baseline). Previous studies showed that the ABE does not occur in older adults when the encoding time is too short (500 ms/word) or when encoding is incidental, likely due to aging-related reductions in cognitive resources or limitations of processing speed. METHOD: In the present study, younger and older adults encoded words presented for 1000 ms under intentional instructions. In addition, to determine the potential impact of the retention interval, the recognition task was performed after a delay of 2 minutes (Experiment 1) or 20 minutes (Experiment 2). RESULTS: Under these conditions, older adults showed a significant ABE and the size of the effect was comparable to that achieved by younger adults. The magnitude of the ABE was vulnerable to the passage of time because the recognition advantage of target-paired words decreased sharply from 2 to 20 minutes. CONCLUSIONS: Taken together, our data demonstrate that younger and older adults may have comparable ABE effects under specific conditions and are similarly sensitive to interference.

Exploring the roles of distinctiveness and performance anticipation in the Attentional Boost Effect.

We tested the validity of two alternative accounts of the Attentional Boost Effect (ABE) - the finding that words associated with to-be-responded targets are recognized better than words associated with to-be-ignored distractors. The distinctiveness hypothesis assumes that, during recognition, participants probe their memories for distinctive information confirming that a word was studied (e.g., "I remember having pressed the spacebar, so I must have studied the word"). This strategy cannot be used in a between-subjects condition in which participants cannot appreciate the differences between target - and distractor-paired words. In agreement, Experiments 1A and 1B found that the ABE was significant in a within-subjects design, whereas it was eliminated in a between-subjects design. On the other hand, the performance anticipation hypothesis assumes that, during the study phase, participants anticipate the need of responding to a subset of target-paired words: this would create a persistent performance anticipation that would prevent them from effectively encoding distractor-paired words. In contrast with this account, we found that, when blocks of five distractor trials were regularly alternated with blocks of five target trials in Experiment 2, recognition accuracy decreased linearly in both conditions. Overall, these results suggest that distinctiveness, but not performance anticipation, might underlie the ABE.

Positive and negative effects of collaboration on suggestibility and false memory in online groups.

Previous studies demonstrated the positive and negative effects of collaboration on memory (both veridical and false recall) and suggestibility in face-to-face contexts. However, it remains unclear whether the same results can be observed in a virtual context. To clarify this issue, the present study examined the performance of 10 nominal triads and 10 collaborative triads in a fully online setting. Participants interacted live, in videoconference and were tested with the Gudjonsson Suggestibility Scale (GSS) and the Deese/Roediger-McDermott (DRM) task. For the GSS, the results replicated the in-person pattern of results, with collaborative triads showing the standard inhibition effect in the immediate and delayed (after 24 h) recall tasks; in addition, collaborative triads were less suggestible than nominal triads. For the DRM, we likewise found that collaboration decreased the recall and recognition of both studied items (the standard inhibitory effect) and critical lures (the error-pruning effect). We therefore conclude that remembering in a virtual context exhibits the same general properties as its in-person counterpart, at least when using a videoconference setting.

Effects of pointing movements on visuospatial working memory in a joint-action condition: Evidence from eye movements.

Previous studies showed that (a) performing pointing movements towards to-be-remembered locations enhanced their later recognition, and (b) in a joint-action condition, experimenter-performed pointing movements benefited memory to the same extent as self-performed movements. The present study replicated these findings and additionally recorded participants' fixations towards studied arrays. Each trial involved the presentation of two consecutive spatial arrays, where each item occupied a different spatial location. The item locations of one array were encoded by mere visual observation (the no-move array), whereas the locations of the other array were encoded by observation plus pointing movements (the move array). Critically, in Experiment 1, participants took turns with the experimenter in pointing towards the move arrays (joint-action condition), while in Experiment 2 pointing was performed only by the experimenter (passive condition). The results showed that the locations of move arrays were recognized better than the locations of no-move arrays in Experiment 1, but not in Experiment 2. The pattern of eye-fixations was in line with behavioral findings, indicating that in Experiment 1, fixations to the locations of move arrays were higher in number and longer in duration than fixations to the locations of no-move arrays, irrespective of the agent who performed the movements. In contrast, no differences emerged in Experiment 2. We propose that, in the joint-action condition, self- and other-performed pointing movements are coded at the same representational level and their functional equivalency is reflected in a similar pattern of eye-fixations.

Maternal mind-mindedness and communicative functions in free-play and mealtime contexts: Stability, continuity and relations with child language at 16 months.

