Questions tagged [neuroscience]

A field of science that studies nervous systems. Use [neuroimaging] tag for questions about fMRI data analysis.

Filter by
Sorted by
Tagged with
1
vote
0answers
12 views

Fluctuations in the HH Model

The Hodgkin Huxley Model describes the voltage that flows through a membrane of a nerve cell - this voltage is subject to arbitrary fluctuations that result from the stochastic closing and opening of ...
0
votes
0answers
10 views

Does anyone have any experience in segmenting motor evoked potentials?

I'm working in EEG and motor imagery and was wondering what the best way to go about sectioning my data points for feature analysis / time synchronizing with events or observable features. Are there ...
1
vote
0answers
28 views

Regression on unevenly distributed high dimensional dataset

I have a very high dimensional (20K+ hand engineered features) biological dataset to predict a single continuous output variable (such as a mental state exam scores for a dementia patient). The output ...
0
votes
0answers
30 views

How to perform machine learning on data with many trials on individual subjects

I have an EEG dataset. The data are epoched around an event of interest and are of the form channels x timepoints x trials. There are many of these types of datasets for several subjects. Because ...
1
vote
1answer
28 views

Updating Prediction Errors in Gradient Ascent (Friston's Free-energy)

Background In Rafal Bogacz's tutorial on the free-energy framework for modelling perception and learning, section 2.3 we have: $$\dot{\phi} = \frac{\partial F}{\partial\phi} = \varepsilon_u g'(\phi) ...
1
vote
0answers
69 views

Feedback Neural Network

I'm looking for a Neural Network has feedback weights. Feedback weights are connections between neurons from a layer to a previous layer. For instance: from the output layer to the input layer. I did ...
0
votes
1answer
20 views

How to find difference between data recorded for 1431 variables for X subjects, across 3 time points?

I am doing research using magnetoencephalography (MEG). I'm performing coherence analysis which, briefly, is a measure of neuronal synchronicity and functional connectivity. For each subject scanned ...
0
votes
0answers
21 views

How to test whether event A affects the frequency at which event B occurs

I conducted an experiment in which I measured the occurrence of some event A over time. I then intervened in the system, periodically introducing event B. I hypothesise that event B affects the ...
64
votes
12answers
17k views

Why do neural networks need so many training examples to perform?

A human child at age 2 needs around 5 instances of a car to be able to identify it with reasonable accuracy regardless of color, make, etc. When my son was 2, he was able to identify trams and trains, ...
0
votes
0answers
50 views

biological basis for excluding values outside 3 standard deviations from the mean? [duplicate]

Is there any biological basis for excluding outliers in a dataset of blood cytokine levels (e.g. values outside 3 standard deviations from the mean for each cytokine) as measured by multiplex ...
0
votes
1answer
45 views

For EEG analysis, why is it more efficient to use the raw data than images of the data?

Data Science publications for EEG analysis like EEGNet: A Compact Convolutional Network for EEG-based Brain-Computer Interfaces use the raw EEG data (see: github vlawhern/arl-eegmodels ) rather than ...
0
votes
2answers
48 views

Bonferroni correction and discussion of the results

In a study in which I analyze several biomarkers through logistic and linear regressions, should I discuss in the discussion of the paper the results with p <0.05 (they only have a nominal ...
1
vote
0answers
52 views

Statistic analysis on dependent and simultaneously independent data

Let's assume that I have a datasheet looking like that: ...
48
votes
4answers
5k views

Does correlation = 0.2 mean that there is an association “in only 1 in 5 people”?

In The Idiot Brain: A Neuroscientist Explains What Your Head is Really Up To, Dean Burnett wrote The correlation between height and intelligence is usually cited as being about $0.2$, meaning ...
0
votes
1answer
41 views

Couldn't ANN's be modeled on any part of the body (not just the brain)?

It's commonly said that ANN's are modeled after the brain, but as we know, neurons are also found elsewhere in the human body. So if someone was being provocative and said that ANN's could equally ...
2
votes
1answer
933 views

How to reverse factor analysis (FA) and reconstruct original variables?

