**Introduction to Neural Networks
U. of Minnesota, Final Study Guide
Psy 5038
Fall, 2014
**The final
exam will primarily cover material from the second half of the semester.

**Sample short answer questions
**Define and describe the relation of the following key words or phrases to
neural networks. Provide examples where appropriate.(Answer 8 out of 12 items
drawn from set below; 3 points each).

K-means | topographic representation | "S" vs. "C" units | EM |

Gibbs sampling | Oja's rule | principal components analysis | sparse distributed representation |

directed vs. undirected graph | K-nearest neighbor classifier | "explaining away" | support vector machine |

grandmother cell | Bayesian optimal cue integration | encoder network | topology-preserving map (Kohonen) |

contingent adaptation | cortical maps | loss and risk functions | belief propagation |

MAP estimation | MCMC | logistic regression |
anti-Hebbian |

Bayesian decision theory | projective field | bidirectional processing | coarse coding |

marginalization & conditioning | "features of intermediate complexity" | rejection sampling | MRF |

**Sample essay questions
**(choice of 2 essays drawn from those listed below; 12 points
each).

Discuss the pros and cons of distributed vs. localized representations with examples from theoretical considerations and neurophysiology (e.g. Quiroga et al., 2005).

Explain how Belief Propagation can be used to interpolate a function given sparse data.

Give an account of just one of the following approaches to self-organization: a) Kohonen, 1982; or b) principal components for dimensionality reduction.

Discuss how probabilistic information might be represented in a population of neurons, and how that information could be used for optimal inference (Pouget et al. 2006; Knill and Pouget, 2004; Ma, 2012).

Describe the Metropolis-Hastings algorithm.

What is a mixture model? How can EM be used to estimate the parameters of the model?

Describe and discuss Serre et al's (2007) feedforward model of recognition. Could it help to explain Kirchner & Thorpe's 2006 result?

Describe and discuss Ullman et al's (2002) feedforward model of recognition. Explain how to extend this to a bidirectional model of visual recognition (Epshtein et al., 2008).

What are possible computational functions of bidirectional processing between cortical areas? (see Bullier , 2001; Kersten & Yuille, 2014)

Explain how the Kalman filter can be used to model neural processing or behavior (Rao & Ballard 1999 or Wolpert et al. 1995).