Temporal order judgment reveals how number magnitude affects visuospatial attention

The existence of spatial components in the mental representation of number magnitude has raised the question regarding the relation between numbers and spatial attention. We present six experiments in which this relation was examined using a temporal order judgment task to index attentional allocation. Results demonstrate that one important consequence of numerical processing is the automatic allocation of spatial attention, which in turn affects the perception of the temporal order of visual events. Given equal onset time, left-side stimuli are perceived to occur before right-side stimuli when a small number (1, 2) is processed, whereas right-side stimuli are perceived to occur before left-side stimuli when a larger number (8, 9) is processed. In addition, we show that this attentional effect is specific to quantity processing and does not generalize to non-numerical ordinal sequences.     

Regular Minimality and Thurstonian-type modeling

A Thurstonian-type model for pairwise comparisons is any model in which the response (e.g., “they are the same” or “they are different”) to two stimuli being compared depends, deterministically or probabilistically, on the realizations of two randomly varying representations (perceptual images) of these stimuli. The two perceptual images in such a model may be stochastically interdependent but each has to be selectively dependent on its stimulus. It has been previously shown that all possible discrimination probability functions for same–different comparisons can be generated by Thurstonian-type models of the simplest variety, with independent percepts and deterministic decision rules. It has also been shown, however, that a broad class of Thurstonian-type models, called “well-behaved” (and including, e.g., models with multivariate normal perceptual representations whose parameters are smooth functions of stimuli) cannot simultaneously account for two empirically plausible properties of same–different comparisons, Regular Minimality (which essentially says that “being least discriminable from” is a symmetric relation) and nonconstancy of the minima of discrimination probabilities (the fact that different pairs of least discriminable stimuli are discriminated with different probabilities). These results have been obtained for stimulus spaces represented by regions of Euclidean spaces. In this paper, the impossibility for well-behaved Thurstonian-type models to simultaneously account for Regular Minimality and nonconstancy of minima is established for a much broader notion of well-behavedness applied to a much broader class of stimulus spaces (any Hausdorff arc-connected ones). The universality of Thurstonian-type models with independent perceptual images and deterministic decision rules is shown (by a simpler proof than before) to hold for arbitrary stimulus spaces.     

Impact of negative affectively charged stimuli and response style on cognitive-control-related neural activation: An ERP study

The canonical AX-CPT task measures two forms of cognitive control: sustained goal-oriented control (“proactive” control) and transient changes in cognitive control following unexpected events (“reactive” control). We modified this task by adding negative and neutral International Affective Picture System (IAPS) pictures to assess the effects of negative emotion on these two forms of cognitive control. Proactive and reactive control styles were assessed based on measures of behavior and electrophysiology, including the N2 event-related potential component and source space activation (Low Resolution Tomography [LORETA]). We found slower reaction-times and greater DLPFC activation for negative relative to neutral stimuli. Additionally, we found that a proactive style of responding was related to less prefrontal activation (interpreted to reflect increased efficiency of processing) during actively maintained previously cued information and that a reactive style of responding was related to less prefrontal activation (interpreted to reflect increased efficiency of processing) during just-in-time environmentally triggered information. This pattern of results was evident in relatively neutral contexts, but in the face of negative emotion, these associations were not found, suggesting potential response style-by-emotion interaction effects on prefrontal neural activation.     

Mere acceptance produces apparent attitude in the Implicit Association Test

Two experiments examined mere acceptance effects in the Implicit Association Test (IAT). They tested whether accepting a stimulus as conforming to a rule produces responding consistent with positive attitude in the IAT. In Experiment 1, accepted stimuli were more easily categorized with pleasant personality characteristics than rejected stimuli; they were preferred according to the logic of the IAT. Accepted word stimuli were also responded to faster overall, suggesting that it was easier to make the accept than the reject response. In Experiment 2, numerical stimuli that conformed to a rule showed the same IAT preference effect over non-confirming stimuli, even when the rule conforming stimuli were more difficult to categorize. Three sources of this apparent preference for rule-conforming stimuli are considered: (1) the semantic relatedness of the concepts “accept” and “pleasant” on the one hand, and “reject” and “unpleasant” on the other; (2) that rejected non-category members are more salient (‘pop-out’) and thus are more easily categorized with the more salient unpleasant personality characteristics; or (3) that accepting rule-conforming stimuli is experienced as a pleasant event. Regardless of the mechanism underlying the mere acceptance effect, the IAT can produce apparent preferences for stimuli towards which participants have no positive attitude.     

