Conceptual combination during novel and existing compound word reading in context: A self-paced reading study.

According to the relation-interpretation-competition-evaluation (RICE) hypothesis, compound word processing involves selecting a relational meaning (e.g., moonlight is 'light from moon') from a larger set of competing possible relational meanings. Prior lexical decision experiments with existing compound words have demonstrated that greater entropy of conceptual relations, i.e., greater competition between conceptual relations, impedes lexical processing speed. The present study addresses two unresolved issues: First, it is unclear whether the competition effect generalizes to the processing of novel compounds (e.g., grassladder), and second, it is not yet known whether competition between possible relational meanings extends to compounds when they are read in a sentence context. A series of self-paced reading tasks examined whether the competition effect operates regardless of (i) compound type (existing vs. novel), and (ii) whether sentence context (semantically supportive vs. semantically non-supportive) moderates the competition effect. The experiments confirmed that reading times of novel and existing compounds read in sentences were impacted by entropy of conceptual relations. Moreover, the effect was equally strong in both sentence context types. Additional analyses indicated that relational meanings are more ambiguous and flexible across different contexts for novel compounds compared to existing compounds.

Motion cues increase focused attention towards purely visual stimuli in a nocturnal primate and drive stimulus interaction and approach/avoidance in a context-dependent manner.

Visual information is of pivotal ecological importance to monkeys, apes, and humans, whereas its role in nocturnal primate ecology is less well understood. We explored how purely visual information modulates the behavior of a nocturnal primate. Abstract (shape), photographic (shape + detail), or video (shape + detail + motion) representations of arthropod prey (Zophobas morio; food context) or a male conspecific (social context) were systematically presented to 22 individuals of the gray mouse lemur (Microcebus murinus) using a touchscreen. We assessed stimulus-directed touch interactions, durations of focused visual attention towards the different stimuli, and durations spent in the half of the setup-chamber more distant to the touchscreen (as quantification of approach/avoidance). Focused attention towards the stimulus generally increased from abstract and photographic to videographic stimuli. For the food context, indications for a parallel increase in stimulus-directed touch interactions from abstract stimulus to video were found. Approach/avoidance was independent of the stimulus type within both contexts. A comparison between the contexts under the video condition revealed higher durations of visual attention and lower stimulus avoidance in the food context compared to the social context. The number of touch interactions with the video stimulus was not generally context-dependent, but context-dependency related to sex: In the food context, animals with high and low numbers of touch interactions were equally distributed across sexes. In the social context, females showed the highest numbers of touch interactions. Numbers in males declined compared to the food context. Our results demonstrate for the first time that purely visual information modulates mouse lemur behavior and focused attention in a content- and context-specific manner, suggesting that vision is of high importance for the ecology of these nocturnal primates. The findings emphasize the need for further vision-based experiments to gain deeper insight into the evolution of visual information processing and cognition in nocturnal primates.

CompLex: an eye-movement database of compound word reading in English.

The CompLex database presents a large-scale collection of eye-movement studies on English compound-word processing. A combined total of 440 participants completed eye-tracking experiments in which they silently read unspaced English compound words (e.g., goalpost) embedded in sentence contexts (e.g., Dylan hit the goalpost when he was aiming for the net.). Three studies were conducted using participants representing the non-college-bound population (300 participants), and four studies included participants recruited from the student population (140 participants). The database comprises trial-level eye-movement data (47,763 trials), participant data (including a measure of reading experience estimated via the Author Recognition Test), and lexical characteristics for the set of 931 English compound words used as critical stimuli in the studies. One contribution of the present paper is a set of regression analyses conducted on the full database and individual experiments. We report that the most reliable and consistent main effects were those elicited by compound word length, left constituent frequency, right constituent frequency, compound frequency and semantic transparency. Separately, we also found that the effect of left frequency and compound word length is weaker among more frequent compounds. Another contribution is a power analysis, in which we determined the sample sizes required to reliably detect effect sizes that are comparable to those observed in our regression models. These sample size estimates serve as a recommendation for researchers wishing to either collect eye-movement data for compound word reading, or use the current database as a resource for the study of English compound word processing.

LADEC: The Large Database of English Compounds.

