Research

Current Studies

The CCNC has various ongoing studies. For more information on the current projects in the lab or to find contact information to participate in a study, please see the information below.

What: Participation involves interviews about your past mental health, tests of concentration and memory, and completing two decision-making computer task involving making decisions such as choosing between gamble options and risking potential reward and loss in an MRI scanner.

Who: Currently recruiting individuals with Schizophrenia and non-clinical control subjects with no history of mental health issues.

Where: This study takes place across two visits, the 1st may be at Goodman Hall in Indianapolis or IU-Bloomington, the 2nd visit must be at IU-Bloomington.

For more info, visit https://legacy.indianactsi.org/component/clinicaltrial/trial?Itemid=121&id=7950

If interested in partipating, please contact iubccnc@indiana.edu 

Nancy Lundin is leading a series of collaborative projects focused on characterizing semantic, phonemic, and organizational aspects of speech in individuals across the psychotic spectrum.

What: These projects focus on data from the verbal fluency task (VFT) and free speech discourse samples. In VFT, individuals are asked to name items from a particular category (e.g., “animals”) or words that begin with a certain letter (e.g., “S”) in a short time period. Task performance requires executive function ability, semantic memory, and adequate processing speed, and performance is often reduced in individuals with psychosis. We apply automated techniques to VFT data to measure the semantic and phonemic clustering of responses and examine individuals’ ability to efficiently search through memory similar to the ways in which animals forage for food. We also use fMRI to investigate the neural mechanisms of clustering and switching in VFT, including the specific role of the cerebellum. Lastly, we analyze linguistic cohesion in discourse samples from individuals with psychosis to quantify one’s tendency to make connections between ideas that promote effective communication.

Overall, we combine theories and methods from fields of psychopathology, neuroscience, and cognitive science to characterize thought disorder and further our understanding of the cerebellum’s role in fluid linguistic processes.

Lab Techniques

Methods

The CCNC uses a broad range of methods, including behavioral testing, diagnostic interviewing, cognitive and neurological assessment, and neuroimaging and neurostimulation techniques.

Electroencephalography (EEG) is a technique used to measure brain activity. Sensors on the scalp detect weak voltage fluctuations that arise from the summation of neural activity, specifically post-synaptic potentials largely from cortical pyramidal cells oriented in the same direction. EEG is used to measure neural dynamics on a millisecond-level scale while individuals are resting and/or performing a task (e.g., working memory, language, auditory tasks). Some benefits of EEG are its noninvasive and relatively inexpensive nature as well as its precise temporal resolution. A limitation of EEG is its poor spatial resolution (locating where in the brain the activity is coming from) relative to techniques such as functional magnetic resonance imaging (fMRI).

Common methods of analyzing EEG data include: 1) event-related potentials (ERPs), or peaks in neural activity time-locked to stimuli (e.g., pictures, sounds), and 2) time-frequency analysis, or examining the strength and synchrony of neural activity in particular frequencies (e.g., alpha activity is considered to be synchronized neuronal activity oscillating around 8-13 Hz). EEG can be useful in studying basic neural functioning in healthy humans as well as in detecting differences in cognitive and sensory processes across individuals with psychopathology. Common applications of EEG in clinical settings are characterizing seizures in individuals with epilepsy and aiding in diagnosing sleep disorders.

Magnetic resonance imaging (MRI) is a noninvasive technique used to produce three dimensional images of tissue structures and to observe various physiological functions. The MRI produces a strong magnetic field, and the protons within the body of a subject must align with this field. During the imaging process, a subject is placed under a large magnetic field and must remain very still in order to capture clear images of the brain. 


One specific type of MRI is functional magnetic resonance imaging (fMRI), which allows for observation of both neural structure and function. While a subject performs specific cognitive tasks in the MRI scanner, it enables researchers to determine which brain regions are activated by detecting changes in neural blood flow. When a brain region becomes more active, more blood also flows to that region. Blood-oxygen-level dependent (BOLD) signals produced by fMRI measure the changes in blood flow to certain areas of the brain while performing a task. fMRI can also measure neural activity via BOLD signal when a subject is not engaged in a specific task (resting state fMRI)


Some advantages of MRI (and fMRI) is its noninvasive nature, allowing subjects to be safely scanned without risks of radiation, and its high degree of spatial resolution which provides better tissue contrast than other imaging modalities. For clinical uses, this high spatial resolution is key to making many different psychological and physiological diagnoses. In research, fMRI also has the advantage of detecting both altered brain activation patterns and altered brain connectivity. However, BOLD signal is only an indirect measure of brain activity, and may be influenced by a variety of other factors. Also, fMRI tends to have poorer temporal resolution because the blood flow changes lag behind the electrical communication between neurons. 

