An Initial Training Set-Size Effect on Same/Different Abstract-Concept Learning
Nakamura, T., Wright, A. A., Katz, J. S., Bodily, K. D., & Sturz, B. R.
Journal of Comparative Psychology 2009, 123/1; 79-89 PDF
Three groups of pigeons were trained in a same/different task with 32, 64, or 1,024 color-picture stimuli. They were tested with novel transfer pictures. The training-testing cycle was repeated with training-set doublings. The 32–item group learned the same/different task as rapidly as a previous 8-item group and transferred better than the 8-item group at the 32-item training set. The 64- and 1,024-item groups learned the task only somewhat slower than other groups, but their transfer was better and equivalent to baseline performances. These results show that pigeons trained with small sets (e.g., 8 items) have carryover effects that hamper transfer when the training set is expanded. Without carryover effects (i.e., initial transfer from the 32– and 64–item groups), pigeons show the same degree of transfer as rhesus and capuchin monkeys at these same set sizes. This finding has implications for the general ability of abstract-concept learning across species with different neural architectures.
An fMRI analysis of object priming and workload in the precuneus complex
Korsnes, M. S., Wright, A. A., & Gabrieli, J. D. E.
Neuropsychologia 2008, 46(5), 1454-1462 PDF
Drawings depicting familiar objects and unreal structures were presented twice, and participants (N= 16)
determined whether line drawings were real (familiar) or unreal (unfamiliar). The second presentation (repetition) of a drawing was typically responded to faster and more accurately than the first presentation and was accompanied by reduced activation in occipitotemporal (fusiform) and lateral precuneus regions, and increased activation in medial precuneus regions. The behavioral effects and reduced activations (e.g., lateral precuneus) on the second presentation were less pronounced for unreal objects than for real objects. Activation changes in the medial precuneus – increased activation on repetition and reduced activation for novel unreal objects – was further supported by the increased activation in this area during rest and reduced activation when workload was increased (i.e., processing novel unreal objects). The results from the present study in conjunction with those from several previous studies converge on the conclusion that the occipitotemporal and lateral regions of the precuneus are primarily involved in object priming, whereas the medial portion of precuneus primarily activates and deactivates as a function of workload.
Learning strategies in matching to sample: If-then and configural learning by pigeons
Katz, J. S., Bodily, K. D., Wright, A. A.
Behavioural Processes 2008, 77, 223-230 PDF
Pigeons learned a matching-to-sample task with a split training-set design in which half of the stimulus displays were untrained and tested following acquisition. Transfer to the untrained displays along with no novel-stimulus transfer indicated that these pigeons learned the task (partially) via if-then rules. Comparisons to other performance measures indicated that they also partially learned the task via configural learning (learning the gestalt of the whole stimulus display). Differences in the FR-sample requirement (1 vs. 20) had no systematic effect on the type of learning or level of learning obtained. Differences from a previous study [Wright, A.A., 1997. Concept learning and learning strategies. Psychol. Sci. 8, 119–123] are discussed, including the effect of displaying the stimuli vertically (traditional display orientation) or horizontally from the floor.
Matching-to-sample abstract-concept learning by pigeons
Bodily, K. D., Katz, J. S., & Wright, A. A.
Journal of Experimental Psychology: Animal Behavior Processes 2008, 34, No. 1, 178-184 PDF
Abstract concepts—rules that transcend training stimuli— have been argued to be unique to some species. Pigeons, a focus of much concept-learning research, were tested for learning a matching-to-sample abstract concept. Five pigeons were trained with three cartoon stimuli. Pigeons pecked a sample 10 times and then chose which of two simultaneously presented comparison stimuli matched the sample. After acquisition, abstract-concept learning was tested by presenting novel cartoons on 12 out of 96 trials for 4 consecutive sessions. A cycle of doubling the training set followed by retraining and novel-testing was repeated eight times, increasing the set size from 3 to 768 items. Transfer performance improved from chance (i.e., no abstract-concept learning) to a level equivalent to baseline performance (>80%) and was similar to an equivalent function for same/different abstract-concept learning. Analyses assessed the possibility that item-specific choice strategies accounted for acquisition and transfer performance. These analyses converged to rule out item-specific strategies at all but the smallest set-sizes (3–24 items). Ruling out these possibilities adds to the evidence that pigeons learned the relational abstract concept of matching-to-sample.
An Experimental Analysis of memory processing
Wright, A. A.
