Class-consistent Differential Reinforcement And Stimulus Class Formation In Pigeons

Match-to-sample training clusters of A1 (sample): B1/B2 (comparisons), A2: B2/B1, B1: A1/A2, B2: A2/A1, B1: C1/C2, B2: C2/C1, C1: B1/B2, and C2: B2/B1 were presented to pigeons with class-consistent differential reinforcement using two dissimilar types of food reinforcers. Distinctive class-consistent response patterns occurred to the samples during the fixed-ratio 5 sample observing response requirement. Subsequent tests, modeled from the equivalence class paradigm demonstrated the emergence (80% class consistent) of the transitive-like A-C and C-A relations for 4 and 2 of 12 pigeons, respectively, and a strong trend (over 70%) for 7 and 6 others, respectively; the emergence of the reflexive-like identity relation when the nonidentical comparison was from the other class; and the disruption of the trained within-class relation with the addition of a reflexive comparison. After directional training of C1: D1/D2 and C2: D2/D1, tests indicated no emergence of the symmetric-like D-C relation or the composite D-B and D-A relations, but the B-D and A-D transitive-like relation occurred with some pigeons. Off-baseline training with class-consistent differential reinforcement contingent on responding to the D stimuli alone produced distinctive responding and, in turn, a trend to D-C symmetric-like control in 4 of 12 pigeons, as well as a shift toward class-consistent control on D-B and D-A test trials. Class-consistent differential reinforcement that produced distinctive sample behavior promoted stimulus control relations like those that circumscribe equivalence class formation. Respondent—operant interactions permit an analysis of the possible enrollment of stimulus values of distinctive responding to the discriminative stimuli forming the stimulus classes via processes corresponding to naming in humans.     

Testing response-stimulus equivalence relations using differential responses as a sample

This study tested the notion that an equivalence relation may include a response when differential responses are paired with stimuli presented during training. Eight normal adults learned three kinds of computer mouse movements as differential response topographies (R1, R2, and R3). Next, in matching-to-sample training, one of the response topographies was used to select a comparison stimulus B (B1, B2, or B3) conditionally upon presentation of sample stimulus A (A1, A2, or A3), and to select stimulus D (D1, D2, or D3) conditionally upon presentation of stimulus C (C1, C2, or C3). After two sample-comparison-response relations (ABR and CDR) were established, 18 sample-comparison relations were tested (BA, DC, RA, RB, RC, RD, AC, CA, AD, DA, BC, CB, BD, DB, AA, BB, CC, and DD). In the RA, RB, RC, and RD tests, the differential responses (R1, R2, and R3) were used as sample stimuli. All subjects made class-consistent comparison selections in the tests. This study provides evidence that responses may become members of an equivalence class.     

Students with the initial “A” don’t get better grades

It has been claimed that students whose first or last name begins with the letters A or B have higher grade point averages than students whose first or last name begins with the letters C or D. We critique the analysis behind this claim, raising a number of issues that lead us to question the validity of the claim. We also test for a relation between student initial and GPA using two new datasets and find no evidence to support such a relation.     

抑制性控制在幼儿执行功能与心理理论中的作用

将执行功能任务和心理理论任务中的共同成分——抑制性控制区分为3个不同的难度水平,从而构成心理理论任务（错误信念）的3个变式A1、A2、A3和执行功能任务（白天/黑夜）的3个变式B1、B2、B3。实验1以48名4岁幼儿为被试,探讨对两类任务中各自的3个变式所包含的抑制性控制的难度区分的适当性,结果表明幼儿在两类任务中各自的3个变式上的正确率差异显著,说明其抑制性控制的确表现出了高、中、低3个不同的难度水平;实验2根据实验1所设计的两类任务,以144名3~6岁幼儿为被试,探讨了不同抑制性控制的难度水平在幼儿执行功能和心理理论的相关中的作用,结果表明抑制性控制的难度水平是影响幼儿执行功能与心理理论的相关的一个重要因素。     

