Is awareness necessary for true inference?

In transitive inference, participants learn a set of context-dependent discriminations that can be organized into a hierarchy that supports inference. Several studies show that inference occurs with or without task awareness. However, some studies assert that without awareness, performance is attributable to pseudoinference. By this account, inference-like performance is achieved by differential stimulus weighting according to the stimuli's proximity to the end items of the hierarchy. We implement an inference task that cannot be based on differential stimulus weighting. The design itself rules out pseudoinference strategies. Success on the task without evidence of deliberative strategies would therefore suggest that true inference can be achieved implicitly. We found that accurate performance on the inference task was not dependent on explicit awareness. The finding is consistent with a growing body of evidence that indicates that forms of learning and memory supporting inference and flexibility do not necessarily depend on task awareness.     

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.     

3—7岁儿童不同类型的传递性推理的发展研究

本研究从发展的角度研究了3-7岁儿童在解决三类传递性推理问题时能力发展和策略发展状况,真传递性推理指推理的传递性是确定的,个体根据前提关系可以做出确定的传递性推理结论,不确定性传递性推理指该类推理的传递性是不确定的,关系是否传递需要根据实际的情况和社会经验来确定,否定性传递性推理指根据前提关系得出不能进行传递性的必然结论。结果表明：（1）三类传递性推理的解题能力随年龄的增长而不断增强,在7岁左右初步形成。（2）三类传递性推理,能力发展有不同的起始点、快速发展期以及初步形成期。真传递性推理发展最早最快,不确定传递性推理最晚最慢。（3）3-7岁儿童解决三类传递性推理问题时使用了猜测、视觉判断、定向反应、经验推测和逻辑推理等策略,然而随着年龄的增大,主导策略由准策略向真策略转换。     

TRANSITIVE INFERENCE IN RATS:

Abstract— Rats were trained to discriminate between boxes covered with distinctive odors There were six stimulus odors, labeled A through F, and the problems learned formed the five premises A+B−, B+C−, C+D−, D+E−, and E+F− Combming the premises, the relative values of the stimuli were A>B>C>D>E>F In two experiments, linear arrangement groups learned these premises with Boxes A through F placed in a linear spatial sequence Nonlinear groups had boxes either randomly changed from one position to another (Experiment 1) or placed m a circular arrangement (Experiment 2) Tests of transitive inference between the B and D stimuli were carried out in an environment different from that m which premise training took place Only the groups trained with a linear arrangement of boxes showed evidence of transitive inference These findings offer support for a spatial coding hypothesis of transitive inference in animals     

“TRANSITIVE INFERENCE” IN MULTIPLE CONDITIONAL DISCRIMINATIONS

We used multiple conditional discriminations to study the inferential abilities of pigeons. Using a five-term stimulus series, pigeons were trained to respond differentially to four overlapping pairs of concurrently presented stimuli: A+B?, B+C?, C+D?, and D+E?, where plus and minus indicate the stimulus associated with reinforcement and extinction, respectively. Transitive inference in such situations has been defined as a preference for Stimulus B over Stimulus D in a transfer test. We measured this and other untrained preferences (A vs. C, A vs. D, B vs. E, etc.) during nonreinforced test trials. In three experiments using a novel, rapid training procedure (termed autorun), we attempted to identify the necessary and sufficient conditions for transitive inference. We used two versions of autorun: response-based, in which the subject was repeatedly presented with the least well-discriminated stimulus pair; and time-based, in which the subject was repeatedly presented with the least-experienced stimulus pair. In Experiment 1, using response-based autorun, we showed that subjects learned the four stimulus pairs faster than, but at a level comparable to, a previous study on transitive inference in pigeons (Fersen, Wynne, Delius, & Staddon, 1991), but our animals failed to show transitive inference. Experiments 2 and 3 compared time- and response-based autorun. Discrimination performance was maintained, but transitive inference was observed only on the second exposure to the response-based procedure. These results show that inferential behavior in pigeons is not a reliable concomitant of good performance on a series of overlapping discriminations. The necessary and sufficient conditions for transitive inference in pigeons remain to be fully defined.     