Journal of the Experimental Analysis of Behavior 2007, 88. 405-433 PDF
Rhesus monkeys were trained and tested in visual and auditory list-memory tasks with sequences of four travel pictures or four natural/environmental sounds followed by single test items. Acquisitions of the visual list-memory task are presented. Visual recency (last item) memory diminished with retention delay, and primacy (first item) memory strengthened. Capuchin monkeys, pigeons, and humans showed similar visual-memory changes. Rhesus learned an auditory memory task and showed octave generalization for some lists of notes—tonal, but not atonal, musical passages. In contrast with visual list memory, auditory primacy memory diminished with delay and auditory recency memory strengthened. Manipulations of interitem intervals, list length, and item presentation frequency revealed proactive and retroactive inhibition among items of individual auditory lists. Repeating visual items from prior lists produced interference (on nonmatching tests) revealing how far back memory extended. The possibility of using the interference function to separate familiarity vs. recollective memory processing is discussed.
The generalization hypothesis of abstract-concept learning: Learning strategies and related issues in Macaca mulatta, Cebus apella, and Columba livia
Wright, A. A., & Katz, J. S.
Journal of Comparative Psychology 2007, 121, 387-397 PDF
The generalization hypothesis of abstract-concept learning was tested with a meta-analysis of rhesus monkeys (Macaca mulatta), capuchin monkeys (Cebus apella), and pigeons (Columba livia) learning a same/different (S/D) task with expanding training sets. The generalization hypothesis states that as the number of training items increases, generalization from the training pairs will increase and could explain the subjects’ accurate novel-stimulus transfer. By contrast, concept learning is learning the relationship between each pair of items; with more training items subjects learn more exemplars of the rule and transfer better. Having to learn the stimulus pairs (the generalization hypothesis) would require more training as the set size increases, whereas learning the concept might require less training because subjects would be learning an abstract rule. The results strongly support concept or rule learning despite severely relaxing the generalization-hypothesis parameters. Thus, generalization was not a factor in the transfer from these experiments, adding to the evidence that these subjects were learning the S/D abstract concept.
Issues in the comparative cognition of abstract-concept learning
Katz, J. S., Wright, A. A., & Bodily, K. D.
Comparative Cognition and Behavior Reviews 2007, 2, 79-92 PDF
Abstract-concept learning, including same/different and matching-to-sample concept learning, provides the basis for many other forms of “higher” cognition. The issue of which species can learn abstract concepts and the extent to which abstract-concept learning is expressed across species is discussed. Definitive answers to this issue are argued to depend on the subjects’ learning strategy (e.g., a relational-learning strategy) and the particular procedures used to test for abstract-concept learning. Some critical procedures that we have identified are: How to present the items to-be-compared (e.g., in pairs), a high criterion for claiming abstract-concept learning (e.g., transfer performance equivalent to baseline performance), and systematic manipulation of the training set (e.g., increases in the number of rule exemplars when transfer is less than baseline performance). The research covered in this article on the recent advancements in abstract-concept learning show this basic ability in higher-order cognitive processing is common to many animal species and that “uniqueness” may be limited more to how quickly new abstract concepts are learned rather than to the ability itself.
Wright, A. A. & Katz, J. S.
Behavioural Processes 2006, 72, 234-254 PDF
Mechanisms of same/different concept learning by rhesus monkeys, capuchin monkeys, and pigeons were studied in terms of how these species learned the task (e.g., item-specific learning versus relational learning) and how rapidly they learned the abstract concept, as the training set size was doubled. They had similar displays, training stimuli, test stimuli, and contingencies. The monkey species learned the abstract concept at similar rates and more rapidly than pigeons, thus showing a quantitative difference across species. All species eventually showed full concept learning (novel-stimulus transfer equivalent to baseline: 128-item set size for monkeys; 256-item set for pigeons), thus showing a qualitative similarity across species. Issues of stimulus regularity/symmetry, generalization from item pairs, and familiarity processing were not considered to be major factors in the final performances, converging on the conclusion that these species were increasingly controlled by the sample-test relationship (i.e., relational processing) leading to full abstract-concept learning.
Katz, J. S. & Wright, A. A.
Journal of Experimental Psychology: Animal Behavior Processes 2006, 32, 80-86 PDF
Eight pigeons were trained and tested in a simultaneous same/different task. After pecking an upper picture, they pecked a lower picture to indicate same or a white rectangle to indicate different. Increases in the training set size from 8 to 1,024 items produced improved transfer from 51.3% to 84.6%. This is the first evidence that pigeons can perform a two-item same/different task as accurately with novel items as training items and both above 80% correct. Fixed-set control groups ruled out training time or transfer testing as producing the high level of abstract-concept learning. Comparisons with similar experiments with rhesus and capuchin monkeys showed that the ability to learn the same/different abstract concept was similar but that pigeons require more training exemplars.