The Large Database of English Compounds (LADEC) consists of over 8,000 English words that can be parsed into two constituents that are free morphemes, making it the largest existing database specifically for use in research on compound words. Both monomorphemic (e.g., wheel) and multimorphemic (e.g., teacher) constituents were used. The items were selected from a range of sources, including CELEX, the English Lexicon Project, the British Lexicon Project, the British National Corpus, and Wordnet, and were hand-coded as compounds (e.g., snowball). Participants rated each compound in terms of how predictable its meaning is from its parts, as well as the extent to which each constituent retains its meaning in the compound. In addition, we obtained linguistic characteristics that might influence compound processing (e.g., frequency, family size, and bigram frequency). To show the usefulness of the database in investigating compound processing, we conducted a number of analyses that showed that compound processing is consistently affected by semantic transparency, as well as by many of the other variables included in LADEC. We also showed that the effects of the variables associated with the two constituents are not symmetric. In short, LADEC provides the opportunity for researchers to investigate a number of questions about compounds that have not been possible to investigate in the past, due to the lack of sufficiently large and robust datasets. In addition to directly allowing researchers to test hypotheses using the information included in LADEC, the database will contribute to future compound research by allowing better stimulus selection and matching.

A psycholinguistic study of intergroup bias and its cultural propagation.

Intergroup bias is the tendency for people to inflate positive regard for their in-group and derogate the out-group. Across two online experiments (N = 922) this study revisits the methodological premises of research on language as a window into intergroup bias. Experiment 1 examined (i) whether the valence (positivity) of language production differs when communicating about an in- vs. out-group, and (ii) whether the extent of this bias is influenced by the positivity of input descriptors that were initially presented to participants as examples of how an in-group or out-group characterize themselves. Experiment 2 used the linear diffusion chain method to examine how biases are transmitted through cultural generations. Valence of verbal descriptions were quantified using ratings obtained from a large-scale psycholinguistic database. The findings from Experiment 1 indicated a bias towards employing positive language in describing the in-group (exhibiting in-group favoritism), particularly in cases where the input descriptors were negative. However, there was weak evidence for increased negativity aimed at the out-group (i.e., out-group derogation). The findings from Experiment 2 demonstrated that in-group positivity bias propagated across cultural generations at a higher rate than out-group derogation. The results shed light on the formation and cultural transmission of intergroup bias.

Semantic richness effects in isolated spoken word recognition: Evidence from massive auditory lexical decision.

While known to influence visual lexical processing, the semantic information we associate with words has recently been found to influence auditory lexical processing as well. The present work explored the influence of semantic richness in auditory lexical decision. Study 1 recreated an experiment investigating semantic richness effects in concrete nouns (Goh et al., 2016). In Study 2, we expanded the stimulus set from 442 to 8,626 items, exploring the robustness of effects observed in Study 1 against a larger data set with increased diversity in both word class and other characteristics of interest. We also utilized generalized additive mixed models to investigate potential nonlinear effects. Results indicate that semantic richness effects become more nuanced and detectable when a wider set of items belonging to different parts of speech is examined. Findings are discussed in the context of models of spoken word recognition. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Sex matters in echoacoustic orientation: gender differences in the use of acoustic landmarks in Phyllostomus discolor (lesser spear-nosed bat).

Sex-specific differences in orientation strategies are well known for several rodent and primate species with females relying more on landmarks when it comes to visually guided orientation, whereas males preferentially use Euclidean cues. We used the echolocating bat Phyllostomus discolor for a behavioural study on gender differences in the use of acoustic landmarks. The experimental animals (6 males, 6 females) had to learn and perform a simple orientational task, firstly in the absence of landmarks and subsequently in the presence of four acoustic landmarks of which one was occasionally removed during the critical experiment. The results presented here show that gender differences in the use of acoustic landmarks exist in P. discolor, which supports our hypothesis that the phenomenon is independent of the modality that is used to sense the environment during orientation. Therefore, our findings allow for the prediction of similar phenomena in other acoustically orienting mammals. Interestingly, due to the specific ecology of P. discolor, our results partially contradict the evolutionary theories on gender-specific orientation, as will be discussed. Finally, we consider our finding as being one of several important steps toward establishing bats as a new model organism in neuroscientific studies on allocentric spatial cognition in mammals.

Age affects procedural paired-associates learning in the grey mouse lemur (Microcebus murinus).

