Modern scores for traditional tests - Review of the diagnostic potential of scores derived from word list learning tests in mild cognitive impairment and early Alzheimer's Disease.

Episodic memory impairment is one of the early hallmarks in Alzheimer's Disease. In the clinical diagnosis and research, episodic memory impairment is typically assessed using word lists that are repeatedly presented to and recalled by the participant across several trials. Until recently, total learning scores, which consist of the total number of words that are recalled by participants, were almost exclusively used for diagnostic purposes. The present review aims at summarizing evidence on additional scores derived from the learning trials which have recently been investigated more frequently regarding their diagnostic potential. These scores reflect item acquisition, error frequencies, strategy use, intertrial fluctuations, and recall consistency. Evidence was summarized regarding the effects of clinical status on these scores. Preclinical, mild cognitive impairment and mild Alzheimer's Disease stages were associated with a pattern of reduced item acquisition, more errors, less strategy use, and reduced access of items, indicating slowed and erroneous encoding. Practical implications and limitations of the present research will be discussed.

ORCA: A picture database of object-scene arrangements for cross-cultural and aging research.

In recent years, cross-cultural research on the modulation of basic cognitive processes by culture has intensified - also from an aging perspective. Despite this increased research interest, only a few cross-culturally normed non-verbal stimulus sets are available to support cross-cultural cognitive research in younger and older adults. Here we present the ORCA (Official Rating of Complex Arrangements) picture database, which includes a total of 720 object-scene compositions sorted into 180 quadruples (e.g., two different helmets placed in two different deserts). Each quadruple contains visually and semantically matched pairs of objects and pairs of scenes with varying degrees of semantic fit between objects and scenes. A total of 95 younger and older German and Chinese adults rated every object-scene pair on object familiarity and semantic fit between object and scene. While the ratings were significantly correlated between cultures and age groups, small but significant culture and age differences emerged. Object familiarity was higher for older adults than younger adults and for German participants than for Chinese participants. Semantic fit was rated lower by German older adults and Chinese younger adults as compared to German younger adults and Chinese older adults. Due to the large number of stimuli, our database is particularly well suited for cognitive and neuroscientific research on cross-cultural and age-related differences in perception, attention, and memory.

Not so different after all? An event-related potential study on item and source memory for object-scene pairs in German and Chinese young adults.

In recent years, several cross-cultural studies reported that Westerners focus more on central aspects of a scene (e.g., an object) relative to peripheral aspects (e.g., the background), whereas Easterners more evenly allocate attention to central and peripheral aspects. In memory tasks, Easterners exhibit worse recognition for the central object when peripheral aspects are changed, whereas Westerners are less affected by peripheral changes. However, most of these studies rely on hit rates without correcting for response bias, whereas studies accounting for response bias failed to replicate cultural differences in memory tasks. In this event-related potential (ERP) study, we investigated item and source memory for semantically unrelated object-scene pairs in German and Chinese young adults using memory measures corrected for response bias (i.e., the discrimination index Pr). Both groups completed study-test cycles with either item memory tests or source memory tests. In item memory blocks, participants completed an old/new recognition test for the central object. Source memory blocks entailed an associative recognition test for the association between object and background. Item and source memory were better for intact than for recombined pairs. However, as verified with frequentist and Bayesian analyzes, this context effect was not modulated by culture. The ERP results revealed an old/new effect for the item memory task in both groups which was again not modulated by culture. Our findings suggest that cultural differences in young adults do not manifest in intentional memory tasks probing memory for object-scene pairs without semantic relations when using bias-corrected memory measures.

Even young children make multiple predictions in the complex visual world.

Children can anticipate upcoming input in sentences with semantically constraining verbs. In the visual world, the sentence context is used to anticipatorily fixate the only object matching potential sentence continuations. Adults can process even multiple visual objects in parallel when predicting language. This study examined whether young children can also maintain multiple prediction options in parallel during language processing. In addition, we aimed at replicating the finding that children's receptive vocabulary size modulates their prediction. German children (5-6 years, n = 26) and adults (19-40 years, n = 37) listened to 32 subject-verb-object sentences with semantically constraining verbs (e.g., "The father eats the waffle") while looking at visual scenes of four objects. The number of objects being consistent with the verb constraints (e.g., being edible) varied among 0, 1, 3, and 4. A linear mixed effects model on the proportion of target fixations with the effect coded factors condition (i.e., the number of consistent objects), time window, and age group revealed that upon hearing the verb, children and adults anticipatorily fixated the single visual object, or even multiple visual objects, being consistent with the verb constraints, whereas inconsistent objects were fixated less. This provides first evidence that, comparable to adults, young children maintain multiple prediction options in parallel. Moreover, children with larger receptive vocabulary sizes (Peabody Picture Vocabulary Test) anticipatorily fixated potential targets more often than those with smaller ones, showing that verbal abilities affect children's prediction in the complex visual world.