The impact of semantic distance and induced stress on analogical reasoning: A neurocomputational account

In a study of reasoning with four-term verbal analogy problems, we explored the relationship between the effects of an acute, mild stressor and the complexity of the reasoning process. Participants judged whether analogy problems in the form A:B :: C:D were valid or invalid, on the basis of whether the relation in the A:B term matched that in the C:D term. Half of the problems contained a C:D pair semantically near the A:B pair (e.g., NOSE:SCENT :: TONGUE:TASTE), and the other half contained ones semantically far from A:B (e.g., NOSE:SCENT :: ANTENNA:SIGNAL). After an initial block without stress, participants were randomly assigned to count backward by 13?s from 1,000 while being told to go faster, or to count forward by 1?s from 0. The stress-induced participants reported a significant increase in state anxiety as compared to controls immediately after the mental arithmetic task. Stressed participants performed less accurately (as measured by d') on both near and far analogy problems, mainly due to an increase in false alarms. We were able to model the influence of semantic distance using the ??learning and inference with schemas and analogies?? (LISA) model. Our findings indicated that even mild increases in stress impair analogical reasoning. However, the decrement does not seem to directly involve the integration of relations, but rather is due to a shift in decision strategy: Under stress, people show an increased tendency to endorse analogies as valid when the terms in the individual pairs are semantically related to each other, even if the overall analogical relationship is not valid.     

The wording of conclusions in relational reasoning

Literature on relational reasoning mainly focuses on the performance question. It is typically argued that problem difficulty relies on the number of "mental models" compatible with the problem. However, no study has ever investigated the wording of conclusions that participants formulate. In the present work, we analyze the relational terms that people use in drawing conclusions from spatial relation problems (A is to the left of B, B is to the left C, D is in front of A, E is in front C, What is the relation between D and E?). We observed a general preference for expressing conclusions with 'left' rather than conclusions with 'right'. We also found that three factors had an influence on the wording of the conclusions: the linguistic form of premises, the question type and the presentation format. On the other hand, the number of models and premise order did not affect the wording of conclusions. Our study shows that the type of conclusion produced provides a new key to identifying the mental processes involved in spatial reasoning. Implications for the two main approaches to reasoning processes (i.e. the analogical and the propositional approaches) are discussed.     

The effects of nodality on the formation of equivalence classes

A four-member equivalence class (A → B → C → D) can be formed by training AB, BC, and CD. The nodal stimuli, B and C, mediate all of the derivative (transitive and equivalence) relations in the class. The derivative relations AC, CA, BD, and DB are separated by one node, whereas AD and DA are separated by two nodes. How do the number of nodes that separate the stimuli in a derivative relation influence the induction of stimulus control exerted by that relation? Seven college students learned two four-member classes made up of nonsense syllables. After training, all derivative relations were presented repeatedly without informative feedback. Stimulus control exerted by each derivative relation was assessed concurrently. For the 7 subjects, control exerted by the derivative relations increased gradually with repeated presentations. With 6 of the 7 subjects, the one-node relations exerted more control than the two-node relations during the process. However, the disparity between the one- and two-node relations decreased with repeated presentations. Eventually, all derivative relations exerted complete control. The control exerted by derivative relations during induction was inversely related to the number of nodes separating the terms in the derivative relations. These results demonstrate that nodal distance is a determinant of the relatedness of stimuli in equivalence classes. The findings are discussed in terms of remote association, semantic memory networks, and the study of transitive inference.     