The ability to associate memorized objects with their location in space gradually declines during normal aging and can drastically be affected by neurodegenerative diseases. This study investigates object-location paired-associates learning (PAL) in the grey mouse lemur (Microcebus murinus), a nonhuman primate model of brain aging. Touchscreen-based testing of 6 young adults (1-5 years) and 6 old adults (> 7 years) in the procedural rodent dPAL-task revealed significant age-related performance decline, evident in group differences in the percentage of correct decision during learning and the number of sessions needed to reach a predefined criterion. Response pattern analyses suggest decreased susceptibility to relative stimulus-position biases in young animals, facilitating PAL. Additional data from a subset of "overtrained" individuals (n = 7) and challenge sessions using a modified protocol (sPAL) further suggest that learning criteria routinely used in animal studies on PAL can underestimate the endpoint at which a stable performance is reached and that more conservative criteria are needed to improve construct validity of the task. To conclude, this is the first report of an age effect on dPAL and corroborates the role of mouse lemurs as valuable natural nonhuman primate models in aging research.

Conditioning learning in an attentional task relates to age and ventricular expansion in a nonhuman primate (Microcebus murinus).

The grey mouse lemur (Microcebus murinus) is a promising nonhuman primate model for brain ageing and neurodegenerative diseases. Age-related cognitive decline in this model is well described, however, data on possible relations between attention and age, as they are known from humans, are missing. We tested 10 mouse lemurs in a touchscreen-based version of the 5-choice-serial-reaction-time-task (5CSRTT) on visuo-spatial attention: subjects had to interact with a briefly presented stimulus occurring unpredictably in one out of five locations on the touchscreen. Animals were trained to an 80 % performance at a four seconds stimulus presentation duration (SPD) and subsequently challenged by a SPD of two seconds. Additionally, ventricular expansion was assessed using structural magnetic resonance imaging. Trials to the 80 % criterion at four seconds SPD correlated significantly with age and with ventricular expansion, especially around the occipital lobe. Once criterion performance was reached, two seconds challenge performance was independent of age. In four subjects that were additionally challenged with 1.5, 1.0, 0.8, or 0.6 s SPDs or variable delays preceding stimulus presentation, performance linearly declined with decreasing SPD, i.e. increasing attentional demand. In conclusion, this is the first report of 5CSRTT data in mouse lemurs and demonstrates the general applicability of this task of visuo-spatial attention to this nonhuman primate model. Results further demonstrate age-related deficits in learning during acquisition of the 5CSRTT and suggest that both may be linked through age-related atrophy of occipital structures and a resulting deficit in central visual processes.

Double-edged effects of tamoxifen-in-oil-gavage on an infectious murine model for multiple sclerosis.

Tamoxifen gavage is a commonly used method to induce genetic modifications in cre-loxP systems. As a selective estrogen receptor modulator (SERM), the compound is known to have immunomodulatory and neuroprotective properties in non-infectious central nervous system (CNS) disorders. It can even cause complete prevention of lesion development as seen in experimental autoimmune encephalitis (EAE). The effect on infectious brain disorders is scarcely investigated. In this study, susceptible SJL mice were infected intracerebrally with Theiler's murine encephalomyelitis virus (TMEV) and treated three times with a tamoxifen-in-oil-gavage (TOG), resembling an application scheme for genetically modified mice, starting at 0, 18, or 38 days post infection (dpi). All mice developed 'TMEV-induced demyelinating disease' (TMEV-IDD) resulting in inflammation, axonal loss, and demyelination of the spinal cord. TOG had a positive effect on the numbers of oligodendrocytes and oligodendrocyte progenitor cells, irrespective of the time point of application, whereas late application (starting 38 dpi) was associated with increased demyelination of the spinal cord white matter 85 dpi. Furthermore, TOG had differential effects on the CD4+ and CD8+ T cell infiltration into the CNS, especially a long lasting increase of CD8+ cells was detected in the inflamed spinal cord, depending of the time point of TOG application. Number of TMEV-positive cells, astrogliosis, astrocyte phenotype, apoptosis, clinical score, and motor function were not measurably affected. These data indicate that tamoxifen gavage has a double-edged effect on TMEV-IDD with the promotion of oligodendrocyte differentiation and proliferation, but also increased demyelination, depending on the time point of application. The data of this study suggest that tamoxifen has also partially protective functions in infectious CNS disease. These effects should be considered in experimental studies using the cre-loxP system, especially in models investigating neuropathologies.

Neurobiological substrates of animal personality and cognition in a nonhuman primate (Microcebus murinus).

