Paired-associate versus cross-situational: How do verbal working memory and word familiarity affect word learning?

Word learning is one of the first steps into language, and vocabulary knowledge predicts reading, speaking, and writing ability. There are several pathways to word learning and little is known about how they differ. Previous research has investigated paired-associate (PAL) and cross-situational word learning (CSWL) separately, limiting the understanding of how the learning process compares across the two. In PAL, the roles of word familiarity and working memory have been thoroughly examined, but these same factors have received very little attention in CSWL. We randomly assigned 126 monolingual adults to PAL or CSWL. In each task, names of 12 novel objects were learned (six familiar words, six unfamiliar words). Logistic mixed-effects models examined whether word-learning paradigm, word type and working memory (measured with a backward digit-span task) predicted learning. Results suggest better learning performance in PAL and on familiar words. Working memory predicted word learning across paradigms, but no interactions were found between any of the predictors. This suggests that PAL is easier than CSWL, likely because of reduced ambiguity between the word and the referent, but that learning across both paradigms is equally enhanced by word familiarity, and similarly supported by working memory.

Paired associates learning is disrupted after unilateral parietal lobe controlled cortical impact in rats: A trial-by-trial behavioral analysis.

Approximately 60-70 million people suffer from traumatic brain injury (TBI) each year. Animal models continue to be paramount in understanding mechanisms of cellular dysfunction and testing new treatments for TBI. Enhancing the translational potential of novel interventions therefore necessitates testing pre-clinical intervention strategies with clinically relevant cognitive assays. This study used a unilateral parietal lobe controlled cortical impact (CCI) model of TBI and tested rats on a touchscreen-based Paired Associates Learning (PAL) task, which is part of the Cambridge Neuropsychological Test Automated Battery. In humans, the PAL task has been used to assess cognitive deficits in the ability to form stimulus-location associations in a multitude of disease states, including TBI. Although the use of PAL in animal models could be important for understanding the clinical severity of cognitive impairment post-injury and throughout intervention, to date, the extent to which a rat model of TBI produces deficits in PAL task performance has not yet been reported. This study details the behavioral consequences of the CCI injury model with a Trial-by-Trial analysis of PAL performance that enables behavioral strategy use to be inferred. Following behavior, the extent of the injury was quantified with histology and staining for the presence of glial fibrillary acid protein and ionized calcium-binding adapter molecule 1. Rats that received unilateral CCI were impaired on the PAL task and showed more aberrant response-driven behavior. The magnitude of PAL impairment was also correlated with Iba1 staining in the thalamus. These observations suggest that PAL could be useful for pre-clinical assessments of novel interventions for treating TBI.

Age-related impairments on the touchscreen paired associates learning (PAL) task in male rats.

Discovery research in rodent models of cognitive aging is instrumental for identifying mechanisms of behavioral decline in old age that can be therapeutically targeted. Clinically relevant behavioral paradigms, however, have not been widely employed in aged rats. The current study aimed to bridge this translational gap by testing cognition in a cross-species touchscreen-based platform known as paired-associates learning (PAL) and then utilizing a trial-by-trial behavioral analysis approach. This study found age-related deficits in PAL task acquisition in male rats. Furthermore, trial-by-trial analyses and testing rats on a novel interference version of PAL suggested that age-related impairments were not due to differences in vulnerability to an irrelevant distractor, motivation, or to forgetting. Rather, impairment appeared to arise from vulnerability to accumulating, proactive interference, with aged animals performing worse than younger rats in later trial blocks within a single testing session. The detailed behavioral analysis employed in this study provides new insights into the etiology of age-associated cognitive deficits.

Computerized paired associate learning performance and imaging biomarkers in older adults without dementia.

