Barbara J Knowlton

Barbara J Knowlton
University of California, Los Angeles | UCLA · Department of Psychology

PhD

About

193
Publications
57,214
Reads
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21,373
Citations
Citations since 2016
39 Research Items
7072 Citations
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Introduction
Our lab is interested in the cognitive neuroscience of memory. Current projects include the neural basis of skills and habits, and the effect of item value or importance on memory encoding
Additional affiliations
July 1995 - present
University of California, Los Angeles
Position
  • Professor
Education
September 1984 - June 1990
Stanford University
Field of study
  • Neuroscience

Publications

Publications (193)
Article
Full-text available
The material in The Cognitive Unconscious began as a master’s thesis that examined the manner in which knowledge of fairly complex, patterned material could be acquired without any conscious effort to learn it and with little to no awareness of what had been learned. It was dubbed implicit learning and, over more than fifty years, became a vigorous...
Chapter
The material in The Cognitive Unconscious began as a master’s thesis that examined the manner in which knowledge of fairly complex, patterned material could be acquired without any conscious effort to learn it and with little to no awareness of what had been learned. It was dubbed implicit learning and, over more than fifty years, became a vigorous...
Article
Objective: Memory deficits in individuals with schizophrenia are well-established, but less is known about how schizophrenia affects metacognitive processes such as metamemory. We investigated metamemory ability using the value-directed remembering task, which assesses the degree to which participants use value cues to guide their learning of a li...
Article
Full-text available
Changing how an issue is framed can influence both decision-making and metacognition, but framing a memory task in terms of gains and losses could also impact how learners prioritize information according to its value or importance. We investigated how framing task instructions and feedback in terms of gains and losses influences learners’ ability...
Article
Full-text available
The ability to prioritize valuable information is critical for the efficient use of memory in daily life. When information is important, we engage more effective encoding mechanisms that can better support retrieval. Here, we describe a dual-mechanism framework of value-directed remembering in which both strategic and automatic processes lead to di...
Article
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Knowledge without awareness, or implicit knowledge, influences a variety of behaviors. It is unknown however, whether implicit knowledge of statistical structure informs visual perceptual decisions or whether explicit knowledge of statistical probabilities is required. Here, we measured visual decision-making performance using a novel task in which...
Article
Full-text available
Compared to blocked practice, interleaved practice of different tasks leads to superior long-term retention despite poorer initial acquisition performance. This phenomenon, the contextual interference effect, is well documented in various domains but it is not yet clear if it persists in the absence of explicit knowledge in terms of fine motor sequ...
Preprint
Full-text available
Knowledge without awareness, or implicit knowledge, influences a variety of behaviors. It is unknown however, whether implicit knowledge of statistical structure informs visual perceptual decisions or whether explicit knowledge of statistical probabilities is required. Here, we measured visual decision-making performance using a novel task in which...
Article
Full-text available
Background While deep brain stimulation has been successful in treating movement disorders, such as in Parkinson’s disease, its potential application in alleviating memory disorders is inconclusive. Objective/Hypothesis: We investigated the role of the location of the stimulating electrode on memory improvement and hypothesized that entorhinal whit...
Article
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Previous work has shown that memory performance in older adults is affected by activation of a stereotype of age-related memory decline. In the present experiment, we examined whether stereotype threat would affect metamemory in older adults; that is, whether under stereotype threat they make poorer judgments about what they could remember. We test...
Article
There is substantial evidence linking early-life stress (ELS) to negative health outcomes in adulthood, including addiction. However, the neurocognitive and behavioral mechanisms through which ELS increases these risks remain unclear. To address this gap in knowledge, we developed a novel instrumental learning paradigm to explore the effects of ELS...
Preprint
Full-text available
How the human brain supports accurate navigation of a learned environment has been an active topic of research for nearly a century (1−5). In rodents, the theta rhythm within the medial temporal lobe (MTL) has been proposed as a neural basis for fragmenting incoming information and temporally organizing experiences and is thus widely implicated in...
Article
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The effect of stress on the balance between goal-directed behavior and stimulus–response habits has been demonstrated in a number of studies, but the extent to which stressful events that occur during development affect the balance between these systems later in life is less clear. Here, we examined whether individuals with a history of early-life...