INTRODUCTION: The gray mouse lemur (Microcebus murinus) is an important nonhuman primate model in biomedical research. Numerous studies investigated mouse lemur behavior and possible factors underlying interindividual variation in both, animal personality and cognitive performance. Some effects, such as an age-related decline in executive functioning, have robustly been found across laboratory colonies; however, little is known about the brain structural substrates in mouse lemurs. METHODS: Here, we provide first exploratory data linking in vivo magnetic resonance imaging of 34 mouse lemurs to performance in a standardized, touchscreen-based task on object discrimination and reversal learning as well as to animal personality under different scenarios in an open field. RESULTS: High interindividual variability in both brain morphometric and behavioral measurements was found, but only few significant correlations between brain structure and behavior were revealed: Object discrimination learning was linked to the volume of the hippocampus and to temporal lobe thickness, while reversal learning was linked to thalamic volume and the thickness of the anterior cingulate lobe. Emergence latency into the open field correlated with volume of the amygdala. General exploration-avoidance in the empty open-field arena correlated with thicknesses of the anterior cingulate lobe and fronto-parietal substructures. Neophilia, assessed as exploration of a novel object placed in the arena, among others, related to the volume of the caudate nucleus. CONCLUSION: In summary, our data suggest a prominent role of temporal structures (including the hippocampus) for learning capability, as well as thalamic and anterior cingulate structures for cognitive flexibility and response inhibition. The amygdala, the anterior cingulate lobe, and the caudate nucleus are particularly linked to animal personality in the open-field setting. These findings are congruent with the comparative psychological literature and provide a valuable basis for future studies elucidating aspects of behavioral variation in this nonhuman primate model.

Age-related decline in executive function as a hallmark of cognitive ageing in primates: an overview of cognitive and neurobiological studies.

Executive function (EF) is a complex construct that reflects multiple higher-order cognitive processes such as planning, updating, inhibiting and set-shifting. Decline in these functions is a hallmark of cognitive ageing in humans, and age differences and changes in EF correlate with age-related differences and changes in association cortices, particularly the prefrontal areas. Here, we review evidence for age-related decline in EF and associated neurobiological changes in prosimians, New World and Old World monkeys, apes and humans. While EF declines with age in all primate species studied, the relationship of this decline with age-related alterations in the prefrontal cortex remains unclear, owing to the scarcity of neurobiological studies focusing on the ageing brain in most primate species. In addition, the influence of sex, vascular and metabolic risk, and hormonal status has rarely been considered. We outline several methodological limitations and challenges with the goal of producing a comprehensive integration of cognitive and neurobiological data across species and elucidating how ageing shapes neurocognitive trajectories in primates with different life histories, lifespans and brain architectures. Such comparative investigations are critical for fostering translational research and understanding healthy and pathological ageing in our own species. This article is part of the theme issue 'Evolution of the primate ageing process'.

Sensory Island Task (SIT): A New Behavioral Paradigm to Study Sensory Perception and Neural Processing in Freely Moving Animals.

A central function of sensory systems is the gathering of information about dynamic interactions with the environment during self-motion. To determine whether modulation of a sensory cue was externally caused or a result of self-motion is fundamental to perceptual invariance and requires the continuous update of sensory processing about recent movements. This process is highly context-dependent and crucial for perceptual performances such as decision-making and sensory object formation. Yet despite its fundamental ecological role, voluntary self-motion is rarely incorporated in perceptual or neurophysiological investigations of sensory processing in animals. Here, we present the Sensory Island Task (SIT), a new freely moving search paradigm to study sensory processing and perception. In SIT, animals explore an open-field arena to find a sensory target relying solely on changes in the presented stimulus, which is controlled by closed-loop position tracking in real-time. Within a few sessions, animals are trained via positive reinforcement to search for a particular area in the arena ("target island"), which triggers the presentation of the target stimulus. The location of the target island is randomized across trials, making the modulated stimulus feature the only informative cue for task completion. Animals report detection of the target stimulus by remaining within the island for a defined time ("sit-time"). Multiple "non-target" islands can be incorporated to test psychometric discrimination and identification performance. We exemplify the suitability of SIT for rodents (Mongolian gerbil, Meriones unguiculatus) and small primates (mouse lemur, Microcebus murinus) and for studying various sensory perceptual performances (auditory frequency discrimination, sound source localization, visual orientation discrimination). Furthermore, we show that pairing SIT with chronic electrophysiological recordings allows revealing neuronal signatures of sensory processing under ecologically relevant conditions during goal-oriented behavior. In conclusion, SIT represents a flexible and easily implementable behavioral paradigm for mammals that combines self-motion and natural exploratory behavior to study sensory sensitivity and decision-making and their underlying neuronal processing.

