Ilana J Bennett

University of California, Riverside | UCR · Department of Psychology

Preadolescence is a period of increased vulnerability for anxiety, especially among Latina girls. Reduced microstructure (fractional anisotropy; FA) of white matter tracts between limbic and prefrontal regions may underlie regulatory impairments in anxiety. However, developmental research on the association between anxiety and white matter microstr...

The ability to learn associations between events is critical for everyday functioning (e.g., decision making, social interactions) and has been attributed to structural differences in white matter tracts connecting cortical regions to the hippocampus (e.g., fornix) and striatum (e.g., internal capsule) in younger-old adults (ages 65-85 years). Howe...

Adults of all ages are worse at recognizing pairs of items that were previously seen together relative to the individual items, and this paired-associative memory deficit is exacerbated in aging. Less is known about memory for higher associative loads, which place greater demands on binding processes that link items into a cohesive memory trace, am...

Background The presence of β-amyloid (Aβ) extracellular plaques and hyper-phosphorylated tau neurofibrillary tangles characterize the pathology of Alzheimer's disease (AD) and mild cognitive impairment (MCI). Individuals carrying the apolipoprotein E-ϵ4 (APOE-ϵ4) allele are at increased risk of cognitive decline and developing AD pathology. The 18F...

The pathology of Alzheimer's disease (AD) and mild cognitive impairment (MCI) is characterized by the presence of beta-amyloid extracellular plaques and neurofibrillary tangles containing hyper-phosphorylated tau. Individuals carrying the apolipoprotein E-e4 (APOE-e4) allele are at increased risk of cognitive decline and developing AD pathology. Th...

Recent advances in diffusion-weighted imaging have enabled us to probe the microstructure of even gray matter non-invasively. However, these advanced multi-shell protocols are often not included in large-scale studies as they significantly increase scan time. In this study, we investigated whether one set of multi-shell diffusion metrics commonly u...

Younger-old adults (ages 65-85 years) exhibit declines in the ability to learn associations between events, which has been attributed to structural degradation of white matter tracts connecting the prefrontal cortex to the hippocampus (e.g., fornix) and striatum (e.g., internal capsule). However, deficits in associative learning abilities may incre...

Magnetic resonance imaging (MRI) studies of brain and neurocognitive aging rarely include oldest-old adults (ages 80+). But predictions of neurocognitive aging theories derived from MRI findings in younger-old adults (ages ~55-80) may not generalize into advanced age, particularly given the increased prevalence of cognitive impairment/dementia in t...

Magnetic resonance imaging (MRI) studies of brain and neurocognitive aging rarely include oldest-old adults (ages 85+). But predictions of neurocognitive aging theories derived from MRI findings in younger-old adults (ages 65-85) may not generalize into advanced age, particularly given the increased prevalence of cognitive impairment/dementia in th...

Healthy aging is accompanied by declines in the ability to learn associations between events, even when their relationship cannot be described. Previous functional magnetic resonance imaging (fMRI) studies have attributed these implicit associative learning (IAL) deficits to differential engagement of the hippocampus and basal ganglia in older rela...

Evidence from animal and histological studies has indicated that accumulation of iron in the brain results in reactive gliosis that contributes to cognitive deficits. The current study extends these findings to human cognitive aging and suggests that magnetic resonance imaging (MRI) techniques like quantitative relaxometry can be used to study iron...

Diffusion imaging studies have observed age-related degradation of white matter that contributes to cognitive deficits separately in younger-old (ages 65-89) and oldest-old (ages 90+) adults. But it remains unclear whether these age effects are magnified in advanced age groups, which may reflect disease-related pathology. Here, we tested whether ag...

Introduction: Locus coeruleus (LC) is the primary source of norepinephrine to the brain and its efferent projections innervate many brain regions, including the thalamus. LC degrades with normal aging, but not much is known regarding whether its structural connectivity evolves with age or predicts aspects of cognition. Methods: Here, we use high...

Evidence from animal and histological studies have indicated that accumulation of iron in the brain results in reactive gliosis that contributes to cognitive deficits. The current study extends these findings to human cognitive aging and suggests that magnetic resonance imaging (MRI) techniques like quantitative relaxometry can be used to study iro...

Whereas adults across the lifespan can accurately recognize previously encountered items, they are worse at remembering precisely which items were previously seen together, and this associative memory deficit is exacerbated in older adults. However, the literature is dominated by studies of pair-wise associations, with very few examinations of high...

Aging entails a multifaceted complex of changes in macro- and micro-structural properties of human brain gray matter (GM) and white matter (WM) tissues, as well as in intellectual abilities. To better capture tissue-specific brain aging, we combined volumetric and diffusivity properties to derive subject-specific age scores for each tissue. We comp...

