Publications by authors named "Sharif Kronemer"

Pupillometry is a popular method because pupil size is easily measured and sensitive to central neural activity linked to behavior, cognition, emotion, and perception. Currently, there is no method for online monitoring phases of pupil size fluctuation. We introduce rtPupilPhase-an open-source software that automatically detects trends in pupil size in real time.

View Article and Find Full Text PDF

Afterimages are illusory, visual conscious perceptions. A widely accepted theory is that afterimages are caused by retinal signaling that continues after the physical disappearance of a light stimulus. However, afterimages have been reported without preceding visual, sensory stimulation (e.

View Article and Find Full Text PDF

Pupillometry is a popular method because pupil size is easily measured, sensitive to central neural activity, and associated with behavior, cognition, emotion, and perception. Currently, there is no method for online monitoring phases of pupil size fluctuation. We introduce - an open source software that automatically detects trends in pupil size in real time, enabling novel implementations of real time pupillometry towards achieving numerous research and translational goals.

View Article and Find Full Text PDF

Afterimages are illusory, visual conscious perceptions. A widely accepted theory is that afterimages are caused by retinal signaling that continues after the physical disappearance of a light stimulus. However, afterimages have been reported without preceding visual, sensory stimulation (e.

View Article and Find Full Text PDF

The full neural circuits of conscious perception remain unknown. Using a visual perception task, we directly recorded a subcortical thalamic awareness potential (TAP). We also developed a unique paradigm to classify perceived versus not perceived stimuli using eye measurements to remove confounding signals related to reporting on conscious experiences.

View Article and Find Full Text PDF

Understanding the neural basis of consciousness is a fundamental goal of neuroscience, and sensory perception is often used as a proxy for consciousness in empirical studies. However, most studies rely on reported perception of visual stimuli. Here we present behavior, high density scalp EEG and eye metric recordings collected simultaneously during a novel tactile threshold perception task.

View Article and Find Full Text PDF

The earliest cortical neural signals following consciously perceived visual stimuli in humans are poorly understood. Using intracranial electroencephalography, we investigated neural activity changes associated with the earliest stages of stimulus detection during visual conscious perception. Participants (N = 10; 1,693 electrode contacts) completed a continuous performance task where subjects were asked to press a button when they saw a target letter among a series of nontargets.

View Article and Find Full Text PDF
Article Synopsis
  • Semi-structured interviews were conducted with cerebellar ataxia patients and their caregivers to explore how the disease affects their quality of life.
  • The study identified and categorized 15 themes related to changes experienced, particularly focusing on motor, cognitive, and psychosocial aspects.
  • Findings highlighted agreements between patients and informants on the severity of symptoms and established connections between motor impairments and psychosocial difficulties, providing valuable insights for education and prognosis.
View Article and Find Full Text PDF
Article Synopsis
  • The study investigates neural activity during the initial stages of visual consciousness using recordings from epilepsy patients, focusing on signal detection in the brain.
  • Results reveal that within 0-50ms after a visual word appears, there are increases in gamma activity in key brain areas, signaling early processing regardless of whether the word is later remembered.
  • Additionally, after the initial response, later changes in gamma power occur across various regions, highlighting a complex network involved in visual perception and memory recall, particularly in the left hemisphere for words that are remembered.
View Article and Find Full Text PDF

The cerebellum recognizes sequences from prior experiences and uses this information to generate internal models that predict future outcomes in a feedforward manner [Front Hum Neurosci 8: 475, 2014; Cortex 47: 137-44, 2011; Cerebellum 7: 611-5, 2008; J Neurosci 26: 9107-16, 2006]. This process has been well documented in the motor domain, but the cerebellum's role in cognitive sequencing, within the context of implicit versus explicit processes, is not well characterized. In this study, we tested individuals with cerebellar ataxia and healthy controls to clarify the role of the cerebellum sequencing using variations on implicit versus explicit and motor versus cognitive demands across five experiments.

View Article and Find Full Text PDF

While cerebellar ataxia (CA) is a neurodegenerative disease known for motor impairment, changes in mood have also been reported. A full account of neuropsychiatric symptomology in CA may guide improvements in treatment regimes, measure the presence and severity of sub-clinical neuropsychiatric disturbance symptomology in CA, and compare patient versus informant symptom recognition. Neuropsychiatric phenomena were gathered from CA patients with genetic and unknown etiologies and their informants (e.

View Article and Find Full Text PDF

Dynamic attention states are necessary to navigate the ever changing task demands of daily life. Previous investigations commonly utilize a block paradigm to study sustained and transient changes in attention networks. fMRI investigations have shown that sustained attention in visual block design attention tasks corresponds to decreased signal in the default mode and visual processing networks.

View Article and Find Full Text PDF

Working memory is vital for basic functions in everyday life. During working memory, one holds a finite amount of information in mind until it is no longer required or when resources to maintain this information are depleted. Convergence of neuroimaging data indicates that working memory is supported by the motor system, and in particular, by regions that are involved in motor planning and preparation, in the absence of overt movement.

View Article and Find Full Text PDF

Background: Volatile interpersonal relationships are a core feature of borderline personality disorder (BPD) and lead to devastating disruption of patients' personal and professional lives. Quantitative models of social decision making and learning hold promise for defining the underlying mechanisms of this problem. In this study, we tested BPD and control subject weighting of social versus nonsocial information and their learning about choices under stable and volatile conditions.

View Article and Find Full Text PDF

Poor visuospatial skills can disrupt activities of daily living. The cerebellum has been implicated in visuospatial processing, and patients with cerebellar injury often exhibit poor visuospatial skills, as measured by impaired memory for the figure within the Rey-Osterrieth complex figure task (ROCF). Visuospatial skills are an inherent aspect of the ROCF; however, figure organization (i.

View Article and Find Full Text PDF

Conscious perception occurs within less than 1 s. To study events on this time scale we used direct electrical recordings from the human cerebral cortex during a conscious visual perception task. Faces were presented at individually titrated visual threshold for 9 subjects while measuring broadband 40-115 Hz gamma power in a total of 1621 intracranial electrodes widely distributed in both hemispheres.

View Article and Find Full Text PDF

Human immunodeficiency virus (HIV) became a treatable illness with the introduction of combination antiretroviral therapy (CART). As a result, patients with regular access to CART are expected to live decades with HIV. Long-term HIV infection presents unique challenges, including neurocognitive impairments defined by three major stages of HIV-associated neurocognitive disorders (HAND).

View Article and Find Full Text PDF

Human immunodeficiency virus (HIV) is often contracted through engaging in risky reward-motivated behaviors such as needle sharing and unprotected sex. Understanding the factors that make an individual more vulnerable to succumbing to the temptation to engage in these risky behaviors is important to limiting the spread of HIV. One potential source of this vulnerability concerns the degree to which an individual is able to resist paying attention to irrelevant reward information.

View Article and Find Full Text PDF

Working memory (WM) involves the ability to maintain and manipulate information held in mind. Neuroimaging studies have shown that secondary motor areas activate during WM for verbal content (e.g.

View Article and Find Full Text PDF

Consciousness remains a mystery despite centuries of inquiry, but neuroscience research is beginning to offer insights into the conscious brain. Although the influence of neuroscience in decoding consciousness is growing, it is distinctly absent from collegiate education. Many psychology and neuroscience textbooks devote a single paragraph or an appendix to consciousness.

View Article and Find Full Text PDF