Areas of Study: Brain, Behavior, and Cognition
The Brain, Behavior, and Cognition program offers a multidisciplinary approach to the study of cognition and brain function. Its aim is to provide students with the theoretical and methodological skills necessary to conduct independent research and to become productive scholars and teachers in this area. Mentorship comes from nine faculty members in Psychology, and can be enhanced by collaboration with faculty from other departments such as Animal and Nutritional Sciences, Biochemistry and Molecular Biology, Linguistics, and Zoology. The faculty in Brain, Behavior, and Cognition offers a wide range of knowledge and experience analyzing behavior and applying the techniques of traditional experimental psychology, psychophysics, and modern neuroscience to the study of related cognitive, perceptual, biological and neurological mechanisms.
Most graduate students work on research projects that are part of a faculty member's on-going research, but students are encouraged to develop independent lines of research. Currently, faculty members have interests in basic memory processes; reading comprehension; psycholinguistics; language development; physiological mechanisms that underlie certain memory, stress, and mood disorders; psychopharmacology; psychoneuroimmunology; animal learning and behavior; comparative psychology; basic visual processes including spatial and temporal properties of stereopsis illusions, color vision, and physiological optics.
Animal labs include a variety of computer-controlled apparatus for training diverse behavioral tasks. These include a Morris water maze, video tracking system for open field, automated radial arm mazes, swim stress apparatus, chambers for olfactory discrimination and memory, rodent operant chambers for training DM and DNM with retractable levers, avian operant chambers with video displays and touchscreens, serial reaction task chambers, and shuttle boxes. Additional behavioral apparatus include measures of motor function, analgesia, behavioral despair, and fear conditioning. The labs are well-equipped for stereotaxic surgery, histology, light-microscopy and image analysis, intracranial infusion of drugs, neurochemistry and receptor binding studies, assessment of immune function, and stress-controllability programs.
Vision labs are equipped with a four-channel xenon-arc-based Maxwellian view optical system, a computer-based stereo Maxwellian view optical system, and a two-channel rear projection free-view optical system.
Cognitive labs consist of state-of-the-art computers and associated equipment.
R e s e a r c h P r o j e c t s
Robert Drugan / Kenneth Fuld / Brett Gibson / Andrew Leber / John Limber / Robert Mair / Jill McGaughy / Edward O'Brien / William Wren Stine
Robert Drugan
Stress Controllability And Drug Reactivity
Although the central nervous system (CNS) sites of action of minor tranquilizers are well understood, it is unclear how emotion or stress can alter the effects of these compounds. My research examines the influence of stress on the behavioral reactivity to such compounds as alcohol and valium. Using shock-, swim- and restraint-stress and a rotarod treadmill for measuring motor incoordination, we have shown that the nature of the stress and stress controllability markedly influence the ataxic potency of these compounds. We have also evaluated sex differences in these measures of intoxication. We plan on complementing the above findings with in vitro radioligand receptor binding analysis of the benzodiazepine/GABA receptor in the near future.
Drugan, R.C., Wiedholz, L.M., Holt, A., Kent, S. & Christianson, J.P. (in press). Environmental and immune stressors enhance alcohol-induced motor ataxia in rat. Pharmacology, Biochemistry and Behavior.
Drugan, R. C., Coyle, T. S., Healy, D. J., & Chen, S. (1996). Stress controllability influences the ataxic properties of both ethanol and midazolam in the rat. Behavioral Neuroscience, 110(2), 360-367.
Stress Controllability And Learning And Memory
Exposure to inescapable stress has been shown to interfere with subsequent learning and memory. We have developed a new stress controllability paradigm using forced swimming as the stressor. We have tested the effects of stress and coping in this new paradigm on standard shuttle-escape learning as well as navigational learning and memory in a Morris water maze task. We find fundamental differences between our new model and the standard shock stress controllability paradigm. We are currently exploring the parameters necessary for these differences.
Drugan, R.C., Christianson, J.P., Stine, W.W., and Soucy, D.P. (2009) Swim stress-induced ultrasonic vocalizations forecast resilience in rat. Behavioral Brain Research, 202: 142-145.
Christianson, J. P. and Drugan, R. C. (2005) Intermittent cold water swim stress increases immobility and interferes with escape performance in rat. Behavioral Brain Research, 156 (1): 58-62.
Drugan, R. C., Eren, S., Hazi, A., Silva, J., Christianson, J. P., and Kent, S. (2005) Impact of water temperature and stressor controllability on swim stress-induced changes in body temperature, serum corticosterone, and immobility in rats. Pharmacology, Biochemistry and Behavior, in press.