Sex-specific patterns of age-related cerebral atrophy in a nonhuman primate Microcebus murinus.

Steadily aging populations result in a growing need for research regarding age-related brain alterations and neurodegenerative pathologies. By allowing a good translation of results to humans, nonhuman primates, such as the gray mouse lemur Microcebus murinus, have gained attention in this field. Our aim was to examine correlations between atrophy-induced brain alterations and age, with special focus on sex differences in mouse lemurs. For cerebral volumetric measurements, in vivo magnetic resonance imaging was performed on 59 animals (28♀♀/31♂♂) aged between 1.0 to 11.9 years. Volumes of different brain regions, cortical thicknesses, and ventricular expansions were evaluated. Analyses revealed significant brain atrophies with increasing age, particularly around the caudate nucleus, the thalamus, and frontal, parietal, and temporo-occipital regions. Especially old females showed a strong decline in cingulate cortex thickness and had higher values of ventricular expansion, whereas cortical thickness of the splenium and occipital regions decreased mainly in males. Our study, thus, provides first evidence for sex-specific, age-related brain alterations in a nonhuman primate, suggesting that mouse lemurs can help elucidating the mechanism underlying sex disparities in cerebral aging, for which there is mixed evidence in humans.

Linking cognition to age and amyloid-ß burden in the brain of a nonhuman primate (Microcebus murinus).

The gray mouse lemur (Microcebus murinus) is a valuable model in research on age-related proteopathies. This nonhuman primate, comparable to humans, naturally develops tau and amyloid-ß proteopathies during aging. Whether these are linked to cognitive alterations is unknown. Here, standardized cognitive testing in pairwise discrimination and reversal learning in a sample of 37 aged (>5 years) subjects was combined with tau and amyloid-ß histochemistry in individuals that died naturally. Correlation analyses in successfully tested subjects (n = 22) revealed a significant relation between object discrimination learning and age, strongly influenced by outliers, suggesting pathological cases. Where neuroimmunohistochemistry was possible, as subjects deceased, the naturally developed cortical amyloid-ß burden was significantly linked to pretraining success (intraneuronal accumulations) and discrimination learning (extracellular deposits), showing that cognitive (pairwise discrimination) performance in old age predicts the natural accumulation of amyloid-ß at death. This is the first description of a direct relation between the cortical amyloid-ß burden and cognition in a nonhuman primate.

A paradox of apparent brainless behavior: The time-course of compound word recognition.

A review of the behavioral and neurophysiological estimates of the time-course of compound word recognition brings to light a paradox whereby temporal activity associated with lexical variables in behavioral studies predates temporal activity of seemingly comparable lexical processing in neuroimaging studies. However, under the assumption that brain activity is a cause of behavior, the earliest reliable behavioral effect of a lexical variable must represent an upper temporal bound for the origin of that effect in the neural record. The present research provides these behavioral bounds for lexical variables involved in compound word processing. We report data from five naturalistic reading studies in which participants read sentences containing English compound words, and apply a distributional technique of survival analysis to resulting eye-movement fixation durations (Reingold & Sheridan, 2014). The results of the survival analysis of the eye-movement record place a majority of the earliest discernible onsets of orthographic, morphological, and semantic effects at less than 200 ms (with a range of 138-269 ms). Our results place constraints on the absolute time-course of effects reported in the neurolinguistic literature, and support theories of complex word recognition which posit early simultaneous access of form and meaning.

Electrophysiological evidence for the integral nature of tone in Mandarin spoken word recognition.

Current models of spoken word recognition have been predominantly based on studies of Indo-European languages. As a result, less is known about the recognition processes involved in the perception of tonal languages (e.g., Mandarin Chinese), and the role of lexical tone in speech perception. One view is that words in tonal languages are processed phonologically through individual segments, while another view is that they are processed lexically as a whole. Moreover, a recent study claimed to be the first to discover an early phonological processing stage in Mandarin (Huang et al., 2014). There seems to be a lack of investigations concerning tonal languages, as no clear conclusions have been reached about the nature of tonal processes, or a model of spoken word recognition that best incorporates lexical tone. The current study addressed these issues by presenting 18 native Mandarin speakers with aural sentences with medial target words. These either matched or mismatched the preceding visually presented sentences with medial target words (e.g, /jia1/home). Violation conditions involved target words that differed in the following ways: tone violation, where only the tone was different (e.g., /jia4/"price"), onset violation, where only the onset was different (e.g., /xia1/"shrimp"), and syllable violation, where both the tone and the onset were different (e.g., /tang2/"candy"). We did not find evidence for an early phonological processing stage in Mandarin. Instead, our findings indicate that Mandarin syllables are processed incrementally through phonological segments and that tone is strongly associated with lexical access. These results are discussed with respect to modifications for existing models in spoken word recognition to incorporate the processes involved with tonal language recognition.