Mechanisms of inferential order judgments in humans (Homo sapiens) and rhesus monkeys (Macaca mulatta)

If A > B, and B > C, it follows logically that A > C. The process of reaching that conclusion is called transitive inference (TI). Several mechanisms have been offered to explain transitive performance. Scanning models claim that the list is scanned from the ends of the list inward until a match is found. Positional discrimination models claim that positional uncertainty accounts for accuracy and reaction time patterns. In Experiment 1, we trained rhesus monkeys (Macaca mulatta) and humans (Homo sapiens) on adjacent pairs (e.g., AB, BC, CD, DE, EF) and tested them with previously untrained nonadjacent pairs (e.g., BD). In Experiment 2, we trained a second list and tested with nonadjacent pairs selected between lists (e.g., B from List 1, D from List 2). We then introduced associative competition between adjacent items in Experiment 3 by training 2 items per position (e.g., B?C?, B?C?) before testing with untrained nonadjacent items. In all 3 experiments, humans and monkeys showed distance effects in which accuracy increased, and reaction time decreased, as the distance between items in each pair increased (e.g., BD vs. BE). In Experiment 4, we trained adjacent pairs with separate 9- and 5-item lists. We then tested with nonadjacent pairs selected between lists to determine whether list items were chosen according to their absolute position (e.g., D, 5-item list > E, 9-item list), or their relative position (e.g., D, 5-item list < E, 9-item list). Both monkeys' and humans' choices were most consistent with a relative positional organization.     

Comparatives,logical structures,and encoding in a transitive inference task

Four- to five-year-old children were asked questions on length involving single or double comparatives in a transitive inference task. The number of comparatives varied within or across pairs. The pairs of sticks were colorcoded. Initial pair-wise discrimination training on four adjacent pairs from a five-stick array with only verbal feedback was followed by tests, without feedback, on all possible pairs. When both comparatives were used, Ss learned adjacent pairs faster and more often reached criterion than when only one comparative term was used in training. In testing, Ss were successful on transitive inference tests only when the double-comparative relation was used within pairs during training. Retraining with visual feedback increased the number of Ss solving the inference test only in this condition. The findings are discussed in terms of how children may use processes other than logical operations to make transitive inferences.     

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.     

Reasoning from transitive premises: An EEG study

Neuroimaging studies have contributed to a major advance in understanding the neural and cognitive mechanisms underpinning deductive reasoning. However, the dynamics of cognitive events associated with inference making have been largely neglected. Using electroencephalography, the present study aims at describing the rapid sequence of processes involved in performing transitive inference (A B; B C therefore “A C”; with AB meaning “A is to the left of B”). The results indicate that when the second premise can be integrated into the first one (e.g. A B; B C) its processing elicits a P3b component. In contrast, when the second premise cannot be integrated into the first premise (e.g. A B; D C), a P600-like components is elicited. These ERP components are discussed with respect to cognitive expectations.     

Transitive inference by pigeons: Does the geometric presentation of the stimuli make a difference?

In studies of transitive inference (TI), nonhuman animals are typically trained with the following 5-term task: A+B?, B+C?, C+D?, D+E? where the letters stand for arbitrary stimuli and [+] indicates that choice is reinforced and [?] indicates that choice is not reinforced. A TI effect is found when, given the untrained test pair BD, subjects choose B. TI effects have been found in many nonhuman species. Although reinforcement history has been posited as an account of the TI effect, it has failed to account for a variety of conditions under which TI effects have been found. A more cognitive account of TI is that organisms are able to form a representation of the series (A > B > C > D > E). In support of this hypothesis, Roberts and Phelps (Psychol Sci 5:368–374, 1994) found that presentation of the pairs of stimuli in a linear arrangement facilitated TI performance by rats, whereas presentation of the pairs of stimuli in a circular arrangement did not. Using methods adapted from Roberts and Phelps, we trained pigeons on either a linear or a circular arrangement of stimuli with the 5-term task. Results indicated that on the BD test pair, pigeons trained with a circular arrangement did not differ from those trained with a linear arrangement. Furthermore, we found that memory for training pairs was variable and was highly correlated with degree of TI. The results suggest that regardless of how pigeons are able to represent the stimuli, choice was not affected by the spatial arrangement of the stimuli during training.     