A Combined Intervention of Aerobic Exercise and Video Game in Older Adults: The Efficacy and Neural Basis on Improving Mnemonic Discrimination.

BACKGROUND: Mnemonic discrimination is very vulnerable to aging. Previous studies have reported that aerobic exercise and enriched cognitive stimulation (e.g., video games) could improve mnemonic discrimination in older adults. The animal model suggested that combining the 2 training methods could result in a larger improvement. However, there is limited evidence on the potential superior efficacy of combined intervention with human participants. Moreover, the neural basis of this potential superior is poorly understood. METHODS: We conducted a 16-week intervention trial with 98 community-dwelling older adults assigned to one of the four groups (combined training, aerobic cycling alone, video game alone, or passive control). Mnemonic discrimination was measured as the primary behavioral outcome, hippocampal volume, and functional connectivity of the default mode network (DMN) were measured as neural indicators. RESULTS: Participants receiving the combined intervention demonstrated the largest effect size of mnemonic discrimination improvement. Magnetic resonance image results indicated aerobic exercising increased left hippocampal volume, while video-game training counteracted the decline of DMN functional connectivity with aging. The synergy of hippocampal structural and functional plasticity observed in the combined training group explained why the largest intervention benefits were obtained by this group. CONCLUSION: Despite the nonrandomized design (i.e., likely self-selection bias), our results provide new evidence that combined intervention of exercise and cognitive training is more effective than single intervention for older adults. Parallel to animal studies, aerobic exercise and the video game with enriched cognitive stimulation could induce hippocampal plasticity through separate structural and functional pathways. CLINICAL TRIALS REGISTRATION NUMBER: ChiCTR1900022702.

Explore with Me: Peer Observation Decreases Risk-Taking but Increases Exploration Tendencies across Adolescence.

It has been assumed that adolescents increase risk-taking tendencies when peers are present but findings on experimental decision-making have been inconclusive. Most studies focus on risk-taking tendencies, ignoring the effects peer presence can exert over other cognitive processes involved in decision-making, as well as any other underlying developmental and individual differences. In the present study, the trial-by-trial choice behavior was analyzed in a task in which adolescents adjust to dynamically changing risk probabilities. Using Bayesian modeling, the study aimed to infer about peer presence effects on risk-taking tendencies but also on reactions to, exploration of, and learning from positive and negative outcomes of risk-taking. 184 pre- to late adolescents (M = 14.09 years, min = 8.59, max = 18.97, SD = 2.95, 47% female) conducted the Balloon Analog Risk Task under two conditions: Once alone and once in the presence of a (non-existent) peer observing them virtually. Findings revealed that (a) peer observation reduced risk-taking but increased exploration tendencies and (b) that individual differences modulated this effect. Especially female pre-adolescents increased their openness to explore different choice outcomes when a peer observed their behavior. These results support the assumption that the occurrence and direction of peer influences on risk-taking depend on a person-environment interaction, emphasizing the dynamic role peers play in adolescent risk-taking.

Ratings of name agreement and semantic categorization of 247 colored clipart pictures by young German children.

Developmental and longitudinal studies with children increasingly use pictorial stimuli in cognitive, psychologic, and psycholinguistic research. To enhance validity and comparability within and across those studies, the use of normed pictures is recommended. Besides, creating picture sets and evaluating them in rating studies is very time consuming, in particular regarding samples of young children in which testing time is rather limited. As there is an increasing number of studies that investigate young German children's semantic language processing with colored clipart stimuli, this work provides a first set of 247 colored cliparts with ratings of German native speaking children aged 4 to 6 years. We assessed two central rating aspects of pictures: Name agreement (Do pictures elicit the intended name of an object?) and semantic categorization (Are objects classified as members of the intended semantic category?). Our ratings indicate that children are proficient in naming and even better in semantic categorization of objects, whereas both seems to improve with increasing age of young childhood. Finally, this paper discusses some features of pictorial objects that might be important for children's name agreement and semantic categorization and could be considered in future picture rating studies.

Age-related differences in expectation-based novel word learning.

