We have recently identified a type of neural activity that reflects the subject's engagement in a task. This task- related activity, which we have measured using both intrinsic-signal optical imaging and functional magnetic resonance imaging, is independent of external visual stimuli and is, instead, linked to internal brain states such as arousal and endogenous attention. Here, we propose a series of experiments that test several hypotheses about task-related brain activity, using a wide range of neurophysiological methods.
Aim 1 will test whether hemodynamic activity (measured with optical imaging or with fMRI) can be separated into a linear sum of neurally distinct stimulus-evoked and task-related components.
Aim 2 will test whether the task-related component is widespread but possibly a function of task modality (e.g. visual vs. auditory) and not spatially global.
Aim 3 will test whether the task-related component reflects the degree of engagement (a form of arousal or attention) and is thus a function of reward, difficulty and timing. The endogenous processes that we propose to investigate are implicated a variety of neurological and psychiatric disorders. For example, individuals with ADHD demonstrate a wide variety of attentional deficits, but their most pronounced deficits are related to sustained attention, i.e., maintaining a steady level of performance on an infrequent task over a prolonged period of time. It is likely that the task-related component that we are proposing to study is related to sustained attention, and knowledge gained from the proposed experiments may provide insights into ADHD and related disorders.

Public Health Relevance

The proposed research will yield new information about task-related, endogenous brain states, which are distinct from stimulus-evoked, externally-driven patterns of neural activity. Endogenous brain states are related to attention and arousal, cognitive functions that are implicated in a number of neurological and psychiatric disorders, including schizophrenia and autism. Deficits in visual attention are present in unilateral neglect, schizophrenia, and Attention Deficit Hyperactivity Disorder (ADHD).

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY025330-02
Application #
9188569
Study Section
Mechanisms of Sensory, Perceptual, and Cognitive Processes Study Section (SPC)
Program Officer
Flanders, Martha C
Project Start
2015-12-01
Project End
2019-11-30
Budget Start
2016-12-01
Budget End
2017-11-30
Support Year
2
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Columbia University (N.Y.)
Department
Neurosciences
Type
Schools of Medicine
DUNS #
621889815
City
New York
State
NY
Country
United States
Zip Code
10032
Herman, Max Charles; Cardoso, Mariana M B; Lima, Bruss et al. (2017) Simultaneously estimating the task-related and stimulus-evoked components of hemodynamic imaging measurements. Neurophotonics 4:031223