A test of transitive inferences in free-flying honeybees: unsuccessful performance due to memory constraints

We asked whether honeybees, Apis mellifera, could solve a transitive inference problem. Individual free-flying bees were conditioned with four overlapping premise pairs of five visual patterns in a multiple discrimination task (A+ vs. B-, B+ vs. C-, C+ vs. D-, D+ vs. E-, where + and - indicate sucrose reward or absence of it, respectively). They were then tested with the nonadjacent pairs A vs. E and B vs. D. Preference of B to D is consistent with the use of the implicit hierarchy A > B > C > D > E. Equal choice of B and D supports choice based on the associative strength of the stimuli. The bees' choice was determined by their memory constraints: experience with the last premise pair (D+ vs. E-) predominated. In the tests, bees preferred A to E and chose equally B and D. An analysis of the performance in terms of a reward/penalty ratio showed that B had a higher associative strength than D. Thus, bees do not establish transitive inferences but, rather, guide their choices by the joint action of a recency effect and the associative strength of the stimuli. The former supports choice of D, whereas the latter supports choice of B, thus determining equal choice of B and D in the tests.     

Maintained nodal-distance effects in equivalence classes

Twelve subjects were trained to select one of two stimuli from a pair (the B pair) when presented with one of two stimuli from another pair (the A pair), thus establishing two AB relations, A1-B1 and A2-B2. In a similar fashion, additional stimuli were used to establish BC, CD, and DE relations. Trials used to train all relations occurred in each session. Once performances were established, probe trials were introduced that tested for the emergence of untrained relations (e.g., B1-D1 or A1-E1). These emergent relations were categorized according to nodal distance (i.e., the number of stimuli across which transitivity would have to hold in order for the relation to emerge). For example, a test for A2-C2 crosses one node (B2), whereas a test for A1-E1 crosses three nodes (B1, C1, and D1). Only 2 of the subjects formed equivalence classes. The evocation of class-appropriate responding by each emergent-relation probe was an inverse function of nodal distance for all 12 subjects. In addition, performance on the originally trained relations was disrupted by the introduction of probes. The 2 subjects who exhibited equivalence classes were then trained to make different numbers of key presses in the presence of each of the four A and E stimuli. In a response-transfer test, the B, C, and D stimuli evoked the responses trained to the A and E stimuli in the same equivalence class. Likelihood of class-appropriate responses was an inverse function of nodal distance, and this pattern persisted across testing. Reaction times in the transfer test were an inverted U-shaped function of nodal distance. Because training of the baseline relations occurred concurrently and the B, C, and D stimuli were presented an equal number of times before the transfer test, the test performances illustrate effects of nodal distance that were not confounded by order or amount of experience with the stimuli. The results imply that ordered, sequential exposure to individual stimulus relations may facilitate the development of equivalence classes and that the relatedness of stimuli within an equivalence class is a relatively permanent inverse function of nodal distance.     

A new approach to the formation of equivalence classes in pigeons

Four pigeons were given simultaneous discrimination training with visual patterns arbitrarily divided into two sets, with the stimuli in one set designated A1, B1, C1, and D1 and those in the other set designated A2, B2, C2, and D2. In sequentially introduced training phases, the pigeons were exposed to a series of reversals to establish AB and then CD equivalences. In subsequent testing sessions, a subset of stimuli from one set served as positive stimuli and those from the other set as negative stimuli on training trials, and transfer of the reinforced relation to other members of the sets was tested with nonreinforced probe trials. The pigeons were trained further on AC and BD equivalences and then were tested for the emergence of untrained AD and BC equivalences. Two of the 4 pigeons exhibited the emergence of one of these untrained equivalences, evidence for the emergence of transitive relations. This finding suggests that the pigeons established three-member functional equivalence classes by incorporating separately trained multiple equivalence relations. Repeated reversal training and probe testing enabled us to explore the formation and expansion of functional equivalence classes in pigeons.     

