Investigating the Effect of Contextual Cueing with Face Stimuli on Electrophysiological Measures in Younger and Older Adults.

Extracting repeated patterns from our surroundings plays a crucial role in contextualizing information, making predictions, and guiding our behavior implicitly. Previous research showed that contextual cueing enhances visual search performance in younger adults. In this study, we investigated whether contextual cueing could also improve older adults' performance and whether age-related differences in the neural processes underlying implicit contextual learning could be detected. Twenty-four younger and 25 older participants performed a visual search task with contextual cueing. Contextual information was generated using repeated face configurations alongside random new configurations. We measured RT difference between new and repeated configurations; ERPs to uncover the neural processes underlying contextual cueing for early (N2pc), intermediate (P3b), and late (r-LRP) processes; and multiscale entropy and spectral power density analyses to examine neural dynamics. Both younger and older adults showed similar contextual cueing benefits in their visual search efficiency at the behavioral level. In addition, they showed similar patterns regarding contextual information processing: Repeated face configurations evoked decreased finer timescale entropy (1-20 msec) and higher frequency band power (13-30 Hz) compared with new configurations. However, we detected age-related differences in ERPs: Younger, but not older adults, had larger N2pc and P3b components for repeated compared with new configurations. These results suggest that contextual cueing remains intact with aging. Although attention- and target-evaluation-related ERPs differed between the age groups, the neural dynamics of contextual learning were preserved with aging, as both age groups increasingly utilized more globally grouped representations for repeated face configurations during the learning process.

Exploring the role of working memory gate opening process in creativity: An ERP study using the reference-back paradigm.

We investigated the relationship between the gate opening process of working memory and an individual's proficiency in divergent (DT) and convergent thinking (CT) using the reference-back paradigm. Event-related potentials and reaction times were measured across groups with varying DT (N = 40, 27.35 ± 5.05 years) and CT levels (N = 40, 27.88 ± 4.95 years). Based on the role of striatal dopamine in supporting cognitive flexibility, which facilitates DT, and considering the significance of phasic dopamine activity as the gate opening signal originating from the basal ganglia, we assumed that the gate opening process may contribute differently to DT and CT. Despite the absence of behavioural differences in gate opening costs, distinct neural patterns emerged. In the early time windows (P1, N1), gate opening effects were detected in both DT and CT groups, with a notable interaction influenced by the level of DT, resulting in significant effects within the lower DT group. The P2 component showed a gate opening effect only in the higher DT group. In the P3 time window, the process unfolded comparably in all groups. Our results suggest that groups with different levels of convergent thinking (based on Matrix reasoning) and those with lower DT (based on Creativity Index) tend to select and activate the prefrontal cortex representation containing the required task information at an earlier stage, compared to those with better DT. This could be beneficial especially in the early phase of idea generation, as more elements become available to create associations and original ideas.

Mechanisms of spatial contextual cueing in younger and older adults.

The contextual cueing effect is the phenomenon observed when response time (RT) becomes faster in visual search in repeated context compared with a new one. In the present study, we explored whether the mechanisms involved in the effect are age dependent. We investigated it in younger (N = 20, 12 women, 21.2 ± 1.75 years) and older (N = 19, nine women, 67.05 ± 3.94 years) adults. We found a faster target identification in the repeated configurations with similar magnitude in the two age groups, which indicates that this contextual cueing effect remained intact even in the older participants. To shed light on the underlying mechanisms, we measured and compared the amplitude of three event-related potentials: N2pc, P3, and response-locked LRP. In the younger group, the larger contextual cueing effect (novel-minus-repeated RT difference) correlated positively with a larger difference in amplitude for repeated compared with novel configurations for both the N2pc and the P3 components, but there was no correlation with the response-locked lateralized readiness potential (rLRP) amplitude difference. However, in the older group, only the rLRP amplitude difference between novel and repeated configurations showed an enhancement with larger contextual cueing. These results suggest that different mechanisms are responsible for the contextual effect in the two age groups. It has both an early and an intermediate locus in younger adults: effective attentional allocation and successful stimulus categorization, or decision-making confidence are involved; while in older adults, a late locus was identified: a more efficient response organization led to a faster reaction.

Investigating the involvement of cognitive control processes in innovative and adaptive creativity and their age-related changes.