I saw this interesting topic: How to reverse PCA and reconstruct original variables from several principal components? and a nice answer with a very useful example of Iris data in Matlab. I would like ...
0
votes
1answer
20 views

How to determine needed amount of random samples of whole population?

I wrote an algorithm that categorizes a large set of electrophysiological data, way more than I could go through per hand (think over 10.000 cells). I want to take randomly drawn sample cells out of ...
2
votes
0answers
76 views

Finding time intervals where two groups of time series are significantly different

I have two sets of time series, let's call them $C$ and $D$. Assume that $C$ ($D$) has $n$ ($m$) samples (each sample is a time-series of length $T$). I want to assess if there are periods of time ...
1
vote
1answer
68 views

Cross-fertilization of neural network/machine learning theory and R&D in physiology

Clearly, the development of neural networks has been based, at least initially, on those occurring in actual animals, human or otherwise. Conversely, how have neural-network or machine-learning models/...
1
vote
1answer
746 views

Comparing results of unsupervised clustering to a known classification

Disclaimer: I'm looking for a bit of help as I'm only a simple neuroscientist and even working out what to google in this area is a tricky prospect. Here goes: I have a set of data (3d positions in ...
7
votes
1answer
169 views

Meaning of low power in neuroscience after combining results of many meta-analyses (Button et al 2013)

In a 2013 review article in Nature Neuroscience, Button et al. Power failure: why small sample size undermines the reliability of neuroscience, it was stated that: the average statistical power of ...
3
votes
0answers
171 views

May outliers represent significant values?

Each element of a 56x1 vector represents the functional association between two brain networks. I want to assess which of these 56 values are significant. One way to deal with this is to use an ...
5
votes
1answer
664 views

To what extent are convolutional neural networks inspired by biology?

I have read in several places that convolutional neural networks were biologically inspired. In what ways do CNNs mirror biology, and in what ways don't they? Is there a more biologically plausible ...
0
votes
1answer
66 views

How predict time series B given A; predict time series transform?

Assume a unidirectional circuit that transforms information. If one records the activity from the middle and end of the circuit they will end up with two times series. My goal is to predict the ...
0
votes
1answer
49 views

Machine Learning application to neuroscientific data

I have the following question, and it is (for me) an open research question. I really don't have a feeling if it is a difficult question or a trivial one, getting a better feeling for approaches I ...
0
votes
1answer
65 views

What is a d-prime experiment

I am reading about Roc curves and have encountered the term ""D-prime experiment" does anyone know what it is?
4
votes
1answer
265 views

Linear model: only the whole model significant?

This is the result of a linear model (MatLab, LinearModel.fit): ...
2
votes
1answer
2k views

Correlation with repeated measures

For each of my 20 subjects, I have: physiological parameter: brain activity (y1) at time T1; physiological parameter: brain activity (y2) at time T2; behavioral parameter: reaction time (X); I want ...
5
votes
2answers
867 views

Bootstrap to test differences between correlation coefficients

I have two correlation coefficients ($r_1$ and $r_2$), obtained within the same sample (20 subjects). My aim is to test it they are significantly different. $r_1$ is the correlation between a ...
3
votes
1answer
139 views

Approximating Bernoulli distributions as Poisson distributions in analysis of neural data

I'm reading Analysis of Neural Data, by Kass et al (2014), where Kass argues that spike trains can be viewed as point processes (in chapter 19). Furthermore, he goes on to convert spike trains (that ...
0
votes
1answer
191 views

Tests for comparing correlation values. The winner is?

The question is relatively simple, but trivial. I have data divided by one fixed effect (Emotion, with 2 conditions: A and B), and I have a covariate, for each of my 20 subjects. My aim is to 1) ...
2
votes
0answers
281 views

Is Fisher's z transformation necessary when comparing the variances of correlation coefficients?