Adult language users can infer the meaning of a previously unfamiliar word from a single exposure to this word in a semantically and thematically constrained context, henceforth, predictive context (Borovsky et al., 2010 Cognition, 116(2), 289-296; Borovsky et al., 2012 Language Learning and Development, 8(3), 278-302). Children use predictive contexts to anticipate upcoming stimuli (Borovsky et al., 2012 Language Learning and Development, 8(3), 278-302; Mani & Huettig, 2012 Journal of Experimental Psychology: Human Perception and Performance, 38(4), 843-847), but the extent to which they rely on prediction to learn novel word forms is unclear (Gambi et al., 2021 Cognition, 211, 104650). Here, we examine children's one-shot learning from predictive contexts using a modified version of the one-shot learning ERP paradigm for children aged 7-13 years. In a first learning phase, we presented audio recordings of expected words and unexpected novel pseudowords in strongly and weakly constraining sentence contexts. In the following priming phase, the same recorded words and pseudowords were used as primes to identical/synonymous, related, and unrelated target words. We measured N400 modulations to the word and pseudoword continuations in the learning phase and to the identical/synonymous, related, or unrelated target words in the priming phase. When initially presented in strongly constraining sentences, novel pseudowords primed synonymous targets equally well as word primes of the same intended meaning. This pattern was particularly pronounced in older children. Our findings suggest that, around early adolescence, children can use single exposures to constraining contexts to infer the meaning of novel words and to integrate these novel words in their lexicons.

Developmental differences in processing the valence and magnitude of incentive cues: Mid-adolescents are more sensitive to potential gains than early- or late-adolescents.

Recent research has focused on the interaction between motivation and cognitive control and shown that both are important for goal-directed behavior. There also is evidence for developmental differences in the sensitivity and behavioral effectiveness of incentives, showing that mid-adolescents might be especially susceptible to rewards. Further pursuing this line of research, the present study examined developmental differences in incentive processing and whether these potential differences also would correspond to changes in cognitive control. We compared the processing of high and low potential gains and losses in early-, mid-, and late adolescents by means of event-related potentials (ERPs) and examined whether these incentives also led to specific performance differences in task-switching. We expected that potential gains compared to potential losses and high compared to low incentives would lead to more preparatory updating as reflected in the P3b and consequently to better task performance and smaller global and local switch costs as indicators of cognitive control in all age groups. Furthermore, we expected that mid-adolescents should be especially sensitive to high gains and thus show the most pronounced enhancements in task performance and global and local switch costs in trials with high gains, respectively. Our results corroborate the idea of a special sensitivity to high rewards during mid-adolescence. The analysis of ERPs showed age-related differences in the processing of incentive cues that also varied with cognitive control demands. However, the different incentives did not impact age-related differences in indices of cognitive control, but had a general effect on response speed.

Patients with amnestic MCI Fail to Adapt Executive Control When Repeatedly Tested with Semantic Verbal Fluency Tasks.

OBJECTIVE: Semantic verbal fluency (SVF) tasks require individuals to name items from a specified category within a fixed time. An impaired SVF performance is well documented in patients with amnestic Mild Cognitive Impairment (aMCI). The two leading theoretical views suggest either loss of semantic knowledge or impaired executive control to be responsible. METHOD: We assessed SVF 3 times on 2 consecutive days in 29 healthy controls (HC) and 29 patients with aMCI with the aim to answer the question which of the two views holds true. RESULTS: When doing the task for the first time, patients with aMCI produced fewer and more common words with a shorter mean response latency. When tested repeatedly, only healthy volunteers increased performance. Likewise, only the performance of HC indicated two distinct retrieval processes: a prompt retrieval of readily available items at the beginning of the task and an active search through semantic space towards the end. With repeated assessment, the pool of readily available items became larger in HC, but not patients with aMCI. CONCLUSION: The production of fewer and more common words in aMCI points to a smaller search set and supports the loss of semantic knowledge view. The failure to improve performance as well as the lack of distinct retrieval processes point to an additional impairment in executive control. Our data did not clearly favour one theoretical view over the other, but rather indicates that the impairment of patients with aMCI in SVF is due to a combination of both.

Rational speech comprehension: Interaction between predictability, acoustic signal, and noise.