Learning processes in matching and oddity: The oddity preference effect and sample reinforcement
Wright, A. A. & Delius, J. D.
Journal of Experimental Psychology: Animal Behavior Processes 2005, 31, 425-432 PDF
Eight pigeons learned either matching (to sample) or oddity (from sample) with or without reward for sample responding. The training stimuli were coarse-white, fine-black, or smooth-mauve gravels in pots with buried grain as the reinforcer. Oddity without sample reward was learned most rapidly, followed by matching with sample reward, oddity with sample reward, and matching without sample reward. Transfer was related to acquisition rate: The oddity group without sample reward showed full (equal to baseline) color and texture transfer; the matching group with sample reward showed partial texture transfer; other groups showed no transfer. Sample reward was shown to determine rate of acquisition of matching and oddity and the oddity preference effect. The results are discussed in terms of item-specific associations operating early in learning prior to any relational learning between sample and comparison stimuli.
Wright, A.A., Rivera, J.J., Katz, J.S., & Bachevalier, J.
Journal of Experimental Psychology: Animal Behavior Processes 2003, 29 (3), 184-198 PDF
Three capuchin monkeys (Cebus apella) touched the lower of 2 pictures (same) or a white rectangle (different), increased same/different abstract-concept learning (52% to 87%) with set-size increases (8 to 128 pictures), and were better than 3 rhesus monkeys (Macaca mulatta). Three other rhesus that touched the top picture before choices learned similar to capuchins but were better at list-memory learning. Both species' serial position functions were similar in shape and changes with retention delays, Other species showed qualitatively similar shape changes but quantitatively different time-course changes. In abstract concept learning, qualitative similarity was shown by complete concept learning, whereas a quantitative difference would have been a set -size slope difference. Qualitative similarity is discussed in relation to general-process versus modular cognitive accounts.
Interference processes in monkey auditory list memory
Wright, A.A. & Roediger, H.L.
Psychonomic Bulletin & Review 2003, 10(3), 696-702 PDF
A rhesus monkey’s memory was tested for single items and four-item lists of natural and environmental sounds. Memory items were presented from a center speaker, followed by a retention delay and then a choice response to a test sound presented simultaneously from two side speakers. Recognition of the last item of four-item lists was much poorer than that of single items at 0-, 1-, and 2-sec delays, despite there being the same temporal relations between study and test. This result showed that the first three items proactively interfered with memory of the last list item. Proactive interference dissipated after 2 sec, revealing a recency effect that eventually equaled single-item performance. Recognition of the first item of four-item lists was much poorer than single items at 20- and 30-sec delays, showing that the last three items retroactively interfered with memory of the first list item. The results point to the critical nature of interference processes in the understanding of serial position functions.
Mechanisms of same/Different abstract-concept learning by rhesus monkeys
Katz, J.S., Wright, A.A., & Bachevalier, J.
Journal of Experimental Psychology: Animal Behavior Processes 2002, 28 (4), 358-368 PDF
Experiments with 9 rhesus monkeys (Macaca mulatta) showed, for the first time, that abstract-concept learning varied with the training stimulus set size. In a same/different task, monkeys required to touch a top picture before choosing a bottom picture (same) or white rectangle (different) learned rapidly. Monkeys not required to touch the top picture or presented with the top picture for a fixed time learned slowly or not at alL No abstract-concept learning occurred after 8-item training but progressively improved with larger set sizes and was complete following 128-item training. A control monkey with a constant 8-item set ruled out repeated training and testing. Contrary to the unique-species account, it is argued that different species have quantitative, not qualitative, differences in abstract-concept learning.
Monkey auditory list memory: Tests with mixed and blocked retention delays
Animal Learning & Behavior 2002, 30, 158-164 PDF
A rhesus monkey was tested in an auditory list memory task with blocked and mixed retention delays. Each list of four natural or environmental sounds (from a center speaker) was followed by a retention delay (0, 1, 2, 10, 20, or 30 sec) and then by a recognition test (from two side speakers). The monkey had been tested for 12 years in tasks with blocked delays. An earlier (4 years prior) blocked-delay test was repeated, with virtually identical results. The results from the mixed-delay test were likewise similar. Thus, the peculiarities of blocked-delay testing, such as delay predictability or differences in list spacing, apparently do not alter this monkey’s memory for auditory lists. It is concluded from this and other evidence that the monkey’s serial position functions reflect mnemonic processes that change with changes in retention delay and are not artifacts of the blocked-delay procedure. The nature of the monkey’s auditory memory is discussed.