Consciousness is still in business

In a recent study (Hassin, Bargh, Engell, & McCulloch, 2009, Exp. 4) half of the participants were informed of the occasional occurrence of location regularities (patterns) in visual stimulus sets, while the other half was not. Evidence was presented to the effect that uninformed participants extracted the patterns from the displays better than the informed participants. The authors interpret their finding as demonstrating that working memory (WM) can operate non-consciously. However, inspection of the data suggests that rather than being more effective than the informed participants in extracting patterns, uninformed participants were more strongly affected by the “Broken Patterns” that served as misleading cues. Thus whereas the findings may support the possibility of non-conscious operation of low level WM functions, they nevertheless underscore the importance of conscious awareness as far as higher level functions are concerned.     

Transitive inference in rats (Rattus norvegicus).

Although Piagetian theory proposes that the ability to make transitive inferences is confined to humans above age 7, recent evidence has suggested that this logical ability may be more broad based. In nonverbal tests, transitive inference has been demonstrated in preschool children and 2 species of nonhuman primates. In these experiments, I demonstrate evidence of transitive inference in rats (Rattus norvegicus). I used an ordered series of 5 olfactory stimuli (A < B < C < D < E) from which correct inferences were made about the novel B versus D pair. Control procedures indicated that performance did not depend on the recency with which the correct answer was rewarded during training and may be disrupted by the addition of logically inconsistent premises (F > E and A > F). The possibility that logical transitivity may reflect a form of spatial paralogic rather than formal deductions from a syllogistic-verbal system is discussed.     

Learning strategy differentially impacts memory connections in children and adults

Even once children can accurately remember their experiences, they nevertheless struggle to use those memories in flexible new ways—as in when drawing inferences. However, it remains an open question as to whether the developmental differences observed during both memory formation and inference itself represent a fundamental limitation on children's learning mechanisms, or rather their deployment of suboptimal strategy. Here, 7–9-year-old children (N = 154) and young adults (N = 130) first formed strong memories for initial (AB) associations and then engaged in one of three learning strategies as they viewed overlapping (BC) pairs. We found that being told to integrate—combine ABC during learning—both significantly improved children's ability to explicitly relate the indirectly associated A and C items during inference and protected the underlying pair memories from forgetting. However, this finding contrasted with implicit evidence for memory-to-memory connections: Adults and children both formed A-C links prior to any knowledge of an inference test—yet for children, such links were most apparent when they were told to simply encode BC, not integrate. Moreover, the accessibility of such implicit links differed between children and adults, with adults using them to make explicit inferences but children only doing so for well-established direct AB pairs. These results suggest that while a lack of integration strategy may explain a large share of the developmental differences in explicit inference, children and adults nevertheless differ in both the circumstances under which they connect interrelated memories and their ability to later leverage those links to inform flexible behaviours.

Research Highlights

• Children and adults view AB and BC pairs related through a shared item, B. This provides an opportunity for learners to connect A–C in memory.
• Being encouraged to integrate ABC during learning boosted performance on an explicit test of A–C connections (children and adults) and protected from forgetting (children).
• Children and adults differed in when implicit A–C connections were formed—occurring primarily when told to separately encode BC (children) versus integrate (adults), respectively.
• Adults used implicit A–C connections to facilitate explicit judgments, while children did not. Our results suggest developmental differences in the learning conditions promoting memory-to-memory connections.