Psychoneuroendocrinology/Psychoneuroimmunology
It is clear that stress can alter both the endocrine and immune systems. These systems are critical for our ability to effectively fight off disease. In addition, the nature of stress as well as the ability to cope with stress may affect these two systems. We are currently testing out new swim stress model on endocrine and immune endpoints including corticosterone and cytokine production in plasma. We find some similarities and some differences between our new model and the standard shock stress model. We are currently investigating the parametric aspects of our paradigm to uncover etiology of these differences.
Levay, E. A., Govic, A., Hazi, A., Flannery, G., Christianson, J. P. Drugan, R. C., and Kent, S. (2006) Endocrine and immune correlates of behaviorally identified swim stress resilient and vulnerable rats. Brain, Behavior and Immunity, 20, 488-497.
Brown, P.L., Hurley, C., Repucci, N., and Drugan, R.C. (2001)Behavioral Analysis Of Stress Controllability Effects In A New Swim Stress Paradigm. Pharmacology, Biochemistry And Behavior, 68: 263-272.
Austin, M., Myles, V., Brown, P.L., Mammola, B. and Drugan, R.C. (1999). FG-7142 And Restraint-Induced Alterations In The Ataxic Effects Of Alcohol And Midazolam Are Time Depedent. Pharmacology, Biochemistry and Behavior, 62: (1): 45-51.
Drugan, R.C., Coyle, T.S., Healy, D.J. and Chen, S. (1996). Stress Controllability Influences The Ataxic Properties Of Both Ethanol And Modazolam In The Rat. Behavioral Neuroscience, 110 (2): 110-117.
Healy, D.J. & Drugan, R.C. (1996). Escapable Stress Modulates Retention Of Spatial Learning In Rats: Preliminary Evidence Of Neurosteroids. Psychobiology, 24(2): 110-117.
Kenneth Fuld
Macular pigment studies
Light bears the mixed blessing of, on the one hand, providing the necessary stimulus for our sense of vision, but on the other hand, damaging the very biological tissue that is responsible for mediating this sense. Increasing evidence suggests that visible, and perhaps even only moderately intense visible light, has the potential to produce actinic damage to the photoreceptors of the eye and the adjacent retinal pigment epithelium. Furthermore, the deleterious effect of light is thought to be additive. The suggestion has been made that this additive, harmful effect of light may be the basis for age-related macular degeneration (AMD). This disease is one of the leading causes of blindness and, among the elderly, is the most prevalent of the untreatable diseases of blindness. A host of factors have been implicated in the etiology of AMD, including (but not limited to) iris pigmentation, race, sex, cardiovascular variables, exposure to certain chemicals, and diet. There is now growing evidence that macular pigment, a photostable pigment found in and around the fovea, may also play a role in this disease. Specifically, it has been suggested that macular pigment may mitigate the harmful effects of light. Individuals vary in how much of this pigment they have, and it may be that those who have relatively little run the risk of incurring receptor degeneration as a result of (or possibly being independent of) AMD. Our research has been aimed at determining factors that control or are associated with the amount of macular pigment in a given individual. We measure this amount using a non-invasive psychophysical procedure.
In collaboration with Dr. Joanne Curran-Celentano, from the Department of Animal and Nutritional Sciences, we also measure, using high performance liquid chromatography, blood levels of the substances comprising macular pigment. Macular pigment has been identified as consisting of a pair of carotenoids, zeaxanthin and lutein. These are not produced by the body; rather, they are absorbed through one's diet. Perhaps the reason that dietary factors seem to contribute to AMD and related disorders (such as solar retinopathy) is that diet may be partly responsible for the level of macular pigment that an individual has. Little is known about the absorption, transportation, and deposition of dietary carotenoids, and a more specific goal of our research is to examine these processes.
Wenzel, A.J., Sheehan, J.P., Gerweck, C., Stringham, J.M., Fuld, K., & Curran-Celentano, J. (2007). Macular pigment optical density at four retinal loci during 120 days of lutein supplementation. Ophthalmic and Physiological Optics, 27, 329-335.
Wenzel, A. J., Fuld, K., Stringham, J. M., & Curran-Celentano, J. (2006). Macular pigment optical density and photophobia light threshold. Vision Research, 46, 4615-4622.
Wenzel, A. J., Fuld, K., & Stringham, J. M. (2003). Light exposure and macular pigment optical density. Investigative Ophthalmology and Visual Science, 44, 306-309.