Generic language use reveals domain differences in young children's expectations about animal and artifact categories

The goal of the present study was to explore domain differences in young children's expectations about the structure of animal and artifact categories. We examined 5-year-olds’ and adults’ use of category-referring generic noun phrases (e.g., “Birds fly”) about novel animals and artifacts. The same stimuli served as both animals and artifacts; thus, stimuli were perceptually identical across domains, and domain was indicated exclusively by language. Results revealed systematic domain differences: children and adults produced more generic utterances when items were described as animals than artifacts. Because the stimuli were novel and lacking perceptual cues to domain, these findings must be attributed to higher-order expectations about animal and artifact categories. Overall, results indicate that by age 5, children are able to make knowledge-based domain distinctions between animals and artifacts that may be rooted in beliefs about the coherence and homogeneity of categories within these domains.     

The role of the response-reinforcer contingency in negative automaintenance

When a response key is briefly illuminated before a grain reinforcer is presented, key pecking is reliably developed and maintained in pigeons, even if pecking prevents reinforcement (negative automaintenance). This experiment demonstrated that pigeons are sensitive to a negative response-reinforcer contingency, even though it does not eliminate responding. Within individual pigeons, two kinds of trials were compared: red key trials, in which reinforcement was negatively contingent on responding, and white key trials, in which reinforcement was unrelated to responding. Reinforcement frequency in non-contingent trials was yoked to the obtained reinforcement frequency in negatively contingent trials. All eight pigeons pecked substantially more on the non-contingent key than on the negative key, and preferred the non-contingent key to the negative key on occasional “choice” trials where both were presented together. When the stimuli correlated with the two conditions were reversed, the pigeons' behavior also shifted. These response differences are taken as evidence that pigeons are sensitive to the negative response-reinforcer contingency.     

Subjective expected utility without preferences

This paper proposes a theory of subjective expected utility based on primitives only involving the fact that an act can be judged either “attractive” or “unattractive”. We give conditions implying that there are a utility function on the set of consequences and a probability distribution on the set of states such that attractive acts have a subjective expected utility above some threshold. The numerical representation that is obtained has strong uniqueness properties.     

Dimension integration: Testing models without trade-offs

This paper tests a behavioral property called dimension integration. The test evaluates models, such as lexicographic semi-orders and the priority heuristic, which assume that a person uses only one dimension at a time. It provides a way to compare such models against those that assume a person combines information from different dimensions. The test allows one to test the hypothesis that different people use different lexicographic semi-orders with different threshold parameters. In addition, by use of a “true and error” model, it is possible to “correct” for unreliability of choice in order to estimate the proportions of participants who show different response patterns that can be classified as integrative or not integrative. An experiment with 260 participants was conducted in which people made choices between two-branch gambles. The aggregate results violate the priority heuristic and six lexicographic semi-orders. The data also refute the theory that people use a mixture of these lexicographic semi-orders. In addition, few individuals appear to show response patterns consistent with non-integrative models. Instead, they show that most individuals show patterns consistent with the hypothesis that they combine information between dimensions.     