     

The role of cues to differential absolute size in children's transitive inferences

To investigate the role that "nonlogical" cues might play in transitive inference, 6- and 7-year-olds were given a three-term transitive task in which perceptual cues to differential absolute size were either present or absent. Relationships between the taught premises and the relational information that was physically present were manipulated using four basic conditions: "congruent," "inverse," "pretended," or "persuaded." Both age groups showed identical overall premise memory, but the younger group tended to reason more on the basis of the perceptual information rather than on the successfully encoded premise information. Contrasts between the various conditions showed that categorical effects can be circumvented in three-term problems with appropriate controls, that there may be qualitative as well as quantitative differences in transitive inference with age, and that transitive inference is not based solely on memory. The findings also indicate that, although 7-year-olds are competent in "logic-based" transitive inference, they experience great difficulty on tasks involving pretend information.     

Knowing and avoiding: The influence of distractor awareness on oculomotor capture

Kramer, Hahn, Irwin, and Theeuwes (2000) reported that the interfering effect of distractors is reduced when participants are aware of the to-be-ignored information. In contrast, recent evidence indicates that distractor interference increases when individuals are aware of the distractors. In the present investigation, we directly assessed the influence of distractor awareness on oculomotor capture, with the hope of resolving this contradiction in the literature and gaining further insight into the influence of awareness on attention. Participants completed a traditional oculomotor capture task. They were not informed of the presence of the distracting information (unaware condition), were informed of distractors (aware condition), or were informed of distractor information and told to avoid attending to it (avoid condition). Being aware of the distractors yielded a performance benefit, relative to the unaware condition; however, this benefit was eliminated when participants were told to actively avoid distraction. This pattern of results reconciles past contradictions in the literature and suggests an inverted-U function of awareness in distractor performance. Too little or too much emphasis yields a performance decrement, but an intermediate level of emphasis provides a performance benefit.     

情绪面孔的意识神经相关物及其无意识自动加工：来自事件相关电位的证据

意识的神经相关物尚有争议, 且个体能否无意识自动检测视觉环境变化尚不清楚。本研究采用非注意视盲范式操控视觉意识, 并引入具有社会信息的情绪面孔, 探讨意识的神经相关物以及视觉意识与自动检测变化机制的关系。在A阶段, 部分被试对任务无关的情绪面孔处于无意识水平; 在B阶段, 所有被试对任务无关的情绪面孔处于意识水平; 在C阶段, 所有被试对任务相关的情绪面孔处于意识水平。结果显示, 任务无关的情绪面孔的意识过程诱发视觉意识负波(visual awareness negativity, VAN)、晚期正成分(late positivity, LP)和晚期枕区正成分(late occipital positivity, LOP)。此外, 无意识的情绪面孔能诱发视觉失匹配负波(visual mismatch negativity, vMMN), 且其幅值不受意识影响, 但是受任务相关性调制。这些结果提示对情绪面孔的视觉意识在不同的时间进程上有不同的ERP指标——VAN反映早期知觉经验, 而LP和LOP反映晚期意识过程, 而且面孔情绪信息的自动加工独立于视觉意识, 但是受视觉注意调制。     

Detecting conscious awareness from involuntary autonomic responses

Can conscious awareness be ascertained from physiological responses alone? We evaluate a novel learning-based procedure permitting detection of conscious awareness without reliance on language comprehension or behavioural responses. The method exploits a situation whereby only consciously detected violations of an expectation alter skin conductance responses (SCRs). Thirty participants listened to sequences of piano notes that, without their being told, predicted a pleasant fanfare or an aversive noise according to an abstract rule. Stimuli were presented without distraction (attended), or while distracted by a visual task to remove awareness of the rule (unattended). A test phase included occasional violations of the rule. Only participants attending the sounds reported awareness of violations and only they showed significantly greater SCR for noise occurring in violation, vs. accordance, with the rule. Our results establish theoretically significant dissociations between conscious and unconscious processing and furnish new opportunities for clinical assessment of residual consciousness in patient populations.     