Introduction: Based on the two-factor model of creativity, two distinct types of creative problem solving can be differentiated: innovative ("do things differently") and adaptive ("do things better"). Flexible cognitive control is a crucial concept in connection with both general and specific styles of creativity: innovative problem-solving benefits from broader attention and flexible mental set shifting; while adaptive creativity relies on focused attention and persistent goal-oriented processes. We applied an informatively cued task-switching paradigm which is suitable for measuring different cognitive control processes and mechanisms like proactive and reactive control. We hypothesized that adaptive creativity is connected to effective proactive control processes, while innovative creativity is based on reactive task-execution. As we have found no previous evidence how age-related changes in cognitive control affects creative cognition; we also examined the effect of healthy aging on different problem-solving styles in an explorative way. Methods: Our participants, 37 younger (18-30 years) and 37 older (60-75 years) adults, were divided into innovative and adaptive creative groups according to the Torrance Test of Creative Thinking's Figural Subtest (Hungarian version). Results: Our results showed that among younger adults the adaptively creative group had larger cue-locked CNV component (effective preparatory activity connected to proactive control), while the innovatively creative group had a larger target-locked P3b component (effective target evaluation and categorization in line with reactive control) which supports a functional difference in the two creative styles. By contrast, in older adults innovative problem-solving showed larger mixing costs (less effective maintenance and selection of task sets), and the lack of trial type effect on target-locked N2b (target-induced goal reactivation and less effective conflict resolution); while adaptive problem-solving caused them to make fewer errors (accuracy-oriented behavior). Discussion: All in all, innovative and adaptive creativity is based on distinct cognitive control mechanisms in both age-groups, but their processing level is affected by age-related changes.

The effect of ambiguous and unambiguous stimuli on target processing in less creative and more creative groups.

In the present study our aim was to examine how the processing of task-irrelevant stimuli changes with creativity and aging, and how this processing influences task-relevant responding. We hypothesized that the degree in which irrelevant stimuli attract attention and occupy cognitive capacity, thereby interfering with the motor task, depends not only on the stimuli's saliency, but also on the participants' creativity and age. We investigated event-related potentials (ERP) and behavioural data in four groups - more creative and less creative younger (18-30 years) and older (60-75 years) adults - by presenting unambiguous and ambiguous portrait paintings and photos of faces in equal proportions before and after the target stimuli. Our results showed that aging affected behavioural and ERP responses, but there were no interactions between age groups, creativity and the three types of stimuli. Older adults were not more exposed to the interference caused by distractor stimuli as they compensated with bilateral activity to reach a similar performance to the younger group. The reaction time was faster for targets when they followed the faces rather than the portrait paintings, so, faces may have been less salient to the participants than paintings. The three types of stimuli were differentiated in all the processing stages. Creativity had a measured effect in the earliest (P1) stage with more creative groups being able to distinguish between unambiguous and ambiguous stimuli; and also, in the last processing stage (CNV), in which task-irrelevant stimuli, particularly photos of faces, were less distracting for more creative participants in task preparation. The results show that creativity in general has an influence even at the earliest stage of visual perception.

The modulatory effect of adaptive task-switching training on resting-state neural network dynamics in younger and older adults.

With increasing life expectancy and active aging, it becomes crucial to investigate methods which could compensate for generally detected cognitive aging processes. A promising candidate is adaptive cognitive training, during which task difficulty is adjusted to the participants' performance level to enhance the training and potential transfer effects. Measuring intrinsic brain activity is suitable for detecting possible distributed training-effects since resting-state dynamics are linked to the brain's functional flexibility and the effectiveness of different cognitive processes. Therefore, we investigated if adaptive task-switching training could modulate resting-state neural dynamics in younger (18-25 years) and older (60-75 years) adults (79 people altogether). We examined spectral power density on resting-state EEG data for measuring oscillatory activity, and multiscale entropy for detecting intrinsic neural complexity. Decreased coarse timescale entropy and lower frequency band power as well as increased fine timescale entropy and higher frequency band power revealed a shift from more global to local information processing with aging before training. However, cognitive training modulated these age-group differences, as coarse timescale entropy and lower frequency band power increased from pre- to post-training in the old-training group. Overall, our results suggest that cognitive training can modulate neural dynamics even when measured outside of the trained task.

Does Creativity Influence Visual Perception? - An Event-Related Potential Study With Younger and Older Adults.

We do not know enough about the cognitive background of creativity despite its significance. Using an active oddball paradigm with unambiguous and ambiguous portrait paintings as the standard stimuli, our aim was to examine whether: creativity in the figural domain influences the perception of visual stimuli; any stages of visual processing; or if healthy aging has an effect on these processes. We investigated event related potentials (ERPs) and applied ERP decoding analyses in four groups: younger less creative; younger creative; older less creative; and older creative adults. The early visual processing did not differ between creativity groups. In the later ERP stages the amplitude for the creative compared with the less creative groups was larger between 300 and 500 ms. The stimuli types were clearly distinguishable: within the 300-500 ms range the amplitude was larger for ambiguous rather than unambiguous paintings, but this difference in the traditional ERP analysis was only observable in the younger, not elderly groups, who also had this difference when using decoding analysis. Our results could not prove that visual creativity influences the early stage of perception, but showed creativity had an effect on stimulus processing in the 300-500 ms range, in indexing differences in top-down control, and having more flexible cognitive control in the younger creative group.