Hammond, B. R., Curran-Celentano, J., Judd, S., Fuld, K., Krinsky, N. I., Wooten, B. R., & Snodderly, D. M. (1996). Sex differences in macular pigment optical density: Relation to plasma carotenoid concentrations and dietary patterns. Vision Research, 36, 2001-2012.
Hammond, B. R., Fuld, K., & Snodderly, D. M. (1996). Iris color and macular pigment optical density. Experimental Eye Research, 62, 715-720.
Hammond, B. R., Fuld, K., & Curran-Celentano, J. (1995). Macular pigment density in monozygotic twins. Investigative Ophthalmology and Visual Science, 36, 2531-2541.
Hammond, B. R., & Fuld, K. (1992). Interocular differences in macular pigment density. Investigative Ophthalmology and Visual Science, 33, 350-355.
Photophobia studies
The feeling of discomfort associated with either sustained intense illumination or the sudden and precipitous increase in the intensity of illumination is known as photophobia. In some disease states, photophobia can even occur under moderate or low levels of illumination. Using electromyography and psychophysical methods, we are determining specific stimulus conditions that give rise to this phenomenon.
Wenzel, A. J., Fuld, K., Stringham, J. M., & Curran-Celentano, J. (2006). Macular pigment optical density and photophobia light threshold. Vision Research, 46, 4615-4622.
Stringham, J. M., Fuld, K., & Wenzel, A. J. (2004). Spatial properties of photophobia. Investigative Ophthalmology and Visual Science, 45, 3838-3848.
Stringham, J. M., Fuld, K., & Wenzel, A. J. (2003). Action spectrum for photophobia. Journal of the Optical Society of America A, 20, 1852-1858.
Color Vision Studies
We have focused our research on the achromatic component of color vision (blackness and whiteness). Within the framework of Opponent Colors Theory, we have developed ways of measuring the spectral responsivity of the white-black channel, and we have related this to the color dimension of saturation. Our results so far indicate that saturation can be predicted to a good first approximation by a cone-based, nonlinear, chromatic and achromatic valence model that includes a small contribution from rods.
Kulp, T. D., & Fuld, K. (1995). The prediction of hue and saturation for non-spectral lights. Vision Research, 35, 2967-2983.
Fuld, K. (1991). The contribution of chromatic and achromatic valence to spectral saturation. Vision Research, 31, 237-246.
Kulp, T. D., & Fuld, K. (1989). Black spectral responsivity. Journal of the Optical Society of America A, 6, 1233-1237.
Fuld, K., Otto, T. A., & Slade, C. W. (1986). Spectral responsivity of the white-black channel. Journal of the Optical Society of America A, 3, 1182-1188.
Brett Gibson
Spatial learning and memory
Many animals rely upon navigational systems to move throughout their environment in order to obtain resources for survival. Gibson’s work has examined the nature of the spatial cues that animals learn about during navigation and how these cues interact to control spatial behavior within a navigational system (e.g., landmark navigation). In addition, he has investigated how animals encode and store these spatial cues, and the nature of the spatial representation.
Gibson has also investigated how different navigational systems (e.g., dead reckoning, landmark navigation, motor patterns) interact when an animal is placed in a new environment. Specifically, he has examined whether spatial information entering multiple spatial systems can be acquired in parallel, as a body of literature in the neurosciences suggests, or whether these systems compete for associative control of behavior, as many models of learning would predict. The results from this research may be used to better reconcile the learning and neurobiological literatures.
Gibson, B. M., Wilks, T., & Kelly, D. (in press). Rats learn to use geometry cues during search for a goal. Journal of Comparative Psychology.
Gibson, B. M., Wasserman, E. A., & Kamil, A. C. (in press). Pigeons are efficient travelers when given traveling salesperson problems. Journal of Experimental Psychology: Animal Behavior Processes.
Gibson, B. M., Leichtman, M., Kung, D., Simpson, M. (2007). Use of landmark features and geometry by children and adults during a two-dimensional search task. Learning and Motivation, 38, 89-102.
Gibson, B.M., Juranovich, I., Shettleworth, S. J., Pratt, J., & Klein, R. (2005). Looking for inhibition of return (IOR) in the pigeon. Learning and Behavior, 33(3), 296-308.
Gibson, B. M. & Shettleworth, S. J. (2005). Place vs. response learning revisited: Tests of blocking on the radial maze. Behavioral Neuroscience, 119, 2, 567-586.