The present study aimed at investigating the contextual stability, the contextual continuity and the concurrent associations between maternal measures (general language, communicative functions and mind-mindedness) and child measures (total number of word types and tokens) in two different contexts, free-play and mealtime. To this purpose, the interactions occurring between 25 mothers and their 16-month-old children in each context were video-recorded, transcribed and later coded for the selected measures. Significant contextual stability was observed in the mothers' production of general language measures (total number of utterances, total number of words and MLU), in the children's production of word types and tokens, and in some communicative functions (Tutorial, Control and Asynchronous). No contextual stability was found for the mothers' production of attuned mind-related comments. For continuity, both mothers and children produced more utterances and words in the free-play than in the mealtime context; the production of attuned mind-related comments and the use of the Control function were also more frequent in the free-play context. Lastly, the analysis of the concurrent correlations indicated that, especially in the mealtime context, the number of words produced by children was positively associated with the number of words produced by mothers and by their use of the Tutorial and Didactic functions, but negatively associated with their use of the Control function. The mothers' production of attuned mind-related comments bore no relation with children's expressive language. Similarities and differences with previous findings are discussed.

Pointing movements and visuo-spatial working memory in a joint setting: the role of motor inhibition.

Previous studies have shown that, under specific conditions, arrays that have been pointed at encoding are recognized better than passively viewed ones. According to one interpretation, the superior recognition of pointed-to arrays can be explained by the motor inhibition of passively viewed arrays. The present study sought to determine whether a similar motor inhibition can be induced also when the participants observed a co-actor perform the pointing movements. Participants were presented with two spatial arrays, one of which was encoded via observation only (the no-move array), while the other was encoded with pointing movements (the move array); movements were performed either by the participant or by the experimenter. Experiment 1 replicated the advantage of self-pointed arrays over passively viewed arrays. Experiment 2 showed that, when participants passively observed the pointing movements performed by the experimenter, move arrays were recognized no better than no-move arrays. Finally, Experiment 3 demonstrated that, in a joint-action condition in which participants alternated with the experimenter in making pointing movements, the advantage of experimenter-pointed arrays over passively viewed arrays was significant and similar in size to the advantage produced by self-performed movements. Importantly, a series of cross-experiment comparisons indicated that the higher recognition of both self- and experimenter-pointed arrays in Experiment 3 could be explained by the motor inhibition of no-move arrays. We propose that, in a joint condition, the pointing movements performed by the experimenter were represented in the same functional way as self-performed movements and that this produced the motor inhibition of passively viewed arrays.

The attentional boost effect enhances the recognition of bound features in short-term memory.

In the Attentional Boost Effect (ABE), images or words encoded with unrelated to-be-responded targets are later remembered better than images or words encoded with to-be-ignored distractors. In the realm of short-term memory, the ABE has been previously shown to enhance the short-term recognition of single-feature stimuli. The present study replicated this finding and extended it to a condition requiring the encoding and retention of colour-shape associations. Across four experiments, participants studied arrays of four coloured squares (the colour-only condition), four gray shapes (the shape-only condition) or four coloured shapes (the binding condition), paired with either a target letter (to which participants had to respond by pressing the spacebar) or a distractor letter (for which no response was required). After a short delay, they were presented with a probe array and asked to decide whether it matched or not the encoded array. Results showed that, in all conditions, the recognition of target-paired arrays was significantly better than the recognition of distractor-paired arrays. These findings suggest that the ABE can enhance feature binding.

Collaborative remembering reduces suggestibility: A study with the Gudjonsson Suggestibility Scale.

Collaboration during the retrieval phase can have both negative and positive effects (referred to as collaborative inhibition and error pruning, respectively) on emotional and eyewitness memory. To further elucidate these issues, the present experiment used the Gudjonsson Suggestibility Scale to investigate the question of whether collaborative remembering reduced post-event suggestibility. Collaborative and nominal pairs listened to the GSS2, provided immediate and delayed (after 30 min) free recalls, and answered a series of leading questions before or after receiving a negative feedback about their performance. We found no evidence of collaborative inhibition in the immediate and delayed free recall tasks. Importantly, however, collaborative pairs produced less confabulated elements in the free recall tasks, were considerably less prone to give in to leading questions (both before and after receiving the negative feedback), and exhibited lower levels of Total Suggestibility, compared to both nominal and individual dyads. Taken together, these results support the conclusion that collaboration can have a beneficial influence on eyewitnesses' accuracy, by strengthening their resistance to post-event suggestibility.

