I am trying to understand the mental processes that enable humans and animals to visually detect objects and discriminate one from another. I develop quantitative models and use simulations to predict the data from a variety of experiments on these matters.

Research in my laboratory has focused on visual discrimination and information processing in pigeons. I have been interested in such things as expectation and attention, stimulus features and dimensions, and the effects of context and memory load on recognition after short delays. Though I no longer do experiments, I have been using quantitative models to analyze and predict extensive existing data on the course of conditioning, reaction time, and other behavioral measures from animal subjects. The work also makes contact with a large amount of research on human cognition. The current goal is to construct a unified model that accounts for both (1) the many stimulus-related phenomena of classical and instrumental conditioning and (2) the patterns of reaction time that accompany the ongoing discrimination among stimuli.

My lab had continuous grant support for research from 1958 to 2010 through the National Institute of Mental Health (NIMH) and the National Science Foundation. I have not applied for support this year.

Blough, D. S. (in press) Reaction-time explorations of visual perception, attention and decision in pigeons. In E. Wasserman & T. Zentall (Eds), Comparative Cognition: Experimental Explorations of Animal Intelligence, Ch. 5. New York, NY: Oxford Univ.

Blough, D. S. (2004) Reaction time signatures of discriminative processes: Differential effects of stimulus similarity and incentive. Learning & Behavior, 32, 157-172

Blough, D. S. (2002) Measuring the search image: Expectation, detection and recognition in pigeon visual search. Journal of Experimental Psychology: Animal Behavior Processes, 28, 397-405

Blough, D. S. (2001) The perception of similarity. In R. B. Cook (Ed) Avian Visual Cognition cyber-book at http://www.pigeon.psy.tufts.edu/avc/toc.htm.

Blough, D. S. (2001) Some contributions of signal detection theory to the analysis of stimulus control in animals. Behavioural Processes, 54, 127-136.

Blough, D. S. (2000) Effects of priming, discriminability and reinforcement on reaction-time components in pigeon visual search. Journal of Experimental Psychology: Animal Behavior Processes, 26, 50-63.

Blough, D. S. (1998) Context reinforcement degrades discriminative control: A memory approach. Journal of Experimental Psychology: Animal Behavior Processes, 24, 1-15.

Lacourse, D. M. & Blough, D. S. (1998) Effects of discriminability, probability of reinforcement, and handling cost on visual search and prey choice. Animal Learning & Behavior, 26, 290-298.

Blough, D. S. & Blough, P. M. (1997) Form perception and attention in pigeons. Animal Learning & Behavior, 25, 1-20.

Blough, D. S. (1996) Error factors in pigeon discrimination and delayed matching. Journal of Experimental Psychology: Animal Behavior Processes, 22, 118-131

Blough, D. S. (1993 b) Effects on search speed of the probability of target-distractor combinations. Journal of Experimental Psychology: Animal Behavior Processes, 19, 231-243.

Fujita, K., Blough, D.S. & Blough, P.M. (1993). Effects of the inclination of context lines on perception of the Ponzo illusion by pigeons. Animal Learning & Behavior, 21, 29-34

Blough, D. S. (1993 a). Reaction time drifts identify objects of attention in pigeon visual search. Journal of Experimental Psychology: Animal Behavior Processes, 19, 107-120.

Blough, D. S. (1992) Features of forms in pigeon perception. In W. Honig & G. Fetterman (Eds.), (pp. 263-277) Cognitive Aspects of Stimulus Control. Hillsdale, NJ: Erlbaum.

Blough, D. S. (1992) Effects of stimulus frequency and reinforcement variables on reaction time. Journal of the Experimental Analysis of Behavior, 57, 47-50

Fujita, K., Blough, D. S. & Blough, P. M. (1991) Pigeons see the Ponzo illusion. Animal Learning & Behavior, 19, 283-293

Blough, D. S. (1991) Perceptual analysis in pigeon visual search. In G. Lockhead & J. Pomerantz (Eds), The Perception of Structure. (pp 213-226) Washington, DC: American Psychological Assn.