Reorganization of equivalence classes: effects of preliminary training and meaningful stimuli

In Condition 1, adults learned the baseline relations for the three equivalence classes A1‐B1‐C1‐D1‐E1, A2‐B2‐C2‐D2‐E2, and A3‐B3‐C3‐D3‐E3. Classes contained abstract shapes in the ABS and four preliminary training groups. Each class in the PIC group contained one picture and four abstract shapes. Before class formation for four other groups, preliminary training involved establishing identity (CC) or arbitrary (CX) relations either with or without a delay. Without preliminary training, classes formed with low and high likelihoods in the ABS and PIC groups, respectively. Preliminary training with no delay produced modest increases in class formation, while preliminary training with delay produced large increases in class formation. Condition 2 replicated Condition 1 but with training of reassigned BC and CD relations that linked C from one class to B and D from another class: B1‐C2, B2‐C3, B3‐C1, C2‐D1, C3‐D2, and C1‐D3. Subsequent tests assessed the emergence of the reorganized classes A1‐B1 ‐C2 ‐D1‐E1, A2‐B2‐ C3 ‐D2‐E2, and A3‐B3‐ C1 ‐D3‐E3. All preliminary training procedures increased likelihood of forming the reorganized classes to the level seen in the PIC group. Greater gains were produced by preliminary training with no delays than with delays. Test performances also showed how preliminary training influenced baseline acquisition speed and participant‐defined relations.     

Transitive inference in pigeons: Control for differential value transfer

Transitive inference (TI) effects have been demonstrated in several nonhuman species using a nonverbal version of the task in which A is better than B is represented in a simple simultaneous discrimination, A+B?. Following five-term training (e.g., A+B?, B+C?, C+D?, D+E?), the choice of B over D on test trials is taken as evidence of TI. Recently, differential value transfer from the S+ to the S? in a simultaneous discrimination has been proposed as a noncognitive basis for these effects. Two experiments were conducted to control for differential value transfer. The results suggest that differential value transfer is not the only basis for nonhuman TI performance. An alternative account based on spatial mapping is discussed.     

Six-member stimulus classes generated by conditional-discrimination procedures

In conditional-discrimination procedures with three sets of stimuli, A, B, and C, three stimuli per set (A1A2A3, B1B2B3, and C1C2C3), subjects (children and adults) learned to select Set-B and Set-C comparisons conditionally upon Set-A samples (A1B1, A1C1, A2B2, A2C2, A3B3, A3C3). If the conditional-discrimination procedures also generated equivalence relations, three 3-member stimulus classes would be demonstrable, A1B1C1, A2B2C2, and A3B3C3. In addition to these three sets, the present experiments used three other sets of stimuli--D, E, and F. The subjects learned to select Set-E and Set-F comparisons conditionally upon Set-D samples (D1E1, D1F1, D2E2, D2F2, D3E3, D3F3). This established a second group of three 3-member stimulus classes, D1E1F1, D2E2F2, and D3E3F3. In all, two groups of three 3-member classes were established by teaching subjects 12 conditional discriminations. The two groups of 3-member classes were then combined (successfully for 5 of 8 subjects) into a single group of three 6-member classes by teaching the subjects three more conditional relations (E1C1, E2C2, and E3C3). With three other children, enlarging the classes one member at a time also produced 6-member classes. As a consequence of class formation, 60 untrained conditional relations emerged from 15 that had been explicitly taught. Six of the subjects also proved capable of naming the stimuli consistently in accord with their class membership, but two subjects demonstrated class formation even in the absence of consistent naming.     

Remembering change: The critical role of recursive remindings in proactive effects of memory

In three experiments, we examined the role of the detection and recollection of change in proactive effects of memory in a classic A–B, A–D paradigm. Participants studied two lists of word pairs that included pairs repeated across lists (A–B, A–B), pairs with the same cue but a changed response (A–B, A–D) in the second list, and control pairs (A–B, C–D). The results revealed that performance on A–B, A–D pairs reflected a mixture of facilitation and interference effects. Proactive facilitation occurred when changes in responses were detected and recollected, whereas proactive interference occurred when change was not detected or when it was not recollected. We describe detecting change as involving recursive remindings that result in memory for the List 1 response being embedded in the representation of memory for the List 2 response. These embedded representations preserve the temporal order of the responses. Our findings highlight the importance of detection and recollection of change for proactive effects of memory.     