The hippocampus and memory of verbal and pictorial material. Learning and Memory
Papanicolaou, A.C., Simos, P.G., Castillo, E.M., Brier, J.I., Wright, A.A., & Katz, J.S.
Learning and Memory 2002, 9, 99-104 PDF
Recognition ofwords and kaleidoscope pictures showed a double dissociation oflef t and right hippocampal activity using magnetic source imaging (MSI). MSI has advantages over alternative imaging techniques that measure hemodynamic changes for identifying regional changes in brain activity in real time and on an individual subject basis without the need for image subtraction. In this study, lists ofwords or kaleidoscope pictures were presented for memorization followed by tests of list items and foils during which brain activity was recorded. There was greater activation in the left than the right hippocampus with abstract nouns (e.g., relief) and greater activation in the right than the left hippocampus with kaleidoscope pictures. This dissociation was evident on a case by case basis. This study demonstrates the specialization ofthe two medial temporal lobe (MTL) regions, including the hippocampi, for mnemonic processing ofverbal and pictorial items that are difficult to encode verbally.
Object and spatial relational memory in adult rhesus monkeys is impaired by neonatal lesions of the hippocampal formation but not the amygdaloid complex
Alvarado, M.C., Wright, A.A., & Bachevalier, J.
Hippocampus 2002, 12, 421-433 PDF
Adult rhesus monkeys with neonatal aspiration lesions of the hippocampal formation or the amygdaloid complex (including their respective subjacent cortices) and their age-matched controls were tested on the transverse patterning problem (A+ vs. B-, B+ vs. C- and C+ vs. A-) and a spatial version of the delayed nonmatching-to-sample (DNMS) task with delays of 10 s to 30 s, 60 s, 120 s, and 600 s. Monkeys with neonatal damage to the amygdaloid complex learned both tasks and did not differ from controls at any delay of the spatial DNMS task. Monkeys with neonatal hippocampal damage, however, were unable to learn transverse patterning, though they easily transferred to a linear series (A+ vs. B-, B+ vs. C-, and C+ vs. X-). Three of the four were also unable to reach criterion on the spatial DNMS task within the limits of testing, and the performance of all four monkeys deteriorated with increasing choice delays. The data suggest a role of the primate hippocampal region in both object and spatial relational learning.
Music perception and octave generalization in rhesus monkeys
Wright, A.A., Rivera, J.J., Hulse, S.H., Shyan, M., & Neiworth, J.J.
Journal of Experimental Psychology: General 2000, 129, 291-307 PDF
Two rhesus monkeys were tested for octave generalization in 8 experiments by transposing 6- and 7-note musical passages by an octave and requiring same or different judgments. The monkeys showed no octave generalization to random-synthetic melodies, atonal melodies, or individual notes. They did show complete octave generalization to childhood songs (e.g., "Happy Birthday") and tonal melodies (from a tonality algorithm). Octave generalization was equally strong for 2-octave transpositions but not for 0.5- or 1.5-octave transpositions of childhood songs, These results combine to show that tonal melodies form musical gestalts for monkeys, as they do for humans, and retain their identity when transposed with whole octaves so that chroma (key) is preserved. This conclusion implicates similar transduction, storage, processing, and relational memory of musical passages in monkeys and humans and has implications for nature-nurture origins of music perception.
Auditory list memory and interference processes in monkeys
Journal of Experimental Psychology: Animal Behavior Processes 1999, 25, 284-296 PDF
Memory of 2 rhesus monkeys (Macaca mulatta) was tested in a serial robe recognition task with lists of 4 natural or environmental sounds, different retention intervals, and different manipulations of interference. At short retention intervals, increasing the separation of list items reduced the primacy effect and produced a recency effect. Similar results were shown by increasing interference across lists through item repetitions or making the first 2 list items high-interference items. These results indicated that decreasing first-item performance reduced proactive interference on memory of the last list items. At long (20 s) retention intervals, making the last list items of high interference reduced the recency effect, reduced retroactive interference, and produced a primacy effect. Taken together, interference plays a role in determining the primacy and recency effects of the serial-position function.