Gibson, B. M. & Kamil, A. C. (2005) The use of an operant psychophysical task to examine the spatial discriminative abilities of three Corvid birds. Learning and Behavior, 33,
59-66.
Gibson, B. M. & Shettleworth, S. J. (2003). Competition among spatial cues in a naturalistic food carrying task. Learning & Behavior, 31, 143-159.
Gibson, B. M. & Kamil, A. C. (2001). Tests for cognitive mapping in Clark’s nutcrackers (Nucifraga columbiana). Journal of Comparative Psychology, 115, 403-417.
Gibson, B. M. (2001). Cognitive maps not used by humans (Homo sapiens) during a dynamic navigational task. Journal of Comparative Psychology, 115, 397-402.
Gibson, B. M. & Kamil, A. C. (2001). Search for a hidden goal by Clark’s nutcrackers (Nucifraga columbiana) is more accurate inside than outside a landmark array. Animal Learning & Behavior, 29, 234-249.
Gibson, B. M., Shettleworth, S. J., & McDonald, R. J. (2001) Finding a goal on dry land and in the water: Differential effects of disorientation on spatial learning. Behavioural Brain Research, 123, 103-111.
Categorical learning and foraging
Animals’ sensory systems are flooded with a multitude of complex stimuli. When categorizing these stimuli, an animal can either memorize the individual properties of each stimulus, or use the relationships defining similar stimuli to delineate a group. Gibson’s research has indicated that pigeons will learn to use the identity of the individual items in a display, or the relations among the items in a display to categorize images when both serve as redundant and relevant cues. With respect to foraging, Gibson’s interests include the investigation of Inhibition of Return (IOR) and change detection in animals.
Gibson, B. M., Lazareva, O. F., Wasserman, E. A., Gosselin, F., & Schyns, P. G. (in press). Geons and bubbles: object recognition by pigeons. Current Biology.
Gibson, B. M., Wasserman, E. A., & Cook, R. G. (2006). Not all same-different discriminations are created equal: Evidence contrary to a unidimensional account of same-different learning. Learning and Motivation, 37, 189-208.
Gibson, B. M., Wasserman, E. A., Gosselin, F. & Schyns, P.G. (2005). Pigeons and people discriminate human faces using similar features. Journal of Experimental Psychology: Animal Behavior Processes, 31(3), 376-382.
Gibson, B. M. & Wasserman, E. A. (2004). Time-course of control by identity and relational cues during same-different discrimination training. Learning & Behavior, 32, 183-189.
Gibson, B. M. & Wasserman, E. A., Frei, L., & Miller, K. (2004). Recent advances in operant conditioning technology: A versatile and affordable computerized touchscreen system. Behavior Research Methods Instruments and Computers.
Gibson, B. M. & Wasserman, E. A. (2003). Pigeons learn stimulus identity and stimulus relations when both serve as redundant, relevant cues during same-different discrimination training. Journal of Experimental Psychology: Animal Behavior Processes, 29, 84-91.
Andrew Leber
Attentional Control
Our senses (e.g., vision, hearing, etc.) are among the most remarkable gifts of nature, as they grant us the ability to collect a nearly limitless amount of information from our environment. However, with the obvious benefits comes a problem: we are severely limited in how much of the information we can consciously process simultaneously. For a simple example, notice the impossibility of listening to two people speaking at once. As a result of our processing limitations, we must develop and employ strategies to selectively attend to the information that is most relevant to our behavioral goals while ignoring the information that is not. Attention researchers have made great progress in identifying what kinds of strategies can be used; however, little work has been done to predict when and how these strategies are used. In my research, I have participated in attempts to address this gap in our understanding.
Leber, A.B., Kawahara, J. -I., & Gabari, Y. (in press). Long-term, abstract learning of attentional set. Journal of Experimental Psychology: Human Perception and Performance.
Folk, C. L., Leber, A. B., & Egeth, H. E. (2008). Top-down control settings and the attentional blink: Evidence for non-spatial contingent capture. Visual Cognition, 16 (5), 616-642.
Lamy, D., Carmel, T., Egeth, H. E., & Leber, A. B. (2006). Effects of search mode and inter-trial priming on singleton search. Perception & Psychophysics, 68 (6), 919-932.
Leber, A. B., & Egeth, H. E. (2006). Attention on autopilot: Past experience and attentional set. Visual Cognition, 14, 565-583.
Leber, A. B., & Egeth, H. E. (2006). It’s under control: Top-down search strategies can override attentional capture. Psychonomic Bulletin & Review, 13 (1), 132-138.