Nature unmirrored,epistemology naturalized

A. Knowledge and Justification: The nature of epistemic justification and its supervenience.B. Understanding and Validation: Two projects of epistemology, one to understand justification, the other to promote it.C. Epistemic Rationalism: A simple foundationalism of intuition and deduction.D. Reliabilism: A broader foundationalism.E. Foundationalism Assailed.F. Nature Unmirrored: Rorty reviewed.G. Reliabilist Foundationalism: Two problems.H. Coherence: A more radical response to the failure of rationalism.I. Perspectival Coherence: The requirement of an epistemic perspective and its relation to foundationalism.J. Epistemology of Epistemology.K. How to Naturalize Epistemology: Quine reviewed.L. Epistemology Naturalized: Through the Project of Validation.     

Establishing auditory stimulus control over an eight-member equivalence class via conditional discrimination procedures

Two eight-member equivalence classes of visual stimuli were established during three phases of a training program. In Phase 1, two training arrangements were compared. In one, 3 subjects were taught on different trials to select from a single pair of comparison stimuli (A1, A2) in response to eight sample stimuli that were trained in pairs (B1, B2; C1, C2; D1, D2; E1, E2). In the second arrangement, subjects were taught to select from four pairs of comparisons (B1, B2; C1, C2; D3, D2; E2, E2) in response to two samples (A1, A2). Training with the single pair of comparison stimuli resulted in the development of equivalence relations (B1C1, B2C2, D1B1, D2B2, B1E1, B2E2, C1D1, C2D2, C1E1, C2E2, D1E1, D2E2, and their reciprocals) between the sample stimuli without direct training of these relations. In the other training arrangement, these relations among the comparison stimuli developed in the performance of 1 subject only. In Phase 2, three new pairs of stimuli (F1, F2; G1, G2; H1, H2) were substituted for three of the original pairs (B1, B2; C1, C2; D1, D2) and the training arrangements for the groups were reversed. Following training, the performances that showed equivalence relations on the probes in the first phase also showed equivalence relations in the second phase. If such relations did not develop in the first phase, they did not do so in the second phase. In Phase 3, relations between stimuli across the two previous phases (e.g., B1F1, B2F2, B1G1, B2H2, C1F1, etc.) were investigated. The 4 subjects whose performances showed the development of these relations were taught to select one stimulus from each class (E1 and E2) in response to a verbal label (I1 and I2) and then were tested to see if the verbal label controlled responding to the remaining members of the class (e.g., I1A1, I2A2, I1B1, I2B2, etc.). For 3 subjects, this generalized control occurred; for the 4th, generalization occurred only after verbal training with a second pair of visual stimuli (F1 and F2). In retests several months later, these auditory-visual relations were found to be intact or, if not, were recovered without direct training.     

The effect of logarithmic transformation on estimating the parameters of the generalized matching law

This study examined stimulus class membership established via stimulus-reinforcer relations. Mentally retarded subjects learned conditional discriminations with four two-member sets of visual stimuli (A, B, C, and D). On arbitrary-matching trials, they selected comparison stimuli B1 and B2 conditionally upon samples A1 and A2, respectively, and C1 and C2 conditionally upon B1 and B2, respectively. On identity-matching trials, they selected all stimuli as comparisons conditionally upon identical stimuli as samples. Throughout training, correct selections of A1, B1, C1, and D1 were followed by one reinforcer, R1, and those of A2, B2, C2, and D2 were followed by another, R2. Subsequent tests documented the formation of two four-member stimulus classes, A1-B1-C1-D1 and A2-B2-C2-D2. The class membership of the A, B, and C stimuli could have been based on equivalence relations that resulted from the arbitrary-matching training. D1 and D2 had never appeared on arbitrary-matching trials, however. Their class membership must have been based on relations with R1 and R2, respectively. Results thus confirm a previous finding that stimulus classes can be expanded via stimulus-reinforcer relations. They also define more precisely the potential nature of those classes and the conditions under which class membership can be established.     