Article
Valuable items are often remembered better than less valuable items, but research on the mechanisms supporting this value effect is limited. In the current study, we sought to determine how items might be differentially encoded based on their value. In Experiment 1, participants studied words associated with point-values which were followed by a cu...
Article
White matter microstructure changes substantially in aging. To better understand how the integrity of white matter structures supports the selective learning of rewarding material, 23 healthy older adults were tested on a value-directed remembering task. This task involved successive free recall word lists where items differed in importance, as den...
Article
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Studies demonstrate that dynamic assessment (i.e., learning potential) improves the prediction of response to rehabilitation over static measures in individuals with schizophrenia. Learning potential is most commonly assessed using neuropsychological tests under a test-train-test paradigm to examine change in performance. Novel learning potential a...
Article
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When given a long list of items to remember, people typically prioritize the memorization of the most valuable items. Prior neuroimaging studies have found that cues denoting the presence of high value items can lead to increased activation of the mesolimbic dopaminergic reward circuit, including the nucleus accumbens (NAcc) and ventral tegmental a...
Article
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Increasing contextual interference (CI) during practice benefits learning, making it a desirable difficulty. For example, interleaved practice (IP) of motor sequences is generally more difficult than repetitive practice (RP) during practice but leads to better learning. Here we investigated whether CI in practice modulated resting-state functional...
Article
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People with Parkinson's disease (PD) show impaired decision-making when sensory and memory information must be combined. This recently identified impairment results from an inability to accumulate the proper amount of information needed to make a decision and appears to be independent of dopamine tone and reinforcement learning mechanisms. Although...
Chapter
Full-text available
Data from experimental animals and human subjects has provided convergent evidence for the key role of the striatum in the formation of stimulus-response habits. Habits can be distinguished from associative memories that support goal-directed actions based on their insensitivity to reward devaluation and contingency degradation. Behavior on many in...
Article
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Research on the neural basis of human habit learning has made significant advances in recent years, creating a need for synthesis of disparate results. We conducted a meta-analytic review of fMRI studies on human habit learning to evaluate the hypothesis that the human putamen plays a similar role to the rodent dorsolateral striatum in habitual beh...
Article
Valuable items are often remembered better than items that are less valuable by both older and younger adults, but older adults typically show deficits in binding. Here, we examine whether value affects the quality of recognition memory and the binding of incidental details to valuable items. In Experiment 1, participants learned English words each...
Chapter
Full-text available
Learned procedures are critical in our daily lives, yet learning them can often occur without awareness. Unlike declarative learning, in procedural learning it is generally difficult to verbalize what has been learned. In this chapter we discuss the behavioral characteristics and neural underpinnings of learning different forms of procedures, inclu...
Article
Although a number of studies examined recollection and familiarity memory in schizophrenia, most of studies have focused on nonsocial episodic memory. Little is known about how schizophrenia patients remember social information in everyday life and whether social episodic memory changes over the course of illness. This study aims to examine episodi...
Article
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We examined the effects of value on recognition by assessing its contribution to recollection and familiarity. In three experiments, participants studied English words, each associated with a point-value they would earn for correct recognition, with the goal of maximizing their score. In Experiment 1, participants provided Remember/Know judgments....
Article
Full-text available
People tend to show better memory for information that is deemed valuable or important. By one mechanism, individuals selectively engage deeper, semantic encoding strategies for high value items (Cohen, Rissman, Suthana, Castel, & Knowlton, 2014). By another mechanism, information paired with value or reward is automatically strengthened in memory...
Article
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The cerebellum has been shown to be important for skill learning, including the learning of motor sequences. We investigated whether cerebellar transcranial direct current stimulation (tDCS) would enhance learning of fine motor sequences. Because the ability to generalize or transfer to novel task variations or circumstances is a crucial goal of re...
Article
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Richard Thompson’s seminal contributions to neuroscience include the discovery of the cerebellar interpositus nucleus as the site of essential plasticity in the formation of the conditioned eyeblink response. In this section, context for this body of research is provided, as well as new findings on cerebellar function using a range of procedures. C...