An example of discovery research involving the transfer of stimulus control

The initial purpose of the present study was to replicate procedures for teaching preschool children to recruit attention at appropriate times by having an experimenter signal the availability and unavailability of attention (i.e., arrange a multiple schedule involving reinforcement and extinction; Tiger & Hanley, 2004). Following the development of discriminated social responding, the schedule-correlated stimuli were removed (i.e., a mixed schedule of reinforcement was arranged). However, discriminated responding continued during these conditions. Further evaluation suggested that stimulus control over children's social responding had transferred from the schedule-correlated stimuli to the delivery of reinforcement. The effect of a history of reinforcement under multiple-schedule conditions on performance under mixed schedules was then replicated with 2 participants in a reversal design. These findings suggest that following experience with schedule-correlated stimuli, these stimuli may be removed with only modest disruption to discriminated responding.     

CS-dependent response probability in an auditory masked-detection task: considerations based on models of Pavlovian conditioning.

Experimental studies were performed using a Pavlovian-conditioned eyeblink response to measure detection of a variable-sound-level tone (T) in a fixed-sound-level masking noise (N) in rabbits. Results showed an increase in the asymptotic probability of conditioned responses (CRs) to the reinforced TN trials and a decrease in the asymptotic rate of eyeblink responses to the non-reinforced N presentations as a function of the sound level of the T. These observations are consistent with expected behaviour in an auditory masked detection task, but they are not consistent with predictions from a traditional application of the Rescorla-Wagner or Pearce models of associative learning. To implement these models, one typically considers only the actual stimuli and reinforcement on each trial. We found that by considering perceptual interactions and concepts from signal detection theory, these models could predict the CS dependence on the sound level of the T. In these alternative implementations, the animals response probabilities were used as a guide in making assumptions about the "effective stimuli".     

On the role of stimulus preference assessment in the evaluation of contingent access to stimuli associated with stereotypy during behavioral acquisition

Previous authors have reported successful behavioral acquisition in children diagnosed with autism using contingent access to stereotypic responding as reinforcement. Other studies have demonstrated robust reinforcement effects when consequences were selected using stimulus preference assessments. We conducted two stimulus preference assessments with a six-year-old female diagnosed with autism. Her acquisition of a non-vocal imitation response was then evaluated during two reinforcement conditions: contingent access to (i) a stimulus associated with stereotypic object manipulation and (ii) a stimulus unassociated with such stereotypy. Both stimuli were identified from the stimulus preference assessments. Nearly identical response patterns were observed in both conditions; correct responses to verbal prompts greatly increased while correct responses to gestural and physical prompts decreased to near-zero levels. These preliminary findings are discussed in the context of improving stimulus selection in this area. © 1998 John Wiley & Sons, Ltd.     

Ginzberg's theory of occupational choice: A reanalysis of increasing realism

A causal model of indicators was derived from Ginzberg, Ginsburg, Axelrad, and Herma's developmental framework of occupational choice. This theoretical perspective suggests that high school age adolescents' “fantasy” choices are diverted into more “realistic” anticipations mainly through awareness of the work world and work roles and perceived “reality factors” (perceived goal-blocks) which function to inhibit the maintenance of such “fantasy” desires. Panel data from a three-state sample of nonmetropolitan Southern males interviewed while in the tenth-grade in 1966 and reinterviewed in 1968 were examined using path analytic models. Findings suggest that “realistic” choices (expectations) demonstrate an increasing dissociation from earlier “fantasy” choices (aspirations) primarily through the formation of perceived “reality factors.” An alternative model which incorporates race as a predetermined variable seems to indicate that racial differences in occupational knowledge affect the formation of perceived “reality factors” which are significant mediators of social origin for high school seniors' occupational expectations. While race affects occupational knowledge directly, most of the causal effects of race on 1968 expectations are actually due to the association of race with SES. Areas of other research are specified.     