This cross-sectional study examined whether performance on the computerized Paired Associate Learning (PAL) task from the Cambridge Neuropsychological Test Automated Battery is associated with amyloid positivity as measured by Positron Emission Tomography, regional volume composites as measured by Magnetic Resonance Imaging, and cognitive impairment. Participants from the BIOCARD Study (N = 73, including 62 cognitively normal and 11 with mild cognitive impairment; M age = 70 years) completed the PAL task, a comprehensive clinical and neuropsychological assessment, and neuroimaging as part of their annual study visit. In linear regressions covarying age, sex, years of education and diagnosis, higher PAL error scores were associated with amyloid positivity but not with medial temporal or cortical volume composites. By comparison, standard neuropsychological measures of episodic memory and global cognition were unrelated to amyloid positivity, but better performance on the verbal episodic memory measures was associated with larger cortical volume composites. Participants with mild cognitive impairment demonstrated worse cognitive performance on all of the cognitive measures, including the PAL task. These findings suggest that this computerized visual paired associate learning task may be more sensitive to amyloid positivity than standard neuropsychological tests, and may therefore be a promising tool for detecting amyloid positivity in non-demented participants.

Experiencia de estudiantes universitarios de salud al publicar en una revista académica de pregrado / Experience of university health students when publishing in an undergraduate academic journal

Objetivo principal: Conocer la experiencia de estudiantes de carreras de la salud al publicar un artículo en una revista académica de pregrado, creada en el marco de los proyectos de innovación de una universidad chilena. Metodología: Investigación de diseño mixto, en la que se utilizó un cuestionario electrónico con preguntas abiertas, de selección y tipo Likert, previa firma de consentimiento informado. Se evaluaron las variables descritas como el proceso de publicación, las instrucciones a los autores, la comunicación con el equipo editor, la satisfacción con la publicación y el acceso electrónico a la revista. El cuestionario cualitativo contempló las dimensiones razones de publicar y aportes a los valores y competencias de la universidad. Se realizó análisis cuantitativo y análisis de contenido con enfoque cualitativo de una muestra de 54 estudiantes. Resultados principales: La comunicación con el equipo editor obtuvo la más alta calificación (83,33%). La calificación más baja (37%) fue obtenida en el acceso al número completo de la revista ya publicado. Los estudiantes reportaron que se fortaleció el valor de la “responsabilidad” y la competencia “visión analítica” luego de publicar. Conclusión principal: La experiencia de publicar fue muy bien evaluada por los estudiantes. La motivación de publicar fortalece competencias y valores y se consolida como una experiencia positiva. Los estudiantes se sienten parte de una comunidad del conocimiento colaborativa entre pares. Se debe mejorar algunos procesos editoriales que fortalezcan la comunicación con los estudiantes que son autores.(AU)

Objective: Know the experience of health career students by publishing an article in an undergraduate academic journal, created within the framework of innovation projects of a Chilean university. Methods: Mixed design research in which an electronic questionnaire with open-ended, selection and Likert questions was used, prior signature of informed consent. The variables described as the publication process, instructions to the authors, communication with the editorial team, satisfaction with the publication and electronic access to the journal were evaluated. The qualitative questionnaire contemplated the dimensions reasons for publishing and contributions to the values ​​and competencies of the university. Quantitative analysis and content analysis were performed with a qualitative approach from a sample of 54 students. Results: Communication with the editorial team obtained the highest rating (83.33%). The lowest rating (37%) was obtained in access to the full issue of the journal already published. Students reported that the value of "responsibility" and competence "analytical vision" was strengthened after publishing. Conclusions: The publishing experience was very well evaluated by the students. The motivation to publish strengthens skills and values and is consolidated as a positive experience. Students feel part of a collaborative peer-to-peer knowledge community. Some editorial processes that strengthen communication with students who are authors must be improved.(AU)

Asymmetric Weights and Retrieval Practice in an Autoassociative Neural Network Model of Paired-Associate Learning.