I am working on functional connectivity between brain regions, where functional connectivity is represented by the Pearson correlation coefficient between the time series (fMRI) of brain regions. I am ...
0
votes
0answers
70 views

Classifying spikes as excitatory or inhibitory based on their shape

I have two classes of spike, namely, excitatory spikes and inhibitory spikes. In the figure you can see their shapes. I want to classify my spikes based on these two shapes. The shape in the figure ...
2
votes
1answer
84 views

Reliability of single case reports vs group inference

In his paper "Ten ironic rules for non-statistical reviewers", Karl Friston includes the following tongue-in-cheek response of a fictional author to a reviewer who complains about the sample size ...
1
vote
0answers
128 views

Neuroimaging in SPM & GIFT - Regressor Convolution and fitting a GLM to ICA data

I have two kind of disparate questions. I am attempting to replicate the following paper: http://www.sciencedirect.com/science/article/pii/S1053811916300428 I am using SPM to perform preprocessing ...
65
votes
1answer
7k views

40,000 neuroscience papers might be wrong

I saw this article in the Economist about a seemingly devastating paper [1] casting doubt on "something like 40,000 published [fMRI] studies." The error, they say, is because of "erroneous statistical ...
2
votes
0answers
34 views

Studying how parameters affect standard deviation of skewed data

I'm running a bunch of simulations that are modeling the first time a neuron fires when it receives stochastic input and has intrinsic noise. The program I wrote creates a dataset of a bunch of time ...
3
votes
0answers
201 views

Comparing neuron “jitter” values across trials

I'm asking this question on the statistics forum because I'm wondering a bit about drawing appropriate conclusions supported by statistics from skewed data (if it belongs on another area of stack ...
0
votes
2answers
1k views

How to compute the firing rate of a neuron with different duration of trials?

I have recorded data from a neuron from different trials. Each trial we show a stimulus to a rat and then we measure the neural activity. I want to measure the PSTH which is peristimulus time ...
4
votes
1answer
570 views

What does the number of independent components produced by ICA depend on?

I'm a student working on my bachelor thesis performing independent component analysis (ICA) on some fMRI data using MELODIC FSL. I would like to ask some questions regarding the results of ICA. ...
2
votes
0answers
574 views

Shifting input over image for CNN object detection?

I've got a CNN which is trained supervised and calculates if a specific object is present in an image. Since I am interested in the object's position in the image I tried to alter my architecture so ...
3
votes
1answer
168 views

Comparing Functional Connectivity as measured by fMRI

This question has been giving me a headache for a while so I'll define the problem before asking the question. fMRI is a measure of Blood Oxygenation Level Dependent signal. Higher the blood ...
4
votes
3answers
462 views

Do I have a justified reason to exclude a non-significant covariate from my ANCOVA? How interesting is unequal variance?

I am comparing glutamate concentrations across groups (2 groups). I planned on controlling for age and IQ, simply because this is what is always done in cognitive neuroscience. When doing this, age ...
24
votes
4answers
5k views

What can we learn about the human brain from artificial neural networks?

I know my question/title is not very specific, so I will try to clearify it: Artificial neural networks have relatively strict designs. Of course, generally, they are influenced by biology and try to ...
2
votes
1answer
186 views

Nonparametric changepoint detection for a point process

I have a bunch of point processes that are generated by some unknown model. There is a marked pause that seems to begin and end at the same time in each process. I would like to measure this pause. I ...
0
votes
3answers
6k views

How to interpret this autocorrelogram graph?

I am new to statistics. I found a script which makes a autocorrelogram graph(see attached) of spike timings of a neuron. I got the graph but I am not able to interpret it. Matlab Code below. ...
1
vote
1answer
79 views

Statistical test for the difference in center positions of two receptive fields

I am a neuroscientist, and have neuronal response measurements for a large range of stimuli delivered to my subjects. I use this data to construct receptive fields (RFs), which show the mean response ...
18
votes
4answers
2k views

Non-transitivity of correlation: correlations between gender and brain size and between brain size and IQ, but no correlation between gender and IQ

I found a following explanation on a blog and I would like to get more information about the non-transitivity of correlation: We have the following indisputable facts: On average, there is ...
1
vote
1answer
2k views

Sparse coding vs. sparse PCA, are they the same thing?

Are they the same thing? If not, could someone possibly explain the difference or point to the seminal papers describing the approaches? I am looking not for a detailed technical exposition, but a ...
19
votes
2answers
16k views

How to interpret PCA on time-series data?

I am trying to understand the use of PCA in a recent journal article titled "Mapping brain activity at scale with cluster computing" Freeman et al., 2014 (free pdf available on the lab website). They ...