BOOK REVIEWS

Thomist Realism and the Linguistic Turn. B y J ohn P. O'C allaghan .
John Buridan: Portrait of a Fourteenth-Century Arts Master. B y J ack Z upko .
Matters of the Mind. B y W illiam L yons .
Reason and Nature: Essays in the Theory of Rationality. E dited by J osé L uis B ermúdez and A lan M illar . Mind Association Occasional Series.
Common Sense, Reasoning, and Rationality. E dited by R enée E lio . New Directions in Cognitive Science.
Cause and Chance: Causation in an Indeterministic World. E dited by P hil D owe and P aul N oordhof .
Humans and Other Animals. B y J ohn D upré .
Logical Form and Language. E dited by G erhard P reyer and G eorg P eter .
Action and its Explanation. B y D avid -H illel R uben .
Reasons and Purposes: Human Rationality and the Teleobgkal Explanation of Action. B y G.F. S chueler .
Libertarian Accounts of Free Will. B y R andolph C larke .
Rationality, Rules and Ideals: Critical Essays on Bernard Gert's Moral Theory. E dited by W alter S innott -A rmstrong and R obert A udi .
Forms of Justice: Critical Perspectives on David Miller's Political Philosophy. E dited by D aniel A. B ell and A vner D e -S halit .
Children, Family and the State. B y D avid A rchard .
Interpretation and Construction: Art, Speech and the Law. B y R obert S tecker .
Imagination, Philosophy, and the Arts. E dited by M atthew K ieran and D ominic M c I ver L opes .
The Creation of Art: New Essays in Philosophical Aesthetics. E dited by B erys G aut and P aisley L ivingston .     

Transfer of value from S+ to S- in simultaneous discriminations in humans

When animals learn a simultaneous discrimination, some of the value of the positive stimulus (S+) appears to transfer to the negative stimulus (S-). The present experiments demonstrate that such value transfer can also be found in humans. In Experiment 1 humans were trained on 2 simple simultaneous discriminations, the first between a highly positive stimulus, A (1,000 points); and a negative stimulus, B (0 points); and the second between a less positive stimulus, C (100 points); and a negative stimulus, D (0 points). On test trials, most participants preferred B over D. In Experiments 2 and 3 the value of the 2 original discriminations was equated in training (A[100]B[0] and C[100]D[0]). In Experiment 2 the values of the positive stimuli were then altered (A[1,000]C[0]); again, most participants preferred B over D. In Experiment 3, however, when the values of B and D were altered (B[1,000]D[0]), participants were indifferent to A and C. Thus, the mechanism that underlies value transfer in humans appears to be related to Pavlovian second-order conditioning. Similar mechanisms may be involved in assimilation processes in social contexts.     

Reversal of baseline relations and stimulus equivalence: I. Adults

Following the emergence of two four-member equivalence classes (A1B1C1D1 and A2B2C2D2), 5 students were exposed to a series of phases including a baseline conditional discrimination reversal (i.e., choosing D2 was reinforced and D1 punished given Sample A1; choosing D1 was reinforced and D2 punished given Sample A2), the delayed introduction of CD/DC transitivity/equivalence probes, DE conditional discrimination training, a second baseline conditional discrimination reversal (i.e., choosing C2 was reinforced given B1, etc.), and a return to original baseline reinforcement contingencies. Results showed that baseline and symmetry probe performances were extremely sensitive to baseline modifications. In contrast, patterns on transitivity/equivalence probes remained predominantly consistent with the originally established equivalence classes, although there were exceptions on some E probe relations for 2 subjects. The dissociation between baseline and symmetry versus transitivity/equivalence patterns may have important implications because it is not easily accounted for by current models of equivalence phenomena.