Neural Mechanisms for Perceptual Decision Making in Humans

Cuny City College, New York NY

Investigators

Abstract

In daily life, humans are constantly faced with decisions about what they see, hear or feel - decisions that, though simple, are critical to acting in accordance with their goals. For example, when driving, how close one's car is to the car in front must be continuously monitored so that the appropriate action - stepping on the break - can be performed in a timely manner. Despite the simplicity of such decisions, our actions are highly variable because many factors influence the decision process in the brain, for example, (1) how much we know in terms of when to expect a relevant event, (2) whether it is more important to act rapidly or to take longer in order to be more accurate, (3) in what location we expect a relevant sensory event to occur, and (4) how much practice we have had in making a given type of decision. There is currently very little empirical knowledge on these factors because the decision process itself is very difficult to measure noninvasively in humans. With support from the National Science Foundation, Dr. Simon Kelly of the City College of New York (CCNY), along with collaborator Dr Redmond O'Connell of Trinity College Dublin, will measure electrical activity from specific regions of the human brain using electroencephalography (EEG) and mathematical algorithms for source separation while participants perform decision making tasks that rely on each of the four aforementioned factors. Crucially, a new paradigm design and signal analysis framework and algorithms will be used which provides the unprecedented ability to measure distinct neural elements of the decision process, namely, 1) the representation of the sensory information itself, 2) the accumulation of that information over time, and 3) the planning of action in accordance with the emerging decision. The findings, taken together, will shed light on some of the most enigmatic aspects of how humans perceive and behave in their sensory environments. A vast array of neurological and psychiatric disorders are associated with deficits in speed and/or accuracy on laboratory tasks in which they make responses to sensations according to task instructions. The advances made in the current project will open the unprecedented possibility to parse such deficits on the neural systems level, and establish the specific stage of processing and nature of computations that are impaired. This has great potential impact on diagnosis and treatment in mental health. All data and code from this project will be made available online for anyone aspiring to gain further insights from the data, or generate new data using these paradigms. The project entails close collaboration between biomedical engineers and psychologists, and stands to promote such interdisciplinary synergy more generally in the neuroscience community. All experiments lend themselves to student participation and highly valuable learning experiences, which will be strongly encouraged. Early-stage researchers at the postdoctoral, doctoral and undergraduate level will be trained as a part of this project. The demographic make-up of the research team at CCNY strongly counters the prevailing representation in science and engineering, with 8 of the total 11 lab members belonging to under-represented groups in STEM disciplines. All members will gain research training and experience, as well as cross-cultural exposure through the international collaboration with Trinity College.