Not all identification tasks are born equal: testing the involvement of production processes in perceptual identification and lexical decision.

The distinction between identification and production processes suggests that implicit memory should require more attention resources when there is a competition between alternative solutions during the test phase. The present two experiments assessed this hypothesis by examining the effects of divided attention (DA) at encoding on the high- and low-response-competition versions of perceptual identification (Experiment 1) and lexical decision (Experiment 2). In both experiments, words presented in the high-response-competition condition had many orthographic neighbours and at least one higher-frequency neighbour, whereas words presented in the low-response-competition condition had few orthographic neighbours and no higher-frequency neighbour. Consistent with the predictions of the identification/production distinction, Experiment 1 showed that DA reduced repetition priming in the high-, but not in the low-response-competition version of perceptual identification; in contrast, DA had comparable effects in the two versions of lexical decision (Experiments 2). These findings provide the first experimental evidence in support of the hypothesis that perceptual identification, a task nominally based on identification processes, might involve a substantive production component.

Divided attention enhances the recognition of emotional stimuli: evidence from the attentional boost effect.

The present study examined predictions of the early-phase-elevated-attention hypothesis of the attentional boost effect (ABE), which suggests that transient increases in attention at encoding, as instantiated in the ABE paradigm, should enhance the recognition of neutral and positive items (whose encoding is mostly based on controlled processes), while having small or null effects on the recognition of negative items (whose encoding is primarily based on automatic processes). Participants were presented a sequence of negative, neutral and positive stimuli (pictures in Experiment 1, words in Experiment 2) associated to target (red) squares, distractor (green) squares or no squares (baseline condition). They were told to attend to the pictures/words and simultaneously press the spacebar of the computer when a red square appeared. In a later recognition task, stimuli associated to target squares were recognised better than stimuli associated to distractor squares, replicating the standard ABE. More importantly, we also found that: (a) the memory enhancement following target detection occurred with all types of stimuli (neutral, negative and positive) and (b) the advantage of negative stimuli over neutral stimuli was intact in the DA condition. These findings suggest that the encoding of negative stimuli depends on both controlled (attention-dependent) and automatic (attention-independent) processes.

Collaboration in implicit memory: evidence from word-fragment completion and category exemplar generation.

Recent studies have begun to investigate the effects of collaboration on explicit tests such as free recall, cued recall, and recognition. In contrast, little is known about the impact of this variable on implicit memory. To bridge this gap, the present study compared the performance of nominal and collaborative groups in two implicit memory tasks-word-fragment completion (WFCT) and category exemplar generation (CEGT). Both the disruption-of-individual-retrieval-strategies and the retrieval blocking hypotheses predicted no significant negative effects of collaboration on repetition priming; in contrast, the retrieval inhibition hypothesis predicted lower priming in collaborative than in nominal groups in both tasks. The results supported the former hypotheses, because priming scores in the WFCT and the CEGT did not differ between collaborative and individual groups. Interestingly; however, a significant collaborative inhibition was obtained in the CEGT (but not in the WFCT) when considering the raw proportions of studied and unstudied exemplars generated. The latter finding might indicate that the performance of collaborative groups can be significantly impaired by the disruption of within-category order resulting from the exposure to the exemplars generated by other group members, even when participants do not explicitly attempt to retrieve the stimuli presented at encoding.

Pointing movements both impair and improve visuospatial working memory depending on serial position.

Two experiments investigated the effects of pointing movements on the item and order recall of random, horizontal, and vertical arrays consisting of 6 and 7 squares (Experiment 1) or 8 and 9 squares (Experiment 2). In the encoding phase, participants either viewed the items passively (passive-view condition) or pointed towards them (pointing condition). Then, after a brief interval, they were requested to recall the locations of the studied squares in the correct order of presentation. The critical result was that, for all types of arrays, the effects of the encoding condition varied as a function of serial position: for the initial and central positions accuracy was higher in the passive-view than in the pointing condition (confirming the standard inhibitory effect of pointing movements on visuospatial working memory), whereas the reverse pattern occurred in the final positions-showing a significant advantage of the pointing condition over the passive-view condition. Findings are interpreted as showing that pointing can have two simultaneous effects on the recall of spatial locations, a positive one due to the addition of a motor code and a negative one due to the attentional requirements of hand movements, with the net impact on serial recall depending on the amount of attention resources needed for the encoding of each position. Implications for the item-order hypothesis and the perceptual-gestural account of working memory are also discussed.