Rizzuto and Kahana (2001) applied an autoassociative Hopfield network to a paired-associate word learning experiment in which (1) participants studied word pairs (e.g., ABSENCE-HOLLOW), (2) were tested in one direction (ABSENCE-?) on a first test, and (3) were tested in the same direction again or in the reverse direction (?-HOLLOW) on a second test. The model contained a correlation parameter to capture the dependence between forward versus backward learning between the two words of a word pair, revealing correlation values close to 1.0 for all participants, consistent with neural network models that use the same weight for communication in both directions between nodes. We addressed several limitations of the model simulations and proposed two new models incorporating retrieval practice learning (e.g., the effect of the first test on the second) that fit the accuracy data more effectively, revealing substantially lower correlation values (average of .45 across participants, with zero correlation for some participants). In addition, we analyzed recall latencies, finding that second test recall was faster in the same direction after a correct first test. Only a model with stochastic retrieval practice learning predicted this effect. In conclusion, recall accuracy and recall latency suggest asymmetric learning, particularly in light of retrieval practice effects.

Altered motor cortical plasticity in patients with hepatic encephalopathy: A paired associative stimulation study.

OBJECTIVE: Hepatic encephalopathy (HE) is a potentially reversible brain dysfunction caused by liver failure. Altered synaptic plasticity is supposed to play a major role in the pathophysiology of HE. Here, we used paired associative stimulation with an inter-stimulus interval of 25 ms (PAS25), a transcranial magnetic stimulation (TMS) protocol, to test synaptic plasticity of the motor cortex in patients with manifest HE. METHODS: 23 HE-patients and 23 healthy controls were enrolled in the study. Motor evoked potential (MEP) amplitudes were assessed as measure for cortical excitability. Time courses of MEP amplitude changes after the PAS25 intervention were compared between both groups. RESULTS: MEP-amplitudes increased after PAS25 in the control group, indicating PAS25-induced synaptic plasticity in healthy controls, as expected. In contrast, MEP-amplitudes within the HE group did not change and were lower than in the control group, indicating no induction of plasticity. CONCLUSIONS: Our study revealed reduced synaptic plasticity of the primary motor cortex in HE. SIGNIFICANCE: Reduced synaptic plasticity in HE provides a link between pathological changes on the molecular level and early clinical symptoms of the disease. This decrease may be caused by disturbances in the glutamatergic neurotransmission due to the known hyperammonemia in HE patients.

Plastic responsiveness of motor cortex to paired associative stimulation depends on cerebellar input.

OBJECTIVE: The extent of plastic responses of motor cortex (M1) to paired associative stimulation (PAS) varies among healthy subjects. Continuous theta-burst stimulation (cTBS) of cerebellum enhances the mean PAS-induced plasticity in groups of healthy subjects. We tested whether the initial status of Responder or Non -Responder to PAS, influenced the effect of cerebellar stimulation on PAS-induced plasticity. METHODS: We assessed in 19 young healthy volunteers (8 Responders, 11 Non-Responders to PAS), how cTBS and iTBS (intermittent TBS) applied to the cerebellum before a PAS protocol influenced the plastic responsiveness of M1 to PAS. We tested whether the PAS-induced plastic effects could be depotentiated by a short cTBS protocol applied to M1 shortly after PAS and whether cerebellar stimulation influenced GABA-ergic intracortical inhibition and M1 plasticity in parallel. RESULTS: Cerebellar cTBS restored the M1 response to PAS in Non-Responders while cerebellar iTBS turned the potentiating response to PAS to a depressive response in both groups. The depotentiation protocol abolished both responses. CONCLUSION: Non-Responder status to PAS is a state of M1 amenable to bidirectional plastic modulation when primed by a change in cerebello-thalamic drive. SIGNIFICANCE: The meaning of lack of responsiveness to certain protocols probing plasticity should be reconsidered.

Adult neurogenesis mediates forgetting of multiple types of memory in the rat.

