A stimulus is detected by a receptor and the response is salivation. How many synapses are involved in the reflex pathway? Assume the sensory neuron has a receptor membrane and that there is an integrating neuron. 

A certain system uses two-factor authentication. Let the first method be A1 and the second one  A2. Also, assume that the guessing entropy for A1 is e1 bits and the guessing entropy for A2 is e2 bits.  A1 and A2 are defined to be independent if e1 and e2 do not depend on each other. Consider the password-hardening paper discussed in class. The use of a password is method A1 which has entropy e1. A2 is defined by the keystroke timing-derived hardening features and it provides entropy e2. Are these two factors (A1 and A2) independent of each other? What is an upper bound on the entropy that can be provided by this method? Provide your answer as a function of e1 and e2. Explain your answer.  (2+2+4pts.) Assume in a system, more accurate recording of timing is possible and users can be categorized as really fast, fast, slow, and really slow. Thus, multiple thresholds will be defined to determine which of these describes the timing of a certain feature of a user. Can this higher accuracy of keystroke timing be used to develop a more secure password-hardening authentication method? How will the instruction table be defined when these new feature values are used?  If the password is n characters long, what will be the size of the instruction table in this system? What would be the best case hardening entropy (entropy only due to the keystroke timing and pressure-derived features) in this system?  (2+2+4+4 pts.) As users gain more experience typing the same password, they tend to type it faster. Assume users are slow when a new password is chosen, but the password typing pattern changes and they become fast soon after a new password is chosen. Also, passwords are not changed frequently. Assume an attacker has knowledge of such typing behavior of users. The attacker gains access to Bob’s instruction table and history files but does not know when Bob’s current password was first used.  Explain the strategy that should be used by the attacker to choose shares in the instruction table to minimize the computational effort required for reconstructing the hardened password to gain access to Bob’s account.  (4 pts.)

A bookstore recorded the method of payment used by customers in a single day.  Of their 213 customers, 173 used credit cards to pay for their purchases, and the graph below indicates the percentages of the different credit cards used. Which card represents the mode of the data? 

PART III – SHOW ALL WORK FOR THESE QUESTIONS!

This question uses the same information as the previous question. The scores on a test have been organized into the stem-and-leaf plot below.  What is the mode of this data?  

Which commonly assessed category of cognition as part of neuropsychological evaluation comprises interrelated self-regulatory control processes involved in the selection, initiation, organization, execution, and monitoring of goal-directed behavior?

In psychiatry, which of the following is a common reason to refer a patient for a neuropsychological evaluation?

PART II – Short answer For these questions, fill in the blank with your response.

According to Erikson, if a child does not successfully accomplish the initiative vs. guilt psychosocial stage, which of the following associated virtues will he/she not develop?

Which functional neuroimaging modality measures the level of oxygenation in brain tissue to map the neuroanatomic activation that occurs with various challenges; provides many advantages compared to other functional imaging techniques; and has been used extensively in research involved in psychotic disorders, mood and anxiety disorders, substance-related disorders, neurocognitive and neurodevelopmental disorders, and more recently, the effects of psychotropic medications?