Introduction: During speech comprehension, multiple sources of information are available to listeners, which are combined to guide the recognition process. Models of speech comprehension posit that when the acoustic speech signal is obscured, listeners rely more on information from other sources. However, these models take into account only word frequency information and local contexts (surrounding syllables), but not sentence-level information. To date, empirical studies investigating predictability effects in noise did not carefully control the tested speech sounds, while the literature investigating the effect of background noise on the recognition of speech sounds does not manipulate sentence predictability. Additionally, studies on the effect of background noise show conflicting results regarding which noise type affects speech comprehension most. We address this in the present experiment. Methods: We investigate how listeners combine information from different sources when listening to sentences embedded in background noise. We manipulate top-down predictability, type of noise, and characteristics of the acoustic signal, thus creating conditions which differ in the extent to which a specific speech sound is masked in a way that is grounded in prior work on the confusability of speech sounds in noise. Participants complete an online word recognition experiment. Results and discussion: The results show that participants rely more on the provided sentence context when the acoustic signal is harder to process. This is the case even when interactions of the background noise and speech sounds lead to small differences in intelligibility. Listeners probabilistically combine top-down predictions based on context with noisy bottom-up information from the acoustic signal, leading to a trade-off between the different types of information that is dependent on the combination of a specific type of background noise and speech sound.

Mishearing as a Side Effect of Rational Language Comprehension in Noise.

Language comprehension in noise can sometimes lead to mishearing, due to the noise disrupting the speech signal. Some of the difficulties in dealing with the noisy signal can be alleviated by drawing on the context - indeed, top-down predictability has shown to facilitate speech comprehension in noise. Previous studies have furthermore shown that strong reliance on the top-down predictions can lead to increased rates of mishearing, especially in older adults, which are attributed to general deficits in cognitive control in older adults. We here propose that the observed mishearing may be a simple consequence of rational language processing in noise. It should not be related to failure on the side of the older comprehenders, but instead would be predicted by rational processing accounts. To test this hypothesis, we extend earlier studies by running an online listening experiment with younger and older adults, carefully controlling the target and direct competitor in our stimuli. We show that mishearing is directly related to the perceptibility of the signal. We furthermore add an analysis of wrong responses, which shows that results are at odds with the idea that participants overly strongly rely on context in this task, as most false answers are indeed close to the speech signal, and not to the semantics of the context.

Semantic Predictability Facilitates Comprehension of Degraded Speech in a Graded Manner.

Previous studies have shown that at moderate levels of spectral degradation, semantic predictability facilitates language comprehension. It is argued that when speech is degraded, listeners have narrowed expectations about the sentence endings; i.e., semantic prediction may be limited to only most highly predictable sentence completions. The main objectives of this study were to (i) examine whether listeners form narrowed expectations or whether they form predictions across a wide range of probable sentence endings, (ii) assess whether the facilitatory effect of semantic predictability is modulated by perceptual adaptation to degraded speech, and (iii) use and establish a sensitive metric for the measurement of language comprehension. For this, we created 360 German Subject-Verb-Object sentences that varied in semantic predictability of a sentence-final target word in a graded manner (high, medium, and low) and levels of spectral degradation (1, 4, 6, and 8 channels noise-vocoding). These sentences were presented auditorily to two groups: One group (n =48) performed a listening task in an unpredictable channel context in which the degraded speech levels were randomized, while the other group (n =50) performed the task in a predictable channel context in which the degraded speech levels were blocked. The results showed that at 4 channels noise-vocoding, response accuracy was higher in high-predictability sentences than in the medium-predictability sentences, which in turn was higher than in the low-predictability sentences. This suggests that, in contrast to the narrowed expectations view, comprehension of moderately degraded speech, ranging from low- to high- including medium-predictability sentences, is facilitated in a graded manner; listeners probabilistically preactivate upcoming words from a wide range of semantic space, not limiting only to highly probable sentence endings. Additionally, in both channel contexts, we did not observe learning effects; i.e., response accuracy did not increase over the course of experiment, and response accuracy was higher in the predictable than in the unpredictable channel context. We speculate from these observations that when there is no trial-by-trial variation of the levels of speech degradation, listeners adapt to speech quality at a long timescale; however, when there is a trial-by-trial variation of the high-level semantic feature (e.g., sentence predictability), listeners do not adapt to low-level perceptual property (e.g., speech quality) at a short timescale.

Age differences in decision making under known risk: The role of working memory and impulsivity.