Magnetic resonance spectroscopy (MRS), also termed nuclear magnetic resonance (NMR) when not in vivo, is a neuroimaging technique that quantifies the concentration of select brain metabolites that are highly abundant, including compounds such as glutamate, phenylalanine, taurine, creatine, choline, and GABA. Metabolites are identified by their chemical shifts. Chemical shifts are determined by deflections of applied magnetic field gradients and radio frequencies at which hydrogen protons resonate within a given compound or chemical environment. Phosphorous, sodium, carbon, and fluorine are also often used to characterize resonance frequencies. MRS data is typically measured from a small three-dimensional portion of the brain, or “voxel”, selected by the researcher.

Although MRS has low spatial and temporal resolution, it can be a valuable non-invasive technique. In addition to identifying time- and psychopathology-related metabolite differences, MRS is commonly used to identify tumors, neural trauma, and metabolic disorders. 

Diffusion tensor imaging (DTI) is a neuroimaging technique used to depict the white matter anatomy of the brain. It is currently the only measure that allows for visualization of white matter in vivo. Images are created based on the diffusion of water molecules, utilizing a process called tractography to select and follow the direction of neuronal tracts within the brain. Due to DTI’s high sensitivity to micro properties of tissues, DTI has become increasingly popular for both clinical and research purposes.

Transcranial direct current stimulation (tDCS) is a non-invasive neurostimulation technique. tDCS can be used to indirectly induce excitation (termed “anodal” stimulation) or inhibition (termed “cathodal” stimulation) of brain regions. This is thought to occur by changing the threshold at which large groups of neurons fire. tDCS is accomplished by placing thin, wide sponge electrodes soaked in saline (i.e. salt solution) on the scalp or other parts of the body. The active and reference electrodes are configured to send a weak excitatory or inhibitory current through the scalp and skull to a brain region of interest. tDCS stimulation is 1000 times smaller than the strength of a static shock, like that received when you touch a metal doorknob after dragging your feet on a carpet.

tDCS can be used with behavioral, neuroimaging, or cognitive tasks to determine the role of various neural regions in task performance by attempting to improve or dampen participant performance/ability. Moreover, tDCS can be used in both healthy populations and individuals with psychopathology to understand differences in the contribution of neural regions in various diagnostic/demographic groups. Because tDCS is such a new technique, its mechanisms of action and the extent of its effects are not yet fully understood.

Population

The CCNC is interested in understanding psychosis and related disorders. Our studies often recruit individuals with schizophrenia, bipolar disorder, schizotypal personality disorder, past and present cannabis users, and relatives. We are so thankful to the individuals who participate in our studies and their families!

Schizophrenia is a mental health condition characterized by several symptoms which may occur in a variety of combinations. The two cardinal symptoms of schizophrenia, and psychotic disorders in general, are delusions and hallucinations. Delusions are adamant beliefs that are typically not susceptible to conflicting evidence, and can be paranoid, grandiose, referential, religious, or somatic in nature. Hallucinations are experiences involving the conscious perception of stimuli (e.g. hearing voices, seeing shadow figures) that are not present or perceived by other people.

Several other symptoms are typical in psychotic disorders and schizophrenia. Disorganized speech and thinking may be observed as loose-associations, tangentially, and incoherence during discussion. Movement can be abnormal or uncoordinated, and in some cases catatonic (e.g. lack of movement or stereotyped movements).

Schizophrenia is also associated with a cluster of negative symptoms, which are the absence of typical qualities such as motivation to achieve goals, interest in socialization, pleasure in enjoyable activities, self-produced amount of speech, and emotion expressivity in appearance and voice.   

