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The present study aimed to determine how older bilingual subjects' naming performance is affected by their knowledge of two languages. Twenty-nine aging (mean age = 74.0; SD = 7.1) Spanish–English bilinguals were asked to name all pictures in the Boston Naming Test (BNT) first in their dominant language and then in their less-dominant language. Bilinguals with similar naming scores in each language, or relatively balanced bilinguals, named more pictures correctly when credited for producing a correct name in either language. Balanced bilinguals also named fewer pictures in their dominant language than unbalanced bilinguals, and named more pictures correctly in both languages if the pictures had cognate names (e.g., dart is dardo in Spanish). Unbalanced bilinguals did not benefit from the alternative (either-language) scoring procedure and showed cognate effects only in their nondominant language. These findings may help to guide the interpretation of neuropsychological data for the purpose of determining cognitive status in older bilinguals and can be used to develop models of bilingual language processing. Bilinguals' ability to name pictures reflects their experience with word forms in both languages. (JINS, 2007, 13, 197–208.)

Newly acquired declarative memory traces are believed to be reactivated during NonREM sleep to promote their hippocampo-neocortical transfer for long-term storage. Yet it remains a major challenge to unravel the underlying neuronal mechanisms. Using simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) recordings in humans, we show that sleep spindles play a key role in the reactivation of memory-related neocortical representations. On separate days, participants either learned face-scene associations or performed a visuomotor control task. Spindle-coupled reactivation of brain regions representing the specific task stimuli was traced during subsequent NonREM sleep with EEG-informed fMRI. Relative to the control task, learning face-scene associations triggered a stronger combined activation of neocortical and hippocampal regions during subsequent sleep. Notably, reactivation did not only occur in temporal synchrony with spindle events but was tuned by ongoing variations in spindle amplitude. These learning-related increases in spindle-coupled neocortical activity were topographically specific because reactivation was restricted to the face- and scene-selective visual cortical areas previously activated during pre-sleep learning. Spindle-coupled hippocampal activation was stronger the better the participant had performed at prior learning. These results are in agreement with the notion that sleep spindles orchestrate the reactivation of new hippocampal–neocortical memories during sleep. ► Subjects learned face-scene associations or performed a visuomotor control task. ► EEG-fMRI during subsequent NREM sleep revealed spindle-related brain activation. ► Contrasting learning and control nights revealed spindle-related reactivation. ► Reactivation was restricted to category-specific neocortical sites and hippocampus. ► Reactivation was time-locked to sleep spindles and dependent on their amplitude.

Astronauts on interplanetary missions - such as to Mars - will be exposed to space radiation, a spectrum of highly-charged, fast-moving particles that includes 56 Fe and 28 Si. Earth-based preclinical studies show space radiation decreases rodent performance in low- and some high-level cognitive tasks. Given astronaut use of touchscreen platforms during training and space flight and given the ability of rodent touchscreen tasks to assess functional integrity of brain circuits and multiple cognitive domains in a non-aversive way, here we exposed 6-month-old C57BL/6J male mice to whole-body space radiation and subsequently assessed them on a touchscreen battery. Relative to Sham treatment, 56 Fe irradiation did not overtly change performance on tasks of visual discrimination, reversal learning, rule-based, or object-spatial paired associates learning, suggesting preserved functional integrity of supporting brain circuits. Surprisingly, 56 Fe irradiation improved performance on a dentate gyrus-reliant pattern separation task; irradiated mice learned faster and were more accurate than controls. Improved pattern separation performance did not appear to be touchscreen-, radiation particle-, or neurogenesis-dependent, as 56 Fe and 28 Si irradiation led to faster context discrimination in a non-touchscreen task and 56 Fe decreased new dentate gyrus neurons relative to Sham. These data urge revisitation of the broadly-held view that space radiation is detrimental to cognition.