This study examined whether age differences in risky decision making are dependent on known probability and value of outcomes (i.e., the expected value [EV]), the valence of anticipated outcomes (gains or losses), and individual differences in working memory and impulsivity. We used a task that varied risk independently from EV so that taking risks could be advantageous or disadvantageous. Results indicated differential developmental courses for the sensitivity to EV and outcome valence from early to late adolescence. An increase in risk-advantageous but a decrease in risk-disadvantageous behavior was obtained between early-to-mid and late adolescence. All adolescents showed higher risky behavior when losses rather than gains were expected. Age differences in the sensitivity to EV were fully mediated by individual differences in working memory but not by self-reported impulsivity, suggesting that decision making under known risk is strongly limited by the maturation of cognitive control processes. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Training and Transfer of Cue Updating in Older Adults Is Limited: Evidence From Behavioral and Neuronal Data.

Cognitive control processes, such as updating task-relevant information while switching between multiple tasks, are substantially impaired in older adults. However, it has also been shown that these cognitive control processes can be improved by training interventions, e.g., by training in task switching. Here, we applied an event-related potential (ERP) approach to identify whether a cognitive training improves task-preparatory processes such as updating of relevant task goals. To do so, we applied a pretest-training-posttest design with eight training sessions. Two groups of older adults were either trained in task switching (treatment group) or in performing single tasks (control group) and we compared their performance to a group of untrained younger adults. To foster cue updating in the treatment group, we applied a cue-based switching task in which the two task cues were randomly selected prior to target presentation so that participants had time to prepare for the upcoming task. In contrast, the control group also received task cues but those were redundant as only one task had to be performed. We also examined whether training in cue updating during task switching can be transferred to a similar cognitive control task measuring updating of context information, namely a modified version of the AX-Continuous Performance Task (AX-CPT). The results revealed training-specific improvements in task switching, that is, a larger improvement in blocks requiring switching in comparison to single tasks at the behavioral level. In addition, training specific-effects were also found at the neuronal level. Older adults trained in cue updating while switching showed a reduction in mixing costs in the cue-related P3, indicating an improvement in preparatory updating processes. Additionally, P3 topography changed with training from a very broad to a parietally focused scalp distribution similar to the one found in younger adults. However, we did not obtain training-specific improvements in context updating in the AX-CPT neither at the behavioral level nor at the neuronal level. Results are discussed in the context of the ongoing debate on whether transfer of cognitive training improvements is possible.

The interplay between cognitive control and emotional processing in children and adolescents.

This study examined interactions between cognitive control and emotional processing throughout adolescent development. In particular, we investigated whether age differences in response inhibition and initiation were influenced by an emotional expression of faces and whether the effects differed from processing of nonemotional features of faces. Therefore, we applied two versions of a Go/No-go task, an emotional task requiring responding or withholding responding to happy and angry faces, and a gender task including decisions to female and male faces in a large sample (N = 187, age range = 9-18 years). Considering theoretical assumptions of dual-system models that mid-adolescents are more susceptible to the processing of emotional contents, we expected more inefficient response inhibition on happy and angry trials than on neutral trials. We also expected that these effects would be specific to emotional contents. Results indicated that both response inhibition and initiation showed linear improvements with increasing age. Response inhibition was hampered in the presence of happy and angry faces, especially in mid-adolescents and late adolescents. In contrast, response initiation was highly facilitated to happy faces, indicating a happy effect, leading to more accurate responding in all age groups and to faster responding especially in late adolescents. Children, in contrast to late adolescents, were more accurate in response inhibition and initiation when the gender was task relevant. Results are in line with dual-system models, assuming a higher sensitivity to emotional features from mid-adolescents onward but not to other features such as gender.

Plasticity in brain activity dynamics after task-shifting training in older adults.

Cognitive control is supported by a dynamic interplay of transient (i.e., trial-related) brain activation across fronto-parietal networks and sustained (i.e., block-related) activation across fronto-striatal networks. Older adults show disturbances in this dynamic functional recruitment. There is evidence suggesting that cognitive-control training may enable older adults to redistribute their brain activation across cortical and subcortical networks, which in turn can limit behavioral impairments. However, previous studies have only focused on spatial rather than on temporal aspects of changes in brain activation. In the present study, we examined training-related functional plasticity in old age by applying a hybrid fMRI design that sensitively tracks the spatio-temporal interactions underlying brain-activation changes. Fifty healthy seniors were assigned to a task-shifting training or an active-control group and their pretest/posttest activation-change maps were compared against 25 untrained younger adults. After training, older adults showed the same performance as untrained young adults. Compared to the control group, task-shifting training promoted proactive (i.e., early, cue-related) changes in transient mechanisms supporting the maintenance and top-down biasing of task-set representations in a specific prefrontal circuitry; reactive (i.e., late, probe-related) changes in transient mechanisms supporting response-selection processes in dissociable fronto-parietal networks; overall reductions of sustained activation in striatal circuits. Results highlight the importance of spatio-temporal interactions in training-induced neural changes in age.