Blough, D. S. & Blough, P. M. (1990) Reaction time assessments of visual perception in pigeons. In M. Berkley & W. Stebbins (Eds), Comparative Perception, pp. 245-276. New York: Wiley.

Blough, D. S. (1989) Form similarity and categorization in pigeon visual search. In Commons, M. L., Kosslyn, S. M. & Herrnstein, R. J. Quantitative Analyses of Behavior, VIII: Pattern Recognition and Concepts in Animals, People, and Machines, 129-143. Hillsdale, NJ: Erlbaum.

Allan, S. E. & Blough, D. S. (1989) Feature-based search asymmetries in pigeons and humans. Perception and Psychophysics, 46, 456-464.

Blough, D. S. (1989) Odd-item search in pigeons: display size and transfer effects. J. Experimental Psychology: Animal Behavior Processes, 15, 14-22.

Blough, P. M. & Blough, D. S. (1989) Visual effects of opiates in pigeons: II. Contrast sensitivity to sinewave gratings. Psychopharmacology, 97, 85-88.

Blough, P. M. & Blough, D. S. (1989) Visual effects of opiates in pigeons: I. Target location in visual search. Psychopharmacology, 97, 80-84.

Blough, D. S. (1989) Contrast as seen in visual search reaction times. Journal of the Experimental Analysis of Behavior, 52, 199-211.

Blough, D. S. (1988) Quantitative relations between visual search speed and target-distractor similarity. Perception & Psychophysics, 43, 57-71.

Blough, D. S. (1987) Counterpoint. J. of the Experimental Analysis of Behavior, 48, 468-469.

Blough, D. S. (1986) Odd-item search by pigeons: Method, instrumentation, and uses. Behavior Research Methods, Instruments, & Computers, 18, 413-419

Blough, D. S. & Franklin, J. (1985) Pigeon discrimination of letters and other forms in texture displays. Perception & Psychophysics, 38, 523-532

Blough, P.M. & Blough, D. S. (1985) Sequential effects in dimensional contrast. Journal of the Experimental Analysis of Behavior, 44, 233-244

Blough, D. S. (1985) Discrimination of letters and random dot patterns by pigeons and humans. Journal of Experimental Psychology: Animal Behavior Processes, 11, 261-280

Blough, D. S. (1985) Behavioral psychophysics. In Encyclopedia of Science and Technology (Sixth Edition). New York: McGraw Hill .

Blough, D. S. (1984) Form recognition in pigeons. In Roitblat, Bever, & Terrace (Eds.), Animal Cognition, New York: Columbia University Press.

Blough, D. S. (1983) Alternative accounts of stimulus control. In Commons, Herrnstein, and Wagner (Eds.), Quantitative Analysis of Behavior, Vol. 4: Acquisition II. New York: Ballinger.

Todrin, D. C., & Blough, D. S. (1983) The discrimination of mirror-image forms by pigeons. Perception & Psychophysics, 34, 397-402.

Uhlrich, D. J., Blough, P. M., & Blough, D. S. (1982) The pigeon's distant visual acuity as a function of viewing angle. Vision Research, 23, 429-431.

Blough, D. S. (1982) Pigeon perception of letters of the alphabet. Science, 218, 397-398.

Blough, D. S. (1979) Effects of the number and form of stimuli on visual search in the pigeon. Journal of Experimental Psychology: Animal Behavior Processes, 5, 211-223.

Blough, P. M., & Blough, D. S. (1978) The reaction-time/luminance relationship for pigeons to lights of different spectral compositions. Perception & Psychophysics, 23, 468-474.

Blough, D. S. (1978) Reaction times of pigeons on a wavelength discrimination task. Journal of the Experimental Analysis of Behavior, 30, 133-137

Blough, D. S. & Blough, P. M. (1977) Animal psychophysics. In Honig & Staddon (Eds.), Handbook of Operant Behavior. Englewood Cliffs, NJ: Prentice-Hall.

Blough, D. S. (1977) Photoelectric recording of pigeon-peck responses to computer driven visual displays. Behavior Research Methods & Instrumentation, 9, 259-262.

Blough, D. S (1977) Visual search in the pigeon: Hunt and peck method. Science, 196, 1013-1014.