Visual list memory in capuchin monkeys (Cebus apella)
Journal of Comparative Psychology 1999, 113, 74-80 PDF
Memory of 3 capuchin monkeys, Cebus apella, was tested with lists of 4 travel-slide pictures and different retention intervals. They touched different areas of a video monitor to indicate whether a test picture was in a list. At short retention intervals (0 s, 1 s, 2 s), memory was good for the last list items (recency effect). At a 10-s retention interval, memory improved for 1st list items (primacy effect). At long retention intervals (20 s and 30 s), primacy effects were strong and recency effects had dissipated. The pattern of retention-interval changes was similar to rhesus monkeys, humans, and pigeons. The time course of recency dissipation was similar to rhesus monkeys. The capuchin's superior tool-use ability was discussed in relation to whether it reflects a superior general cognitive ability, such as memory. In terms of visual memory, capuchin monkeys were not shown to be superior to rhesus monkeys.
Elmore, L. C., Ma, W.J., Magnotti, J.F., Leising, K. K., Passaro, A.D., Katz, J.S., Wright, A. A., (2011). Visual Short-Term Memory Compared in Rhesus Monkeys and Humans. Current Biology, 21, 975–979. PDF, see also Supplemental Information
Wright, A. A., Katz, J. S., Magnotti, J. F, Elmore, L. C, Babb, S., & Alwin, S. (2010, December). Testing pigeon memory in a change detection task. Psychonomic Bulletin & Review. 17 (2), 243-249. doi:10.3758/PBR.17.2.243. PDF
Wright, A. A., & Lickteig, M. T. (2010, November). What is learned when concept learning fails: A theory of restricted-domain relational learning. Learning & Motivation. 4(4), 273-286. PDF
Wright, A. A. (2010 October). Functional relationships for determining similarities and differences in comparative cognition. Behavioural Processes, 85, 246–251. PDF
Schmidtke, K. A., Katz, J. S., & Wright A. A. (2010). Differential outcomes facilitate same/different concept learning. Animal Cognition. 13:583–589 DOI 10.1007/s10071-009-0292-2. PDF
Katz, J. S., Sturz, B. R., & Wright, A. A. (2010). Domain is a moving target for relational learning. Behavioural Processes, 83, 172-175. PMCID: PMC282002. PDF
Katz, J. S., Sturz, B. R., & Wright, A. A. (2010). Testing the translational-symmetry hypothesis of abstract-concept learning in pigeons. Learning & Behavior, 38, 35-41. PMID: 20063050 PDF
Wright, A. A., & Katz, J. S. (2009). A case for restricted-domain relational learning. Psychonomic Bulletin & Review, 16, 907-913. PMID: 19815797 PDFElmore, L. C., Wright, A. A., Rivera, J. J., & Katz, J. S. (2009). Individual differences: Either relational learning or item-specific learning in a Same/Different Task. Learning & Behavior, 37, 204-213. PMID:19380897. PDF
Wright, A.A. (1998). Auditory and visual serial position functions obey different laws. Psychonomic Bulletin and Review, 5, 564-584. PDF
Wright, A.A. (1998). Auditory list memory in rhesus monkeys. Psychological Science, 9, 91-98. PDF
Wright, A.A. and Rivera, J J. (1997). Memory of auditory lists by rhesus monkeys. Journal of Experimental Psychology: Animal Behavior Processes, 23, 441-449. PDF
Wright, A.A. (1997). Concept learning and learning strategies. Psychological Science, 8, 119-123. PDF
Seimann, M., Delius, J.D., and Wright, A.A. (1996). Transitive responding in pigeons: Influences of stimulus frequency and reinforcement. Behavioural Processes, 37, 185-195. PDF
Wright, A.A. and Roberts, W.A. (1996). Monkey and human face perception: Inverted-face effects for human faces but not monkey faces or scenes. Journal of Cognitive Neuroscience, 8, 278-290. PDF
Neiworth, J.J. and Wright, A.A. (1994). Monkeys (Macaca mulatta) learn category matching in a nonidentical same/different task. Journal of Experimental Psychology: Animal Behavior Processes, 20, 429-435. PDF
Wright, A.A. (1994). Primacy effects in animal memory and human nonverbal memory. Animal Learning & Behavior, 22, 219-223. PDF
Wright, A.A. and Delius, J.D. (1994) Scratch and match: Pigeons learn matching and oddity with gravel stimuli. Journal of Experimental Psychology: Animal Behavior Processes, 20, 108-112. PDF