Article
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The ability to inhibit unwanted responses is critical for effective control of behavior, and inhibition failures can have disastrous consequences in real-world situations. Here, we examined how prior exposure to negative emotional stimuli affects the response-stopping network. Participants performed the stop-signal task, which relies on inhibitory...
Article
We found microstructural differences between adolescent COS siblings and age-matched control participants with greater mean diffusivity (MD) in the putamen in controls compared to COS siblings
Article
Full-text available
Effective learning results not only in improved performance on a practiced task, but also in the ability to transfer the acquired knowledge to novel, similar tasks. Using a modified serial reaction time (RT) task, the authors examined the ability to transfer to novel sequences after practicing sequences in a repetitive order versus a nonrepeating i...
Article
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Associations between co-occurring stimuli are formed in the medial temporal lobe (MTL). Here, we recorded from 508 single and multi-units in the MTL while participants learned and retrieved associations between unfamiliar faces and unfamiliar scenes. Participant's memories for the face-scene pairs were later tested using cued recall and recognition...
Article
Background: Individuals with schizophrenia exhibit marked and disproportional impairment in social cognition, which is associated with their level of community functioning. However, it is unclear whether social cognitive impairment is stable over time, or if impairment worsens as a function of illness chronicity. Moreover, little is known about th...
Article
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Practicing tasks arranged in an interleaved manner generally leads to superior retention compared to practicing tasks repetitively, a phenomenon known as the contextual interference (CI) effect. We investigated the brain network of motor learning under CI, i.e., the CI network, and how it was affected by aging. 16 younger and 16 older adults practi...
Article
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Significance Neurons within the human hippocampus have been shown to respond to individual concepts such as varying photographs of a single famous person. However, the relationship between these invariant neuronal responses and hippocampal-dependent memory remains elusive. The current study explores whether the specificity of human hippocampal neur...
Article
While impairments in memory recall are apparent in aging, older adults show a remarkably preserved ability to selectively remember information deemed valuable. Here, we use fMRI to compare brain activation in healthy older and younger adults during encoding of high and low value words to determine whether there are differences in how older adults a...
Article
Patients with childhood onset schizophrenia (COS) display widespread gray matter (GM) structural brain abnormalities. Healthy siblings of COS patients share some of these structural abnormalities, suggesting that GM abnormalities are endophenotypes for schizophrenia. Another possible endophenotype for schizophrenia that has been relatively unexplor...
Article
Examining the function of individual human hippocampal subfields remains challenging because of their small sizes and convoluted structures. Previous human fMRI studies at 3 T have successfully detected differences in activation between hippocampal cornu ammonis (CA) field CA1, combined CA2, CA3, and dentate gyrus (DG) region (CA23DG), and the subi...
Article
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While an awareness of age-related changes in memory may help older adults gain insight into their own cognitive abilities, it may also have a negative impact on memory performance through a mechanism of stereotype threat (ST). The consequence of ST is under-performance in abilities related to the stereotype. Here, we examined the degree to which ex...
Article
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Analogical mapping highlights shared relations that link 2 situations, potentially at the expense of information that does not fit the dominant pattern of correspondences. To investigate whether analogical mapping can alter subsequent recognition memory for features of a source analog, we performed 2 experiments with 4-term proportional analogies (...
Article
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A number of prior fMRI studies have focused on the ways in which the midbrain dopaminergic reward system coactivates with hippocampus to potentiate memory for valuable items. However, another means by which people could selectively remember more valuable to-be-remembered items is to be selective in their use of effective but effortful encoding stra...
Article
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Episodic memory is vulnerable to age-related change, with older adults demonstrating both impairments in retrieving contextual details and susceptibility to interference among similar events. Such impairments may be due in part to an age-related decline in the ability to encode distinct memory representations. Recent research has examined how manip...
Article
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Patients with and at risk for psychosis may have difficulty using associative strategies to facilitate episodic memory encoding and recall. In parallel studies, patients with first-episode schizophrenia (n = 27) and high psychosis risk (n = 28) compared with control participants (n = 22 and n = 20, respectively) underwent functional MRI during a re...