Serences, J., Shomstein, S., Leber, A. B., Golay, X., Egeth, H. E, & Yantis, S. (2005). Coordination of voluntary and stimulus-driven attentional control in human cortex. Psychological Science, 16 (2), 114-122.
Lamy, D., Leber, A., & Egeth, H. E. (2004). Effects of stimulus-driven salience within feature search mode. Journal of Experimental Psychology: Human Perception and Performance, 30 (6), 1019-1031.
Folk, C. L., Leber, A. B., & Egeth, H. E. (2002). Made you blink! Contingent attentional capture produces a spatial blink. Perception & Psychophysics, 64 (5), 741-753.
Cognitive Flexibility
The demands of our daily routines dictate that we constantly switch from one task to another. Consider that a quick five-minute session at your computer may entail rapid juggling between emailing your boss, instant messaging a friend, and perhaps even working on a paper. While we are quite apt at fluidly transitioning from one task to another, there are real costs -- in both speed and accuracy – for switching (e.g., sending your boss the less-than-professional email that was intended for a friend). What mechanisms underlie these costs? Can we predict variations in one's degree of flexibility over time? With my collaborators, I have been primarily using functional MRI to address these questions.
Leber, A. B., Turk-Browne, N. B., & Chun, M. M. (2008). Neural predictors of moment-to-moment fluctuations in cognitive flexibility. Proceedings of the National Academy of Sciences, USA, 105 (36), 13592-13597.
John Limber
(*not currently accepting new students)
Human language is one of the cornerstones of modern cognitive science. The study of language cuts across many of the old "areas" of psychology--perception, cognition, social, and the neurosciences. My specific interests have focused on the use, development, and evolution of human language--along with related topics of animal communication, cognitive development, and consciousness. Many of the students who have worked closely with me have developed their own teaching and research specialties over a range of topics including child development, experimental psychology, history of psychology, psycholinguistics, research methods, and reading.
I invite you to learn more about my teaching and research interests by visiting my webpage: http://pubpages.unh.edu/~jel/
Robert Mair
Thalamic control of cognitive function
The midline and intralaminar thalamic nuclei are organized to exert state-dependent control of cognitive function. They are driven by state-related inputs from arousal, motor, visceral, and somatosensory/nociceptive systems and exhibit increased activity when subjects perform tasks that require attentional effort. Individual nuclei project to restricted areas of frontal cortex, basal ganglia, and the hippocampal system. Clinical studies have implicated these areas in diseases that impair cognition and other aspects of awareness, including schizophrenia, mood disorders, ADHD, amnesia, Parkinson's disease, Huntington's chorea, delirium, dementia, akinetic mutism, and persistent vegetative state.
Our work addresses three related questions:
How do the midline/intralaminar nuclei affect the capacity for attention, memory, and intentional action?
Our early studies showed that thiamine deficiency produces intralaminar lesions and behavioral signs of amnesia that resemble the effects of Korsakoff's disease in humans. Subsequent investigations have shown that lesions of the rostral intralaminar nuclei affect the capacity for working memory and other aspects of executive function mediated by frontal cortex and striatum. Our current interests are directed at differentiating the functions affected by the midline and caudal intralaminar nuclei. We have also begun to use microstimulation methods to study the effects of activating discrete areas of medial thalamus in rats performing tasks that measure specific aspects of attention and memory.
How are the functions of the midline/intralaminar nuclei related to the brain systems they innervate?
The midline/intralaminar nuclei are the main source of thalamic input to striatum and are reciprocally connected to all areas of frontal cortex. The ventral midline nuclei are the main thalamic input to hippocampus and represent the most direct route for prefrontal cortex to influence hippocampal activity. We have carried out a series of studies examining the effects of discrete lesions in frontal cortex, the basal ganglia, and the hippocampal system on behavioral tasks known to be sensitive to rostral intralaminar lesions. Our current interests are directed at extending this research to functions mediated by other parts of the midline/intralaminar complex.
How are the functions of the midline/intralaminar nuclei influenced by nonspecific arousal systems?
We are using a combination of neurotransmitter-specific lesions and microinjection studies to examine the influence of cholinergic, monoaminergic, and peptidergic systems that innervate the midline/intralaminar nuclei. The goals of this work are to understand the role of these systems in the state-dependent control of cognition and to explore the utility of treating cognitive disorders by stimulating the midline/intralaminar nuclei.
Bailey, K.R. & Mair, R.G. (2007). Effects of frontal cortex lesions on action sequence learning in the rat. European Journal of Neuroscience 25, 2905-2915.