Spatio-Temporal Neural Changes After Task-Switching Training in Old Age.

In the present study, we aimed at examining selective neural changes after task-switching training in old age by not only considering the spatial location but also the timescale of brain activation changes (i.e., sustained/block-related or transient/trial-related timescales). We assigned a sample of 50 older adults to a task-switching training or an active single-task control group. We administered two task paradigms, either sensitive to transient (i.e., a context-updating task) or sustained (i.e., a delayed-recognition working-memory task) dynamics of cognitive control. These dynamics were captured by utilizing an appropriate event-related or block-related functional magnetic resonance imaging design. We captured selective changes in task activation during the untrained tasks after task-switching training compared to an active control group. Results revealed changes at the neural level that were not evident from only behavioral data. Importantly, neural changes in the transient-sensitive context updating task were found on the same timescale but in a different region (i.e., in the left inferior parietal lobule) than in the task-switching training task (i.e., ventrolateral PFC, inferior frontal junction, superior parietal lobule), only pointing to temporal overlap, while neural changes in the sustained-sensitive delayed-recognition task overlapped in both timescale and region with the task-switching training task (i.e., in the basal ganglia), pointing to spatio-temporal overlap. These results suggest that neural changes after task-switching training seem to be critically supported by the temporal organization of neural processing.

Are Mid-Adolescents Prone to Risky Decisions? The Influence of Task Setting and Individual Differences in Temperament.

Recent developmental models assume a higher tendency to take risks in mid-adolescence, while the empirical evidence for this assumption is rather mixed. Most of the studies applied quite different tasks to measure risk-taking behavior and used a narrow age range. The main goal of the present study was to examine risk-taking behavior in four task settings, the Treasure Hunting Task (THT) in a gain and a loss domain, the Balloon Analogue Risk Task (BART), and the STOPLIGHT task. These task settings differ in affective task moderators, like descriptive vs. experienced outcomes, anticipation of gains vs. losses, static vs. dynamic risk presentation, and time pressure vs. no time pressure and were applied in a sample of 187 participants from age 9-18. Beneath age trends, we were interested in their association with individual differences in approach behavior, venturesomeness, impulsivity, and empathy above age, gender, and fluid intelligence. Our findings revealed that risk-taking behavior is only low to moderately correlated between the four task contexts, suggesting that they capture different aspects of risk-taking behavior. Accordingly, a mid-adolescent peak in risk propensity was only found under time pressure in the STOPLIGHT that was associated with higher impulsivity and empathy. In contrast, risky decisions decreased with increasing age in task settings, in which losses were anticipated (THT Loss), and this was associated with higher cognitive abilities. We found no age differences when gains were anticipated, neither in a static (THT Gain) nor in a dynamic task setting (BART). These findings clearly suggest the need to consider affective task moderators, as well as individual differences in temperament and cognitive abilities, in actual models about adolescent development.

Exploitation vs. exploration-computational temporal and semantic analysis explains semantic verbal fluency impairment in Alzheimer's disease.

Impaired Semantic Verbal Fluency (SVF) in dementia due to Alzheimer's Disease (AD) and its precursor Mild Cognitive Impairment (MCI) is well known. Yet, it remains open whether this impairment mirrors the breakdown of semantic memory retrieval processes or executive control processes. Therefore, qualitative analysis of the SVF has been proposed but is limited in terms of methodology and feasibility in clinical practice. Consequently, research draws no conclusive picture which of these afore-mentioned processes drives the SVF impairment in AD and MCI. This study uses a qualitative computational approach-combining temporal and semantic information-to investigate exploitation and exploration patterns as indicators for semantic memory retrieval and executive control processes. Audio SVF recordings of 20 controls (C, 66-81 years), 55 MCI (57-94 years) and 20 AD subjects (66-82 years) were assessed while groups were matched according to age and education. All groups produced, on average, the same amount of semantically related items in rapid succession within word clusters. Conversely, towards AD, there was a clear decline in semantic as well as temporal exploration patterns between clusters. Results strongly point towards preserved exploitation-semantic memory retrieval processes-and hampered exploration-executive control processes-in AD and potentially in MCI.