Here, we view the mental lexicon as a semantic network where words are connected if they are semantically related. Steyvers and Tenenbaum ( Cognitive Science, 29 , 41–78, 2005 ) proposed that the growth of semantic networks follows preferential attachment , the observation that new nodes are more likely to connect to preexisting nodes that are more well connected (i.e., the rich get richer). If this is the case, well-connected known words should be better at acquiring new links than poorly connected words. We tested this prediction in three paired-associate learning (PAL) experiments in which participants memorized arbitrary cue–response word pairs. We manipulated the semantic connectivity of the cue words, indexed by the words’ free associative degree centrality. Experiment 1 is a reanalysis of the PAL data from Qiu and Johns ( Psychonomic Bulletin & Review , 27 , 114–121, 2020 ), in which young adults remembered 40 cue–response word pairs (e.g., nature – chain ) and completed a cued recall task. Experiment 2 is a preregistered replication of Qiu and Johns. Experiment 3 addressed some limitations in Qiu and Johns’s design by using pseudowords as the response items (e.g., boot – arruity ). The three experiments converged to show that cue words of higher degree centrality facilitated the recall/recognition of the response items, providing support for the notion that better-connected words have a greater ability to acquire new links (i.e., the rich do get richer). Importantly, while degree centrality consistently accounted for significant portions of variance in PAL accuracy, other psycholinguistic variables (e.g., concreteness, contextual diversity) did not, suggesting that degree centrality is a distinct variable that affects the ease of verbal associative learning.

Background: Recent advances have been made in the application of cognitive training strategies as interventions for mental disorders. One novel approach, cognitive control training (CCT), uses computer-based exercises to chronically increase prefrontal cortex recruitment. Activation of prefrontal control mechanisms have specifically been identified with attenuation of emotional responses. However, it is unclear whether recruitment of prefrontal resources alone is operative in this regard, or whether prefrontal control is important only in the role of explicit emotion regulation. This study examined whether exposure to cognitive tasks before an emotional challenge attenuated the effects of the emotional challenge. Aims: We investigated whether a single training session could alter participants' reactivity to subsequent emotional stimuli on two computer-based tasks as well as affect ratings made during the study. We hypothesized that individuals performing the Cognitive Control (CC) task as compared to those performing the Peripheral Vision (PV) comparison task would (1) report reduced negative affect following the mood induction and the emotion task, and (2) exhibit reduced reactivity (defined by lower affective ratings) to negative stimuli during both the reactivity and recovery phases of the emotion task and (3) show a reduced bias towards threatening information. Method: Fifty-nine healthy participants were randomized to complete CC tasks or PV, underwent a negative mood induction, and then made valence and arousal ratings for IAPS images, and completed an assessment of attentional bias. Results: Results indicated that a single-session of CC did not consistently alter participants' responses to either task. However, performance on the CC tasks was correlated on subsequent ratings of emotional images. Conclusions: While overall these results do not support the idea that affective responding is altered by making healthy volunteers use their prefrontal cortex before the affective task, they are discussed in the context of study design issues and future research directions.

The present study explored the effects of auditory–motor coupling and individual differences in pitch perception on verbal learning. Participants (N = 47) learned a list of foreign-language vocabulary word pairs under isochronous or self-initiated auditory stimulation while cycling on a stationary bike. As expected, better movement consistency—i.e., lower cycling variability and more stable synchronization with the vocabulary presentation—was weakly associated with improved memory performance. Interestingly, we found inter-individual differences in the pattern of results: participants with fundamental pitch perception (FPP) benefited from isochronous stimulation immediately after learning (Day 1), but not after overnight consolidation (Day 2), whereas participants with spectral pitch perception (SPP) showed a long-term memory benefit from isochronous stimulation. This suggests that auditory processing characteristics modulate whether isochronous input supports early encoding or later consolidation. Furthermore, musically experienced participants showed more variable pedaling in the self-initiated condition, possibly reflecting deliberate modulation of input timing. In contrast, isochronous stimulation reduced variability across all participants, indicating implicit synchronization even without an explicit instruction to synchronize. Overall, these findings highlight the role of individual auditory and motor traits in shaping the cognitive benefits of sensorimotor coupling during learning.

Whereas some older adults show significant cognitive deficits, others perform as well as young adults. We investigated the neural basis of these different aging patterns using positron emission tomography (PET). In PET and functional MRI (fMRI) studies, prefrontal cortex (PFC) activity tends to be less asymmetric in older than in younger adults (Hemispheric Asymmetry Reduction in Old Adults or HAROLD). This change may help counteract age-related neurocognitive decline (compensation hypothesis) or it may reflect an age-related difficulty in recruiting specialized neural mechanisms (dedifferentiation hypothesis). To compare these two hypotheses, we measured PFC activity in younger adults, low-performing older adults, and high-performing older adults during recall and source memory of recently studied words. Compared to recall, source memory was associated with right PFC activations in younger adults. Low-performing older adults recruited similar right PFC regions as young adults, but high-performing older adults engaged PFC regions bilaterally. Thus, consistent with the compensation hypothesis and inconsistent with the dedifferentiation hypothesis, a hemispheric asymmetry reduction was found in high-performing but not in low-performing older adults. The results suggest that low-performing older adults recruited a similar network as young adults but used it inefficiently, whereas high-performing older adults counteracted age-related neural decline through a plastic reorganization of neurocognitive networks.