Transitivity for height versus speed: To what extent do the under-7s really have a transitive capacity?

Transitive inference underpins many human reasoning competencies. The dominant task (the “extensive training paradigm”) employs many items and large amounts of training, instilling an ordered series in the reasoner's mind. But findings from an alternative “three-term paradigm” suggest transitivity is not present until 7 + years. Interestingly, a second alternative paradigm (the “spatial task”), using simultaneously displayed height relationships to form premise pairs, can uphold the 4-year estimate. However, this paradigm risks cueing children and hence is problematic. We investigated whether a height-task variant might correspond to a more ecologically valid three-term task. A total of 222 4–6-year-olds either completed a modified height task, including an increased familiarisation phase, or a computer-animated task about cartoon characters running a race in pairs. Findings confirmed that both tasks were functionally identical. Crucially, 4-year-olds were at chance on both, whereas 6-year-olds performed competently. These findings contrast with estimates from all three paradigms considered. A theoretical evaluation of our tasks and procedures against previous ones, leads us to two conclusions. First, our estimate slightly amends the 7-year estimate offered by the three-term paradigm, with the difference explained in terms of its greater relevance to child experiences. Second, our estimate can coexist alongside the 4-year estimate from the extensive training paradigm. This is because, applying a recently developed “dual-process” conception of reasoning, anticipates that extensive training benefits a species-general associative system, while the spatial paradigm and three-term paradigm can potentially index a genuinely deductive system, which has always been the target of transitive research.     

Children's memory for the premises in a transitive measurement task assessed by elicited and spontaneous justifications

Two experiments were conducted to test the hypothesis that children who fail to make the transitive inference do so because they do not recall the premises. In the first, 32% of the children who made an incorrect inference in a transitive measurement task justified their inference by the correct premises. In the second, where spontaneous justification was encouraged by testing dyads on the same task, the percentage was 15%. In neither experiment were there children who justified an incorrect inference by incorrect premises or a solo premise. The results are interpreted as showing that not only can incorrect inferers store the correct premises, but that they can also retrieve them adequately. The pattern and outcome of interactions between nontransitive and transitive inferers in the dyad sessions parallelled similar studies with conserver-nonconserver dyads. Both sets of data were taken as reinforcing the commonality between transitivity and the other concrete operations.     

Influences of task concreteness upon transitive responding in humans

The derivation of the conclusion Anna is bigger than Mary from the premises Anna is bigger than Paul and Mary is smaller than Paul is considered an instance of transitive deduction. For a non-verbal presentation, the premise statements were here transformed into a multiple operant discrimination task. Adult subjects were trained with overlapping pairs of a six-member stimulus series (A+B–, A+C–, C+D–, D+E–, E+F–; +: choice rewarded, choice penalized). A computer game-type presentation that hid the actual problem structure from the subjects was employed. The effects of varying the presentation style of the task on the objective performance and the structure awareness of subjects were investigated. A first experiment used random polygons as stimuli and the relations between them were only signalled by the above reinforcement allocations. In a second experiment the stimuli were cartoon figures additionally involved in a dominance hierarchy that was suggested graphically. A third experiment used named items that were related through visible size differences in addition to the reinforcement allocations but was otherwise like an experiment using an abstract format reported by Werner et al. (1992). In all experiments a similar proportion of subjects responded transitively when subsequently tested with the pairs BD, BE and CE by preferentially choosing stimulus B or C. Each subject subsequently filled in a questionnaire, completed a stimulus ordering exercise, and was interviewed to find out whether they were explicitly aware of the stimulus hierarchy underlying each of the tasks. Although the proportion of subjects revealing an explicit transitive responding increased together with the concreteness of the stimuli and their relations across the experiments, the objective performance in terms of choice accuracy did not vary. The accuracy performance on tests could be accurately simulated with a modification of a simple conditioning model. It is concluded that an implicit mode of processing may underlie many instances of transitive responding in humans even when explicit task understanding is reported.