Bhatt, R.S., and Wright, A.A. (1992). Concept learning by monkeys with video picture images and a touch screen. Journal of the Experimental Analysis of Behavior, 57, 219-225. PDF
Wright, A.A. (1992). Learning Mechanisms in Matching to Sample. Journal of Experimental Psychology: Animal Behavior Processes, 18, 67-79. PDF
Sperling, H.G., Wright, A.A., and Mills, S.L. (1991). Color Vision Following Intense Green Light Exposure: Data and a Model. Vision Research, 31, 1797-1812. PDF
Cook, R.G., Wright, A.A., and Sands, S.F. (1991). Interstimulus interval and viewing time effects in monkey list memory. Animal Learning & Behavior, 19, 153-163. PDF
Wright, A.A., Cook, R.G., Rivera, J.J., Shyan, M.R., Neiworth, J.J., and Jitsumori, M. (1990). Naming, Rehearsal, and Interstimulus Interval Effects in Memory Processing. Journal of Experimental Psychology: Learning, Memory, and Cognition, 16, 1043-1059. PDF
Kendrick, D.F., Wright, A.A., and Cook, R.G. (1990). On the role of memory in concept learning by pigeons. the Psychological Record, 40, 359-371
Wright, A.A. (1990). Markov choice processes in simultaneous matching-to-sample at different levels of discriminability. Animal Learning & Behavior, 18, 277-286. PDF
Wright, A.A., Shyan M.R., and Jitsumori, M. (1990). Auditory same/different concept learning by monkeys. Animal Learning & Behavior, 18, 287-294. PDF
Jitsumori, M., Wright, A.A., and Shyan, M.R. (1989). Buildup and Release from proactive interference in a rhesus monkey Journal of Experimental Psychology: Animal Behavior Processes, 15, 329-337. PDF
Wright, A.A., Cook, R.G., and Kendrick, D.F. (1989). Relational and absolute stimulus learning by monkeys in a memory task. Journal of the Experimental Analysis of Behavior, 52, 237-248. PDF
Wright, A.A., and Watkins, M.J. (1987). Animal learning and memory and their relation to human learning and memory. Learning and Motivation, 18, 131-146. PDF
Wright, A.A., Cook, R.G., Rivera, J.J., Sands, S.F., and Delius, J.D. (1988). Concept learning by pigeons: matching- to-sample with trial-unique video picture stimuli. Animal Learning and Behavior, 16, 436-444. PDF
Jitsumori, M., Wright, A.A., and Cook, R.G. (1988). Long- term proactive interference and novelty enhancement effects in monkey list memory. Journal of Experimental Psychology: Animal Behavior Processes, 14, 146-154. PDF
Pope, C.N., Ho, B.T., and Wright, A.A. (1987). Neurochemical and behavioral effects of N-ethyl-acetylcholine aziridinium chloride in mice. Pharmacology, Biochemistry, & Behavior, 6, 365-371. PDF
Shyan, M.R., Wright, A.A., Cook, R.G., and Jitsumori, M. (1987). Acquisition of the auditory same/different task in a rhesus monkey. Bulletin of the Psychonomic Society, 25, 1-4.
Wright, A.A., Sperling, H.G., and Mills, S.L. (1987). Researches on a unilaterally blue-blinded rhesus monkey. Vision Research,27, 1551-1564. PDF
Wright, A.A., Santiago, H.C., Sands, S.F., Kendrick, D.F., and Cook, R.G. (1985). Memory Processing of serial lists by pigeons, monkeys, and people. Science, 229, 287-289. PDF
Wright, A.A., Santiago, H.C., and Sands, S.F. (1984). Monkey Memory: Same/Different concept learning, serial probe acquisition, and probe delay effects. Journal of Experimental Psychology: Animal Behavior Processes, 10, 513-529. PDF
Santiago, H.C., and Wright, A.A. (1984). Pigeon memory: Same/Different concept learning, serial probe recognition acquisition and probe delay effects in the serial position function. Journal of Experimental Psychology: Animal Behavior Processes, 10, 498-512. PDF
Fox, D.A., Costa, L.G. and Wright, A.A. (1982). Spatial vision deficits in adult rats following developmental lead exposure. Toxicologist 3:
Fox, D.A., Wright, A.A., and Costa, L.G. (1982). Visual acuity deficits following neonatal lead exposure: Cholinergic interactions. Neurobehavioral Toxicology Teratology, 4, 689- 693.
Wright, A.A. (1982). Detection of learning and learning to detect. Review of Quantitative Analysis of Behavior, Vol. 1: Discriminative Properties of reinforcement Schedules by M. L. Commons and J. A. Nevin. Contemporary Psychology,27,566-567.