Newman, L.A. & Mair, R.G. (2007) Cholinergic modulation of visuospatial responding in central thalamus. European Journal of Neuroscience 26, 3543-3552.
Bailey, K.R. & Mair, R.G. (2006) The role of striatum in initiation and execution of learned action sequences in rats. The Journal of Neuroscience 26, 1016-1025.
Mair, R.D, Zhang, Y.P., Toupin, M.M., Bailey, K.A., & Mair, R.G.. (2005). Effects of clonidine in the locus coeruleus on measures of prefrontal- and hippocampal-dependent dependent measures of attention and memory in the rat. Psychopharmacology 181, 280-288.
Bailey, K.R. & Mair, R.G. (2005) Lesions of specific and nonspecific thalamic nuclei affect prefrontal cortex-dependent aspects of spatial working memory. Behavioral Neuroscience 119, 410-419.
Zhang, Y.P. Bailey, K.A., Toupin, M.M., & Mair, R.G (2005) Involvement of ventral pallidum in prefrontal cortex-dependent aspects of spatial working memory. Behavioral Neuroscience 119, 399-409.
Bailey, K.R. & Mair, R.G.(2004). Dissociable effects of frontal cortical lesions on measures of visuospatial attention and spatial working memory in the rat. Cerebral Cortex 14, 974-985.
Mair, R.G., Burk, J.A., & Porter, M.C.(2003) Impairment of radial maze delayed nonmatching after lesions of anterior thalamus and parahippocampal cortex. Behavioral Neuroscience 117, 596-605.
Mair, R.G., Koch, J.K., Newman, J.B., & Howard, J.R. & Burk, J.A. (2002) A double dissociation in striatum between serial reaction time and radial maze delayed nonmatching performance in rats. The Journal of Neuroscience 22, 6756-6765.
Mair RG (1994) On the role of thalamic pathology in diencephalic amnesia. Reviews in the Neurosciences 5, 105-140.
McEntee WJ. Mair RG (1990). The Korsakoff Syndrome: A neurochemical perspective. Trends in Neuroscience 13, 340-344.
Jill McGaughy
Cholinergic contribution to memory
Acetylcholine has been shown in electrophysiological studies to produce self-sustained spiking activity in neurons in the entorhinal cortex. Computational modeling and neuroanatomical data support the hypothesis that this activity in the entorhinal cortex may be used to retain novel information over an extended period of time for latter recall without synaptic modification produced by previous exposure. When cholinergic input to the entorhinal cortex is disrupted, new stimuli cause depolarization in the entorhinal cortex but the representation is not sustained and therefore not available for latter recall as tested in a delayed non-match to sample task. The McGaughy lab is working in collaboration with Michael Hasselmo at Boston University to combine behavioral neuroscience studies and computational modeling to understand the function of acetylcholine in the entorhinal and prefrontal cortex in memory.
Neurobiology of attention
Impairments in cognitive functions, specifically attention, are associated with common conditions such as normal aging but may also form the basis of particularly debilitating disorders such as Alzheimer’s dementia and schizophrenia. The effort to understand the neurobiology of attention has justifiably focussed on the cholinergic basal forebrain, but the exact nature of the regulation of this area and how dysfunction in this regulation may influence cognition remains unknown. Studies in rodents have confirmed that the cholinergic basal forebrain is critical to attentional functions and capacities. Recent data suggest that investigations may benefit from shifting focus from the basal forebrain to its neurochemically and neuroanatomically distinct terminal fields. This approach has provided strong evidence that there is a functional heterogeneity among the cholinergic terminals.
Similar to acetylcholine, evidence also supports a similar role of norepinephrine (NE) in mediating cognitive functions such as attention. High levels of tonic firing in the LC, the primary source of NE to the cortex, are correlated with a broadening of attentional scope to assess unexpected changes in the environment. Our recent studies confirmed selective attention deficits following noradrenergic, but not cholinergic deafferention of the frontal cortex.
Using a variety of available neuroanatomical, neurochemical and psychopharmacological techniques, future studies will be aimed at understanding these systems, and how dysfunction in these systems may influence attention.
McCoy, J. G., Tartar, J. L., Bebis, A. C., Ward, C. P., McKenna, J. T., Baxter, M. G., McGaughy, J., McCarley, R. W., Strecker, R. E. (2007). Experimental sleep fragmentation impairs attentional set-shifting. Sleep, 30, 52-60.