The role of perceptual similarity of the task environments in children’s perseverative responding

Perseverative responding is often seen in children’s performance in a variety of contexts. One such context is symbolic comprehension in which 2- and 2½-year-olds demonstrate difficulty in appreciating the association of symbols (pictures and scale models) and their referents and show a high proportion of perseverative responding. Representational-level explanations of perseveration were explored in the current studies via examination of the impact of perceptual similarity of visual environments across trials. Across two experiments, children saw either a picture (Experiment 1) or a scale model (Experiment 2) of a hiding location of a room and were then encouraged to recover the toy from an identical room. Manipulating the perceptual similarity of the environments across successive trials affected performance and perseverative responding. These results highlight the critical role played by perceptual information not only in symbolic tasks but also in many other tasks and have important implications for theories of perseveration.     

Conditioning of within-trial patterns of key pecking in pigeons

The possibility of conditioning systematic patterns of responding during brief discrete trials was studied by requiring hungry pigeons to key peck and then pause or to pause and then key peck in order to gain access to food. These schedules were highly effective in promoting decelerated and accelerated rates of responding, respectively, within individual trials; indeed, performance was quite similar to that observed when explicit external stimuli were correlated with “peck” and “pause” portions of the daily trials. Finally, schedules of reinforcement that did not selectively reinforce peck-pause or pause-peck patterns neither generated these patterns nor maintained them at the previous high levels. The results, therefore, confirm Shimp's (1976) proposal that organized groupings of discrete responses may function as operants—even in the absence of strict response-reinforcer contiguity.     

Local rather than global processing of visual arrays in numerosity discrimination by pigeons (Columba livia)

A series of experiments investigated which stimulus properties pigeons use when they discriminate pairs of visual arrays that differ in numerosity. Transfer tests with novel stimuli confirmed that the birds’ choices were based on relative differences in numerosity. However, pigeons differed from other species in the non-numerical cues that affected their choices. In human and non-human primates, numerical discrimination is often influenced by continuous variables such as surface area or overall stimulus brightness. Pigeons showed little evidence of using those cues, even when summed area and brightness had been correlated with numerosity differences and reward outcome. But when array-element sizes were asymmetrically distributed across numerosities, the birds readily utilized information about item sizes as an additional discriminative cue. These novel results are discussed in relation to pigeons’ tendency to focus on local, rather than global dimensions when they process other non-numerical complex visual stimuli. The findings suggest there may be inter-specific differences in the type of perceptual information that provides the input stage for mechanisms underlying numerical processing. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Establishing discriminative stimulus control within generalized oddity performance,without reinforcement

In two oddity learning studies with children, subjects were reinforced for oddity (or nonoddity) responding on line-tilt or dot numerosity problems. Interposed form and color problems were not reinforced. No instructions to make oddity choices were given. In Experiment I it was found that reinforcement for oddity or nonoddity responding on tilt and numerosity problems produced the corresponding tendency toward oddity or nonoddity performance on these problems and also on the nonreinforced form and color problems. These results show a generalized oddity phenomenon similar to generalized imitation. In Experiment II a third type of nonreinforced problem was presented in this same format: compound stimuli permitting either a color or a form solution. It was found that immediate prior training with nonreinforced form problems, interpolated among the reinforced tilt and numerosity problems, led to form-oddity choices in the compound problems. Similarily, color pretraining produced color-oddity choices. These results show that selective discriminative stimulus control can be obtained in oddity learning, without reinforcement for choices on either of the two dimensions involved.     

Acquisition and extinction of signaled avoidance as a function of intermittent reinforcement

Signaled, shuttle-box avoidance responding in female rats of the Fischer₃₄₄ strain was examined as a function of four separate contingencies of intermittent reinforcement. In Experiment 1, when avoidance responses during acquisition were reinforced 25% of the time with prompt CS termination, animals responded equally often during acquisition and significantly more often during extinction than animals who received such reinforcement on a 100% schedule. Similar results were found under a trace procedure in Experiment 2 when avoidance responses were reinforced 25% of the time with informational feedback stimuli. In contrast, during Experiment 3, when animals were shocked on only 25% of the trials on which they failed to respond, the level of avoidance responding during both acquisition and extinction was significantly less than it was when animals were shocked on a 100% schedule. Comparable results were found in Experiment 4 when avoidance responses during acquisition averted shock on only 25% of the trials. Thus, intermittent reinforcement contingencies involving response-contingent feedback stimuli and shock have differential effects on avoidance responding during both acquisition and extinction trials under the signaled avoidance procedure.     