Wright, A.A., Santiago, H.C., and Sands, S.F. (1983). On the nature of the primacy effect in memory processing. Animal Learning and Behavior, 11, 148-150.
Sands, S.F., Lincoln, C.E., and Wright, A.A. (1982). Pictorial similarity judgments and the organization of visual memory in the rhesus monkey. Journal of Experimental Psychology: General, 111, 369-389. PDF
Sands, S.F., and Wright, A.A. (1982). Monkey and human pictorial memory scanning. Science, 216, 1333-1334. PDF
Wright, A.A., Urcuioli, P.J., Sands, S.F. and Santiago, H.C. (1981). Interference of delayed matching-to-sample in pigeons: Effects of interpolation at different periods within a trial and stimulus similarity. Animal Learning and Behavior, 9, 595-603.
Wright, A.A., and Sands S.F. (1980). A model of detection and decision processes during matching-to-sample by pigeons: Performance with 88 different wavelengths in delayed and simultaneous matching tasks. Journal of Experimental Psychology: Animal Behavior Processes, 7, 191-216. PDF
Sands, S.F., and Wright, A.A. (1980). Serial probe recognition performance by a rhesus monkey and a human with 10- and 20-item lists. Journal of Experimental Psychology: Animal Behavior Processes, 6, 386-396. PDF
Sands, S.F., and Wright, A.A. (1980). Primate memory: retention of serial list items by a rhesus monkey. Science, 209, 938-940.
Sands, S.F., and Wright, A.A. (1979). Enhancement and distribution of retention performance by ACTH in a choice task. Behavioral and Neural Biology, 27, 413-422.
Santiago, H.C., and Wright, A.A. (1980). Brightness contrast: A reinterpretation of compound cue and combined cue experiments with pigeons. Journal of the Experimental Analysis of Behavior, 33, 87-99. PDF
Wright, A.A. (1978). Construction of equal-hue discriminability scales for the pigeon. Journal of the Experimental Analysis of Behavior, 29, 261-266. PDF
Wright, A.A. (1976). Bezold-Brucke hue shift functions for the pigeon. Vision Research, 16, 765-774. PDF
Wright, A.A. (1974). Psychometric and Psychophysical theory within a framework of response bias. Psychological Review, 81, 322-347.
Wright, A.A., and Nevin, J.A. (1974). Signal detection methods for measurement of utility in animals. Journal of the Experimental Analysis of Behavior, 21, 373-380. PDF
Wright, A.A. (1972). Construct a monochromator from a single interference filter. Journal of the Experimental Analysis of Behavior, 18, 61-63. PDF
Schneider, B A., Wright, A.A., Edelheit,W., Hock, P., and Humphrey,C. (1972). Equal loudness contours derived from sensory magnitude judgments. Journal of the Acoustical Society of America, 51, 1951-1959.
Wright, A.A. (1972). The influence of ultraviolet radiation on the pigeon's color discrimination. Journal of the Experimental Analysis of Behavior, 17, 325-337. PDF
Wright, A.A. (1972). Psychometric and psychophysical hue discrimination functions for the pigeon. Vision Research, 12, 1447-1464. PDF
Wright, A.A., and Cumming, W.W. (1971). Color naming functions for the pigeon. Journal of the Experimental Analysis of Behavior, 15, 7-17. PDF
Wright, A. A. (1979). Color vision psychophysics: A comparison of pigeon and human. In A. M. Granda and J. H. Maxwell (Eds.), Neural Mechanisms of Behavior in the Pigeon (pp. 89-127). New York: Plenum Press.
Wright, A. A., Santiago, H. C., Sands, S. F., and Urcuioli, P. J. (1984). Pigeon and monkey serial probe recognition: Acquisition strategies and serial position effects. In H. L. Roitblat, T. Bever, and H. S. Terrace (Eds.), Animal Cognition (pp. 353-374). Hillsdale, N. J.: Erlbaum.
Wright, A. A., Santiago, H. C., Urcuioli, P. J. and Sands, S. F. (1984). Monkey and pigeon acquisition of same/different concept using pictorial stimuli. In M. L. Commons and R. J. Herrnstein (Eds.), Quantitative Analysis of Behavior: Vol. IV. Discrimination Processes (pp. 295-317). Cambridge, Ma: Ballinger.
Sands, S. F., Urcuioli, P. J., Wright, A. A., and Santiago, H. C. (1984). Serial position effects and rehearsal in primate visual memory. In H. L. Roitblat, T. Bever and H. S. Terrace (Eds.), Animal Cognition (pp. 375-388). Hillsdale, N. J.: Erlbaum.