Introduction: Locus coeruleus (LC) is the primary source of norepinephrine to the brain and its efferent projections innervate many brain regions, including the thalamus. LC degrades with normal aging, but not much is known regarding whether its structural connectivity evolves with age or predicts aspects of cognition. Methods: Here, we use high-re...

Older adults are impaired at implicit associative learning (IAL), or the learning of relationships between stimuli in the environment without conscious awareness. These age effects have been attributed to differential engagement of the basal ganglia (e.g. caudate, globus pallidus) and hippocampus throughout learning. However, no studies have examin...

Aging is accompanied by declines in white matter integrity (e.g., demyelination, decreased fiber density) that contribute to cognitive deficits. Diffusion tensor imaging (DTI) studies have observed these integrity declines in vivo separately in younger-old (ages 65-89) and oldest-old (ages 90+) adults. But it remains unclear whether the effect of a...

Healthy aging is accompanied by declines in the ability to learn associations between events, even when their relationship cannot be described. Previous functional magnetic resonance imaging (fMRI) studies have attributed these implicit associative learning (IAL) deficits to differential engagement of the hippocampus and basal ganglia in older rela...

Single-tensor diffusion imaging (DTI) has traditionally been used to assess integrity of white matter. For example, we previously showed that integrity of limbic white matter tracts declines in healthy aging and relates to episodic memory performance. However, multi-compartment diffusion models may be more informative about microstructural properti...

Background: Previous case-control investigations of Type I Chiari malformation (CMI) have reported cognitive deficits and microstructural white matter abnormalities as measured by diffusion tensor imaging (DTI). CMI is also typically associated with pain, including occipital headache, but the relationship between pain symptoms and microstructure is...

Introduction: A fundamental component of episodic memory is the ability to differentiate new and highly similar events from previously encountered events. Numerous functional magnetic resonance imaging (fMRI) studies have identified hippocampal involvement in this type of mnemonic discrimination (MD), but few studies have assessed MD-related activ...

Locus coeruleus (LC) and substantia nigra pars compacta (SNpc) degrade with normal aging, but not much is known regarding how these changes manifest in MRI images, or whether these markers predict aspects of cognition. Here, we use high-resolution diffusion-weighted MRI to investigate microstructural and compositional changes in LC and SNpc in youn...

Locus coeruleus (LC) and substantia nigra pars compacta (SNpc) degrade with normal aging, but not much is known regarding how these changes manifest in MRI images, or whether these markers predict aspects of cognition. Here, we use high-resolution diffusion-weighted MRI to investigate microstructural and compositional changes in LC and SNpc in youn...

Diffusion tensor imaging (DTI) studies have shown: − Linear decreases in the degree of restricted diffusion (fractional anisotropy, FA) across the adult lifespan − Quadratic increases in the rate of diffusion (mean diffusivity, MD;) that accelerate after age 60 − These age-related differences in white matter integrity are most prominent in the genu...

Successful episodic memory relates to engagement of medial temporal lobe (parahippocampal gyrus; PHG) and parieto-occipital (angular gyrus, posterior cingulate, fusiform gyrus) regions during initial item encoding. One key component of episodic memory, known as mnemonic discrimination, is the ability to discriminate highly similar events from those...

Recruitment of the medial temporal lobe (hippocampus, parahippocampal gyrus), inferior frontal, premotor cortex, and parieto-occipital structures during episodic memory encoding has been associated with greater subsequent recall of item details (Kim, 2011). However, engagement of this subsequent recollection network has yet to be explored in mnemon...

Objectives: The current study examined recognition memory dysfunction and its neuroanatomical substrates in cognitively normal older adults and those diagnosed with mild cognitive impairment (MCI). Methods: Participants completed the Mnemonic Similarity Task, which provides simultaneous measures of recognition memory and mnemonic discrimination....

18 Chiari patients (CMI) and 18 matched control participants were tested using a neuropsychological assessment (RBANS), completed self-report measures of pain and mental health, and underwent diffusion-weighted (DTI) scan sequences. Diffusion indices of fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivit...

Aging is known to have deleterious effects on cerebral white matter, yet little is known about these white matter alterations in advanced age. In this study, 94 oldest-old adults without dementia (90-103 years) underwent diffusion tensor imaging to assess relationships between chronological age and multiple measures of integrity in 18 white matter...

Anatomical regions showing hyper- or hypoconnectivity with BA 7.

Cognitive slowing is a prevalent symptom observed in Gulf War Illness (GWI). The present study assessed the extent to which functional connectivity between dorsolateral prefrontal cortex (DLPFC) and other task-relevant brain regions was predictive of GWI-related cognitive slowing. GWI patients (n = 54) and healthy veteran controls (n = 29) were ass...