National character stereotypes mirror language use: A study of Canadian and American tweets.

National character stereotypes, or beliefs about the personality characteristics of the members of a nation, present a paradox. Such stereotypes have been argued to not be grounded in the actual personality traits of members of nations, yet they are also prolific and reliable. Stereotypes of Canadians and Americans exemplify the paradox; people in both nations strongly believe that the personality profiles of typical Canadians and Americans diverge, yet aggregated self-reports of personality profiles of Canadians and Americans show no reliable differences. We present evidence that the linguistic behavior of nations mirrors national character stereotypes. Utilizing 40 million tweets from the microblogging platform Twitter, in Study 1A we quantify the words and emojis diagnostic of Canadians and Americans. In Study 1B we explore the positivity of national language use. In Studies 2A and 2B, we present the 120 most nationally diagnostic words and emojis of each nation to naive participants, and ask them to assess personality of a hypothetical person who uses either diagnostically Canadian or American words and emojis. Personality profiles derived from the diagnostic words of each nation bear close resemblance to national character stereotypes. We therefore propose that national character stereotypes may be partially grounded in the collective linguistic behaviour of nations.

Individual variability in the semantic processing of English compound words.

Semantic transparency effects during compound word recognition provide critical insight into the organization of semantic knowledge and the nature of semantic processing. The past 25 years of psycholinguistic research on compound semantic transparency has produced discrepant effects, leaving the existence and nature of its influence unresolved. In the present study, we examined the influence of semantic transparency and individual reading experience on eye-movement behavior during sentence reading. Eye-movement data were collected from 138 non-college-bound 16- to 26-year-old speakers of English in a sentence-reading task representing a total of 455 different compound words. Measures of individual differences in reading experience were collected from the same participants and consisted of standardized assessments of exposure to printed materials, vocabulary size, and word recognition skill. Statistical analyses revealed facilitatory effects of both Modifier-Compound and Head-Compound transparency throughout the eye-movement record. Moreover, the study reports interactions between Head-Compound transparency and measures of reading experience. Readers with a small amount exposure to printed materials and a limited vocabulary size exhibited slower processing in late eye-movement measures when reading highly transparent compounds relative to opaque compounds. The opposite effect was observed for readers with a relatively large amount of exposure to printed materials and a relatively larger vocabulary size, such that highly transparent compounds facilitated lexical processing. To account for the results, the authors posit a trade-off between 2 cognitive mechanisms, which is modulated by individual reading experience; that is, the benefit of semantic coactivation of closely related concepts, and the cost of discriminating between those concepts. (PsycINFO Database Record

First comparative approach to touchscreen-based visual object-location paired-associates learning in humans (Homo sapiens) and a nonhuman primate (Microcebus murinus).

A recent study suggests that a specific, touchscreen-based task on visual object-location paired-associates learning (PAL), the so-called Different PAL (dPAL) task, allows effective translation from animal models to humans. Here, we adapted the task to a nonhuman primate (NHP), the gray mouse lemur, and provide first evidence for the successful comparative application of the task to humans and NHPs. Young human adults reach the learning criterion after considerably less sessions (one order of magnitude) than young, adult NHPs, which is likely due to faster and voluntary rejection of ineffective learning strategies in humans and almost immediate rule generalization. At criterion, however, all human subjects solved the task by either applying a visuospatial rule or, more rarely, by memorizing all possible stimulus combinations and responding correctly based on global visual information. An error-profile analysis in humans and NHPs suggests that successful learning in NHPs is comparably based either on the formation of visuospatial associative links or on more reflexive, visually guided stimulus-response learning. The classification in the NHPs is further supported by an analysis of the individual response latencies, which are considerably higher in NHPs classified as spatial learners. Our results, therefore, support the high translational potential of the standardized, touchscreen-based dPAL task by providing first empirical and comparable evidence for two different cognitive processes underlying dPAL performance in primates. (PsycINFO Database Record