The formation and retention of hippocampus-dependent memories is impacted by neurogenesis, a process that involves the production of new neurons in the dentate gyrus of the hippocampus. Recent studies demonstrate that increasing neurogenesis after memory formation induces forgetting of previously acquired memories. Neurogenesis-induced forgetting was originally demonstrated in mice, but a recent report suggests that the same effect may be absent in rats. Although a general species difference is possible, other potential explanations for these incongruent findings are that memories which are more strongly reinforced become resilient to forgetting or that perhaps only certain types of memories are affected. Here, we investigated whether neurogenesis-induced forgetting occurs in rats using several hippocampus-dependent tasks including contextual fear conditioning (CFC), the Morris Water Task (MWT), and touchscreen paired associates learning (PAL). Neurogenesis was increased following training using voluntary exercise for 4 weeks before recall of the previous memory was assessed. We show that voluntary running causes forgetting of context fear memories in a neurogenesis-dependent manner, and that neurogenesis-induced forgetting is present in rats across behavioral tasks despite differences in complexity or reliance on spatial, context, or object memories. In addition, we asked whether stronger memories are less susceptible to forgetting by varying the strength of training. Even with a very strong training protocol in the CFC task, we still observed enhanced forgetting related to increased neurogenesis. These results suggest that forgetting due to neurogenesis is a conserved mechanism that aids in the clearance of memories.

Ocular measures during associative learning predict recall accuracy.

The ability to form associations between stimuli and commit those associations to memory is a cornerstone of human cognition. Dopamine and noradrenaline are critical neuromodulators implicated in a range of cognitive functions, including learning and memory. Eye blink rate (EBR) and pupil diameter have been shown to index dopaminergic and noradrenergic activity. Here, we examined how these ocular measures relate to accuracy in a paired-associate learning task where participants (N = 73) learned consistent object-location associations over eight trials consisting of pre-trial fixation, encoding, delay, and retrieval epochs. In order to examine how within-subject changes and between-subject changes in ocular metrics related to accuracy, we mean centered individual metric values on each trial based on within-person and across-subject means for each epoch. Within-participant variation in EBR was positively related to accuracy in both encoding and delay epochs: faster EBR within the individual predicted better retrieval. Differences in EBR across participants was negatively related to accuracy in the encoding epoch and in early trials of the pre-trial fixation: faster EBR, relative to other subjects, predicted poorer retrieval. Visual scanning behavior in pre-trial fixation and delay epochs was also positively related to accuracy in early trials: more scanning predicted better retrieval. We found no relationship between pupil diameter and accuracy. These results provide novel evidence supporting the utility of ocular metrics in illuminating cognitive and neurobiological mechanisms of paired-associate learning.

Facilitation effect of incidental environmental context on the computer screen for paired-associate learning.

Three experiments, in which a total of 198 undergraduates engaged, investigate whether the incidental environmental context on the computer screen influences paired-associate learning. Experiment 1 compared the learning of foreign- and native-language words between a constant context condition, where the stimulus and response pairs were presented twice on the same 5-s video background context, and a varied context condition, where the pairs were presented twice on different video contexts. Repetition in the same context resulted in better learning than in different contexts, evaluated with a paper-and-pencil test. Experiment 2 investigated learning of paired-associate foreign and native words in the same video contexts, or photograph contexts, or on a neutral grey background. Both the video and the photograph contexts equally facilitated the paired-associate learning compared with the grey background. Experiment 3 investigated whether the incidental environmental context similarly facilitated face-name paired-associate learning. We added a new condition of spot illustrations, and a second testing 1 day later. The repetition of face-name pairs within the same complex incidental environmental context on the computer screen (either video or photograph background) facilitated the paired-associate learning. There was no significant difference in learning performance between video and photograph background contexts, which were significantly better than grey or spot-illustration backgrounds which did not differ from each other. The retention interval did not interact with the effect of the background. The present results show that repetition within the same video or photograph context, covering the entire background of the video screen on which each item pair was superimposed, facilitates paired-associate learning.

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.

Buildup and release from proactive interference - Cognitive and neural mechanisms.

