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\begin{document}

\mytitle{10/18/90}

\vspace*{-.25in}
\begin{center} {\large Psycholinguistics} \end{center}

\vspace*{-.25in}
\prob{1}

\subprob{a} The only visual difference between the letter C and the O
is that the C is open and the O is closed. Other than that, they are
very similar. Likewise, in speech there is very little difference
between ba and pa except for the voice onset time. Therefore, by
comparing the categorical perception of the C and O visually is a good
idea since they really only have one difference that distinguishes
them. Thus, just like the ba-pa research showed for voice onset time,
a value of ``closedness'' as it were can be found which separates the
C's from the O's.

\subprob{b} The sequence of visual stimuli would progress from a
normal C to an O by extending the ends of the C closer and closer
together until they meet to form the O. The subjects would see random
visual stimuli from the sequence above and they would be asked to
identify it as a C or an O.

\subprob{c} A graph of results such as the one for the ba-pa categorical
perception would show that the perception of letters is categorical.
That is, if there is a striking separation between what is and isn't
perceived as a C, such that the percentage of people identifying the
visual stimuli as a C drops very rapidly around a certain value of
``closedness''. If, however, there didn't seem to be any average
delineating value between C and non-C and O and non-O, then it could be
reasonably stated that there was no categorical perception of letters.

It is quite possible that there is categorical perception of letters.
Indeed, how do we recognize scrawled letters (when we do)? Most people
have different ways of writing a C, just like most people have different
ways of saying ``ba''. Thus, in order for people to recognize a C for a
C, whether is was produced by a typewriter or by a child, there must be
some sort of categorical perception of letters.

\prob{2}

\subprob{a} The access of ambiguous words is done in parallel. It has
been shown through priming experiments that there is subconscious
awareness of both meanings of an ambiguous word for some period of time
before context or defaulting chooses one meaning over the other.

\subprob{b} In Forster's model, lexically ambiguous words are treated
like any other word insomuch as the bins for the word are searched
normally to find the location of the word in the master lexicon. In the
master lexicon entry for the word, the various meanings of the word are
accessed until one meaning over another is chosen because of context or
default. 

\subprob{c} The language processing system most likely determines the
intended meaning of an ambiguous word by looking at the rest of the
sentence. If, however, there had been some priming or context
immediately preceding the sentence in which the ambiguous word appears,
the meaning of the word which corresponds to this priming or context is
most likely going to be chosen as the intended meaning, at least at
first.

\subprob{d} Priming effects appear to last about 2 milliseconds or so.
This fact doesn't really seem to help the explanation of the use of
priming in ambiguity resolution since the priming effect would most
likely wear off before the sentence with the ambiguous word is
processed. It's hard to see how context or priming effects, which are so
short-lived, could affect ambiguity resolution. Yet it must, since the
context surrounding an ambiguous word should affect its disambiguation.

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