Wright, A. A., Urcuioli, P. J., and Sands, S. F. (1986). Proactive interference in animal memory research. In D. F. Kendrick, M. Rilling and R. Denny (Eds.), Theories of Animal Memory (pp. 101-125). Hillsdale N.J.: Erlbaum.
Sperling, H. G., Wright, A. A., and Mills, S. L. (1987). Intense spectral light induced color blindness in rhesus monkeys. In: G. Verriest (Ed.) Colour Vision Deficiencies (Vol. VII, pp. 5-20). Dordrecht, Netherlands: Martinus Nijhoff/Dr. W. Junk Publishers.
Cook, R. G., Wright, A. A., & Kendrick, D. F. (1990). Visual Categorization by pigeons. In M. L. Commons, R. J. Herrnstein, S. F. Kosslyn, and D. B. Mumford (Eds.), Quantitative Analyses of Behavior: Behavioral Approaches to Pattern Recognition and Concept Formation (Vol. 8, pp. 187-214). Hillsdale, N. J.: Erlbaum.
Wright, A. A. (1989). Memory processing by pigeons, monkeys, and people. In G. H. Bower (Ed.), The Psychology of Learning and Motivation (Vol. 23, pp. 25-70). New York: Academic press.
Wright, A. A. (1991). Memoria y procesos cognitivos en al paloma, el mono y el hombre. In: L. A. Aguado (Ed.) Comparative Cognition (pp. 115-176). Madrid, Spain: Alianza Editorial.
Wright, A. A. (1991). Detection and decision process model of matching to sample. In M. L. Commons, M. Davison, and J. A. Nevin (Eds.), Quantitative Analyses of Behavior (Vol. 10, pp. 191-219). Hillsdale, N. J.: Erlbaum.
Wright, A. A. (1991). Concept learning by monkeys and pigeons. In M. Corballis, K. G. White, and W. Abraham (Eds.), Memory Mechanisms: A Tribute to G. V. Goddard (pp. 247-273). Hillsdale, N. J.: Erlbaum.
Wright, A. A. (1992). The study of animal cognitive processes. In W. K. Honig and G. Fetterman (Eds.). Cognitive Aspects of Stimulus Control (pp. 245-241). Hillsdale, N. J.: Erlbaum.
Shyan M. R. and Wright, A. A. (1993). The effects of language on information processing and abstract concept learning in dolphins, monkeys, and humans. In H. L. Roitblat, L. M. Herman, and P. E. Nachtigall (Eds.). Language and Communication (pp. 385-402). Hillsdale, N. J.: Erlbaum.
Wright, A. A. (1993). When is a stimulus a pattern? In T. Zentall (Ed.) Animal Cognition: A Tribute to Donald A. Riley (pp. 35-41). Hillsdale, N. J.: Erlbaum.
Wright, A. A. (1998). Testing the cognitive capacities of animals. In I. Gormezano and E. A. Wasserman (Eds.), Learning and Memory: The Behavioral and Biological Substrates.
Wright, A. A. (2002). Monkey visual and auditory memory. In S. B. Fountain, M.D. Bunsey, J. H. Danks, and M. K. McBeath (Eds.) Animal Cognition and Sequential Behavior. Boston, MA: Kluwer Academic Publishers.
Wright, A. A. (2002). Concept learning in pigeons: Configural and relational learning strategies. In R. G. Cook (Ed.) Avian Visual Cognition. Cyber book (www.pigeon.psy.tufts.edu/avc/).
Wright, A. A. (2003). Short-term memory: Animals. In J. H., Byrne (Ed.) Encyclopedia of Learning and Memory: Second edition (pp. 669-676). New York: MacMillan Publishing Company.
Wright, A. A. ( 2003). Comparative cognition. In J. H., Byrne (Ed.) Encyclopedia of Learning and Memory: Second edition (pp. 88-95). New York: MacMillan Publishing Company.
Wright, A. A. (2006). Memory Processing. In T. Zentall and E. A. Wasserman (Eds.) Comparative Cognition: Experimental Explorations of Animal Intelligence (pp. 164-185). New York: Oxford University Press.
Katz, J. S., Sturz, B. R., Bodily, K. D., Hernandez, M. & Wright, A. A. (in press). Mechanisms of Same/Different Concept Learning. Advances in Psychology Research. Hauppauge, NY: Nova Science.
Wright, A. A. (in press). Animal Intelligence. In L. Squire (Ed.) Encyclopedia of Neuroscience. Oxford: Elsevier.