Divided attention enhances explicit but not implicit conceptual memory: an item-specific account of the attentional boost effect.

The Attentional Boost Effect (ABE) refers to the counterintuitive finding that words encoded with to-be-responded targets in a divided-attention condition are remembered better than words encoded with distractors. Previous studies suggested that the ABE-related enhancement of verbal memory depends upon the activation of abstract lexical representations. In the present study, we extend this hypothesis by embedding it in the context of a broader perspective, which proposes that divided attention in the ABE paradigm affects item-specific, but not relational, processing. To this purpose, we examined the ABE in the matched tasks of category-cued recall (CCRT: explicit memory) and category exemplar generation (CEGT: implicit memory). In addition, study time was varied (500, 1500 or 4000 ms), to further determine whether the attentional boost manipulation could influence late-phase elaborative processing. In agreement with the predictions of the item-specific account, the results showed that exemplars encoded with targets were recalled better than exemplars encoded with distractors in the CCRT, but not in the CEGT. Moreover, performance in the CCRT increased with study time, whereas the size of the ABE-related enhancement tended to decrease, further confirming that this effect hinges upon early phase encoding processes.

Do early noun and verb production predict later verb and noun production? Theoretical implications.

Many studies have addressed the question of the relative dominance of nouns over verbs in the productive vocabularies of children in the second year of life. Surprisingly, cross-class (noun-to-verb and verb-to-noun) relations between these two lexical categories have seldom been investigated. The present longitudinal study employed observational and parent-report data obtained from thirty mother-child dyads at 1;4, 1;8, and 2;0 to examine this issue. Both the Natural Partitions/Relational Relativity (NP/RR) hypothesis and the Emergentist Coalition Model (ECM) predict that having an initial repertoire of common nouns should facilitate the acquisition of novel verbs, whereas only the ECM suggests that children exploit the syntactic and semantic constraints of known verbs to infer the meaning of novel nouns. In line with the ECM, hierarchical regression analyses indicated that the percentages of nouns produced by children at 1;4 predicted later verbs at 1;8, whereas the percentages of verbs produced at 1;8 predicted later nouns at 2;0.

Testing the Identification/Production Hypothesis of Implicit Memory in Schizophrenia: The Role of Response Competition.

OBJECTIVES: Previous evidence indicates that patients with schizophrenia exhibit reduced repetition priming in production tasks (in which each response cue engenders a competition between alternative responses), but not in identification tasks (in which each response cue allows a unique response). However, cross-task comparisons may lead to inappropriate conclusions, because implicit tests vary on several dimensions in addition to the critical dimension of response competition. The present study sought to isolate the role of response competition, by varying the number of solutions in the context of the same implicit tasks. METHODS: Two experiments investigated the performance of patients with schizophrenia and healthy controls in the high-competition and low-competition versions of word-stem completion (Exp.1) and verb generation (Exp.2). RESULTS: Response competition affected both the proportions of stems completed (higher to few-solution than to many-solution stems) and the reaction times of verb generation (slower to nouns having no dominant verb associates than to nouns having one dominant verb associate). Patients with schizophrenia showed significant (non-zero) priming in both experiments: crucially, the magnitude of this facilitation was equivalent to that observed in healthy controls and was not reduced in the high-competition versions of the two tasks. CONCLUSIONS: These findings suggest that implicit memory is spared in schizophrenia, irrespective of the degree of response competition during the retrieval phase; in addition, they add to the ongoing debate regarding the validity of the identification/production hypothesis of repetition priming.

Implicit memory in schizophrenia: a meta-analysis.

OBJECTIVE: Previous studies examining implicit memory in schizophrenia yielded inconsistent results. The present meta-analysis aimed at determining whether, compared to healthy controls, schizophrenic patients: (a) exhibited reduced priming in the whole set of studies; (b) were differentially impaired in conceptual/perceptual and production/identification tests; and (c) were less efficient in the use of semantic encoding processes. METHOD: A systematic search in PsycINFO and PubMed led to the selection of 22 critical studies (31 effect sizes), comparing repetition priming in 836 schizophrenic patients and 760 healthy controls. Moderators were assessed by classifying implicit tasks into the perceptual/conceptual and identification/production categories, and by distinguishing between perceptual and conceptual encoding instructions. RESULTS: Overall, implicit memory was slightly, but significantly, impaired in schizophrenia (d=0.179). Patients exhibited reduced priming in conceptually-driven tasks (d=0.447), but intact priming in perceptually-driven tasks (d=0.080). No significant difference was observed between identification and production priming (d=0.064 vs. d=0.243). Finally, priming in schizophrenic patients was significantly lower than that of controls when the encoding task required the analysis of the conceptual properties of the stimuli (d=0.261). CONCLUSION: Results suggest that schizophrenia is associated with a specific deficit in the use of conceptual processes, both at encoding and at retrieval. In contrast with theoretical expectations, high levels of response competition did not disproportionately impair the patients' performance.

