PPI (psychophysiological interactions) is a method for finding out whether the correlation in activity between two distant brain areas is different in different psychological contexts – in other words whether there is an interaction between the psychological state and the functional coupling between two brain areas.

Psychophysiological Interaction (PPI) is a type of fMRI functional connectivity analysis that is specifically useful for looking at the statistical dependence of multiple brain regions as modulated by another factor, e.g. a task.

In this chapter we will cover how to analyze task-related data by using a technique called Psychophysiological Interactions (PPI), which reveals whether the functional connectivity between two nodes depends on what task the subject is currently doing. Example of a PPI analysis, taken from Outhred et al. (2015).

两个解决方法：FSL采用的是把心理项与血氧动力学方程进行卷积，得到新的心理项，类似于激活分析了；SPM是将生理项进行去卷积得到神经上的响应进程，然后与生理项相乘，将相乘结果与HRF进行卷积得到交互项。 AFNI也是用后者。 以上解决了事件相关设计的问题，来自Gitelman et al., 2003，如果我们有多于两个的实验条件呢？ 下面gPPI就出现了，是PPI的扩展形式，来自McLaren et al., 2012。 gPPI中，就不把两个条件进行对比了，而是把每个条件分开来，10个条 …

Frequently Asked Questions (PPI) Should I include other task variables in the model? Generally speaking, yes you should. You should include all the task EVs which were in your GLM model, even those which are not involved in generating your PPI regressor. This will make the model overall a better description of the data.

How to run a PPI analysis in Feat. Instructions for implementing a PPI analysis with the Feat gui. See also: Frequently Asked Questions (PPI) 1. Make some decisions. Because you start by choosing and ROI and task contrast, PPI is heavily hypothesis driven.

Psychophysiological interactions (PPIs) analysis is a method for investigating task-specific changes in the relationship between activity in different brain areas, using functional magnetic resonance imaging (fMRI) data. Specifically, PPI analyses ...

2017年11月14日 · 在神经影像学中, 功能性磁共振成像 (fMRI) 测量大脑中的血氧水平依赖性 (黑体) 信号。在大脑的空间独立区域中, 黑体信号的相关度定义了这些区域的功能连通性。在认知功能磁共振成像任务中, 可以使用心理交互 (PPI) 分析来检查在认知任务定义的特定上下文中 ...

Psychophysiological interaction (PPI) is a brain connectivity analysis method for functional brain imaging data, mainly functional magnetic resonance imaging (fMRI). It estimates context-dependent changes in effective connectivity (coupling) between brain regions.

HOW TO RUN PPI IN FSL? The changes in this influence according to the context: a psychological interacMon. Two possible mechanisms: (i) a context chagce in the contribuMon of one area to another; or (ii) a modulaMon of responses in one area to …