Interpretation Of Brain Activity Research Articles

Interpretation of Brain Activity Using Functional Magnetic Resonance Imaging

Functional magnetic resonance imaging (fMRI) has paved the way for the noninvasive measurement of human brain activity. However, it does not directly detect neuronal activity, and its interpretation requires caution. In addition, conventional fMRI usually detects brain activity induced by specific mental states, and conventional analysis methods are prone to drawing unwarranted inferences from brain activity to mental states. To move toward a legitimate inference, we introduce multivoxel pattern-based analyses and an online database system that correctly considers the Bayes' theorem.

Brain reflections: A circuit-based framework for understanding information processing and cognitive control.

Here, I propose a view of the architecture of the human information processing system, and of how it can be adapted to changing task demands (which is the hallmark of cognitive control). This view is informed by an interpretation of brain activity as reflecting the excitability level of neural representations, encoding not only stimuli and temporal contexts, but also action plans and task goals. The proposed cognitive architecture includes three types of circuits: open circuits, involved in feed-forward processing such as that connecting stimuli with responses and characterized by brief, transient brain activity; and two types of closed circuits, positive feedback circuits (characterized by sustained, high-frequency oscillatory activity), which help select and maintain representations, and negative feedback circuits (characterized by brief, low-frequency oscillatory bursts), which are instead associated with changes in representations. Feed-forward activity is primarily responsible for the spread of activation along the information processing system. Oscillatory activity, instead, controls this spread. Sustained oscillatory activity due to both local cortical circuits (gamma) and longer corticothalamic circuits (alpha and beta) allows for the selection of individuated representations. Through the interaction of these circuits, it also allows for the preservation of representations across different temporal spans (sensory and working memory) and their spread across the brain. In contrast, brief bursts of oscillatory activity, generated by novel and/or conflicting information, lead to the interruption of sustained oscillatory activity and promote the generation of new representations. I discuss how this framework can account for a number of psychological and behavioral phenomena.