While schizophrenia is often considered a “severe mental illness”, the impacts of schizophrenia may occur anywhere along a spectrum of impairment. For more information about schizophrenia according to the National Institute of Mental Health, see the links below:

Schizophrenia Overview 

Prevalence and Statistics

Bipolar disorder is a mental health condition characterized by several days of mood irregularity, usually in the form of having “highs” and “lows.” Periodic episodes of mania are characteristic of this disorder, typically involving extremely positive feelings or intense anger, accompanied by excessive talkativeness, overabundance of energy, decreased need for sleep, difficulty concentrating or staying on-track, racing thoughts, and increased engagement in activities. During these periods of mania, individuals may also engage in risky activities that they normally would not, due to the potential for long-term problems (e.g., reckless spending, risky sexual behavior). 

Bipolar I disorder is considered more severe due to periods of mania, while Bipolar II disorder is associated with periods of hypomania, or “lesser mania” lasting only several days or causing less impaired daily functioning. While periods of depression are common in Bipolar disorder, they are not required for a diagnosis. Some people with bipolar disorder also experience psychotic symptoms such as having hallucinations or odd/unrealistic beliefs during episodes of mania or depression.

While bipolar disorder is often considered a “severe mental illness,” the impact of the disorder depends on the individual. For more information about bipolar disorder, visit the National Institute of Mental Health.

Cannabis, also known as marijuana, is a substance derived from the cannabis sativa plant and its medical and recreational use has become increasingly popular over recent years. Common uses of cannabis include treating anxiety, pain, insomnia, and other conditions. The main chemical compound from which cannabis derives its psychoactive properties from is delta-9-tetrahydrocannabinol (THC). The effects of cannabis depend on the individual and the method through which it is consumed (smoking versus oral consumption). Some common effects include: relaxation, euphoria, altered sensory and time perception, and increased appetite. In larger doses, cannabis may also induce psychotic-like experiences such as hallucinations, delusions, and a loss of identity. Within the brain, THC attaches to and activates cannabinoid receptors, which results in the variety of effects cannabis has on cognitive processes and behavior. THC also impacts the brain’s reward system, consequently providing the “high” that many people who use cannabis experience. 

Cannabis use may progress to cannabis use disorder in some individuals; research suggests that up to 30% of people who use cannabis will develop some form of use disorder.  Cannabis dependence occurs when the brain adapts to high quantities of cannabis over time through reducing its sensitivity to cannabinoid neurotransmitters, and cannabis addiction may occur if an individual cannot stop their use of cannabis even if it interferes in interpersonal, occupational, and/or academic areas of life. Over the last couple of decades, cannabis potency is on the rise, with average THC content in present day samples of 15% compared to 4% in the 1990s. Rising potency of cannabis may lead to more severe effects and consequences following use, especially for younger individuals.


For more information on cannabis and its effects, please visit the National Institute of Drug Abuse.

Autism Spectrum Disorder is a developmental disorder that is characterized by deficits in social communication and interactions. In the U.S., the frequency of autism spectrum disorder is about 1% of the population. Autism Spectrum Disorder is said to be a developmental disorder because symptoms are present in the early developmental period. These symptoms include deficits in social communication and maintenance of relationships as well as restrictive and repetitive patterns of behavior. Symptoms are typically recognized during the second year of life but may be seen earlier. The first symptoms of autism spectrum disorder involve a delayed language development and lack of social interests.

Autism is known as a spectrum disorder because the symptoms include a wide range of severities. These social deficits range from failure to initiate a normal back-and-forth conversation to severe deficits in verbal and nonverbal communication skills. The restricted and repetitive behaviors also range from an inability to switch between activities to an inflexibility of behavior and extreme difficulty coping with change. Some restricted and repetitive behaviors include repetition of certain motor movements (e.g., finger flicking), repetitive use of objects, repetitive speech, or a fascination with certain routines and interests (e.g., preoccupation with vacuum cleaners, writing out time tables). 

Currently, as many as 15% of cases of autism spectrum disorder appear to be associated with a known genetic mutation.  Autism spectrum disorder is also diagnosed four times more often in males than females. Treatment for autism spectrum disorder should begin as soon as possible after diagnosis. Early treatment for autism spectrum disorder is important as proper care can reduce individuals’ difficulties while helping them learn new skills and make the most of their strengths. There are many social services programs and other resources that can help. Here are some links for finding these additional services:

Autism Diagnosis

Autism Treatments         

Autism Therapies