Older Adults Automatically Detect Age of Older Adults' Photographs: A Visual Mismatch Negativity Study.

The human face is one of the most frequently used stimuli in vMMN (visual mismatch negativity) research. Previous studies showed that vMMN is sensitive to facial emotions and gender, but investigations of age-related vMMN differences are relatively rare. The aim of this study was to investigate whether the models' age in photographs were automatically detected, even if the photographs were not parts of the ongoing task. Furthermore, we investigated age-related differences, and the possibility of different sensitivity to photographs of participants' own versus different ages. We recorded event-related potentials (ERPs) to faces of young and old models in younger (N = 20; 18-30 years) and older groups (N = 20; 60-75 years). The faces appeared around the location of the field of a tracking task. In sequences the young or the old faces were either frequent (standards) or infrequent (deviants). According to the results, a regular sequence of models' age is automatically registered, and faces violating the models' age elicited the vMMN component. However, in this study vMMN emerged only in the older group to same-age deviants. This finding is explained by the less effective inhibition of irrelevant stimuli in the elderly, and corresponds to own-age bias effect of recognition studies.

Older Adults Encode Task-Irrelevant Stimuli, but Can This Side-Effect be Useful to Them?

We studied whether, due to deteriorating inhibitory functions, older people are more likely to process irrelevant stimuli; and if so, could they later use this information better than young adults. In the study phase of our experiment, a Posner-type gaze-cued version of a Simon task was performed in which we presented task-irrelevant cues, where faces or patches with either left- or right-looking dots for the pupil of the eye preceded the task to press a button congruent or incongruent with the presentation side of the target stimulus. In the follow-up test phase, participants completed an unexpected facial recognition test. In the study phase not only a decreased P1, but also an increased N170 amplitude of the event-related potentials (ERPs) were found in older, compared to younger adults, and also for faces compared to patches. Even though in the test phase both age-groups could recognize the faces better than statistically by chance, neither the older nor the younger participants could discriminate them effectively. The late positive component (LPC)-the ERP correlates of the old/new effect, being the higher amplitude for the earlier presented stimuli when compared with the unseen stimuli during the recognition test-was not evolved in the older group, while a reversed old/new effect was seen in younger participants: higher amplitude was found in New-Right and Old-Wrong conditions (for faces they did not recognize independent of seeing them before) compared to Old-Right and New-Wrong conditions (for faces they thought they recognized from the study phase). In conclusion, although older adults showed enhanced processing of task-irrelevant stimuli compared to younger adults, as indicated by the N170 amplitude, however, they were not able to utilize this information in a later task, as was suggested by the recognition rate and LPC amplitude results.

Age Effects on Distraction in a Visual Task Requiring Fast Reactions: An Event-Related Potential Study.

We investigated the effects of distractors in older and younger participants in choice and simple reaction time tasks with concurrent registration of event-related potentials. In the task the participants had to prevent a disk from falling into a bin after a color or luminosity change (target stimuli). Infrequently, task-irrelevant stimuli (schematic faces or threatening objects) were superimposed on the target stimuli (distractors), or the bin disappeared which required no response (Nogo trials). Reaction time was delayed to the distractors, but this effect was similar in the two age groups. As a robust age-related difference, in the older group a large anterior positivity and posterior negativity emerged to the distractors within the 100-200 ms post-stimulus range, and these components were larger for schematic faces than for threatening objects. sLORETA localized the age-specific effect to the ventral stream of the visual system and to anterior structures considered as parts of the executive system. The Nogo stimuli elicited a late positivity (Nogo P3) with longer latency in the older group. We interpreted the age-related differences as decreased but compensated resistance to task-irrelevant change of the target stimuli.

Can irrelevant but salient visual cues compensate for the age-related decline in cognitive conflict resolution?-An ERP study.

We studied a Posner-type gaze-cued version of a Simon task to characterize age-related changes in visuospatial attention and inhibitory control. Earlier results had indicated that the direction of gaze is a strong social cue that speeds response times; so we wondered whether, as a task-irrelevant stimulus, it could compensate for age-related impairment of inhibitory processes in the elderly. Our results assessed the Simon effect by: reaction time, error rate, the P3 component and the lateralized readiness potential (LRP). We found that the Simon effect was larger in the older group confirming an increased sensitivity to interference and also suggesting a decreased inhibitory control in older adults. LRP results showed that aging and stimulus-response incongruency delayed the selection of the responses-indexed by longer s-LRP latency data-, and also decreased the efficiency of motor inhibition in the Simon task-the s-LRP amplitude of both wrong- and correct-side activation was larger in older adults, and the latency difference of these two components was longer in this age-group. Also a larger N2pc amplitude in the congruent, compared to incongruent gaze condition, showed an increased visuospatial attention when the gaze-cueing drew attention to the target stimulus. This gaze-cueing could not be ignored and hence it modified task processing in the older age group, which was evident in the incongruent Simon condition where the congruent gaze increased older adults' reaction time and their error rate; but there was no difference observed in the congruent Simon condition. Since the anticipated facilitation of reaction times did not occur, we suggest that general slowing and decreased inhibitory functions in the elderly caused the social cue not to be a supporting stimulus but rather to be a further burden on their cognitive processing.