Objective: To determine whether MRI atrophy measures or positron emission tomography (PET) amyloid burden are associated with cognitive status in the oldest old.

Background: Declining visual capacities in older adults have been posited as a driving force behind adult age differences in higher-order cognitive functions (e.g., the “common cause” hypothesis of Lindenberger & Baltes, 1994). McGowan, Patterson and Jordan (2013) also found that a surprisingly large number of published cognitive aging studies fail...

The influence of visual capacities on cognitive performance in older adults has been frequently posited as being a driving force behind age group differences in task performance. This review of the cognitive aging literature explored the relationship between specific visual acuity criteria commonly utilized by aging researchers in order to assess t...

Accurate memory for discrete events is thought to rely on pattern separation to orthogonalize the representations of similar events. Previously, we reported that a behavioral index of pattern separation was correlated with activity in the hippocampus (dentate gyrus, CA3) and with integrity of the perforant path, which provides input to the hippocam...

.Gulf War Illness is associated with toxic exposure to cholinergic disruptive chemicals. The cholinergic system has been shown to mediate the central executive of working memory (WM). The current work proposes that impairment of the cholinergic system in Gulf War Illness patients (GWIPs) leads to behavioral and neural deficits of the central execut...

Cognition arises as a result of coordinated processing among distributed brain regions and disruptions to communication within these neural networks can result in cognitive dysfunction. Cortical disconnection may thus contribute to the declines in some aspects of cognitive functioning observed in healthy aging. Diffusion tensor imaging (DTI) is ide...

In this article we review recent research on diffusion tensor imaging (DTI) of white matter (WM) integrity and the implications for age-related differences in cognition. Neurobiological mechanisms defined from DTI analyses suggest that a primary dimension of age-related decline in WM is a decline in the structural integrity of myelin, particularly...

Functional imaging research has identified frontoparietal attention networks involved in visual search, with mixed evidence regarding whether different networks are engaged when the search target differs from distracters by a single (elementary) versus multiple (conjunction) features. Neural correlates of visual search, and their potential dissocia...

Considerable knowledge has been gained about the brain bases of working memory through research with functional magnetic resonance imaging (fMRI). However, using fMRI to explore the component processes that support working memory is difficult due to the timing of component processes and the lag of the hemodynamic response underlying the blood oxyge...

Previous research has identified subcortical (caudate, putamen, hippocampus) and cortical (dorsolateral prefrontal cortex, DLPFC; frontal motor areas) regions involved in implicit sequence learning, with mixed findings for whether these neural substrates differ with aging. The present study used diffusion tensor imaging (DTI) tractography to recons...

Diffusion tensor imaging (DTI) measures diffusion of molecular water, which can be used to calculate indices of white matter integrity. Early DTI studies of aging primarily focused on two global measures of integrity; the average rate (mean diffusivity, MD) and orientation coherence (fractional anisotropy, FA) of diffusion. More recent studies have...

The integrity of cerebral white matter is critical for efficient cognitive functioning, but little is known regarding the role of white matter integrity in age-related differences in cognition. Diffusion tensor imaging (DTI) measures the directional displacement of molecular water and as a result can characterize the properties of white matter that...

The spatial contextual cuing task (SCCT) (Chun & Jiang, 1998) is an implicit learning task that appears to depend on the medial temporal lobes. This unusual combination has been of interest in functional imaging studies and research with clinical populations, where testing time is at a premium. However, the original version of the SCCT is time-cons...

Implicit learning is thought to underlie the acquisition of many skills including reading. Previous research has shown that some forms of implicit learning are reduced in individuals with dyslexia (e.g., sequence learning), whereas other forms are spared (e.g., spatial context learning). However, it has been proposed that dyslexia-related motor dys...

Age-related implicit learning deficits increase with sequence complexity, suggesting there might be limits to the level of structure that older adults can learn implicitly. To test for such limits, we had 12 younger and 12 older adults complete an alternating serial reaction time task containing subtle structure in which every third trial follows a...

Amnestic mild cognitive impairment (MCI) is a selective episodic memory deficit that often indicates early Alzheimer's disease. Episodic memory function in MCI is typically defined by deficits in free recall, but can also be tested using recognition procedures. To assess both recall and recognition in MCI, MCI (n = 21) and older comparison (n = 30)...

To determine if aging is associated with differences in attentional regulation using behavioral and event-related potential (ERP) measures. Younger (n=13;M=20 years) and older (n=12;M=76 years) subjects performed an auditory cued attention task. Verbal cues correctly (valid) or incorrectly (invalid) predicted the ear receiving a target tone 1.5 s l...