Object-based auditory facilitation of visual search for pictures and words with frequent and rare targets

Auditory and visual processes demonstrably enhance each other based on spatial and temporal coincidence. Our recent results on visual search have shown that auditory signals also enhance visual salience of specific objects based on multimodal experience. For example, we tend to see an object (e.g., a cat) and simultaneously hear its characteristic sound (e.g., “meow”), to name an object when we see it, and to vocalize a word when we read it, but we do not tend to see a word (e.g., cat) and simultaneously hear the characteristic sound (e.g., “meow”) of the named object. If auditory–visual enhancements occur based on this pattern of experiential associations, playing a characteristic sound (e.g., “meow”) should facilitate visual search for the corresponding object (e.g., an image of a cat), hearing a name should facilitate visual search for both the corresponding object and corresponding word, but playing a characteristic sound should not facilitate visual search for the name of the corresponding object. Our present and prior results together confirmed these experiential association predictions. We also recently showed that the underlying object-based auditory–visual interactions occur rapidly (within 220 ms) and guide initial saccades towards target objects. If object-based auditory–visual enhancements are automatic and persistent, an interesting application would be to use characteristic sounds to facilitate visual search when targets are rare, such as during baggage screening. Our participants searched for a gun among other objects when a gun was presented on only 10% of the trials. The search time was speeded when a gun sound was played on every trial (primarily on gun-absent trials); importantly, playing gun sounds facilitated both gun-present and gun-absent responses, suggesting that object-based auditory–visual enhancements persistently increase the detectability of guns rather than simply biasing gun-present responses. Thus, object-based auditory–visual interactions that derive from experiential associations rapidly and persistently increase visual salience of corresponding objects.     

Updating the Baldwin effect : The biological levels behind Piaget's new theory

In 1964, Conrad Waddington (1905–1975) presented a paper in Geneva that led to an internal reassessment of the biological underpinnings of Jean Piaget's (1896–1980) theory. This in turn resulted in an overhaul of the theoretical framework upon which his stage theory of child development had been based, including his appeals to James Mark Baldwin's (1861–1934) “circular reaction.” In addition to leading to the emergence of what has elsewhere been called “Piaget's new theory,” this renovation also resulted in the update of the famous “Baldwin Effect.” Because aspects of the subsequent framework are of contemporary significance, this essay will review some of the work leading up to those updates. In reaching behind the translations to trace the sources of the arguments to which Piaget appealed, the resulting examination fills some of the gaps found in the secondary literature without quibbling over the “correct” English interpretation of translated French terms. We also go beyond how Piaget's writings have been understood in English and extract some useful additional ideas from his sources, including how to conceive of the social context in which development takes place. We see as a result how Waddington and his colleagues, including Paul Weiss (1898–1989), provided a constructive “existence proof” for the formal hierarchy of levels that Piaget had come to by other means.     

Effects of reinforcement scheduling on simultaneous discrimination performance

Pigeons were trained on a discrete-trials, simultaneous discrimination procedure, with confusable stimuli such that asymptotic performance was about 85% correct. Trials were terminated if no response occurred within 2 sec of stimulus onset, so that probability of responding was free to vary. The schedule of reinforcement for correct responses was varied, with the following results: (1) there was no relation between frequency of reinforcement and accuracy of responding. (2) In extinction, the probability of responding fell to low levels, but accuracy remained roughly constant. (3) When reinforcement was available after a fixed number of trials or after a fixed number of correct responses, the probability of responding increased with successive trials after reinforcement, but accuracy was generally constant. (4) When every fifth correct response was reinforced, accuracy decreased immediately after reinforcement if the birds were required to respond on every trial.