The effect of hand motion and object orientation on the automatic detection of orientation: A visual mismatch negativity study.

We investigated the effects of voluntary hand movements and continuously present objects on the automatic detection of deviant stimuli in a passive oddball paradigm. The visual mismatch negativity (vMMN) component of event-related potentials (ERPs) was measured as the index of automatic deviant detection. The stimuli were textures consisting of parallel, oblique bars with frequent (standard) and infrequent (deviant) orientation. Traditional vMMN was measured by the difference between ERPs to frequent (standard) and infrequent (deviant) textures. Additionally, we measured 'genuine' vMMN by comparing the ERPs to deviant and control textures in the equal probability procedure. Compatible and incompatible hand movement directions to the standard texture had no influence on 'traditional' vMMN and elicited no 'genuine' vMMN. However, the deviant texture elicited 'genuine' vMMN if the orientation of a continuously present rectangle was different from the standard (and identical to the deviant) texture orientation. Our results suggest that the direction of voluntary hand movement and the orientation of task-irrelevant visual patterns do not acquire common memory representation, but a continuously present object contributes to the detection of sequential regularity violation.

Chemotherapy drugs cyclophosphamide, cisplatin and doxorubicin induce germ cell loss in an in vitro model of the prepubertal testis.

Long term survival rates for childhood cancers is steadily increasing, however cancer survivors can experience fertility problems as a consequence of chemotherapy treatment. This is particularly problematic for young boys, for whom no fertility preservation treatment is yet established. Here, we have determined the effects on prepubertal mouse testis of three commonly used chemotherapy drugs; cyclophosphamide (using its active metabolite phosphoramide mustard), cisplatin and doxorubicin, exposing testicular fragments to a clinically relevant range of concentrations in vitro. All three drugs induced a specific and highly significant loss of germ cells, including spermatogonial stem cells. In contrast, there was no significant effect on somatic cells, for either Sertoli or interstitial cells. Time course analysis of cleaved Caspase-3 expression showed a significant increase in apoptosis eight hours prior to a detectable decrease in germ cell numbers following exposure to phosphoramide mustard or cisplatin, although this pattern was not seen following doxorubicin-exposure. Moreover, analysis of DNA damage at 16 h showed increased γH2AX expression in response to all three drugs. Overall, results show that cisplatin, doxorubicin and cyclophosphamide all specifically induce loss of germ cells, including of spermatogonial stem cells, in the prepubertal mouse testis at concentrations relevant to human therapeutic exposures.

The role of GluN2B-containing NMDA receptors in short- and long-term fear recall.

N-methyl-d-aspartate (NMDA) receptors are crucial synaptic elements in long-term memory formation, including the associative learning of fearful events. Although NMDA blockers were consistently shown to inhibit fear memory acquisition and recall, the clinical use of general NMDA blockers is hampered by their side effects. Recent studies revealed significant heterogeneity in the distribution and neurophysiological characteristics of NMDA receptors with different GluN2 (NR2) subunit composition, which may have differential role in fear learning and recall. To investigate the specific role of NMDA receptor subpopulations with different GluN2 subunit compositions in the formation of lasting traumatic memories, we contrasted the effects of general NMDA receptor blockade with GluN2A-, GluN2B-, and GluN2C/D subunit selective antagonists (MK-801, PEAQX, Ro25-6981, PPDA, respectively). To investigate acute and lasting consequences, behavioral responses were investigated 1 and 28days after fear conditioning. We found that MK-801 (0.05 and 0.1mg/kg) decreased fear recall at both time points. GluN2B receptor subunit blockade produced highly similar effects, albeit efficacy was somewhat smaller 28days after fear conditioning. Unlike MK-801, Ro25-6981 (3 and 10mg/kg) did not affect locomotor activity in the open-field. In contrast, GluN2A and GluN2C/D blockers (6 and 20mg/kg PEAQX; 3 and 10mg/kg PPDA, respectively) had no effect on conditioned fear recall at any time point and dose. This sharp contrast between GluN2B- and other subunit-containing NMDA receptor function indicates that GluN2B receptor subunits are intimately involved in fear memory formation, and may provide a novel pharmacological target in post-traumatic stress disorder or other fear-related disorders.