Essock, S. M., & Blough, D. S. (1977) Effects of stimulus spacing on steady state gradients of inhibitory stimulus control. Animal Learning and Behavior, 5, 174-176.

Blough, D. S. (1975) Steady-state data and a quantitative model of operant generalization and discrimination. Journal of Experimental Psychology: Animal Behavior Processes, 104, 3-21.

Zuckerman, D. C., & Blough, D. S. (1974) Conditional discrimination in the goldfish. Animal Learning and Behavior, 2, 215-217.

Blough, D. S. (1973) Two-way generalization peak shift after two-key training in the pigeon. Animal Learning and Behavior, 1, 171-174.

Blough, D. S. (1972) New light on a Pavlovian idea: Review of R. A. Boakes & M. S. Halliday (Eds.) "Inhibition and Learning". Science, 178, 295-296.

Blough, D. S. (1972) Recognition by the pigeon of stimuli varying in two dimensions. Journal of the Experimental Analysis of Behavior, 18, 345-367

Blough, D. S., & Yager, D. (1972) Visual psychophysics in animals. In Jameson and Hurvich (Eds.), Visual Psychophysics, Vol. VII/4, Berlin: Springer-Verlag.Blough, D. S., & Blough, P. M. (1977) Animal Psychophysics. In Honig (Ed.), Operant Behavior, New York: Appleton-Century-Crofts.

Blough, D. S., & Lipsitt, P. (1971) The discriminative control of behavior. In J. W. Kling and L. A. Riggs (Eds.), Experimental Psychology. New York: Holt, Rinehart and Winston, Pp. 743-792.

Blough, D. S. (1969) Generalization gradient shape and summation in steady-state tests. Journal of the Experimental Analysis of Behavior, 12, 91-104.

Blough, D. S. (1969) Attention shifts in a maintained discrimination. Science, 166, 125-126.

Blough, P.M., & Blough, D. S. (1968) The distribution of interresponse times in the pigeon during variable-interval reinforcement. Journal of the Experimental Analysis of Behavior, 11, 23-27.

Blough, D. S. (1967) Stimulus generalization as a signal detection in pigeons. Science, 158, 940-941.

Blough, D. S. (1966) The study of animal sensory processes by operant methods. In Honig (Ed.), Operant Behavior: Areas of Research and Application, New York: Appleton-Century-Crofts.

Schrier, A. M., & Blough, D. S. (1966) Photopic spectral sensitivity of macaque monkeys. Journal of Comparative and Physiological Psychology, 62, 457-458.

Blough, D. S. (1966) The reinforcement of least-frequent interresponse times. Journal of the Experimental Analysis of Behavior, 9, 581-591.

Blough, D. S., & Millward, R. M. (1965) Learning: Operant conditioning and verbal learning. In Annual Review of Psychology, Vol. 16, Palo Alto: Annual Reviews.

Blough, D. S. (1965) Definition and measurement in generalization research. In D. Mostofsky (Ed.) Stimulus Generalization, Palo Alto: Stanford University Press.

Blough, D. S., & Blough, P. M. (1964) Experiments in Psychology: Laboratory Studies of Animal Behavior. New York: Holt, Rinehart & Winston.

Schrier, A. M., & Blough, D. S. (1963) Psychophysical studies of vision in monkeys. In Proceedings of the Conference on Research with Primates Beaverton, Oregon: Tektronix.

Blough, D. S. (1963) Interresponse time as a function of continuous variables: A new method and some data. Journal of the Experimental Analysis of Behavior, 6, 237-246.

Blough, D. S., & Schrier, A. M. (1963) Scotopic spectral sensitivity in the monkey. Science, 139, 493--494.

Blough, D. S. (1961) Animal psychophysics. Scientific American, 205, 113-122.

Blough, D. S. (1961) The shape of some wavelength generalization gradients, Journal of the Experimental Analysis of Behavior, 4, 31-40.

Blough, D. S. (1961) Review of M. Sidman "Tactics of Scientific Research" Contemporary Psychology, 6 279-280

Blough, D. S. (1959) Generalization and preference on a stimulus intensity continuum. Journal of the Experimental Analysis of Behavior, 2, 307-317.

