This web page will tell you about my research which is currently funded by an R01 from NICHD and by a K23 (until 2008) from NIDCD (the National Institute on Deafness and Other Communication Disorders, part of the NIH or National Institutes of Health).

To get a quick idea of my research goals you can read the abstracts of my R01 here or of my  Career Development Award (K23), and you can browse through my publications, submitted manuscripts, chapters, and presentations. For more detail you can read some selected abstracts. If  you want to talk to me the best way to contact me is via email at tgollan@ucsd.edu.

To find out where my research program is based you can read about the Alzheimer's Disease Research Center or ADRC and the Language Production Lab or LPL.

The rest of this web page will tell you who I am, about my teaching experience, and about who I work with including students I have mentored.

RESEARCH FRAMEWORK:

  Bilinguals know about twice as many words as monolinguals, and within this roughly doubled knowledge there are many translation equivalents which are pairs of words that mean virtually (if not exactly) the same thing. In monolinguals such word pairs occur only to the extent that within-language synonyms exist (e.g., sofa and couch); for bilinguals, all cross-language translation equivalents may be considered very close synonyms. It would be very surprising if this doubled load didn't produce any difference between bilinguals and monolinguals, and my research suggests that significant differences do exist between groups, although they are subtle, and very specific. The best part about studying bilinguals is that by trying to figure out how bilinguals are different, we get to find out about all kinds of things (e.g., why TOTs happen, how we choose among competing responses, what frequency effects are, what causes people to switch between tasks, etc.).
 
    When compared with monolinguals, bilinguals name pictures more slowly (by about 80 milliseconds; Gollan, Montoya, Fennema-Notestine, & Morris, 2005), have reduced category fluency (i.e., produce fewer words that belong to semantic categories such as Animals and phonemic categories such as words-beginning-with-the-letter-F; Gollan, Montoya, & Werner, 2002), and bilinguals are more likely to have a tip-of-the-tongue or TOT state (Gollan & Silverberg, 2001). TOTs are that frustrating experience you have when you can't remember a word that you are sure you know. Proper names are the most common type of TOT target. If you try to think who wrote the book Animal Farm you might have a TOT for ........George Orwell - or better yet - what was the name of your 10th grade math teacher? ...sorry can't answer that one for you). See Nina Silverberg's web-page for more about TOTs.

    Importantly, bilinguals are disadvantaged relative to monolinguals even when they are tested in their dominant language only. I have also found ways to make differences between bilinguals and monolinguals go away. For example, bilinguals have the same number of TOTs as monolinguals when trying to retrieve words that are similar across languages (e.g., trompeta which is the Spanish word for trumpet; Gollan, Bonanni, & Montoya, 2005), or when retrieving proper names which are also similar across languages (e.g., Tamar is Tamar in both Hebrew and in English). Bilinguals name pictures as quickly as monolinguals if they are given just one extra practice trial with naming a picture (i.e., comparing monolinguals on 2nd naming to bilinguals on 3rd), and bilinguals perform similary to monolinguals on some tasks that don't require a language specific response (e.g., classifying pictures as "human made" or "natural" kinds; Gollan et al., 2005). The appearance of a bilingual disadvantage in some but not in other tasks helps us to understand what sorts of processing is required to complete these tasks, and constrains cognitive models of bilingualism, language processing, and cognitive control more generally. On the flip side of these bilingual disadvantages are a host of obvious advantages that bilingualism entails such as being able to communicate with a broader audience, and diversity of cultural experiences. In addition, bilingualism introduces a number of cognitive processing advantages (e.g., delays age-related decline in cognitive control, delays the onset of Alzheimer's disease) which you can read about by checking out  Ellen Bialystok's research.