Memory in pregnancy and post-partum: Item specific and relational encoding processes in recall and recognition.

It has been recently proposed that pregnant women would perform memory tasks by focusing more on item-specific processes and less on relational processing, compared to post-partum women (Mickes, Wixted, Shapiro & Scarff, ). The present cross-sectional study tested this hypothesis by directly manipulating the type of encoding employed in the study phase. Pregnant, post-partum and control women either rated the pleasantness of word meaning (which induced item-specific elaboration) or named the semantic category to which they belonged (which induced relational elaboration). Memory for the encoded words was later tested in free recall (which emphasizes relational processing) and in recognition (which emphasizes item-specific processing). In line with Mickes et al.'s () conclusions, pregnant women in the item-specific condition performed worse than post-partum women in the relational condition in free recall, but not in recognition. However, compared to the other two groups, pregnant women also exhibited lower recognition accuracy in the item-specific condition. Overall, these results confirm that pregnant women rely on relational encoding less than post-partum women, but additionally suggest that the former group might use item-specific processes less efficiently than post-partum and control women.

Feature binding and the processing of global-local shapes in bilingual and monolingual children.

In the present study, we examined the effects of bilingualism and age on a color-shape binding task (assessing visual working memory) and a global-local task (assessing inhibitory processes) in a sample of 55 bilingual and 49 monolingual children 8 and 10 years old. In the color-shape binding task, corrected recognition scores increased in older children; bilingual children performed better than monolinguals in the shape-only condition, but the two groups were equally accurate in the color-only and combination conditions. In the global-local task, accuracy was higher in bilingual than in monolingual children, particularly on incongruent trials; monolingual children showed a strong global precedence effect (higher accuracy in the global than in the local conditions and greater global-to-local interference), whereas bilingual children exhibited a small, but significant, local precedence effect (higher accuracy in the local than in the global conditions and greater local-to-global interference). These findings confirm and extend previous evidence indicating that the bilingualism advantage is more pronounced in working memory tasks involving inhibitory processes.

Is conceptual implicit memory impaired in schizophrenia? Evidence from lexical decision and category verification.

INTRODUCTION: Implicit memory tasks differ along two orthogonal dimensions, tapping the relative involvement of perceptual/conceptual and identification/production processes. Previous studies have documented a dissociation between perceptual (spared) and conceptual (impaired) implicit memory, using in the latter case a production task (category exemplar generation), in which there is high response competition during the retrieval phase. The present study sought to determine whether the perceptual/conceptual dissociation held when comparing two identification tasks, in which there is no response competition at retrieval. METHODS: In two experiments, repetition priming was assessed in 44 schizophrenic patients and 46 healthy controls in lexical decision (a test based on perceptual identification processes) and category verification (a test based on conceptual identification processes). RESULTS: Schizophrenic patients achieved a priming as high as that of controls in the lexical decision task. In contrast, only controls exhibited significant priming in the category verification task. CONCLUSIONS: It is concluded that schizophrenia is associated with a specific deficit in conceptual implicit memory, irrespective of the degree of response competition in the test phase.

Does pointing facilitate the recall of serial positions in visuospatial working memory?

The present study examined the question of whether pointing enhances the serial recall of visuospatial positions. Thirty-six participants were presented with 40 target arrays varying in length from five to eight items, with each position appearing sequentially in red for 1 s. The task was to reproduce the order of presentation of the positions on a blank matrix. Results showed that, for five-, six-, and seven-item arrays, order memory was significantly better in the passive view than in the pointing condition, and the serial position curves displayed both recency and priority effects. Interestingly, the advantage of the passive-view condition was more pronounced in the early than in the late positions. For eight-item arrays, no significant differences were found between the passive view and the pointing conditions. Overall, the present data provide no evidence in support of the view that pointing facilitates the recall of serial positions.