Article
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Visual imagery plays a fundamental role in autobiographical memory, but several aspects of this role remain unclear. We conducted three experiments to explore this relationship. In the first experiment, we examined the relation between the phenomenological properties of autobiographical memory and several measures of visual-imagery ability. We foun...
Article
We studied healthy, first-degree relatives of patients with schizophrenia to test the hypothesis that deficits in cognitive skill learning are associated with genetic liability to schizophrenia. Using the Weather Prediction Task (WPT), 23 healthy controls and 10 adult first-degree Relatives Of Schizophrenia (ROS) patients were examined to determine...
Article
People experiencing early-life stress (ELS) exhibit increased incidence of behaviors that lead to addiction and obesity as adults. Many of these behaviors may be viewed as resulting from an overreliance on habits as opposed to goal-directed instrumental behavior. This increased habitization may result from alterations in the interactions between do...
Article
Full-text available
Patients with schizophrenia perform poorly on cognitive skill learning tasks. This study is the first to investigate the neural basis of impairment in cognitive skill learning in first-degree adolescent relatives of patients with schizophrenia. We used functional magnetic resonance imaging to compare activation in 16 adolescent siblings of patients...
Article
Full-text available
Memory formation is known to be critically dependent upon the medial temporal lobe (MTL). Despite this well-characterized role, it remains unclear whether and how MTL encoding processes are affected by top-down goal states. Here, we examined the manner in which task demands at encoding affect MTL activity and its relation to subsequent memory perfo...
Article
Full-text available
Practice of tasks in an interleaved order generally induces superior learning compared with practicing in a repetitive order, a phenomenon known as the contextual-interference (CI) effect. Increased neural activity during interleaved over repetitive practice has been associated with the beneficial effects of CI. Here, we used psychophysiological in...
Article
Patients with schizophrenia show deficits in skill learning. We tested the hypothesis that impaired skill learning is associated with liability for schizophrenia by determining if it is present in non-affected siblings of patients. This study examined cognitive skill learning in adolescent siblings of patients with childhood onset schizophrenia (CO...
Article
Full-text available
The representation and manipulation of structured relations is central to human reasoning. Recent work in computational modeling and neuroscience has set the stage for developing more detailed neurocomputational models of these abilities. Several key neural findings appear to dovetail with computational constraints derived from a model of analogica...
Article
Full-text available
In a study of reasoning with four-term verbal analogy problems, we explored the relationship between the effects of an acute, mild stressor and the complexity of the reasoning process. Participants judged whether analogy problems in the form A:B :: C:D were valid or invalid, on the basis of whether the relation in the A:B term matched that in the C...
Article
Full-text available
Practice of tasks in an interleaved order generally induces superior retention compared to practicing in a repetitive order. Younger and older adults practiced serial reaction time tasks that were arranged in a repeated or an interleaved order on 2 successive days. Retention was tested on Day 5. For both groups, reaction times in the interleaved co...
Article
Full-text available
An important result in perception research is that priming in an object naming task is invariant with translation and left-right reflection. A more sensitive object recognition paradigm was used in three experiments in order to investigate the extent to which priming of object identification is affected by changes in left-right orientation and posi...
Article
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We recently demonstrated that older adults can benefit as much as younger adults from learning skills in an interleaved manner. Here we investigate whether optimized learning through interleaved practice (IP) is associated with changes in inter-regional brain connectivity and whether younger and older adults differ in such brain-behavior correlatio...
Article
Full-text available
The medial temporal structures, including the hippocampus and the entorhinal cortex, are critical for the ability to transform daily experience into lasting memories. We tested the hypothesis that deep-brain stimulation of the hippocampus or entorhinal cortex alters memory performance. We implanted intracranial depth electrodes in seven subjects to...
Chapter
Full-text available
The methods of cognitive neuroscience, notably functional neuroimaging and cognitive neuropsychology, are becoming increasingly important in efforts to understand the processes responsible for human higher cognition. Given the complexity of human thinking and reasoning, it is frequently the case that multiple theories can explain behavioral results...
Article
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It has long been known that the medial temporal lobe (MTL) is critical for conscious, or declarative, memory. However, debate continues to surround the precise role of the neural components of this region. The MTL is comprised of several interconnected structures known to be involved in memory, including the hippocampus and the entorhinal, perirhin...