McGaughy, J., Dalley, J. W., Morrison, C. H., Everitt, B. J., Robbins, T. W. (2002). Selective behavioral and neurochemical effects of cholinergic lesions produced by intrabasalis infusions of 192 IgG-saporin on attentional performance in a five-choice serial reaction time task. Journal of Neuroscience, 22, 1905-1913.
Dalley, J. W., McGaughy, J., O’Connell, M. T., Cardinal, R. N., Levita, L. and Robbins, T. W. (2001). Distinct changes in cortical acetylcholine and noradrenaline efflux during contingent and non-contingent performance of a visual attentional task. Journal of Neuroscience, 21, 4908-4914.
McGaughy, J, Everitt, B.J., Robbins, T.W., Sarter, M. (2000). The role of cortical cholinergic afferent projections in cognition: impact of new selective immunotoxins. Behavioural Brain Research, 115, 251-263.
McGaughy, J., Decker, M.W., Sarter, M. (1999). Enhancement of sustained attention performance by the nicotinic acetylcholine receptor agonist ABT-418 in intact but not basal forebrain-lesioned rats. Psychopharmacology, 144, 175-182.
McGaughy, J., Sarter, M. (1998). Sustained attention performance in rats with intracortical infusions of 192 IgG-saporin-induced cortical cholinergic deafferentation: effects of physostigmine and FG 7142. Behavioral Neuroscience, 112, 1519-1525.
McGaughy, J., Sandstrom, M., Ruland, S., Bruno, J. P., Sarter, M. (1997). Lack of effects of dorsal noradrenergic bundle on behavioral vigilance. Behavioral Neuroscience, 111, 646-652.
McGaughy, J., Kaiser, T., Sarter, M. (1996). Behavioral vigilance following infusions of 192 IgG-saporin into the basal forebrain: selectivity of the behavioral impairment and relation to cortical AchE-positive fiber density. Behavioral Neuroscience, 110, 247-265.
McGaughy, J., Sarter, M. (1995). Behavioral vigilance in rats: task validation and effects of aging, amphetamine, and benzodiazepine receptor ligands. Psychopharmacology, 117, 340-357.
McGaughy, J., Turchi, J., Sarter, M. (1994). Crossmodal divided attention in rats: effects of chlordiazepoxide and scopolamine. Psychopharmacology, 115, 213-220.
Edward O'Brien
In order to successfully comprehend written discourse, readers must both have quick and easy access to the vast amounts of information necessary to aid interpretation and "fill-in" the gaps. Two major components of the comprehension process are those involved in the activation of the knowledge necessary for comprehension and those involved in the integration of that information. Although these are not necessarily discrete components, they can be examined as such. The primary focus of my program of research has been to gain a better understanding of the activation component.
Cook, A. E., Gueraud, S., Was, C., & O’Brien, E. J. (in press). Foregrounding effects during reading. Discourse Processes.
Gerrig, R. J., & O'Brien, E. J. (2005). The scope of memory-based processing. Discourse Processes, 39, 225-242.
Guéraud, S., & O'Brien, E. J. (Eds.) (2005) Components of comprehension: A convergence between memory-based processes and explanation-based process. Special issue: Discourse Processes, 39(2-3).
Cook, A. E., Myers, J. L., & O’Brien, E. J. (2005). Processing an anaphor when there is no antecedent. Discourse Processes, 39, 101-120.
O’Brien, E. J., Cook, A. E., & Peracchi, K. A. (2004). Updating a situation model: A reply to Zwaan and Madden (2004). Journal of Experimental Psychology: Learning, Memory, and Cognition, 30(1), 289-291.
Peracchi, K. A. & O’Brien, E. J. (2004). Character profiles and the activation of predictive inferences. Memory & Cognition, 32, 1044-1052.
Rizzella, M. L., & O’Brien, E. J. (2002). Retrieval of concepts in Script-Based Texts and Narratives: The influence of general world knowledge. Journal of Experimental Psychology: Learning, Memory, and Cognition, 28(4), 780-790.
Cook, A. E., Limber, J. L., & O’Brien, E. J. (2001). Situation-based context and the availability of predictive inferences. Journal of Memory and Language, 44(2), 220-234.
O’Brien, E. J., Cook, A. E., Derepentigny, K. A. (2001). Psychology of knowledge activation in text comprehension and problem solving. In Smelser, N.J., & Baltes, P.B. (Eds.) International Encyclopedia of the Social and Behavioral Sciences, (pp. 8114-8117). Oxford: Pergamon.
Myers, J. L., Cook, A. E., Kambe, G., Mason, R. A., & O’Brien, E. J. (2000). Semantic and episodic effects on bridging inferences. Discourse Processes, 29, 179-199.