    My favorite explanation for the disadvantages associated with bilingualism is simply that bilinguals spend less time using words particular to each language relative to monolinguals because bilinguals use each language only some of the time. In other words, the performance differences may be attributed to differences in patterns of language use (instead of to competition between translation equivalents). This explanation is important for explaining why bilinguals have the most TOTs for words that they only know in just one of their languages (see Gollan & Acenas, 2004). Some other evidence that suggests this account is correct is that bilinguals show bigger frequency effects than monolinguals in picture naming, in addition older bilinguals have an easier time managing some of the increased load associated with bilingualism (e.g., there is no age-related slowing for retrieving low-frequency words in the nondominant language; see Gollan, Montoya, Cera, & Sandoval, in press).

This frequency-of-use story is an alternative to the more typical assumption which is that bilinguals suffer from interference between languages. Although, I agree that both languages are always active, my research questions the idea that translation equivalents are in  constant competition. In fact, my research suggests that translations sometimes can cue each other (i.e., the opposite of competition) in both language comprehension and even in production where competition might be expected. For example, we found that bilinguals name pictures more easily if they know the name in both languages. Currently we are investigating if presenting bilinguals with a translation equivalent will cue them out of a TOT state (e.g., if stuck trying to retrieve the word strawberry does it help if we tell them that the Spanish word is fresa?). The notion that bilinguals suffer from constant interference between langauges is also challenged by the fact that bilinguals voluntarily switch back and forth between languages (see Gollan & Ferreira, submitted). 

CLINICAL APPLICATIONS:

  Many cognitive assessment tools tests rely on language and were not designed for use with bilinguals. My research demonstrates that cognitively normal bilinguals perform differently on some of these tests, and to make matters even more complex, I have found that cognitively intact bilinguals produce an "Alzheimer's-like pattern" on a number of different measures. For example, bilinguals are more disadvantaged on semantic than on letter category fluency (see Gollan, Montoya, & Werner, 2002), name fewer pictures correctly on the Boston Naming Test (see Gollan, Fennema-Notestine, Montoya, & Jernigan, 2007), and produce less typical associations in the free association task than monolinguals (e.g., given bride bilinguals say pretty instead of groom which is the most common response in monolinguals). Such results may suggest a "cognitive abnormality" when none is present; instead they reflect the normal consequences of bilingualism for performance.

Currently, we are trying to determine the best way to test bilinguals for the purpose of identifying cognitive impairment in its earliest stages. Interestingly, some language based measures do not reveal a bilingual disadvantage, and some tests that do not seem to require language do reveal a bilingual disadvantage. For example, preliminary results suggest that bilinguals perform as well as monolinguals on the CVLT-III (California Verbal Learning Test-III) which is a very difficult test in which people try to remember a list of 16 words. However, bilinguals were slower to classify pictures as either "fruit" or "vegetable." We are currently trying to determine if the bilingual disadvantage in fruit/vegetable classification resulted from a covert naming strategy that both bilinguals and monolinguals may employ to do this relatively difficult classification task (difficult because fruits and vegetables look alike). We are also studying whether differences between bilinguals and monolinguals will interfere with the early detection of AD in bilinguals, and we are trying to develop better tests to use for this purpose with bilinguals.

    WHO I AM: I am a cognitive neuropsychologist, and a Hebrew-English-Spanish trilingual. Many of the research projects I direct involve comparing bilinguals to monolinguals with two goals: 1) to identify which tasks bilinguals perform differently, and 2) to develop explanations of the differences and similarities between groups. More broadly speaking, my research is aimed at identifying the cognitive mechanisms underlying young and aging bilingualism, and how clinical assessments of cognitive functioning need to be modified to accommodate bilinguals.

    WHERE I WENT TO SCHOOL: I was an undergraduate at Brandeis University where I studied with Art Wingfield who later connected me to a research assistantship at Massachusetts General Hospital with Scott Sokol who is currently working as a clinical neuropsychologist and cantor (read more about that combination of professions here). I got my Ph.D. in clinical and cognitive psychology from the Univeristy of Arizona or UofA where I worked with Merrill Garrett and Ken Forster. I also worked with visiting professor Ram Frost who helped me run experiments in his lab at the Hebrew University in Jerusalem. Most recently, I was fortunate to have worked with Debby Burke as a post-doc at Pomona college, and to have Judy F. Kroll as a mentor on my career development award.