Testing initially learned information before presenting new information has been shown to counteract the deleterious effects of proactive interference by segregating competing sources of information. The present experiments were conducted to demonstrate that testing can also have its effects in part by integrating competing information. Variations of classic A–B, A–D paired-associate learning paradigms were employed that included two lists of word pairs and a cued-recall test. Repeated pairs appeared in both lists (A–B, A–B), control pairs appeared in List 2 only (A–B, C–D), and changed pairs appeared with the same cue in both lists but with different responses (A–B, A–D). The critical manipulation was whether pairs were tested or restudied in an interpolated phase that occurred between Lists 1 and 2. On a final cued-recall test, participants recalled List 2 responses and then indicated when they recollected that responses had earlier changed between lists. The change recollection measure indexed the extent to which competing responses were integrated during List 2. Change was recollected more often for tested than for restudied pairs. Proactive facilitation was obtained in cued recall when change was recollected, whereas proactive interference was obtained when change was not recollected. These results provide evidence that testing counteracted proactive interference in part by making List 1 responses more accessible during List 2, thus promoting integration and increasing later recollection of change. These results have theoretical implications because they show that testing can counteract proactive interference by integrating or segregating competing information.

Objective: To test whether abnormal sensorimotor plasticity in focal hand dystonia is a primary abnormality or is merely a consequence of the dystonic posture. Methods: This study used the paired associative stimulation (PAS) paradigm, an experimental intervention, capable of producing long term potentiation (LTP) like changes in the sensorimotor system in humans. PAS involves transcranial magnetic stimulation combined with median nerve stimulation. 10 patients with cranial and cervical dystonia, who showed no dystonic symptoms in the hand, and nine patients with hemifacial spasm (HFS), a non-dystonic condition, were compared with 10 healthy age matched controls. Motor evoked potential amplitudes and cortical silent period (CSP) duration were measured at baseline before PAS and for up to 60 min (T0, T30 and T60) after PAS in the abductor pollicis brevis and the first dorsal interosseus muscles. Results: Patients with dystonia showed a stronger increase in corticospinal excitability than healthy controls and patients with HFS. In addition, patients with dystonia showed a loss of topographical specificity of PAS induced effects, with a facilitation in both the median and ulnar innervated muscles. While PAS conditioning led to a prolonged CSP in healthy controls and patients with HFS, it had no effect on the duration of the CSP in patients with cranial and cervical dystonia. Conclusion: The data suggests that excessive motor cortex plasticity is not restricted to the circuits clinically affected by dystonia but generalises across the entire sensorimotor system, possibly representing an endophenotypic trait of the disease.

Rationale New pharmacological treatments for the cognitive deficits in schizophrenia are needed. Tetrahydroprotoberberines, such as govadine, are one class of compounds with dopaminergic activities that may be useful in treating some aspects of the cognitive symptoms of the disorder. Objective The objective of the present studies was to test the effects of the d - and l -enantiomers of govadine on the impairment in a paired-associate learning (PAL) task produced by acute MK-801 in rats. We also assessed effects of the typical antipsychotic haloperidol as a comparator compound. Methods MK-801 (0.05, 0.1, 0.15, and 0.2 mg/kg), d - and l -govadine (0.3, 1.0, and 3.0 mg/kg), and haloperidol (0.05, 0.1, and 0.25 mg/kg) were administered acutely to rats well trained on the PAL task in touchscreen-equipped operant conditioning chambers. Results Acute MK-801 impaired performance of PAL in a dose-dependent manner by reducing accuracy and increasing correction trials. l -Govadine (1.0 mg/kg), but not d -govadine, blocked the disruptive effects of MK-801 (0.15 mg/kg) on PAL. Haloperidol failed to affect the MK-801-induced disruption of PAL. Higher doses of l -govadine and haloperidol dramatically impaired performance of the task which confounded interpretation of cognitive outcomes. Conclusion l -Govadine appears unique in its ability to improve performance of the MK-801-induced impairment in the PAL task. This behavioral effect may relate the ability of l -govadine to antagonize dopamine D2 receptors while also promoting dopamine efflux. Future research should further characterize the role of the dopamine system in the rodent PAL task to elucidate the mechanisms of its pro-cognitive effects.