O’Brien, E. J. & Myers, J. L. (1999). Text Comprehension: A view from the bottom up. In Goldman, S.R., Graesser, A.C., & Van den Broek, P. (Eds.) Narrative Comprehension, Causality, and Coherence: Essays in Honor of Tom Trabasso. (pp.35-53). Mahwah, NJ: Lawrence Erlbaum Associates, Inc.
Cook, A. E., Halleran, J. G. & O'Brien, E. J. (1998). What is readily available during reading? A memory-based view of text processing. Discourse Process, 26(2-3), 109-129.
Myers, J. L., & O'Brien, E. J. (1998). Accessing the discourse representation during reading. Discourse Processes, 26(2-3), 131-157.
O'Brien, E. J., Lorch, R.F & Myers, J. L. (1998) Memory-based text processing. Special issue: Discourse Processes.
O'Brien, E. J., Rizzella, M. L., Albrecht, J. E., & Halleran, J. G. (1998). Updating a situation model: A memory-based text processing view. Journal of Experimental Psychology: Learning, Memory and Cognition, 24(5), 1200-1210.
William Wren Stine
Venetian Blind Illusion (Irradiation Stereoscopy)
When one views a set of vertically oriented, black and white bars with both eyes while covering only one eye with a darkened glass (e.g., one lens from a pair of sunglasses), the bars appear to be rotated, much like a set of vertically-oriented Venetian blinds. Though first reported in the mid 40s, only a small number of papers addressing the illusion have been published. We have developed a discrimination technique for measuring the illusion and, using the technique with factorial manipulations of contrast and average luminance, have shown that two of the current theories of the illusion are improbable. We then developed an ideal observer model that showed that a visual system designed to detect edge disparities will see the illusion though the predicted contrast effects are opposite those that we measured. Our current work involves studying the spatial effects of bar width and blur, the illusion¹s temporal characteristics, and the effects of isoluminance.
Stine, W. W., & Hetley, R. S. (2006). A model of perceived bar rotation, the Venetian blind effect, in square-wave gratings as a function of contrast disparity. Perception, 35 Supplement, 10.
Stine, W. W., Hetley, R. S., Hallmark, J., & Filley, E. T. (2004). The Venetian blind effect and Fechner’s paradox: Partitioning luminance and contrast disparity information with square-wave gratings into perceived bar rotation and perceived luminance and contrast. Perception, 33 Supplement, 39.
Stine, W. W., & Filley, E. T. (2003). Inter-ocular contrast-ratio modulation spatial frequency influences the Venetian blind effect in irradiation stereoscopy. Perception, 32 Supplement, 78.
Stine, W. W., & Filley, E. T. (2002). Bias in non-parametric adaptive psychophysical procedures with asymmetric psychophysical functions. Perception, 31 Supplement, 141.
Filley, E. T., & Stine, W. W. (1998). Characterizing the venetian blind effect. Perception, 27 Supplement, 99.
Stine, W. W., & Filley, E. T. (1998). Modeling the venetian blind effect. Perception, 27 Supplement,106.
Kinetic Depth Effect
When one views the shadow of a three-dimensional wire figure rotating, the shadow appears to be that of a three-dimensional rotating wire figure. The visual system can recover the three-dimensional information about the shape of the original figure from the deforming two- dimensional shadow. On occasion, if the stimulus that is used to create the shadow rotates without a shape change, the shadow cast by the stimulus will appear to be that cast by a three- dimensional, rotating stimulus that is changing shape during the rotation. For any given deforming shadow there are an infinite number of figures that could create the shadow. However, if there exists a figure that, when rotated rigidly, will create the shadow, then that figure is unique up to a reflection about the fronto-parallel plane. One can think of the visual system's recovery of three-dimensional information as a choice from among this infinite set of alternatives. We developed a discrimination task in order to measure this choice and found that local shape cues seem to control the choice in the particular stimulus geometry that we used. We have also shown that the results generalize to an infinite class of figures, the choice is probably not governed by the phase relationships of the vertices of the figure, and that stereo information integrates with the local shape cues to constrain the choice to a unique figure. Our efforts are now directed toward studying the role of local shape cues (static monocular depth cues) by directly manipulating their form and the effects of isoluminance.
Sparrow, J. E., & Stine, W. W. (1998). The perceived rigidity of rotating eight-vertex geometric forms: Extracting nonrigid structure from rigid motion. Vision Research, 38, 541-556.