Blough, D. S. (1959) Delayed matching in the pigeon. Journal of the Experimental Analysis of Behavior, 2, 151-160.

Blough, D. S. (1958) A rise in the pigeon's threshold with a red test stimulus during dark adaptation. Journal of the Optical Society of America, 48, 274.

Blough, D. S. (1958) New test for tranquilizers. Science, 127, 586-587.

Blough, D. S. (1958) A method for obtaining psychophysical thresholds from the pigeon. Journal of the Experimental Analysis of Behavior, 1, 31-43.

Verplanck, W. S., & Blough, D. S. (1958) Randomized stimuli and the non-independence of successive responses at the visual threshold. Journal of General Psychology, 59, 263-272.

Blough, D. S. (1957) Effects of drugs on visually controlled behavior in pigeons. In S. Gartattini and V. Ghetti (Eds.), Psychotropic Drugs. Amsterdam: Elsevier; New York: Van Nostrand

Blough, D. S. (1957) Spectral sensitivity in the pigeon. Journal of the Optical Society of America, 47, 827-833.

Blough, D. S. (1957) Some effects of drugs on visual discrimination in the pigeon. Annals of the New York Academy of Science, 66, 733-739.

Blough, D. S. (1957) Effect of lysergic acid diethylamide on absolute visual threshold of the pigeon. Science, 126, 304-305.

Blough, D. S. (1956) Technique for studying effects of drugs on discrimination in the pigeon. Annals of the New York Academy of Science, 65, Art. 4, 334-344.

Blough, D. S. (1956) Dark adaptation in the pigeon. Journal of Comparative and Physiological Psychology, 49, 425-430.

Verplanck, W. C., & Blough, D. S. (1955) An apparatus for the presentation of visual stimuli at low intensities. Journal of General Psychology, 53, 67-77.

Blough, D. S. (1955) Method for tracing dark adaptation in the pigeon. Science, 121, 703-704.

Ratliff, F., & Blough, D. S. Behavior studies of visual processes in the pigeon. USN, ONR, Technical Report, 1954

Blough, D. S. Dark adaptation in the pigeon. Doctoral dissertation, Harvard University, 1954.

Sigma Xi, Phi Beta Kappa, election in 1951
American Academy of Arts and Sciences, election in 1962
Society of Experimental Psychologists, election in 1968
Comparative Cognition Society Research Award, 2004
Fellow, American Psychological Assn., Divs. 3 & 25
Fellow, American Assn. for the Advancement of Science
Edgar J. Marston Chair, Brown University 1980 -
Chair, Board of Governors, Psychonomic Society, 1987

Research review panels:
1963-67 Psychobiology Review Panel, National Science Foundation (NSF)
1968-72 Small Grants Review Committee, National Institute of Mental Health (NIMH)
1975-79 Experimental Psychology Research Review Committee, then Basic Behavioral Sciences
Review Committee, NIMH (Chair, 1977-79)
1987 Special review panel, Basic Behavioral Sciences Committee, NIMH
Editorial service:
1958-70 Editorial Board, Journal of the Experimental Analysis of Behavior
1971-73 Associate Editor, Animal Learning and Behavior
1976-81 Board of Editors, Journal of Experimental Psychology: Animal Behavior Processes
1981-1985 Editor, Journal of Experimental Psychology, Animal Behavior Processes
1997 - - Consulting Editor, Animal Learning and Behavior
Frequent ad-hoc reviewer for various journals

Service in professional organizations:
Board of Directors, Society for the Experimental Analysis of Behavior, 1957-1970
Board of Directors, Eastern Psychological Association, 1977-81 and 1982-85
Board of Governors, Psychonomic Society, 1981-87;
Chair, 1987
Publications Committee, Psychonomic Society, 1986-90
Chair, 1989-90

Professional affiliations:
American Academy of Arts & Sciences
American Association for the Advancement of Science (Fellow)
American Psychological Association (Fellow)
American Psychological Society
Comparative Cognition Society
Eastern Psychological Association
Psychonomic Society