Name	Research Area	E-mail
Ines Antón-Mendez	grammatical encoding, bilingualism	Ines.Anton-Mendez@let.uu.nl
Alan Brown	tip of the tongue states (TOTs), memory	abrown@mail.smu.edu
Karen Emmorey	psycholinguistics of sign-language	emmorey@lcn.salk.edu
Christine Fennema-Notestine	clinical fMRI, sMRI, memory	fennema@ucsd.edu
Victor S. Ferreira	language production	ferreira@psy.ucsd.edu
Susie Flett	priming and TOTs	susanna.Flett@psy.ox.ac.uk
Matthew Finkbeiner	bilingual lexical access	msf@wjh.harvard.edu
Terry L. Jernigan	clinical fMRI, sMRI, memory	tjernigan@ucsd.edu
Judith F. Kroll	bilingualism	jfk7@psu.edu
Erica B. Michael	bilingualism	emichael@andrew.cmu.edu
Jennie Pyers	psycholinguistics of ASL-English bilingualism	jpyers@wellesley.edu
David P. Salmon	aging, Alzheimer's disease, memory	dsalmon@ucsd.edu
Carson Schutze	syntax, morphology	cschutze@humanities.ucla.edu
Nina Silverberg	TOTs and word substitution errors	silverbergn@mail.nih.gov
Robin Thompson	psycholinguistics of sign-language	thompson@ling.ucsd.edu

Graduate and undergraduate research assistants play a major role in helping me to carry out my research. The students listed below are (or were) especially hard working on one or more research projects and I consider them to be professional colleagues.

Lori-Ann Acenas	Senior Honor's Thesis	lorosace78@yahoo.com
Samel Angulo	Faculty Mentor Program	sangulo@sdcc15.ucsd.edu
Marina Bonanni	Senior Honor's Thesis	mbonanni@law.harvard.edu
Cynthia Cera	Senior Research Assistant	cmcera@gmail.com
Mary Champion	Research Assistant	mary.champion@gmail.com
Cassie Gipson	Faculty Mentor Program	cdgipson@ucsd.edu
Rosa I. Montoya	Senior Research Assistant	icantblevethis@gmail.com
Tiffany Sandoval	Graduate Student; JDP Clinical Psychology	ticasand15@hotmail.com
Grace A. Gengoux (used to be Werner)	Research Project	gwerner@education.ucsb.edu

Here is a current update on some students who have graduated: Lori-Ann became a speech pathologist; Sam obtained teaching credentials and also plans to attend graduate school in psychology; Marina graduated Harvard law and is practicing in LA; Cassie is in graduate school in psychology; Rosa graduated from UCSD, works at the ADRC and plans to go to graduate school; Grace got her PhD at UC, Santa Barbara and is on internship at Yale, Mary graduated from UCSD and is working in the lab.

Introduction to Cognitive Science	Pomona College	Fall 2001 & Fall 2002
Cognition & Disorders: What Deficits Reveal about the Mind/Brain	Pomona College	Spring 2001
Introduction to Psychology	University of Arizona	Fall 1995

Do oysters have legs? An extensively studied patient named AC answered this question with “a few.” This same patient was able to tell that people eat oysters but not kangaroos (see Coltheart chapter). Cognitive impairments come in many shapes and sizes. Each case provides a new test of current models of normal functioning. What is a disorder? It is impossible to answer this question without first knowing what “normal” is.  In this course we will study how cognitive neuropsychologists constrain their theories of normal cognitive functioning by testing patients with processing disorders in object and face recognition; attention and consciousness; accessing words and interpreting sentences; meaning, memory and memory distortions; perception of time, numbers, and music; and planning actions.  COURSE TITLE: Cognition & Disorders; TEXT: "What Deficits Reveal about the Human Mind/Brain: A Handbook of Cognitive Neuropsychology", Psychology Press. (Ed. Brenda Rapp).

this web-page last updated in November, 2007