Interference from related memories is generally considered one of the major causes of forgetting in human memory. The most prevalent form of interference may be proactive interference (PI), which refers to the finding that memory of more recently studied information can be impaired by the previous study of other information. PI is a fairly persistent effect, but numerous studies have shown that there can also be release from PI. PI buildup and release have primarily been studied using paired-associate learning, the Brown-Peterson task, or multiple-list learning. The review first introduces the three experimental tasks and, for each task, summarizes critical findings on PI buildup and release, from both behavioral and imaging work. Then, an overview is provided of suggested cognitive mechanisms operating on the encoding and retrieval stages as well as of neural correlates of these mechanisms. The results indicate that, in general, both encoding and retrieval processes contribute to PI buildup and release. Finally, empirical gaps in the current work are emphasized and suggestions for future studies are provided.

Examining three-way binding as a constraint on statistical learning.

Models of statistical learning do not place constraints on the complexity of the memory structure that is formed during statistical learning, while empirical studies using the statistical learning task have only examined the formation of simple memory structures (e.g., two-way binding). On the contrary, the memory literature, using explicit memory tasks, has shown that people are able to form memory structures of different complexities and that more complex memory structures (e.g., three-way binding) are usually more difficult to form. We examined whether complex memory structures such as three-way bindings can be implicitly formed through statistical learning by utilizing manipulations that have been used in the paired-associate learning paradigm (e.g., AB/ABr condition). Through three experiments, we show that while simple two-way binding structures can be formed implicitly, three-way bindings can only be formed with explicit instructions. The results indicate that explicit attention may be a necessary component in forming three-way memory structures and suggest that existing models should place constraints on the representational structures that can be formed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The deceptive nature of associative word pairs: the effects of associative direction on judgments of learning.

The accuracy of judgments of learning (JOLs) in forecasting later recall of cue-target pairs is sensitive to associative direction. JOLs are generally well calibrated for forward associative pairs (e.g., credit-card), but recall accuracy is often overestimated for backward pairs (e.g., card-credit). The present study further examines the effect of associative direction on JOL accuracy by comparing forward and backward pairs to unrelated pairs and symmetrical associates (e.g., salt-pepper)-a novel comparison. The correspondence between initial JOLs and recall accuracy was examined when study was either self-paced with concurrent JOLs (Experiment 1), when study/JOL duration was equated across pair types (Experiment 2), when JOLs were made immediately following study (Experiment 3), and when JOLs were made after a delay (Experiment 4). Across experiments, JOLs accurately estimated correct recall for forward pairs, but overestimated recall for symmetrical, backward, and unrelated pairs-an overestimation that was particularly robust for backward pairs. Calibration plots depicting JOL ratings against their corresponding recall accuracy indicated overestimations occurred for all pair types, though overestimations only occurred at high JOL ratings for symmetrical and forward pairs, a qualitative difference that was not captured in standard analyses of mean JOL and recall rates.

Similar cognitive deficits in mice and humans in the chronic phase post-stroke identified using the touchscreen-based paired-associate learning task.

For many chronic stroke survivors, persisting cognitive dysfunction leads to significantly reduced quality of life. Translation of promising therapeutic strategies aimed at improving cognitive function is hampered by existing, disparate cognitive assessments in animals and humans. In this study, we assessed post-stroke cognitive function using a comparable touchscreen-based paired-associate learning task in a cross-sectional population of chronic stroke survivors (≥ 5 months post-stroke, n = 70), age-matched controls (n = 70), and in mice generated from a C57BL/6 mouse photothrombotic stroke model (at six months post-stroke). Cognitive performance of stroke survivors was analysed using linear regression adjusting for age, gender, diabetes, systolic blood pressure and waist circumference. Stroke survivors made significantly fewer correct choices across all tasks compared with controls. Similar cognitive impairment was observed in the mice post-stroke with fewer correct choices compared to shams. These results highlight the feasibility and potential value of analogous modelling of clinically meaningful cognitive impairments in chronic stroke survivors and in mice in chronic phase after stroke. Implementation of validated, parallel cross-species test platforms for cognitive assessment offer the potential of delivering a more useful framework for evaluating therapies aimed at improving long-term cognitive function post-stroke.

Touchscreen-based location discrimination and paired associate learning tasks detect cognitive impairment at an early stage in an App knock-in mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline with accumulation of amyloid beta (Aß) and neurofibrillary tangles that usually begins 15-30 years before clinical diagnosis. Rodent models that recapitulate aggressive Aß and/or the pathology of neurofibrillary tangles are essential for AD research. Accordingly, non-invasive early detection systems in these animal models are required to evaluate the phenotypic changes, elucidate the mechanism of disease progression, and facilitate development of novel therapeutic approaches. Although many behavioral tests efficiently reveal cognitive impairments at the later stage of the disease in AD models, it has been challenging to detect such impairments at the early stage. To address this issue, we subjected 4-6-month-old male AppNL-G-F/NL-G-F knock-in (App-KI) mice to touchscreen-based location discrimination (LD), different object-location paired-associate learning (dPAL), and reversal learning tests, and compared the results with those of the classical Morris water maze test. These tests are mainly dependent on the brain regions prone to Aß accumulation at the earliest stages of the disease. At 4-6 months, considered to represent the early stage of disease when mice exhibit initial deposition of Aß and slight gliosis, the classical Morris water maze test revealed no difference between groups, whereas touchscreen-based LD and dPAL tasks revealed significant impairments in task performance. Our report is the first to confirm that a systematic touchscreen-based behavioral test battery can sensitively detect the early stage of cognitive decline in an AD-linked App-KI mouse model. This system could be applied in future translational research.

Evidence for preferential attachment: Words that are more well connected in semantic networks are better at acquiring new links in paired-associate learning.

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

The presence of joint predictors generates conjunctive predictions.

The cognitive system readily detects statistical relationships where a cue predicts a specific outcome. What is less known is how the mind generates predictions when multiple cues are presented simultaneously that predict different outcomes. Here, we examine the nature of such predictions. Specifically, we examine whether the presence of joint cues leads to conjunctive predictions that represent the overlap between the outcomes associated with the cues, or disjunctive predictions that represent the total possible outcomes. To test this, we used a visual search paradigm where participants first viewed a cue and then searched for a target in an array. Each cue predicted where the target would appear in one of the four quadrants in the array. After learning the cue-location associations, two cues were presented simultaneously, and participants searched for the target where the target now appeared in each quadrant with equal probability. We found that participants were faster to find the target in conjunctive locations over disjunctive ones upon seeing two cues (Experiment 1). This attentional prioritization was not solely driven by the smaller spatial scope of conjunctive locations (Experiment 2), and was present when two cues were presented in two feature dimensions in a single object (Experiment 3). These results were consistent with a conjunctive account, where the presence of joint cues led to a conjunctive prediction that represented the overlap of the different outcomes associated with each cue. The study sheds a new light on how the mind makes predictions in novel contexts based on existing knowledge.

Perceived similarity ratings predict generalization success after traditional category learning and a new paired-associate learning task.

The current study investigated category learning across two experiments using face-blend stimuli that formed face families controlled for within- and between-category similarity. Experiment 1 was a traditional feedback-based category-learning task, with three family names serving as category labels. In Experiment 2, the shared family name was encountered in the context of a face-full name paired-associate learning task, with a unique first name for each face. A subsequent test that required participants to categorize new faces from each family showed successful generalization in both experiments. Furthermore, perceived similarity ratings for pairs of faces were collected before and after learning, prior to generalization test. In Experiment 1, similarity ratings increased for faces within a family and decreased for faces that were physically similar but belonged to different families. In Experiment 2, overall similarity ratings decreased after learning, driven primarily by decreases for physically similar faces from different families. The post-learning category bias in similarity ratings was predictive of subsequent generalization success in both experiments. The results indicate that individuals formed generalizable category knowledge prior to an explicit demand to generalize and did so both when attention was directed towards category-relevant features (Experiment 1) and when attention was directed towards individuating faces within a family (Experiment 2). The results tie together research on category learning and categorical perception and extend them beyond a traditional category-learning task.